![Stephen Boyd](/assets/img/avatar_default.png)
- Rewrite how clk parents can be specified to be DT/clkdev based instead of just string based * clk-parent-rewrite-1: clk: Cache core in clk_fetch_parent_index() without names clk: fixed-factor: Initialize clk_init_data on stack clk: fixed-factor: Let clk framework find parent clk: Allow parents to be specified via clkspec index clk: Look for parents with clkdev based clk_lookups clk: Allow parents to be specified without string names clk: Add of_clk_hw_register() API for early clk drivers driver core: Let dev_of_node() accept a NULL dev clk: Prepare for clk registration API that uses DT nodes clkdev: Move clk creation outside of 'clocks_mutex'
4668 lines
115 KiB
C
4668 lines
115 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
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* Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
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*
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* Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
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*/
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/clk/clk-conf.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/spinlock.h>
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#include <linux/err.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/pm_runtime.h>
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#include <linux/sched.h>
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#include <linux/clkdev.h>
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#include "clk.h"
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static DEFINE_SPINLOCK(enable_lock);
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static DEFINE_MUTEX(prepare_lock);
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static struct task_struct *prepare_owner;
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static struct task_struct *enable_owner;
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static int prepare_refcnt;
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static int enable_refcnt;
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static HLIST_HEAD(clk_root_list);
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static HLIST_HEAD(clk_orphan_list);
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static LIST_HEAD(clk_notifier_list);
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/*** private data structures ***/
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struct clk_parent_map {
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const struct clk_hw *hw;
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struct clk_core *core;
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const char *fw_name;
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const char *name;
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int index;
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};
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struct clk_core {
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const char *name;
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const struct clk_ops *ops;
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struct clk_hw *hw;
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struct module *owner;
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struct device *dev;
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struct device_node *of_node;
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struct clk_core *parent;
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struct clk_parent_map *parents;
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u8 num_parents;
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u8 new_parent_index;
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unsigned long rate;
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unsigned long req_rate;
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unsigned long new_rate;
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struct clk_core *new_parent;
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struct clk_core *new_child;
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unsigned long flags;
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bool orphan;
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bool rpm_enabled;
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unsigned int enable_count;
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unsigned int prepare_count;
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unsigned int protect_count;
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unsigned long min_rate;
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unsigned long max_rate;
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unsigned long accuracy;
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int phase;
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struct clk_duty duty;
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struct hlist_head children;
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struct hlist_node child_node;
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struct hlist_head clks;
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unsigned int notifier_count;
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#ifdef CONFIG_DEBUG_FS
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struct dentry *dentry;
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struct hlist_node debug_node;
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#endif
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struct kref ref;
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};
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#define CREATE_TRACE_POINTS
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#include <trace/events/clk.h>
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struct clk {
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struct clk_core *core;
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struct device *dev;
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const char *dev_id;
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const char *con_id;
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unsigned long min_rate;
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unsigned long max_rate;
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unsigned int exclusive_count;
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struct hlist_node clks_node;
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};
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/*** runtime pm ***/
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static int clk_pm_runtime_get(struct clk_core *core)
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{
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int ret;
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if (!core->rpm_enabled)
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return 0;
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ret = pm_runtime_get_sync(core->dev);
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return ret < 0 ? ret : 0;
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}
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static void clk_pm_runtime_put(struct clk_core *core)
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{
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if (!core->rpm_enabled)
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return;
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pm_runtime_put_sync(core->dev);
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}
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/*** locking ***/
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static void clk_prepare_lock(void)
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{
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if (!mutex_trylock(&prepare_lock)) {
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if (prepare_owner == current) {
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prepare_refcnt++;
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return;
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}
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mutex_lock(&prepare_lock);
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}
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WARN_ON_ONCE(prepare_owner != NULL);
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WARN_ON_ONCE(prepare_refcnt != 0);
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prepare_owner = current;
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prepare_refcnt = 1;
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}
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static void clk_prepare_unlock(void)
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{
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WARN_ON_ONCE(prepare_owner != current);
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WARN_ON_ONCE(prepare_refcnt == 0);
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if (--prepare_refcnt)
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return;
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prepare_owner = NULL;
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mutex_unlock(&prepare_lock);
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}
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static unsigned long clk_enable_lock(void)
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__acquires(enable_lock)
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{
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unsigned long flags;
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/*
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* On UP systems, spin_trylock_irqsave() always returns true, even if
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* we already hold the lock. So, in that case, we rely only on
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* reference counting.
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*/
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if (!IS_ENABLED(CONFIG_SMP) ||
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!spin_trylock_irqsave(&enable_lock, flags)) {
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if (enable_owner == current) {
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enable_refcnt++;
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__acquire(enable_lock);
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if (!IS_ENABLED(CONFIG_SMP))
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local_save_flags(flags);
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return flags;
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}
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spin_lock_irqsave(&enable_lock, flags);
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}
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WARN_ON_ONCE(enable_owner != NULL);
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WARN_ON_ONCE(enable_refcnt != 0);
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enable_owner = current;
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enable_refcnt = 1;
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return flags;
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}
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static void clk_enable_unlock(unsigned long flags)
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__releases(enable_lock)
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{
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WARN_ON_ONCE(enable_owner != current);
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WARN_ON_ONCE(enable_refcnt == 0);
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if (--enable_refcnt) {
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__release(enable_lock);
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return;
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}
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enable_owner = NULL;
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spin_unlock_irqrestore(&enable_lock, flags);
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}
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static bool clk_core_rate_is_protected(struct clk_core *core)
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{
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return core->protect_count;
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}
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static bool clk_core_is_prepared(struct clk_core *core)
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{
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bool ret = false;
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/*
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* .is_prepared is optional for clocks that can prepare
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* fall back to software usage counter if it is missing
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*/
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if (!core->ops->is_prepared)
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return core->prepare_count;
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if (!clk_pm_runtime_get(core)) {
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ret = core->ops->is_prepared(core->hw);
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clk_pm_runtime_put(core);
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}
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return ret;
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}
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static bool clk_core_is_enabled(struct clk_core *core)
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{
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bool ret = false;
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/*
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* .is_enabled is only mandatory for clocks that gate
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* fall back to software usage counter if .is_enabled is missing
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*/
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if (!core->ops->is_enabled)
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return core->enable_count;
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/*
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* Check if clock controller's device is runtime active before
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* calling .is_enabled callback. If not, assume that clock is
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* disabled, because we might be called from atomic context, from
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* which pm_runtime_get() is not allowed.
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* This function is called mainly from clk_disable_unused_subtree,
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* which ensures proper runtime pm activation of controller before
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* taking enable spinlock, but the below check is needed if one tries
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* to call it from other places.
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*/
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if (core->rpm_enabled) {
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pm_runtime_get_noresume(core->dev);
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if (!pm_runtime_active(core->dev)) {
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ret = false;
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goto done;
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}
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}
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ret = core->ops->is_enabled(core->hw);
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done:
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if (core->rpm_enabled)
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pm_runtime_put(core->dev);
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return ret;
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}
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/*** helper functions ***/
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const char *__clk_get_name(const struct clk *clk)
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{
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return !clk ? NULL : clk->core->name;
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}
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EXPORT_SYMBOL_GPL(__clk_get_name);
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const char *clk_hw_get_name(const struct clk_hw *hw)
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{
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return hw->core->name;
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_name);
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struct clk_hw *__clk_get_hw(struct clk *clk)
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{
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return !clk ? NULL : clk->core->hw;
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}
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EXPORT_SYMBOL_GPL(__clk_get_hw);
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unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
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{
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return hw->core->num_parents;
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
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struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
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{
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return hw->core->parent ? hw->core->parent->hw : NULL;
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_parent);
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static struct clk_core *__clk_lookup_subtree(const char *name,
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struct clk_core *core)
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{
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struct clk_core *child;
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struct clk_core *ret;
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if (!strcmp(core->name, name))
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return core;
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hlist_for_each_entry(child, &core->children, child_node) {
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ret = __clk_lookup_subtree(name, child);
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if (ret)
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return ret;
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}
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return NULL;
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}
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static struct clk_core *clk_core_lookup(const char *name)
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{
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struct clk_core *root_clk;
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struct clk_core *ret;
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if (!name)
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return NULL;
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/* search the 'proper' clk tree first */
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hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
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ret = __clk_lookup_subtree(name, root_clk);
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if (ret)
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return ret;
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}
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/* if not found, then search the orphan tree */
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hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
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ret = __clk_lookup_subtree(name, root_clk);
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if (ret)
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return ret;
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}
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return NULL;
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}
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/**
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* clk_core_get - Find the clk_core parent of a clk
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* @core: clk to find parent of
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* @p_index: parent index to search for
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*
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* This is the preferred method for clk providers to find the parent of a
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* clk when that parent is external to the clk controller. The parent_names
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* array is indexed and treated as a local name matching a string in the device
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* node's 'clock-names' property or as the 'con_id' matching the device's
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* dev_name() in a clk_lookup. This allows clk providers to use their own
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* namespace instead of looking for a globally unique parent string.
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*
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* For example the following DT snippet would allow a clock registered by the
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* clock-controller@c001 that has a clk_init_data::parent_data array
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* with 'xtal' in the 'name' member to find the clock provided by the
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* clock-controller@f00abcd without needing to get the globally unique name of
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* the xtal clk.
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*
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* parent: clock-controller@f00abcd {
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* reg = <0xf00abcd 0xabcd>;
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* #clock-cells = <0>;
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* };
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*
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* clock-controller@c001 {
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* reg = <0xc001 0xf00d>;
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* clocks = <&parent>;
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* clock-names = "xtal";
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* #clock-cells = <1>;
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* };
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*
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* Returns: -ENOENT when the provider can't be found or the clk doesn't
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* exist in the provider. -EINVAL when the name can't be found. NULL when the
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* provider knows about the clk but it isn't provided on this system.
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* A valid clk_core pointer when the clk can be found in the provider.
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*/
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static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
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{
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const char *name = core->parents[p_index].fw_name;
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int index = core->parents[p_index].index;
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struct clk_hw *hw = ERR_PTR(-ENOENT);
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struct device *dev = core->dev;
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const char *dev_id = dev ? dev_name(dev) : NULL;
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struct device_node *np = core->of_node;
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if (np && index >= 0)
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hw = of_clk_get_hw(np, index, name);
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/*
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* If the DT search above couldn't find the provider or the provider
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* didn't know about this clk, fallback to looking up via clkdev based
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* clk_lookups
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*/
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if (PTR_ERR(hw) == -ENOENT && name)
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hw = clk_find_hw(dev_id, name);
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if (IS_ERR(hw))
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return ERR_CAST(hw);
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return hw->core;
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}
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static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
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{
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struct clk_parent_map *entry = &core->parents[index];
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struct clk_core *parent = ERR_PTR(-ENOENT);
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if (entry->hw) {
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parent = entry->hw->core;
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/*
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* We have a direct reference but it isn't registered yet?
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* Orphan it and let clk_reparent() update the orphan status
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* when the parent is registered.
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*/
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if (!parent)
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parent = ERR_PTR(-EPROBE_DEFER);
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} else {
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parent = clk_core_get(core, index);
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if (IS_ERR(parent) && PTR_ERR(parent) == -ENOENT)
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parent = clk_core_lookup(entry->name);
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}
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/* Only cache it if it's not an error */
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if (!IS_ERR(parent))
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entry->core = parent;
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}
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static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
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u8 index)
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{
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if (!core || index >= core->num_parents || !core->parents)
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return NULL;
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if (!core->parents[index].core)
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clk_core_fill_parent_index(core, index);
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return core->parents[index].core;
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}
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struct clk_hw *
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clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
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{
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struct clk_core *parent;
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parent = clk_core_get_parent_by_index(hw->core, index);
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return !parent ? NULL : parent->hw;
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
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unsigned int __clk_get_enable_count(struct clk *clk)
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{
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return !clk ? 0 : clk->core->enable_count;
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}
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static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
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{
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if (!core)
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return 0;
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if (!core->num_parents || core->parent)
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return core->rate;
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/*
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* Clk must have a parent because num_parents > 0 but the parent isn't
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* known yet. Best to return 0 as the rate of this clk until we can
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* properly recalc the rate based on the parent's rate.
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*/
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return 0;
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}
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unsigned long clk_hw_get_rate(const struct clk_hw *hw)
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{
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return clk_core_get_rate_nolock(hw->core);
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_rate);
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static unsigned long __clk_get_accuracy(struct clk_core *core)
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{
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if (!core)
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return 0;
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return core->accuracy;
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}
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unsigned long __clk_get_flags(struct clk *clk)
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{
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return !clk ? 0 : clk->core->flags;
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}
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EXPORT_SYMBOL_GPL(__clk_get_flags);
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unsigned long clk_hw_get_flags(const struct clk_hw *hw)
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{
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return hw->core->flags;
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}
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EXPORT_SYMBOL_GPL(clk_hw_get_flags);
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bool clk_hw_is_prepared(const struct clk_hw *hw)
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{
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return clk_core_is_prepared(hw->core);
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}
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EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
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bool clk_hw_rate_is_protected(const struct clk_hw *hw)
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{
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return clk_core_rate_is_protected(hw->core);
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}
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EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
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bool clk_hw_is_enabled(const struct clk_hw *hw)
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{
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return clk_core_is_enabled(hw->core);
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}
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EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
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bool __clk_is_enabled(struct clk *clk)
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{
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if (!clk)
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return false;
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return clk_core_is_enabled(clk->core);
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}
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EXPORT_SYMBOL_GPL(__clk_is_enabled);
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static bool mux_is_better_rate(unsigned long rate, unsigned long now,
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unsigned long best, unsigned long flags)
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{
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if (flags & CLK_MUX_ROUND_CLOSEST)
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return abs(now - rate) < abs(best - rate);
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return now <= rate && now > best;
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}
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int clk_mux_determine_rate_flags(struct clk_hw *hw,
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struct clk_rate_request *req,
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unsigned long flags)
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{
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struct clk_core *core = hw->core, *parent, *best_parent = NULL;
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int i, num_parents, ret;
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unsigned long best = 0;
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struct clk_rate_request parent_req = *req;
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/* if NO_REPARENT flag set, pass through to current parent */
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if (core->flags & CLK_SET_RATE_NO_REPARENT) {
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parent = core->parent;
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if (core->flags & CLK_SET_RATE_PARENT) {
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ret = __clk_determine_rate(parent ? parent->hw : NULL,
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&parent_req);
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if (ret)
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return ret;
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best = parent_req.rate;
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} else if (parent) {
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|
best = clk_core_get_rate_nolock(parent);
|
|
} else {
|
|
best = clk_core_get_rate_nolock(core);
|
|
}
|
|
|
|
goto out;
|
|
}
|
|
|
|
/* find the parent that can provide the fastest rate <= rate */
|
|
num_parents = core->num_parents;
|
|
for (i = 0; i < num_parents; i++) {
|
|
parent = clk_core_get_parent_by_index(core, i);
|
|
if (!parent)
|
|
continue;
|
|
|
|
if (core->flags & CLK_SET_RATE_PARENT) {
|
|
parent_req = *req;
|
|
ret = __clk_determine_rate(parent->hw, &parent_req);
|
|
if (ret)
|
|
continue;
|
|
} else {
|
|
parent_req.rate = clk_core_get_rate_nolock(parent);
|
|
}
|
|
|
|
if (mux_is_better_rate(req->rate, parent_req.rate,
|
|
best, flags)) {
|
|
best_parent = parent;
|
|
best = parent_req.rate;
|
|
}
|
|
}
|
|
|
|
if (!best_parent)
|
|
return -EINVAL;
|
|
|
|
out:
|
|
if (best_parent)
|
|
req->best_parent_hw = best_parent->hw;
|
|
req->best_parent_rate = best;
|
|
req->rate = best;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
|
|
|
|
struct clk *__clk_lookup(const char *name)
|
|
{
|
|
struct clk_core *core = clk_core_lookup(name);
|
|
|
|
return !core ? NULL : core->hw->clk;
|
|
}
|
|
|
|
static void clk_core_get_boundaries(struct clk_core *core,
|
|
unsigned long *min_rate,
|
|
unsigned long *max_rate)
|
|
{
|
|
struct clk *clk_user;
|
|
|
|
*min_rate = core->min_rate;
|
|
*max_rate = core->max_rate;
|
|
|
|
hlist_for_each_entry(clk_user, &core->clks, clks_node)
|
|
*min_rate = max(*min_rate, clk_user->min_rate);
|
|
|
|
hlist_for_each_entry(clk_user, &core->clks, clks_node)
|
|
*max_rate = min(*max_rate, clk_user->max_rate);
|
|
}
|
|
|
|
void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
|
|
unsigned long max_rate)
|
|
{
|
|
hw->core->min_rate = min_rate;
|
|
hw->core->max_rate = max_rate;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
|
|
|
|
/*
|
|
* __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
|
|
* @hw: mux type clk to determine rate on
|
|
* @req: rate request, also used to return preferred parent and frequencies
|
|
*
|
|
* Helper for finding best parent to provide a given frequency. This can be used
|
|
* directly as a determine_rate callback (e.g. for a mux), or from a more
|
|
* complex clock that may combine a mux with other operations.
|
|
*
|
|
* Returns: 0 on success, -EERROR value on error
|
|
*/
|
|
int __clk_mux_determine_rate(struct clk_hw *hw,
|
|
struct clk_rate_request *req)
|
|
{
|
|
return clk_mux_determine_rate_flags(hw, req, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
|
|
|
|
int __clk_mux_determine_rate_closest(struct clk_hw *hw,
|
|
struct clk_rate_request *req)
|
|
{
|
|
return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
|
|
|
|
/*** clk api ***/
|
|
|
|
static void clk_core_rate_unprotect(struct clk_core *core)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return;
|
|
|
|
if (WARN(core->protect_count == 0,
|
|
"%s already unprotected\n", core->name))
|
|
return;
|
|
|
|
if (--core->protect_count > 0)
|
|
return;
|
|
|
|
clk_core_rate_unprotect(core->parent);
|
|
}
|
|
|
|
static int clk_core_rate_nuke_protect(struct clk_core *core)
|
|
{
|
|
int ret;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return -EINVAL;
|
|
|
|
if (core->protect_count == 0)
|
|
return 0;
|
|
|
|
ret = core->protect_count;
|
|
core->protect_count = 1;
|
|
clk_core_rate_unprotect(core);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_rate_exclusive_put - release exclusivity over clock rate control
|
|
* @clk: the clk over which the exclusivity is released
|
|
*
|
|
* clk_rate_exclusive_put() completes a critical section during which a clock
|
|
* consumer cannot tolerate any other consumer making any operation on the
|
|
* clock which could result in a rate change or rate glitch. Exclusive clocks
|
|
* cannot have their rate changed, either directly or indirectly due to changes
|
|
* further up the parent chain of clocks. As a result, clocks up parent chain
|
|
* also get under exclusive control of the calling consumer.
|
|
*
|
|
* If exlusivity is claimed more than once on clock, even by the same consumer,
|
|
* the rate effectively gets locked as exclusivity can't be preempted.
|
|
*
|
|
* Calls to clk_rate_exclusive_put() must be balanced with calls to
|
|
* clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
|
|
* error status.
|
|
*/
|
|
void clk_rate_exclusive_put(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return;
|
|
|
|
clk_prepare_lock();
|
|
|
|
/*
|
|
* if there is something wrong with this consumer protect count, stop
|
|
* here before messing with the provider
|
|
*/
|
|
if (WARN_ON(clk->exclusive_count <= 0))
|
|
goto out;
|
|
|
|
clk_core_rate_unprotect(clk->core);
|
|
clk->exclusive_count--;
|
|
out:
|
|
clk_prepare_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
|
|
|
|
static void clk_core_rate_protect(struct clk_core *core)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return;
|
|
|
|
if (core->protect_count == 0)
|
|
clk_core_rate_protect(core->parent);
|
|
|
|
core->protect_count++;
|
|
}
|
|
|
|
static void clk_core_rate_restore_protect(struct clk_core *core, int count)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return;
|
|
|
|
if (count == 0)
|
|
return;
|
|
|
|
clk_core_rate_protect(core);
|
|
core->protect_count = count;
|
|
}
|
|
|
|
/**
|
|
* clk_rate_exclusive_get - get exclusivity over the clk rate control
|
|
* @clk: the clk over which the exclusity of rate control is requested
|
|
*
|
|
* clk_rate_exlusive_get() begins a critical section during which a clock
|
|
* consumer cannot tolerate any other consumer making any operation on the
|
|
* clock which could result in a rate change or rate glitch. Exclusive clocks
|
|
* cannot have their rate changed, either directly or indirectly due to changes
|
|
* further up the parent chain of clocks. As a result, clocks up parent chain
|
|
* also get under exclusive control of the calling consumer.
|
|
*
|
|
* If exlusivity is claimed more than once on clock, even by the same consumer,
|
|
* the rate effectively gets locked as exclusivity can't be preempted.
|
|
*
|
|
* Calls to clk_rate_exclusive_get() should be balanced with calls to
|
|
* clk_rate_exclusive_put(). Calls to this function may sleep.
|
|
* Returns 0 on success, -EERROR otherwise
|
|
*/
|
|
int clk_rate_exclusive_get(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_prepare_lock();
|
|
clk_core_rate_protect(clk->core);
|
|
clk->exclusive_count++;
|
|
clk_prepare_unlock();
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
|
|
|
|
static void clk_core_unprepare(struct clk_core *core)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return;
|
|
|
|
if (WARN(core->prepare_count == 0,
|
|
"%s already unprepared\n", core->name))
|
|
return;
|
|
|
|
if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
|
|
"Unpreparing critical %s\n", core->name))
|
|
return;
|
|
|
|
if (core->flags & CLK_SET_RATE_GATE)
|
|
clk_core_rate_unprotect(core);
|
|
|
|
if (--core->prepare_count > 0)
|
|
return;
|
|
|
|
WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
|
|
|
|
trace_clk_unprepare(core);
|
|
|
|
if (core->ops->unprepare)
|
|
core->ops->unprepare(core->hw);
|
|
|
|
clk_pm_runtime_put(core);
|
|
|
|
trace_clk_unprepare_complete(core);
|
|
clk_core_unprepare(core->parent);
|
|
}
|
|
|
|
static void clk_core_unprepare_lock(struct clk_core *core)
|
|
{
|
|
clk_prepare_lock();
|
|
clk_core_unprepare(core);
|
|
clk_prepare_unlock();
|
|
}
|
|
|
|
/**
|
|
* clk_unprepare - undo preparation of a clock source
|
|
* @clk: the clk being unprepared
|
|
*
|
|
* clk_unprepare may sleep, which differentiates it from clk_disable. In a
|
|
* simple case, clk_unprepare can be used instead of clk_disable to gate a clk
|
|
* if the operation may sleep. One example is a clk which is accessed over
|
|
* I2c. In the complex case a clk gate operation may require a fast and a slow
|
|
* part. It is this reason that clk_unprepare and clk_disable are not mutually
|
|
* exclusive. In fact clk_disable must be called before clk_unprepare.
|
|
*/
|
|
void clk_unprepare(struct clk *clk)
|
|
{
|
|
if (IS_ERR_OR_NULL(clk))
|
|
return;
|
|
|
|
clk_core_unprepare_lock(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_unprepare);
|
|
|
|
static int clk_core_prepare(struct clk_core *core)
|
|
{
|
|
int ret = 0;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
if (core->prepare_count == 0) {
|
|
ret = clk_pm_runtime_get(core);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = clk_core_prepare(core->parent);
|
|
if (ret)
|
|
goto runtime_put;
|
|
|
|
trace_clk_prepare(core);
|
|
|
|
if (core->ops->prepare)
|
|
ret = core->ops->prepare(core->hw);
|
|
|
|
trace_clk_prepare_complete(core);
|
|
|
|
if (ret)
|
|
goto unprepare;
|
|
}
|
|
|
|
core->prepare_count++;
|
|
|
|
/*
|
|
* CLK_SET_RATE_GATE is a special case of clock protection
|
|
* Instead of a consumer claiming exclusive rate control, it is
|
|
* actually the provider which prevents any consumer from making any
|
|
* operation which could result in a rate change or rate glitch while
|
|
* the clock is prepared.
|
|
*/
|
|
if (core->flags & CLK_SET_RATE_GATE)
|
|
clk_core_rate_protect(core);
|
|
|
|
return 0;
|
|
unprepare:
|
|
clk_core_unprepare(core->parent);
|
|
runtime_put:
|
|
clk_pm_runtime_put(core);
|
|
return ret;
|
|
}
|
|
|
|
static int clk_core_prepare_lock(struct clk_core *core)
|
|
{
|
|
int ret;
|
|
|
|
clk_prepare_lock();
|
|
ret = clk_core_prepare(core);
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_prepare - prepare a clock source
|
|
* @clk: the clk being prepared
|
|
*
|
|
* clk_prepare may sleep, which differentiates it from clk_enable. In a simple
|
|
* case, clk_prepare can be used instead of clk_enable to ungate a clk if the
|
|
* operation may sleep. One example is a clk which is accessed over I2c. In
|
|
* the complex case a clk ungate operation may require a fast and a slow part.
|
|
* It is this reason that clk_prepare and clk_enable are not mutually
|
|
* exclusive. In fact clk_prepare must be called before clk_enable.
|
|
* Returns 0 on success, -EERROR otherwise.
|
|
*/
|
|
int clk_prepare(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_prepare_lock(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_prepare);
|
|
|
|
static void clk_core_disable(struct clk_core *core)
|
|
{
|
|
lockdep_assert_held(&enable_lock);
|
|
|
|
if (!core)
|
|
return;
|
|
|
|
if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
|
|
return;
|
|
|
|
if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
|
|
"Disabling critical %s\n", core->name))
|
|
return;
|
|
|
|
if (--core->enable_count > 0)
|
|
return;
|
|
|
|
trace_clk_disable_rcuidle(core);
|
|
|
|
if (core->ops->disable)
|
|
core->ops->disable(core->hw);
|
|
|
|
trace_clk_disable_complete_rcuidle(core);
|
|
|
|
clk_core_disable(core->parent);
|
|
}
|
|
|
|
static void clk_core_disable_lock(struct clk_core *core)
|
|
{
|
|
unsigned long flags;
|
|
|
|
flags = clk_enable_lock();
|
|
clk_core_disable(core);
|
|
clk_enable_unlock(flags);
|
|
}
|
|
|
|
/**
|
|
* clk_disable - gate a clock
|
|
* @clk: the clk being gated
|
|
*
|
|
* clk_disable must not sleep, which differentiates it from clk_unprepare. In
|
|
* a simple case, clk_disable can be used instead of clk_unprepare to gate a
|
|
* clk if the operation is fast and will never sleep. One example is a
|
|
* SoC-internal clk which is controlled via simple register writes. In the
|
|
* complex case a clk gate operation may require a fast and a slow part. It is
|
|
* this reason that clk_unprepare and clk_disable are not mutually exclusive.
|
|
* In fact clk_disable must be called before clk_unprepare.
|
|
*/
|
|
void clk_disable(struct clk *clk)
|
|
{
|
|
if (IS_ERR_OR_NULL(clk))
|
|
return;
|
|
|
|
clk_core_disable_lock(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_disable);
|
|
|
|
static int clk_core_enable(struct clk_core *core)
|
|
{
|
|
int ret = 0;
|
|
|
|
lockdep_assert_held(&enable_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
if (WARN(core->prepare_count == 0,
|
|
"Enabling unprepared %s\n", core->name))
|
|
return -ESHUTDOWN;
|
|
|
|
if (core->enable_count == 0) {
|
|
ret = clk_core_enable(core->parent);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
trace_clk_enable_rcuidle(core);
|
|
|
|
if (core->ops->enable)
|
|
ret = core->ops->enable(core->hw);
|
|
|
|
trace_clk_enable_complete_rcuidle(core);
|
|
|
|
if (ret) {
|
|
clk_core_disable(core->parent);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
core->enable_count++;
|
|
return 0;
|
|
}
|
|
|
|
static int clk_core_enable_lock(struct clk_core *core)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
flags = clk_enable_lock();
|
|
ret = clk_core_enable(core);
|
|
clk_enable_unlock(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_gate_restore_context - restore context for poweroff
|
|
* @hw: the clk_hw pointer of clock whose state is to be restored
|
|
*
|
|
* The clock gate restore context function enables or disables
|
|
* the gate clocks based on the enable_count. This is done in cases
|
|
* where the clock context is lost and based on the enable_count
|
|
* the clock either needs to be enabled/disabled. This
|
|
* helps restore the state of gate clocks.
|
|
*/
|
|
void clk_gate_restore_context(struct clk_hw *hw)
|
|
{
|
|
struct clk_core *core = hw->core;
|
|
|
|
if (core->enable_count)
|
|
core->ops->enable(hw);
|
|
else
|
|
core->ops->disable(hw);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_gate_restore_context);
|
|
|
|
static int clk_core_save_context(struct clk_core *core)
|
|
{
|
|
struct clk_core *child;
|
|
int ret = 0;
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node) {
|
|
ret = clk_core_save_context(child);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
if (core->ops && core->ops->save_context)
|
|
ret = core->ops->save_context(core->hw);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void clk_core_restore_context(struct clk_core *core)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
if (core->ops && core->ops->restore_context)
|
|
core->ops->restore_context(core->hw);
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
clk_core_restore_context(child);
|
|
}
|
|
|
|
/**
|
|
* clk_save_context - save clock context for poweroff
|
|
*
|
|
* Saves the context of the clock register for powerstates in which the
|
|
* contents of the registers will be lost. Occurs deep within the suspend
|
|
* code. Returns 0 on success.
|
|
*/
|
|
int clk_save_context(void)
|
|
{
|
|
struct clk_core *clk;
|
|
int ret;
|
|
|
|
hlist_for_each_entry(clk, &clk_root_list, child_node) {
|
|
ret = clk_core_save_context(clk);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
|
|
ret = clk_core_save_context(clk);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_save_context);
|
|
|
|
/**
|
|
* clk_restore_context - restore clock context after poweroff
|
|
*
|
|
* Restore the saved clock context upon resume.
|
|
*
|
|
*/
|
|
void clk_restore_context(void)
|
|
{
|
|
struct clk_core *core;
|
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node)
|
|
clk_core_restore_context(core);
|
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node)
|
|
clk_core_restore_context(core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_restore_context);
|
|
|
|
/**
|
|
* clk_enable - ungate a clock
|
|
* @clk: the clk being ungated
|
|
*
|
|
* clk_enable must not sleep, which differentiates it from clk_prepare. In a
|
|
* simple case, clk_enable can be used instead of clk_prepare to ungate a clk
|
|
* if the operation will never sleep. One example is a SoC-internal clk which
|
|
* is controlled via simple register writes. In the complex case a clk ungate
|
|
* operation may require a fast and a slow part. It is this reason that
|
|
* clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
|
|
* must be called before clk_enable. Returns 0 on success, -EERROR
|
|
* otherwise.
|
|
*/
|
|
int clk_enable(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_enable_lock(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_enable);
|
|
|
|
static int clk_core_prepare_enable(struct clk_core *core)
|
|
{
|
|
int ret;
|
|
|
|
ret = clk_core_prepare_lock(core);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = clk_core_enable_lock(core);
|
|
if (ret)
|
|
clk_core_unprepare_lock(core);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void clk_core_disable_unprepare(struct clk_core *core)
|
|
{
|
|
clk_core_disable_lock(core);
|
|
clk_core_unprepare_lock(core);
|
|
}
|
|
|
|
static void clk_unprepare_unused_subtree(struct clk_core *core)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
clk_unprepare_unused_subtree(child);
|
|
|
|
if (core->prepare_count)
|
|
return;
|
|
|
|
if (core->flags & CLK_IGNORE_UNUSED)
|
|
return;
|
|
|
|
if (clk_pm_runtime_get(core))
|
|
return;
|
|
|
|
if (clk_core_is_prepared(core)) {
|
|
trace_clk_unprepare(core);
|
|
if (core->ops->unprepare_unused)
|
|
core->ops->unprepare_unused(core->hw);
|
|
else if (core->ops->unprepare)
|
|
core->ops->unprepare(core->hw);
|
|
trace_clk_unprepare_complete(core);
|
|
}
|
|
|
|
clk_pm_runtime_put(core);
|
|
}
|
|
|
|
static void clk_disable_unused_subtree(struct clk_core *core)
|
|
{
|
|
struct clk_core *child;
|
|
unsigned long flags;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
clk_disable_unused_subtree(child);
|
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE)
|
|
clk_core_prepare_enable(core->parent);
|
|
|
|
if (clk_pm_runtime_get(core))
|
|
goto unprepare_out;
|
|
|
|
flags = clk_enable_lock();
|
|
|
|
if (core->enable_count)
|
|
goto unlock_out;
|
|
|
|
if (core->flags & CLK_IGNORE_UNUSED)
|
|
goto unlock_out;
|
|
|
|
/*
|
|
* some gate clocks have special needs during the disable-unused
|
|
* sequence. call .disable_unused if available, otherwise fall
|
|
* back to .disable
|
|
*/
|
|
if (clk_core_is_enabled(core)) {
|
|
trace_clk_disable(core);
|
|
if (core->ops->disable_unused)
|
|
core->ops->disable_unused(core->hw);
|
|
else if (core->ops->disable)
|
|
core->ops->disable(core->hw);
|
|
trace_clk_disable_complete(core);
|
|
}
|
|
|
|
unlock_out:
|
|
clk_enable_unlock(flags);
|
|
clk_pm_runtime_put(core);
|
|
unprepare_out:
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE)
|
|
clk_core_disable_unprepare(core->parent);
|
|
}
|
|
|
|
static bool clk_ignore_unused;
|
|
static int __init clk_ignore_unused_setup(char *__unused)
|
|
{
|
|
clk_ignore_unused = true;
|
|
return 1;
|
|
}
|
|
__setup("clk_ignore_unused", clk_ignore_unused_setup);
|
|
|
|
static int clk_disable_unused(void)
|
|
{
|
|
struct clk_core *core;
|
|
|
|
if (clk_ignore_unused) {
|
|
pr_warn("clk: Not disabling unused clocks\n");
|
|
return 0;
|
|
}
|
|
|
|
clk_prepare_lock();
|
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node)
|
|
clk_disable_unused_subtree(core);
|
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node)
|
|
clk_disable_unused_subtree(core);
|
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node)
|
|
clk_unprepare_unused_subtree(core);
|
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node)
|
|
clk_unprepare_unused_subtree(core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return 0;
|
|
}
|
|
late_initcall_sync(clk_disable_unused);
|
|
|
|
static int clk_core_determine_round_nolock(struct clk_core *core,
|
|
struct clk_rate_request *req)
|
|
{
|
|
long rate;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
/*
|
|
* At this point, core protection will be disabled if
|
|
* - if the provider is not protected at all
|
|
* - if the calling consumer is the only one which has exclusivity
|
|
* over the provider
|
|
*/
|
|
if (clk_core_rate_is_protected(core)) {
|
|
req->rate = core->rate;
|
|
} else if (core->ops->determine_rate) {
|
|
return core->ops->determine_rate(core->hw, req);
|
|
} else if (core->ops->round_rate) {
|
|
rate = core->ops->round_rate(core->hw, req->rate,
|
|
&req->best_parent_rate);
|
|
if (rate < 0)
|
|
return rate;
|
|
|
|
req->rate = rate;
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void clk_core_init_rate_req(struct clk_core * const core,
|
|
struct clk_rate_request *req)
|
|
{
|
|
struct clk_core *parent;
|
|
|
|
if (WARN_ON(!core || !req))
|
|
return;
|
|
|
|
parent = core->parent;
|
|
if (parent) {
|
|
req->best_parent_hw = parent->hw;
|
|
req->best_parent_rate = parent->rate;
|
|
} else {
|
|
req->best_parent_hw = NULL;
|
|
req->best_parent_rate = 0;
|
|
}
|
|
}
|
|
|
|
static bool clk_core_can_round(struct clk_core * const core)
|
|
{
|
|
if (core->ops->determine_rate || core->ops->round_rate)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static int clk_core_round_rate_nolock(struct clk_core *core,
|
|
struct clk_rate_request *req)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core) {
|
|
req->rate = 0;
|
|
return 0;
|
|
}
|
|
|
|
clk_core_init_rate_req(core, req);
|
|
|
|
if (clk_core_can_round(core))
|
|
return clk_core_determine_round_nolock(core, req);
|
|
else if (core->flags & CLK_SET_RATE_PARENT)
|
|
return clk_core_round_rate_nolock(core->parent, req);
|
|
|
|
req->rate = core->rate;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __clk_determine_rate - get the closest rate actually supported by a clock
|
|
* @hw: determine the rate of this clock
|
|
* @req: target rate request
|
|
*
|
|
* Useful for clk_ops such as .set_rate and .determine_rate.
|
|
*/
|
|
int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
|
|
{
|
|
if (!hw) {
|
|
req->rate = 0;
|
|
return 0;
|
|
}
|
|
|
|
return clk_core_round_rate_nolock(hw->core, req);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_determine_rate);
|
|
|
|
unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
|
|
{
|
|
int ret;
|
|
struct clk_rate_request req;
|
|
|
|
clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
|
|
req.rate = rate;
|
|
|
|
ret = clk_core_round_rate_nolock(hw->core, &req);
|
|
if (ret)
|
|
return 0;
|
|
|
|
return req.rate;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_hw_round_rate);
|
|
|
|
/**
|
|
* clk_round_rate - round the given rate for a clk
|
|
* @clk: the clk for which we are rounding a rate
|
|
* @rate: the rate which is to be rounded
|
|
*
|
|
* Takes in a rate as input and rounds it to a rate that the clk can actually
|
|
* use which is then returned. If clk doesn't support round_rate operation
|
|
* then the parent rate is returned.
|
|
*/
|
|
long clk_round_rate(struct clk *clk, unsigned long rate)
|
|
{
|
|
struct clk_rate_request req;
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
|
|
req.rate = rate;
|
|
|
|
ret = clk_core_round_rate_nolock(clk->core, &req);
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
return req.rate;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_round_rate);
|
|
|
|
/**
|
|
* __clk_notify - call clk notifier chain
|
|
* @core: clk that is changing rate
|
|
* @msg: clk notifier type (see include/linux/clk.h)
|
|
* @old_rate: old clk rate
|
|
* @new_rate: new clk rate
|
|
*
|
|
* Triggers a notifier call chain on the clk rate-change notification
|
|
* for 'clk'. Passes a pointer to the struct clk and the previous
|
|
* and current rates to the notifier callback. Intended to be called by
|
|
* internal clock code only. Returns NOTIFY_DONE from the last driver
|
|
* called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
|
|
* a driver returns that.
|
|
*/
|
|
static int __clk_notify(struct clk_core *core, unsigned long msg,
|
|
unsigned long old_rate, unsigned long new_rate)
|
|
{
|
|
struct clk_notifier *cn;
|
|
struct clk_notifier_data cnd;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
cnd.old_rate = old_rate;
|
|
cnd.new_rate = new_rate;
|
|
|
|
list_for_each_entry(cn, &clk_notifier_list, node) {
|
|
if (cn->clk->core == core) {
|
|
cnd.clk = cn->clk;
|
|
ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
|
|
&cnd);
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __clk_recalc_accuracies
|
|
* @core: first clk in the subtree
|
|
*
|
|
* Walks the subtree of clks starting with clk and recalculates accuracies as
|
|
* it goes. Note that if a clk does not implement the .recalc_accuracy
|
|
* callback then it is assumed that the clock will take on the accuracy of its
|
|
* parent.
|
|
*/
|
|
static void __clk_recalc_accuracies(struct clk_core *core)
|
|
{
|
|
unsigned long parent_accuracy = 0;
|
|
struct clk_core *child;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (core->parent)
|
|
parent_accuracy = core->parent->accuracy;
|
|
|
|
if (core->ops->recalc_accuracy)
|
|
core->accuracy = core->ops->recalc_accuracy(core->hw,
|
|
parent_accuracy);
|
|
else
|
|
core->accuracy = parent_accuracy;
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
__clk_recalc_accuracies(child);
|
|
}
|
|
|
|
static long clk_core_get_accuracy(struct clk_core *core)
|
|
{
|
|
unsigned long accuracy;
|
|
|
|
clk_prepare_lock();
|
|
if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
|
|
__clk_recalc_accuracies(core);
|
|
|
|
accuracy = __clk_get_accuracy(core);
|
|
clk_prepare_unlock();
|
|
|
|
return accuracy;
|
|
}
|
|
|
|
/**
|
|
* clk_get_accuracy - return the accuracy of clk
|
|
* @clk: the clk whose accuracy is being returned
|
|
*
|
|
* Simply returns the cached accuracy of the clk, unless
|
|
* CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
|
|
* issued.
|
|
* If clk is NULL then returns 0.
|
|
*/
|
|
long clk_get_accuracy(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_get_accuracy(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_accuracy);
|
|
|
|
static unsigned long clk_recalc(struct clk_core *core,
|
|
unsigned long parent_rate)
|
|
{
|
|
unsigned long rate = parent_rate;
|
|
|
|
if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
|
|
rate = core->ops->recalc_rate(core->hw, parent_rate);
|
|
clk_pm_runtime_put(core);
|
|
}
|
|
return rate;
|
|
}
|
|
|
|
/**
|
|
* __clk_recalc_rates
|
|
* @core: first clk in the subtree
|
|
* @msg: notification type (see include/linux/clk.h)
|
|
*
|
|
* Walks the subtree of clks starting with clk and recalculates rates as it
|
|
* goes. Note that if a clk does not implement the .recalc_rate callback then
|
|
* it is assumed that the clock will take on the rate of its parent.
|
|
*
|
|
* clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
|
|
* if necessary.
|
|
*/
|
|
static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
|
|
{
|
|
unsigned long old_rate;
|
|
unsigned long parent_rate = 0;
|
|
struct clk_core *child;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
old_rate = core->rate;
|
|
|
|
if (core->parent)
|
|
parent_rate = core->parent->rate;
|
|
|
|
core->rate = clk_recalc(core, parent_rate);
|
|
|
|
/*
|
|
* ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
|
|
* & ABORT_RATE_CHANGE notifiers
|
|
*/
|
|
if (core->notifier_count && msg)
|
|
__clk_notify(core, msg, old_rate, core->rate);
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
__clk_recalc_rates(child, msg);
|
|
}
|
|
|
|
static unsigned long clk_core_get_rate(struct clk_core *core)
|
|
{
|
|
unsigned long rate;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (core && (core->flags & CLK_GET_RATE_NOCACHE))
|
|
__clk_recalc_rates(core, 0);
|
|
|
|
rate = clk_core_get_rate_nolock(core);
|
|
clk_prepare_unlock();
|
|
|
|
return rate;
|
|
}
|
|
|
|
/**
|
|
* clk_get_rate - return the rate of clk
|
|
* @clk: the clk whose rate is being returned
|
|
*
|
|
* Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
|
|
* is set, which means a recalc_rate will be issued.
|
|
* If clk is NULL then returns 0.
|
|
*/
|
|
unsigned long clk_get_rate(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_get_rate(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_rate);
|
|
|
|
static int clk_fetch_parent_index(struct clk_core *core,
|
|
struct clk_core *parent)
|
|
{
|
|
int i;
|
|
|
|
if (!parent)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < core->num_parents; i++) {
|
|
/* Found it first try! */
|
|
if (core->parents[i].core == parent)
|
|
return i;
|
|
|
|
/* Something else is here, so keep looking */
|
|
if (core->parents[i].core)
|
|
continue;
|
|
|
|
/* Maybe core hasn't been cached but the hw is all we know? */
|
|
if (core->parents[i].hw) {
|
|
if (core->parents[i].hw == parent->hw)
|
|
break;
|
|
|
|
/* Didn't match, but we're expecting a clk_hw */
|
|
continue;
|
|
}
|
|
|
|
/* Maybe it hasn't been cached (clk_set_parent() path) */
|
|
if (parent == clk_core_get(core, i))
|
|
break;
|
|
|
|
/* Fallback to comparing globally unique names */
|
|
if (!strcmp(parent->name, core->parents[i].name))
|
|
break;
|
|
}
|
|
|
|
if (i == core->num_parents)
|
|
return -EINVAL;
|
|
|
|
core->parents[i].core = parent;
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* Update the orphan status of @core and all its children.
|
|
*/
|
|
static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
core->orphan = is_orphan;
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node)
|
|
clk_core_update_orphan_status(child, is_orphan);
|
|
}
|
|
|
|
static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
|
|
{
|
|
bool was_orphan = core->orphan;
|
|
|
|
hlist_del(&core->child_node);
|
|
|
|
if (new_parent) {
|
|
bool becomes_orphan = new_parent->orphan;
|
|
|
|
/* avoid duplicate POST_RATE_CHANGE notifications */
|
|
if (new_parent->new_child == core)
|
|
new_parent->new_child = NULL;
|
|
|
|
hlist_add_head(&core->child_node, &new_parent->children);
|
|
|
|
if (was_orphan != becomes_orphan)
|
|
clk_core_update_orphan_status(core, becomes_orphan);
|
|
} else {
|
|
hlist_add_head(&core->child_node, &clk_orphan_list);
|
|
if (!was_orphan)
|
|
clk_core_update_orphan_status(core, true);
|
|
}
|
|
|
|
core->parent = new_parent;
|
|
}
|
|
|
|
static struct clk_core *__clk_set_parent_before(struct clk_core *core,
|
|
struct clk_core *parent)
|
|
{
|
|
unsigned long flags;
|
|
struct clk_core *old_parent = core->parent;
|
|
|
|
/*
|
|
* 1. enable parents for CLK_OPS_PARENT_ENABLE clock
|
|
*
|
|
* 2. Migrate prepare state between parents and prevent race with
|
|
* clk_enable().
|
|
*
|
|
* If the clock is not prepared, then a race with
|
|
* clk_enable/disable() is impossible since we already have the
|
|
* prepare lock (future calls to clk_enable() need to be preceded by
|
|
* a clk_prepare()).
|
|
*
|
|
* If the clock is prepared, migrate the prepared state to the new
|
|
* parent and also protect against a race with clk_enable() by
|
|
* forcing the clock and the new parent on. This ensures that all
|
|
* future calls to clk_enable() are practically NOPs with respect to
|
|
* hardware and software states.
|
|
*
|
|
* See also: Comment for clk_set_parent() below.
|
|
*/
|
|
|
|
/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE) {
|
|
clk_core_prepare_enable(old_parent);
|
|
clk_core_prepare_enable(parent);
|
|
}
|
|
|
|
/* migrate prepare count if > 0 */
|
|
if (core->prepare_count) {
|
|
clk_core_prepare_enable(parent);
|
|
clk_core_enable_lock(core);
|
|
}
|
|
|
|
/* update the clk tree topology */
|
|
flags = clk_enable_lock();
|
|
clk_reparent(core, parent);
|
|
clk_enable_unlock(flags);
|
|
|
|
return old_parent;
|
|
}
|
|
|
|
static void __clk_set_parent_after(struct clk_core *core,
|
|
struct clk_core *parent,
|
|
struct clk_core *old_parent)
|
|
{
|
|
/*
|
|
* Finish the migration of prepare state and undo the changes done
|
|
* for preventing a race with clk_enable().
|
|
*/
|
|
if (core->prepare_count) {
|
|
clk_core_disable_lock(core);
|
|
clk_core_disable_unprepare(old_parent);
|
|
}
|
|
|
|
/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE) {
|
|
clk_core_disable_unprepare(parent);
|
|
clk_core_disable_unprepare(old_parent);
|
|
}
|
|
}
|
|
|
|
static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
|
|
u8 p_index)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
struct clk_core *old_parent;
|
|
|
|
old_parent = __clk_set_parent_before(core, parent);
|
|
|
|
trace_clk_set_parent(core, parent);
|
|
|
|
/* change clock input source */
|
|
if (parent && core->ops->set_parent)
|
|
ret = core->ops->set_parent(core->hw, p_index);
|
|
|
|
trace_clk_set_parent_complete(core, parent);
|
|
|
|
if (ret) {
|
|
flags = clk_enable_lock();
|
|
clk_reparent(core, old_parent);
|
|
clk_enable_unlock(flags);
|
|
__clk_set_parent_after(core, old_parent, parent);
|
|
|
|
return ret;
|
|
}
|
|
|
|
__clk_set_parent_after(core, parent, old_parent);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __clk_speculate_rates
|
|
* @core: first clk in the subtree
|
|
* @parent_rate: the "future" rate of clk's parent
|
|
*
|
|
* Walks the subtree of clks starting with clk, speculating rates as it
|
|
* goes and firing off PRE_RATE_CHANGE notifications as necessary.
|
|
*
|
|
* Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
|
|
* pre-rate change notifications and returns early if no clks in the
|
|
* subtree have subscribed to the notifications. Note that if a clk does not
|
|
* implement the .recalc_rate callback then it is assumed that the clock will
|
|
* take on the rate of its parent.
|
|
*/
|
|
static int __clk_speculate_rates(struct clk_core *core,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct clk_core *child;
|
|
unsigned long new_rate;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
new_rate = clk_recalc(core, parent_rate);
|
|
|
|
/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
|
|
if (core->notifier_count)
|
|
ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
|
|
|
|
if (ret & NOTIFY_STOP_MASK) {
|
|
pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
|
|
__func__, core->name, ret);
|
|
goto out;
|
|
}
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node) {
|
|
ret = __clk_speculate_rates(child, new_rate);
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
break;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
|
|
struct clk_core *new_parent, u8 p_index)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
core->new_rate = new_rate;
|
|
core->new_parent = new_parent;
|
|
core->new_parent_index = p_index;
|
|
/* include clk in new parent's PRE_RATE_CHANGE notifications */
|
|
core->new_child = NULL;
|
|
if (new_parent && new_parent != core->parent)
|
|
new_parent->new_child = core;
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node) {
|
|
child->new_rate = clk_recalc(child, new_rate);
|
|
clk_calc_subtree(child, child->new_rate, NULL, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* calculate the new rates returning the topmost clock that has to be
|
|
* changed.
|
|
*/
|
|
static struct clk_core *clk_calc_new_rates(struct clk_core *core,
|
|
unsigned long rate)
|
|
{
|
|
struct clk_core *top = core;
|
|
struct clk_core *old_parent, *parent;
|
|
unsigned long best_parent_rate = 0;
|
|
unsigned long new_rate;
|
|
unsigned long min_rate;
|
|
unsigned long max_rate;
|
|
int p_index = 0;
|
|
long ret;
|
|
|
|
/* sanity */
|
|
if (IS_ERR_OR_NULL(core))
|
|
return NULL;
|
|
|
|
/* save parent rate, if it exists */
|
|
parent = old_parent = core->parent;
|
|
if (parent)
|
|
best_parent_rate = parent->rate;
|
|
|
|
clk_core_get_boundaries(core, &min_rate, &max_rate);
|
|
|
|
/* find the closest rate and parent clk/rate */
|
|
if (clk_core_can_round(core)) {
|
|
struct clk_rate_request req;
|
|
|
|
req.rate = rate;
|
|
req.min_rate = min_rate;
|
|
req.max_rate = max_rate;
|
|
|
|
clk_core_init_rate_req(core, &req);
|
|
|
|
ret = clk_core_determine_round_nolock(core, &req);
|
|
if (ret < 0)
|
|
return NULL;
|
|
|
|
best_parent_rate = req.best_parent_rate;
|
|
new_rate = req.rate;
|
|
parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
|
|
|
|
if (new_rate < min_rate || new_rate > max_rate)
|
|
return NULL;
|
|
} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
|
|
/* pass-through clock without adjustable parent */
|
|
core->new_rate = core->rate;
|
|
return NULL;
|
|
} else {
|
|
/* pass-through clock with adjustable parent */
|
|
top = clk_calc_new_rates(parent, rate);
|
|
new_rate = parent->new_rate;
|
|
goto out;
|
|
}
|
|
|
|
/* some clocks must be gated to change parent */
|
|
if (parent != old_parent &&
|
|
(core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
|
|
pr_debug("%s: %s not gated but wants to reparent\n",
|
|
__func__, core->name);
|
|
return NULL;
|
|
}
|
|
|
|
/* try finding the new parent index */
|
|
if (parent && core->num_parents > 1) {
|
|
p_index = clk_fetch_parent_index(core, parent);
|
|
if (p_index < 0) {
|
|
pr_debug("%s: clk %s can not be parent of clk %s\n",
|
|
__func__, parent->name, core->name);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
|
|
best_parent_rate != parent->rate)
|
|
top = clk_calc_new_rates(parent, best_parent_rate);
|
|
|
|
out:
|
|
clk_calc_subtree(core, new_rate, parent, p_index);
|
|
|
|
return top;
|
|
}
|
|
|
|
/*
|
|
* Notify about rate changes in a subtree. Always walk down the whole tree
|
|
* so that in case of an error we can walk down the whole tree again and
|
|
* abort the change.
|
|
*/
|
|
static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
|
|
unsigned long event)
|
|
{
|
|
struct clk_core *child, *tmp_clk, *fail_clk = NULL;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
if (core->rate == core->new_rate)
|
|
return NULL;
|
|
|
|
if (core->notifier_count) {
|
|
ret = __clk_notify(core, event, core->rate, core->new_rate);
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
fail_clk = core;
|
|
}
|
|
|
|
hlist_for_each_entry(child, &core->children, child_node) {
|
|
/* Skip children who will be reparented to another clock */
|
|
if (child->new_parent && child->new_parent != core)
|
|
continue;
|
|
tmp_clk = clk_propagate_rate_change(child, event);
|
|
if (tmp_clk)
|
|
fail_clk = tmp_clk;
|
|
}
|
|
|
|
/* handle the new child who might not be in core->children yet */
|
|
if (core->new_child) {
|
|
tmp_clk = clk_propagate_rate_change(core->new_child, event);
|
|
if (tmp_clk)
|
|
fail_clk = tmp_clk;
|
|
}
|
|
|
|
return fail_clk;
|
|
}
|
|
|
|
/*
|
|
* walk down a subtree and set the new rates notifying the rate
|
|
* change on the way
|
|
*/
|
|
static void clk_change_rate(struct clk_core *core)
|
|
{
|
|
struct clk_core *child;
|
|
struct hlist_node *tmp;
|
|
unsigned long old_rate;
|
|
unsigned long best_parent_rate = 0;
|
|
bool skip_set_rate = false;
|
|
struct clk_core *old_parent;
|
|
struct clk_core *parent = NULL;
|
|
|
|
old_rate = core->rate;
|
|
|
|
if (core->new_parent) {
|
|
parent = core->new_parent;
|
|
best_parent_rate = core->new_parent->rate;
|
|
} else if (core->parent) {
|
|
parent = core->parent;
|
|
best_parent_rate = core->parent->rate;
|
|
}
|
|
|
|
if (clk_pm_runtime_get(core))
|
|
return;
|
|
|
|
if (core->flags & CLK_SET_RATE_UNGATE) {
|
|
unsigned long flags;
|
|
|
|
clk_core_prepare(core);
|
|
flags = clk_enable_lock();
|
|
clk_core_enable(core);
|
|
clk_enable_unlock(flags);
|
|
}
|
|
|
|
if (core->new_parent && core->new_parent != core->parent) {
|
|
old_parent = __clk_set_parent_before(core, core->new_parent);
|
|
trace_clk_set_parent(core, core->new_parent);
|
|
|
|
if (core->ops->set_rate_and_parent) {
|
|
skip_set_rate = true;
|
|
core->ops->set_rate_and_parent(core->hw, core->new_rate,
|
|
best_parent_rate,
|
|
core->new_parent_index);
|
|
} else if (core->ops->set_parent) {
|
|
core->ops->set_parent(core->hw, core->new_parent_index);
|
|
}
|
|
|
|
trace_clk_set_parent_complete(core, core->new_parent);
|
|
__clk_set_parent_after(core, core->new_parent, old_parent);
|
|
}
|
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE)
|
|
clk_core_prepare_enable(parent);
|
|
|
|
trace_clk_set_rate(core, core->new_rate);
|
|
|
|
if (!skip_set_rate && core->ops->set_rate)
|
|
core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
|
|
|
|
trace_clk_set_rate_complete(core, core->new_rate);
|
|
|
|
core->rate = clk_recalc(core, best_parent_rate);
|
|
|
|
if (core->flags & CLK_SET_RATE_UNGATE) {
|
|
unsigned long flags;
|
|
|
|
flags = clk_enable_lock();
|
|
clk_core_disable(core);
|
|
clk_enable_unlock(flags);
|
|
clk_core_unprepare(core);
|
|
}
|
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE)
|
|
clk_core_disable_unprepare(parent);
|
|
|
|
if (core->notifier_count && old_rate != core->rate)
|
|
__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
|
|
|
|
if (core->flags & CLK_RECALC_NEW_RATES)
|
|
(void)clk_calc_new_rates(core, core->new_rate);
|
|
|
|
/*
|
|
* Use safe iteration, as change_rate can actually swap parents
|
|
* for certain clock types.
|
|
*/
|
|
hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
|
|
/* Skip children who will be reparented to another clock */
|
|
if (child->new_parent && child->new_parent != core)
|
|
continue;
|
|
clk_change_rate(child);
|
|
}
|
|
|
|
/* handle the new child who might not be in core->children yet */
|
|
if (core->new_child)
|
|
clk_change_rate(core->new_child);
|
|
|
|
clk_pm_runtime_put(core);
|
|
}
|
|
|
|
static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
|
|
unsigned long req_rate)
|
|
{
|
|
int ret, cnt;
|
|
struct clk_rate_request req;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
/* simulate what the rate would be if it could be freely set */
|
|
cnt = clk_core_rate_nuke_protect(core);
|
|
if (cnt < 0)
|
|
return cnt;
|
|
|
|
clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
|
|
req.rate = req_rate;
|
|
|
|
ret = clk_core_round_rate_nolock(core, &req);
|
|
|
|
/* restore the protection */
|
|
clk_core_rate_restore_protect(core, cnt);
|
|
|
|
return ret ? 0 : req.rate;
|
|
}
|
|
|
|
static int clk_core_set_rate_nolock(struct clk_core *core,
|
|
unsigned long req_rate)
|
|
{
|
|
struct clk_core *top, *fail_clk;
|
|
unsigned long rate;
|
|
int ret = 0;
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
rate = clk_core_req_round_rate_nolock(core, req_rate);
|
|
|
|
/* bail early if nothing to do */
|
|
if (rate == clk_core_get_rate_nolock(core))
|
|
return 0;
|
|
|
|
/* fail on a direct rate set of a protected provider */
|
|
if (clk_core_rate_is_protected(core))
|
|
return -EBUSY;
|
|
|
|
/* calculate new rates and get the topmost changed clock */
|
|
top = clk_calc_new_rates(core, req_rate);
|
|
if (!top)
|
|
return -EINVAL;
|
|
|
|
ret = clk_pm_runtime_get(core);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* notify that we are about to change rates */
|
|
fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
|
|
if (fail_clk) {
|
|
pr_debug("%s: failed to set %s rate\n", __func__,
|
|
fail_clk->name);
|
|
clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
|
|
ret = -EBUSY;
|
|
goto err;
|
|
}
|
|
|
|
/* change the rates */
|
|
clk_change_rate(top);
|
|
|
|
core->req_rate = req_rate;
|
|
err:
|
|
clk_pm_runtime_put(core);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_set_rate - specify a new rate for clk
|
|
* @clk: the clk whose rate is being changed
|
|
* @rate: the new rate for clk
|
|
*
|
|
* In the simplest case clk_set_rate will only adjust the rate of clk.
|
|
*
|
|
* Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
|
|
* propagate up to clk's parent; whether or not this happens depends on the
|
|
* outcome of clk's .round_rate implementation. If *parent_rate is unchanged
|
|
* after calling .round_rate then upstream parent propagation is ignored. If
|
|
* *parent_rate comes back with a new rate for clk's parent then we propagate
|
|
* up to clk's parent and set its rate. Upward propagation will continue
|
|
* until either a clk does not support the CLK_SET_RATE_PARENT flag or
|
|
* .round_rate stops requesting changes to clk's parent_rate.
|
|
*
|
|
* Rate changes are accomplished via tree traversal that also recalculates the
|
|
* rates for the clocks and fires off POST_RATE_CHANGE notifiers.
|
|
*
|
|
* Returns 0 on success, -EERROR otherwise.
|
|
*/
|
|
int clk_set_rate(struct clk *clk, unsigned long rate)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* prevent racing with updates to the clock topology */
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate);
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_rate);
|
|
|
|
/**
|
|
* clk_set_rate_exclusive - specify a new rate get exclusive control
|
|
* @clk: the clk whose rate is being changed
|
|
* @rate: the new rate for clk
|
|
*
|
|
* This is a combination of clk_set_rate() and clk_rate_exclusive_get()
|
|
* within a critical section
|
|
*
|
|
* This can be used initially to ensure that at least 1 consumer is
|
|
* statisfied when several consumers are competing for exclusivity over the
|
|
* same clock provider.
|
|
*
|
|
* The exclusivity is not applied if setting the rate failed.
|
|
*
|
|
* Calls to clk_rate_exclusive_get() should be balanced with calls to
|
|
* clk_rate_exclusive_put().
|
|
*
|
|
* Returns 0 on success, -EERROR otherwise.
|
|
*/
|
|
int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* prevent racing with updates to the clock topology */
|
|
clk_prepare_lock();
|
|
|
|
/*
|
|
* The temporary protection removal is not here, on purpose
|
|
* This function is meant to be used instead of clk_rate_protect,
|
|
* so before the consumer code path protect the clock provider
|
|
*/
|
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate);
|
|
if (!ret) {
|
|
clk_core_rate_protect(clk->core);
|
|
clk->exclusive_count++;
|
|
}
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
|
|
|
|
/**
|
|
* clk_set_rate_range - set a rate range for a clock source
|
|
* @clk: clock source
|
|
* @min: desired minimum clock rate in Hz, inclusive
|
|
* @max: desired maximum clock rate in Hz, inclusive
|
|
*
|
|
* Returns success (0) or negative errno.
|
|
*/
|
|
int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
|
|
{
|
|
int ret = 0;
|
|
unsigned long old_min, old_max, rate;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
if (min > max) {
|
|
pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
|
|
__func__, clk->core->name, clk->dev_id, clk->con_id,
|
|
min, max);
|
|
return -EINVAL;
|
|
}
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
/* Save the current values in case we need to rollback the change */
|
|
old_min = clk->min_rate;
|
|
old_max = clk->max_rate;
|
|
clk->min_rate = min;
|
|
clk->max_rate = max;
|
|
|
|
rate = clk_core_get_rate_nolock(clk->core);
|
|
if (rate < min || rate > max) {
|
|
/*
|
|
* FIXME:
|
|
* We are in bit of trouble here, current rate is outside the
|
|
* the requested range. We are going try to request appropriate
|
|
* range boundary but there is a catch. It may fail for the
|
|
* usual reason (clock broken, clock protected, etc) but also
|
|
* because:
|
|
* - round_rate() was not favorable and fell on the wrong
|
|
* side of the boundary
|
|
* - the determine_rate() callback does not really check for
|
|
* this corner case when determining the rate
|
|
*/
|
|
|
|
if (rate < min)
|
|
rate = min;
|
|
else
|
|
rate = max;
|
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate);
|
|
if (ret) {
|
|
/* rollback the changes */
|
|
clk->min_rate = old_min;
|
|
clk->max_rate = old_max;
|
|
}
|
|
}
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_rate_range);
|
|
|
|
/**
|
|
* clk_set_min_rate - set a minimum clock rate for a clock source
|
|
* @clk: clock source
|
|
* @rate: desired minimum clock rate in Hz, inclusive
|
|
*
|
|
* Returns success (0) or negative errno.
|
|
*/
|
|
int clk_set_min_rate(struct clk *clk, unsigned long rate)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_set_rate_range(clk, rate, clk->max_rate);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_min_rate);
|
|
|
|
/**
|
|
* clk_set_max_rate - set a maximum clock rate for a clock source
|
|
* @clk: clock source
|
|
* @rate: desired maximum clock rate in Hz, inclusive
|
|
*
|
|
* Returns success (0) or negative errno.
|
|
*/
|
|
int clk_set_max_rate(struct clk *clk, unsigned long rate)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_set_rate_range(clk, clk->min_rate, rate);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_max_rate);
|
|
|
|
/**
|
|
* clk_get_parent - return the parent of a clk
|
|
* @clk: the clk whose parent gets returned
|
|
*
|
|
* Simply returns clk->parent. Returns NULL if clk is NULL.
|
|
*/
|
|
struct clk *clk_get_parent(struct clk *clk)
|
|
{
|
|
struct clk *parent;
|
|
|
|
if (!clk)
|
|
return NULL;
|
|
|
|
clk_prepare_lock();
|
|
/* TODO: Create a per-user clk and change callers to call clk_put */
|
|
parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
|
|
clk_prepare_unlock();
|
|
|
|
return parent;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_parent);
|
|
|
|
static struct clk_core *__clk_init_parent(struct clk_core *core)
|
|
{
|
|
u8 index = 0;
|
|
|
|
if (core->num_parents > 1 && core->ops->get_parent)
|
|
index = core->ops->get_parent(core->hw);
|
|
|
|
return clk_core_get_parent_by_index(core, index);
|
|
}
|
|
|
|
static void clk_core_reparent(struct clk_core *core,
|
|
struct clk_core *new_parent)
|
|
{
|
|
clk_reparent(core, new_parent);
|
|
__clk_recalc_accuracies(core);
|
|
__clk_recalc_rates(core, POST_RATE_CHANGE);
|
|
}
|
|
|
|
void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
|
|
{
|
|
if (!hw)
|
|
return;
|
|
|
|
clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
|
|
}
|
|
|
|
/**
|
|
* clk_has_parent - check if a clock is a possible parent for another
|
|
* @clk: clock source
|
|
* @parent: parent clock source
|
|
*
|
|
* This function can be used in drivers that need to check that a clock can be
|
|
* the parent of another without actually changing the parent.
|
|
*
|
|
* Returns true if @parent is a possible parent for @clk, false otherwise.
|
|
*/
|
|
bool clk_has_parent(struct clk *clk, struct clk *parent)
|
|
{
|
|
struct clk_core *core, *parent_core;
|
|
int i;
|
|
|
|
/* NULL clocks should be nops, so return success if either is NULL. */
|
|
if (!clk || !parent)
|
|
return true;
|
|
|
|
core = clk->core;
|
|
parent_core = parent->core;
|
|
|
|
/* Optimize for the case where the parent is already the parent. */
|
|
if (core->parent == parent_core)
|
|
return true;
|
|
|
|
for (i = 0; i < core->num_parents; i++)
|
|
if (!strcmp(core->parents[i].name, parent_core->name))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_has_parent);
|
|
|
|
static int clk_core_set_parent_nolock(struct clk_core *core,
|
|
struct clk_core *parent)
|
|
{
|
|
int ret = 0;
|
|
int p_index = 0;
|
|
unsigned long p_rate = 0;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
if (core->parent == parent)
|
|
return 0;
|
|
|
|
/* verify ops for for multi-parent clks */
|
|
if (core->num_parents > 1 && !core->ops->set_parent)
|
|
return -EPERM;
|
|
|
|
/* check that we are allowed to re-parent if the clock is in use */
|
|
if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
|
|
return -EBUSY;
|
|
|
|
if (clk_core_rate_is_protected(core))
|
|
return -EBUSY;
|
|
|
|
/* try finding the new parent index */
|
|
if (parent) {
|
|
p_index = clk_fetch_parent_index(core, parent);
|
|
if (p_index < 0) {
|
|
pr_debug("%s: clk %s can not be parent of clk %s\n",
|
|
__func__, parent->name, core->name);
|
|
return p_index;
|
|
}
|
|
p_rate = parent->rate;
|
|
}
|
|
|
|
ret = clk_pm_runtime_get(core);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* propagate PRE_RATE_CHANGE notifications */
|
|
ret = __clk_speculate_rates(core, p_rate);
|
|
|
|
/* abort if a driver objects */
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
goto runtime_put;
|
|
|
|
/* do the re-parent */
|
|
ret = __clk_set_parent(core, parent, p_index);
|
|
|
|
/* propagate rate an accuracy recalculation accordingly */
|
|
if (ret) {
|
|
__clk_recalc_rates(core, ABORT_RATE_CHANGE);
|
|
} else {
|
|
__clk_recalc_rates(core, POST_RATE_CHANGE);
|
|
__clk_recalc_accuracies(core);
|
|
}
|
|
|
|
runtime_put:
|
|
clk_pm_runtime_put(core);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_set_parent - switch the parent of a mux clk
|
|
* @clk: the mux clk whose input we are switching
|
|
* @parent: the new input to clk
|
|
*
|
|
* Re-parent clk to use parent as its new input source. If clk is in
|
|
* prepared state, the clk will get enabled for the duration of this call. If
|
|
* that's not acceptable for a specific clk (Eg: the consumer can't handle
|
|
* that, the reparenting is glitchy in hardware, etc), use the
|
|
* CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
|
|
*
|
|
* After successfully changing clk's parent clk_set_parent will update the
|
|
* clk topology, sysfs topology and propagate rate recalculation via
|
|
* __clk_recalc_rates.
|
|
*
|
|
* Returns 0 on success, -EERROR otherwise.
|
|
*/
|
|
int clk_set_parent(struct clk *clk, struct clk *parent)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
ret = clk_core_set_parent_nolock(clk->core,
|
|
parent ? parent->core : NULL);
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_parent);
|
|
|
|
static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (!core)
|
|
return 0;
|
|
|
|
if (clk_core_rate_is_protected(core))
|
|
return -EBUSY;
|
|
|
|
trace_clk_set_phase(core, degrees);
|
|
|
|
if (core->ops->set_phase) {
|
|
ret = core->ops->set_phase(core->hw, degrees);
|
|
if (!ret)
|
|
core->phase = degrees;
|
|
}
|
|
|
|
trace_clk_set_phase_complete(core, degrees);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_set_phase - adjust the phase shift of a clock signal
|
|
* @clk: clock signal source
|
|
* @degrees: number of degrees the signal is shifted
|
|
*
|
|
* Shifts the phase of a clock signal by the specified
|
|
* degrees. Returns 0 on success, -EERROR otherwise.
|
|
*
|
|
* This function makes no distinction about the input or reference
|
|
* signal that we adjust the clock signal phase against. For example
|
|
* phase locked-loop clock signal generators we may shift phase with
|
|
* respect to feedback clock signal input, but for other cases the
|
|
* clock phase may be shifted with respect to some other, unspecified
|
|
* signal.
|
|
*
|
|
* Additionally the concept of phase shift does not propagate through
|
|
* the clock tree hierarchy, which sets it apart from clock rates and
|
|
* clock accuracy. A parent clock phase attribute does not have an
|
|
* impact on the phase attribute of a child clock.
|
|
*/
|
|
int clk_set_phase(struct clk *clk, int degrees)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* sanity check degrees */
|
|
degrees %= 360;
|
|
if (degrees < 0)
|
|
degrees += 360;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
ret = clk_core_set_phase_nolock(clk->core, degrees);
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_phase);
|
|
|
|
static int clk_core_get_phase(struct clk_core *core)
|
|
{
|
|
int ret;
|
|
|
|
clk_prepare_lock();
|
|
/* Always try to update cached phase if possible */
|
|
if (core->ops->get_phase)
|
|
core->phase = core->ops->get_phase(core->hw);
|
|
ret = core->phase;
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_get_phase - return the phase shift of a clock signal
|
|
* @clk: clock signal source
|
|
*
|
|
* Returns the phase shift of a clock node in degrees, otherwise returns
|
|
* -EERROR.
|
|
*/
|
|
int clk_get_phase(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_get_phase(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_phase);
|
|
|
|
static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
|
|
{
|
|
/* Assume a default value of 50% */
|
|
core->duty.num = 1;
|
|
core->duty.den = 2;
|
|
}
|
|
|
|
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
|
|
|
|
static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
|
|
{
|
|
struct clk_duty *duty = &core->duty;
|
|
int ret = 0;
|
|
|
|
if (!core->ops->get_duty_cycle)
|
|
return clk_core_update_duty_cycle_parent_nolock(core);
|
|
|
|
ret = core->ops->get_duty_cycle(core->hw, duty);
|
|
if (ret)
|
|
goto reset;
|
|
|
|
/* Don't trust the clock provider too much */
|
|
if (duty->den == 0 || duty->num > duty->den) {
|
|
ret = -EINVAL;
|
|
goto reset;
|
|
}
|
|
|
|
return 0;
|
|
|
|
reset:
|
|
clk_core_reset_duty_cycle_nolock(core);
|
|
return ret;
|
|
}
|
|
|
|
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (core->parent &&
|
|
core->flags & CLK_DUTY_CYCLE_PARENT) {
|
|
ret = clk_core_update_duty_cycle_nolock(core->parent);
|
|
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
|
|
} else {
|
|
clk_core_reset_duty_cycle_nolock(core);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
|
|
struct clk_duty *duty);
|
|
|
|
static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
|
|
struct clk_duty *duty)
|
|
{
|
|
int ret;
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
if (clk_core_rate_is_protected(core))
|
|
return -EBUSY;
|
|
|
|
trace_clk_set_duty_cycle(core, duty);
|
|
|
|
if (!core->ops->set_duty_cycle)
|
|
return clk_core_set_duty_cycle_parent_nolock(core, duty);
|
|
|
|
ret = core->ops->set_duty_cycle(core->hw, duty);
|
|
if (!ret)
|
|
memcpy(&core->duty, duty, sizeof(*duty));
|
|
|
|
trace_clk_set_duty_cycle_complete(core, duty);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
|
|
struct clk_duty *duty)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (core->parent &&
|
|
core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
|
|
ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
|
|
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
|
|
* @clk: clock signal source
|
|
* @num: numerator of the duty cycle ratio to be applied
|
|
* @den: denominator of the duty cycle ratio to be applied
|
|
*
|
|
* Apply the duty cycle ratio if the ratio is valid and the clock can
|
|
* perform this operation
|
|
*
|
|
* Returns (0) on success, a negative errno otherwise.
|
|
*/
|
|
int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
|
|
{
|
|
int ret;
|
|
struct clk_duty duty;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* sanity check the ratio */
|
|
if (den == 0 || num > den)
|
|
return -EINVAL;
|
|
|
|
duty.num = num;
|
|
duty.den = den;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_unprotect(clk->core);
|
|
|
|
ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
|
|
|
|
if (clk->exclusive_count)
|
|
clk_core_rate_protect(clk->core);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
|
|
|
|
static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
|
|
unsigned int scale)
|
|
{
|
|
struct clk_duty *duty = &core->duty;
|
|
int ret;
|
|
|
|
clk_prepare_lock();
|
|
|
|
ret = clk_core_update_duty_cycle_nolock(core);
|
|
if (!ret)
|
|
ret = mult_frac(scale, duty->num, duty->den);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
|
|
* @clk: clock signal source
|
|
* @scale: scaling factor to be applied to represent the ratio as an integer
|
|
*
|
|
* Returns the duty cycle ratio of a clock node multiplied by the provided
|
|
* scaling factor, or negative errno on error.
|
|
*/
|
|
int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_get_scaled_duty_cycle(clk->core, scale);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
|
|
|
|
/**
|
|
* clk_is_match - check if two clk's point to the same hardware clock
|
|
* @p: clk compared against q
|
|
* @q: clk compared against p
|
|
*
|
|
* Returns true if the two struct clk pointers both point to the same hardware
|
|
* clock node. Put differently, returns true if struct clk *p and struct clk *q
|
|
* share the same struct clk_core object.
|
|
*
|
|
* Returns false otherwise. Note that two NULL clks are treated as matching.
|
|
*/
|
|
bool clk_is_match(const struct clk *p, const struct clk *q)
|
|
{
|
|
/* trivial case: identical struct clk's or both NULL */
|
|
if (p == q)
|
|
return true;
|
|
|
|
/* true if clk->core pointers match. Avoid dereferencing garbage */
|
|
if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
|
|
if (p->core == q->core)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_is_match);
|
|
|
|
/*** debugfs support ***/
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
#include <linux/debugfs.h>
|
|
|
|
static struct dentry *rootdir;
|
|
static int inited = 0;
|
|
static DEFINE_MUTEX(clk_debug_lock);
|
|
static HLIST_HEAD(clk_debug_list);
|
|
|
|
static struct hlist_head *all_lists[] = {
|
|
&clk_root_list,
|
|
&clk_orphan_list,
|
|
NULL,
|
|
};
|
|
|
|
static struct hlist_head *orphan_list[] = {
|
|
&clk_orphan_list,
|
|
NULL,
|
|
};
|
|
|
|
static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
|
|
int level)
|
|
{
|
|
if (!c)
|
|
return;
|
|
|
|
seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
|
|
level * 3 + 1, "",
|
|
30 - level * 3, c->name,
|
|
c->enable_count, c->prepare_count, c->protect_count,
|
|
clk_core_get_rate(c), clk_core_get_accuracy(c),
|
|
clk_core_get_phase(c),
|
|
clk_core_get_scaled_duty_cycle(c, 100000));
|
|
}
|
|
|
|
static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
|
|
int level)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
if (!c)
|
|
return;
|
|
|
|
clk_summary_show_one(s, c, level);
|
|
|
|
hlist_for_each_entry(child, &c->children, child_node)
|
|
clk_summary_show_subtree(s, child, level + 1);
|
|
}
|
|
|
|
static int clk_summary_show(struct seq_file *s, void *data)
|
|
{
|
|
struct clk_core *c;
|
|
struct hlist_head **lists = (struct hlist_head **)s->private;
|
|
|
|
seq_puts(s, " enable prepare protect duty\n");
|
|
seq_puts(s, " clock count count count rate accuracy phase cycle\n");
|
|
seq_puts(s, "---------------------------------------------------------------------------------------------\n");
|
|
|
|
clk_prepare_lock();
|
|
|
|
for (; *lists; lists++)
|
|
hlist_for_each_entry(c, *lists, child_node)
|
|
clk_summary_show_subtree(s, c, 0);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(clk_summary);
|
|
|
|
static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
|
|
{
|
|
if (!c)
|
|
return;
|
|
|
|
/* This should be JSON format, i.e. elements separated with a comma */
|
|
seq_printf(s, "\"%s\": { ", c->name);
|
|
seq_printf(s, "\"enable_count\": %d,", c->enable_count);
|
|
seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
|
|
seq_printf(s, "\"protect_count\": %d,", c->protect_count);
|
|
seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
|
|
seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
|
|
seq_printf(s, "\"phase\": %d,", clk_core_get_phase(c));
|
|
seq_printf(s, "\"duty_cycle\": %u",
|
|
clk_core_get_scaled_duty_cycle(c, 100000));
|
|
}
|
|
|
|
static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
if (!c)
|
|
return;
|
|
|
|
clk_dump_one(s, c, level);
|
|
|
|
hlist_for_each_entry(child, &c->children, child_node) {
|
|
seq_putc(s, ',');
|
|
clk_dump_subtree(s, child, level + 1);
|
|
}
|
|
|
|
seq_putc(s, '}');
|
|
}
|
|
|
|
static int clk_dump_show(struct seq_file *s, void *data)
|
|
{
|
|
struct clk_core *c;
|
|
bool first_node = true;
|
|
struct hlist_head **lists = (struct hlist_head **)s->private;
|
|
|
|
seq_putc(s, '{');
|
|
clk_prepare_lock();
|
|
|
|
for (; *lists; lists++) {
|
|
hlist_for_each_entry(c, *lists, child_node) {
|
|
if (!first_node)
|
|
seq_putc(s, ',');
|
|
first_node = false;
|
|
clk_dump_subtree(s, c, 0);
|
|
}
|
|
}
|
|
|
|
clk_prepare_unlock();
|
|
|
|
seq_puts(s, "}\n");
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(clk_dump);
|
|
|
|
static const struct {
|
|
unsigned long flag;
|
|
const char *name;
|
|
} clk_flags[] = {
|
|
#define ENTRY(f) { f, #f }
|
|
ENTRY(CLK_SET_RATE_GATE),
|
|
ENTRY(CLK_SET_PARENT_GATE),
|
|
ENTRY(CLK_SET_RATE_PARENT),
|
|
ENTRY(CLK_IGNORE_UNUSED),
|
|
ENTRY(CLK_GET_RATE_NOCACHE),
|
|
ENTRY(CLK_SET_RATE_NO_REPARENT),
|
|
ENTRY(CLK_GET_ACCURACY_NOCACHE),
|
|
ENTRY(CLK_RECALC_NEW_RATES),
|
|
ENTRY(CLK_SET_RATE_UNGATE),
|
|
ENTRY(CLK_IS_CRITICAL),
|
|
ENTRY(CLK_OPS_PARENT_ENABLE),
|
|
ENTRY(CLK_DUTY_CYCLE_PARENT),
|
|
#undef ENTRY
|
|
};
|
|
|
|
static int clk_flags_show(struct seq_file *s, void *data)
|
|
{
|
|
struct clk_core *core = s->private;
|
|
unsigned long flags = core->flags;
|
|
unsigned int i;
|
|
|
|
for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
|
|
if (flags & clk_flags[i].flag) {
|
|
seq_printf(s, "%s\n", clk_flags[i].name);
|
|
flags &= ~clk_flags[i].flag;
|
|
}
|
|
}
|
|
if (flags) {
|
|
/* Unknown flags */
|
|
seq_printf(s, "0x%lx\n", flags);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(clk_flags);
|
|
|
|
static int possible_parents_show(struct seq_file *s, void *data)
|
|
{
|
|
struct clk_core *core = s->private;
|
|
int i;
|
|
|
|
for (i = 0; i < core->num_parents - 1; i++)
|
|
seq_printf(s, "%s ", core->parents[i].name);
|
|
|
|
seq_printf(s, "%s\n", core->parents[i].name);
|
|
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(possible_parents);
|
|
|
|
static int clk_duty_cycle_show(struct seq_file *s, void *data)
|
|
{
|
|
struct clk_core *core = s->private;
|
|
struct clk_duty *duty = &core->duty;
|
|
|
|
seq_printf(s, "%u/%u\n", duty->num, duty->den);
|
|
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
|
|
|
|
static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
|
|
{
|
|
struct dentry *root;
|
|
|
|
if (!core || !pdentry)
|
|
return;
|
|
|
|
root = debugfs_create_dir(core->name, pdentry);
|
|
core->dentry = root;
|
|
|
|
debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
|
|
debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
|
|
debugfs_create_u32("clk_phase", 0444, root, &core->phase);
|
|
debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
|
|
debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
|
|
debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
|
|
debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
|
|
debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
|
|
debugfs_create_file("clk_duty_cycle", 0444, root, core,
|
|
&clk_duty_cycle_fops);
|
|
|
|
if (core->num_parents > 1)
|
|
debugfs_create_file("clk_possible_parents", 0444, root, core,
|
|
&possible_parents_fops);
|
|
|
|
if (core->ops->debug_init)
|
|
core->ops->debug_init(core->hw, core->dentry);
|
|
}
|
|
|
|
/**
|
|
* clk_debug_register - add a clk node to the debugfs clk directory
|
|
* @core: the clk being added to the debugfs clk directory
|
|
*
|
|
* Dynamically adds a clk to the debugfs clk directory if debugfs has been
|
|
* initialized. Otherwise it bails out early since the debugfs clk directory
|
|
* will be created lazily by clk_debug_init as part of a late_initcall.
|
|
*/
|
|
static void clk_debug_register(struct clk_core *core)
|
|
{
|
|
mutex_lock(&clk_debug_lock);
|
|
hlist_add_head(&core->debug_node, &clk_debug_list);
|
|
if (inited)
|
|
clk_debug_create_one(core, rootdir);
|
|
mutex_unlock(&clk_debug_lock);
|
|
}
|
|
|
|
/**
|
|
* clk_debug_unregister - remove a clk node from the debugfs clk directory
|
|
* @core: the clk being removed from the debugfs clk directory
|
|
*
|
|
* Dynamically removes a clk and all its child nodes from the
|
|
* debugfs clk directory if clk->dentry points to debugfs created by
|
|
* clk_debug_register in __clk_core_init.
|
|
*/
|
|
static void clk_debug_unregister(struct clk_core *core)
|
|
{
|
|
mutex_lock(&clk_debug_lock);
|
|
hlist_del_init(&core->debug_node);
|
|
debugfs_remove_recursive(core->dentry);
|
|
core->dentry = NULL;
|
|
mutex_unlock(&clk_debug_lock);
|
|
}
|
|
|
|
/**
|
|
* clk_debug_init - lazily populate the debugfs clk directory
|
|
*
|
|
* clks are often initialized very early during boot before memory can be
|
|
* dynamically allocated and well before debugfs is setup. This function
|
|
* populates the debugfs clk directory once at boot-time when we know that
|
|
* debugfs is setup. It should only be called once at boot-time, all other clks
|
|
* added dynamically will be done so with clk_debug_register.
|
|
*/
|
|
static int __init clk_debug_init(void)
|
|
{
|
|
struct clk_core *core;
|
|
|
|
rootdir = debugfs_create_dir("clk", NULL);
|
|
|
|
debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
|
|
&clk_summary_fops);
|
|
debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
|
|
&clk_dump_fops);
|
|
debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
|
|
&clk_summary_fops);
|
|
debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
|
|
&clk_dump_fops);
|
|
|
|
mutex_lock(&clk_debug_lock);
|
|
hlist_for_each_entry(core, &clk_debug_list, debug_node)
|
|
clk_debug_create_one(core, rootdir);
|
|
|
|
inited = 1;
|
|
mutex_unlock(&clk_debug_lock);
|
|
|
|
return 0;
|
|
}
|
|
late_initcall(clk_debug_init);
|
|
#else
|
|
static inline void clk_debug_register(struct clk_core *core) { }
|
|
static inline void clk_debug_reparent(struct clk_core *core,
|
|
struct clk_core *new_parent)
|
|
{
|
|
}
|
|
static inline void clk_debug_unregister(struct clk_core *core)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* __clk_core_init - initialize the data structures in a struct clk_core
|
|
* @core: clk_core being initialized
|
|
*
|
|
* Initializes the lists in struct clk_core, queries the hardware for the
|
|
* parent and rate and sets them both.
|
|
*/
|
|
static int __clk_core_init(struct clk_core *core)
|
|
{
|
|
int ret;
|
|
struct clk_core *orphan;
|
|
struct hlist_node *tmp2;
|
|
unsigned long rate;
|
|
|
|
if (!core)
|
|
return -EINVAL;
|
|
|
|
clk_prepare_lock();
|
|
|
|
ret = clk_pm_runtime_get(core);
|
|
if (ret)
|
|
goto unlock;
|
|
|
|
/* check to see if a clock with this name is already registered */
|
|
if (clk_core_lookup(core->name)) {
|
|
pr_debug("%s: clk %s already initialized\n",
|
|
__func__, core->name);
|
|
ret = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
/* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
|
|
if (core->ops->set_rate &&
|
|
!((core->ops->round_rate || core->ops->determine_rate) &&
|
|
core->ops->recalc_rate)) {
|
|
pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
|
|
__func__, core->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (core->ops->set_parent && !core->ops->get_parent) {
|
|
pr_err("%s: %s must implement .get_parent & .set_parent\n",
|
|
__func__, core->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (core->num_parents > 1 && !core->ops->get_parent) {
|
|
pr_err("%s: %s must implement .get_parent as it has multi parents\n",
|
|
__func__, core->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (core->ops->set_rate_and_parent &&
|
|
!(core->ops->set_parent && core->ops->set_rate)) {
|
|
pr_err("%s: %s must implement .set_parent & .set_rate\n",
|
|
__func__, core->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
core->parent = __clk_init_parent(core);
|
|
|
|
/*
|
|
* Populate core->parent if parent has already been clk_core_init'd. If
|
|
* parent has not yet been clk_core_init'd then place clk in the orphan
|
|
* list. If clk doesn't have any parents then place it in the root
|
|
* clk list.
|
|
*
|
|
* Every time a new clk is clk_init'd then we walk the list of orphan
|
|
* clocks and re-parent any that are children of the clock currently
|
|
* being clk_init'd.
|
|
*/
|
|
if (core->parent) {
|
|
hlist_add_head(&core->child_node,
|
|
&core->parent->children);
|
|
core->orphan = core->parent->orphan;
|
|
} else if (!core->num_parents) {
|
|
hlist_add_head(&core->child_node, &clk_root_list);
|
|
core->orphan = false;
|
|
} else {
|
|
hlist_add_head(&core->child_node, &clk_orphan_list);
|
|
core->orphan = true;
|
|
}
|
|
|
|
/*
|
|
* optional platform-specific magic
|
|
*
|
|
* The .init callback is not used by any of the basic clock types, but
|
|
* exists for weird hardware that must perform initialization magic.
|
|
* Please consider other ways of solving initialization problems before
|
|
* using this callback, as its use is discouraged.
|
|
*/
|
|
if (core->ops->init)
|
|
core->ops->init(core->hw);
|
|
|
|
/*
|
|
* Set clk's accuracy. The preferred method is to use
|
|
* .recalc_accuracy. For simple clocks and lazy developers the default
|
|
* fallback is to use the parent's accuracy. If a clock doesn't have a
|
|
* parent (or is orphaned) then accuracy is set to zero (perfect
|
|
* clock).
|
|
*/
|
|
if (core->ops->recalc_accuracy)
|
|
core->accuracy = core->ops->recalc_accuracy(core->hw,
|
|
__clk_get_accuracy(core->parent));
|
|
else if (core->parent)
|
|
core->accuracy = core->parent->accuracy;
|
|
else
|
|
core->accuracy = 0;
|
|
|
|
/*
|
|
* Set clk's phase.
|
|
* Since a phase is by definition relative to its parent, just
|
|
* query the current clock phase, or just assume it's in phase.
|
|
*/
|
|
if (core->ops->get_phase)
|
|
core->phase = core->ops->get_phase(core->hw);
|
|
else
|
|
core->phase = 0;
|
|
|
|
/*
|
|
* Set clk's duty cycle.
|
|
*/
|
|
clk_core_update_duty_cycle_nolock(core);
|
|
|
|
/*
|
|
* Set clk's rate. The preferred method is to use .recalc_rate. For
|
|
* simple clocks and lazy developers the default fallback is to use the
|
|
* parent's rate. If a clock doesn't have a parent (or is orphaned)
|
|
* then rate is set to zero.
|
|
*/
|
|
if (core->ops->recalc_rate)
|
|
rate = core->ops->recalc_rate(core->hw,
|
|
clk_core_get_rate_nolock(core->parent));
|
|
else if (core->parent)
|
|
rate = core->parent->rate;
|
|
else
|
|
rate = 0;
|
|
core->rate = core->req_rate = rate;
|
|
|
|
/*
|
|
* Enable CLK_IS_CRITICAL clocks so newly added critical clocks
|
|
* don't get accidentally disabled when walking the orphan tree and
|
|
* reparenting clocks
|
|
*/
|
|
if (core->flags & CLK_IS_CRITICAL) {
|
|
unsigned long flags;
|
|
|
|
clk_core_prepare(core);
|
|
|
|
flags = clk_enable_lock();
|
|
clk_core_enable(core);
|
|
clk_enable_unlock(flags);
|
|
}
|
|
|
|
/*
|
|
* walk the list of orphan clocks and reparent any that newly finds a
|
|
* parent.
|
|
*/
|
|
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
|
|
struct clk_core *parent = __clk_init_parent(orphan);
|
|
|
|
/*
|
|
* We need to use __clk_set_parent_before() and _after() to
|
|
* to properly migrate any prepare/enable count of the orphan
|
|
* clock. This is important for CLK_IS_CRITICAL clocks, which
|
|
* are enabled during init but might not have a parent yet.
|
|
*/
|
|
if (parent) {
|
|
/* update the clk tree topology */
|
|
__clk_set_parent_before(orphan, parent);
|
|
__clk_set_parent_after(orphan, parent, NULL);
|
|
__clk_recalc_accuracies(orphan);
|
|
__clk_recalc_rates(orphan, 0);
|
|
}
|
|
}
|
|
|
|
kref_init(&core->ref);
|
|
out:
|
|
clk_pm_runtime_put(core);
|
|
unlock:
|
|
clk_prepare_unlock();
|
|
|
|
if (!ret)
|
|
clk_debug_register(core);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
|
|
* @core: clk to add consumer to
|
|
* @clk: consumer to link to a clk
|
|
*/
|
|
static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
|
|
{
|
|
clk_prepare_lock();
|
|
hlist_add_head(&clk->clks_node, &core->clks);
|
|
clk_prepare_unlock();
|
|
}
|
|
|
|
/**
|
|
* clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
|
|
* @clk: consumer to unlink
|
|
*/
|
|
static void clk_core_unlink_consumer(struct clk *clk)
|
|
{
|
|
lockdep_assert_held(&prepare_lock);
|
|
hlist_del(&clk->clks_node);
|
|
}
|
|
|
|
/**
|
|
* alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
|
|
* @core: clk to allocate a consumer for
|
|
* @dev_id: string describing device name
|
|
* @con_id: connection ID string on device
|
|
*
|
|
* Returns: clk consumer left unlinked from the consumer list
|
|
*/
|
|
static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
|
|
const char *con_id)
|
|
{
|
|
struct clk *clk;
|
|
|
|
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
|
|
if (!clk)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
clk->core = core;
|
|
clk->dev_id = dev_id;
|
|
clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
|
|
clk->max_rate = ULONG_MAX;
|
|
|
|
return clk;
|
|
}
|
|
|
|
/**
|
|
* free_clk - Free a clk consumer
|
|
* @clk: clk consumer to free
|
|
*
|
|
* Note, this assumes the clk has been unlinked from the clk_core consumer
|
|
* list.
|
|
*/
|
|
static void free_clk(struct clk *clk)
|
|
{
|
|
kfree_const(clk->con_id);
|
|
kfree(clk);
|
|
}
|
|
|
|
/**
|
|
* clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
|
|
* a clk_hw
|
|
* @dev: clk consumer device
|
|
* @hw: clk_hw associated with the clk being consumed
|
|
* @dev_id: string describing device name
|
|
* @con_id: connection ID string on device
|
|
*
|
|
* This is the main function used to create a clk pointer for use by clk
|
|
* consumers. It connects a consumer to the clk_core and clk_hw structures
|
|
* used by the framework and clk provider respectively.
|
|
*/
|
|
struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
|
|
const char *dev_id, const char *con_id)
|
|
{
|
|
struct clk *clk;
|
|
struct clk_core *core;
|
|
|
|
/* This is to allow this function to be chained to others */
|
|
if (IS_ERR_OR_NULL(hw))
|
|
return ERR_CAST(hw);
|
|
|
|
core = hw->core;
|
|
clk = alloc_clk(core, dev_id, con_id);
|
|
if (IS_ERR(clk))
|
|
return clk;
|
|
clk->dev = dev;
|
|
|
|
if (!try_module_get(core->owner)) {
|
|
free_clk(clk);
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
kref_get(&core->ref);
|
|
clk_core_link_consumer(core, clk);
|
|
|
|
return clk;
|
|
}
|
|
|
|
static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
|
|
{
|
|
const char *dst;
|
|
|
|
if (!src) {
|
|
if (must_exist)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
*dst_p = dst = kstrdup_const(src, GFP_KERNEL);
|
|
if (!dst)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int clk_core_populate_parent_map(struct clk_core *core)
|
|
{
|
|
const struct clk_init_data *init = core->hw->init;
|
|
u8 num_parents = init->num_parents;
|
|
const char * const *parent_names = init->parent_names;
|
|
const struct clk_hw **parent_hws = init->parent_hws;
|
|
const struct clk_parent_data *parent_data = init->parent_data;
|
|
int i, ret = 0;
|
|
struct clk_parent_map *parents, *parent;
|
|
|
|
if (!num_parents)
|
|
return 0;
|
|
|
|
/*
|
|
* Avoid unnecessary string look-ups of clk_core's possible parents by
|
|
* having a cache of names/clk_hw pointers to clk_core pointers.
|
|
*/
|
|
parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
|
|
core->parents = parents;
|
|
if (!parents)
|
|
return -ENOMEM;
|
|
|
|
/* Copy everything over because it might be __initdata */
|
|
for (i = 0, parent = parents; i < num_parents; i++, parent++) {
|
|
parent->index = -1;
|
|
if (parent_names) {
|
|
/* throw a WARN if any entries are NULL */
|
|
WARN(!parent_names[i],
|
|
"%s: invalid NULL in %s's .parent_names\n",
|
|
__func__, core->name);
|
|
ret = clk_cpy_name(&parent->name, parent_names[i],
|
|
true);
|
|
} else if (parent_data) {
|
|
parent->hw = parent_data[i].hw;
|
|
parent->index = parent_data[i].index;
|
|
ret = clk_cpy_name(&parent->fw_name,
|
|
parent_data[i].fw_name, false);
|
|
if (!ret)
|
|
ret = clk_cpy_name(&parent->name,
|
|
parent_data[i].name,
|
|
false);
|
|
} else if (parent_hws) {
|
|
parent->hw = parent_hws[i];
|
|
} else {
|
|
ret = -EINVAL;
|
|
WARN(1, "Must specify parents if num_parents > 0\n");
|
|
}
|
|
|
|
if (ret) {
|
|
do {
|
|
kfree_const(parents[i].name);
|
|
kfree_const(parents[i].fw_name);
|
|
} while (--i >= 0);
|
|
kfree(parents);
|
|
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void clk_core_free_parent_map(struct clk_core *core)
|
|
{
|
|
int i = core->num_parents;
|
|
|
|
if (!core->num_parents)
|
|
return;
|
|
|
|
while (--i >= 0) {
|
|
kfree_const(core->parents[i].name);
|
|
kfree_const(core->parents[i].fw_name);
|
|
}
|
|
|
|
kfree(core->parents);
|
|
}
|
|
|
|
static struct clk *
|
|
__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
|
|
{
|
|
int ret;
|
|
struct clk_core *core;
|
|
|
|
core = kzalloc(sizeof(*core), GFP_KERNEL);
|
|
if (!core) {
|
|
ret = -ENOMEM;
|
|
goto fail_out;
|
|
}
|
|
|
|
core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
|
|
if (!core->name) {
|
|
ret = -ENOMEM;
|
|
goto fail_name;
|
|
}
|
|
|
|
if (WARN_ON(!hw->init->ops)) {
|
|
ret = -EINVAL;
|
|
goto fail_ops;
|
|
}
|
|
core->ops = hw->init->ops;
|
|
|
|
if (dev && pm_runtime_enabled(dev))
|
|
core->rpm_enabled = true;
|
|
core->dev = dev;
|
|
core->of_node = np;
|
|
if (dev && dev->driver)
|
|
core->owner = dev->driver->owner;
|
|
core->hw = hw;
|
|
core->flags = hw->init->flags;
|
|
core->num_parents = hw->init->num_parents;
|
|
core->min_rate = 0;
|
|
core->max_rate = ULONG_MAX;
|
|
hw->core = core;
|
|
|
|
ret = clk_core_populate_parent_map(core);
|
|
if (ret)
|
|
goto fail_parents;
|
|
|
|
INIT_HLIST_HEAD(&core->clks);
|
|
|
|
/*
|
|
* Don't call clk_hw_create_clk() here because that would pin the
|
|
* provider module to itself and prevent it from ever being removed.
|
|
*/
|
|
hw->clk = alloc_clk(core, NULL, NULL);
|
|
if (IS_ERR(hw->clk)) {
|
|
ret = PTR_ERR(hw->clk);
|
|
goto fail_create_clk;
|
|
}
|
|
|
|
clk_core_link_consumer(hw->core, hw->clk);
|
|
|
|
ret = __clk_core_init(core);
|
|
if (!ret)
|
|
return hw->clk;
|
|
|
|
clk_prepare_lock();
|
|
clk_core_unlink_consumer(hw->clk);
|
|
clk_prepare_unlock();
|
|
|
|
free_clk(hw->clk);
|
|
hw->clk = NULL;
|
|
|
|
fail_create_clk:
|
|
clk_core_free_parent_map(core);
|
|
fail_parents:
|
|
fail_ops:
|
|
kfree_const(core->name);
|
|
fail_name:
|
|
kfree(core);
|
|
fail_out:
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
/**
|
|
* clk_register - allocate a new clock, register it and return an opaque cookie
|
|
* @dev: device that is registering this clock
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* clk_register is the *deprecated* interface for populating the clock tree with
|
|
* new clock nodes. Use clk_hw_register() instead.
|
|
*
|
|
* Returns: a pointer to the newly allocated struct clk which
|
|
* cannot be dereferenced by driver code but may be used in conjunction with the
|
|
* rest of the clock API. In the event of an error clk_register will return an
|
|
* error code; drivers must test for an error code after calling clk_register.
|
|
*/
|
|
struct clk *clk_register(struct device *dev, struct clk_hw *hw)
|
|
{
|
|
return __clk_register(dev, dev_of_node(dev), hw);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_register);
|
|
|
|
/**
|
|
* clk_hw_register - register a clk_hw and return an error code
|
|
* @dev: device that is registering this clock
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* clk_hw_register is the primary interface for populating the clock tree with
|
|
* new clock nodes. It returns an integer equal to zero indicating success or
|
|
* less than zero indicating failure. Drivers must test for an error code after
|
|
* calling clk_hw_register().
|
|
*/
|
|
int clk_hw_register(struct device *dev, struct clk_hw *hw)
|
|
{
|
|
return PTR_ERR_OR_ZERO(__clk_register(dev, dev_of_node(dev), hw));
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_hw_register);
|
|
|
|
/*
|
|
* of_clk_hw_register - register a clk_hw and return an error code
|
|
* @node: device_node of device that is registering this clock
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* of_clk_hw_register() is the primary interface for populating the clock tree
|
|
* with new clock nodes when a struct device is not available, but a struct
|
|
* device_node is. It returns an integer equal to zero indicating success or
|
|
* less than zero indicating failure. Drivers must test for an error code after
|
|
* calling of_clk_hw_register().
|
|
*/
|
|
int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
|
|
{
|
|
return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_hw_register);
|
|
|
|
/* Free memory allocated for a clock. */
|
|
static void __clk_release(struct kref *ref)
|
|
{
|
|
struct clk_core *core = container_of(ref, struct clk_core, ref);
|
|
|
|
lockdep_assert_held(&prepare_lock);
|
|
|
|
clk_core_free_parent_map(core);
|
|
kfree_const(core->name);
|
|
kfree(core);
|
|
}
|
|
|
|
/*
|
|
* Empty clk_ops for unregistered clocks. These are used temporarily
|
|
* after clk_unregister() was called on a clock and until last clock
|
|
* consumer calls clk_put() and the struct clk object is freed.
|
|
*/
|
|
static int clk_nodrv_prepare_enable(struct clk_hw *hw)
|
|
{
|
|
return -ENXIO;
|
|
}
|
|
|
|
static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
|
|
{
|
|
WARN_ON_ONCE(1);
|
|
}
|
|
|
|
static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long parent_rate)
|
|
{
|
|
return -ENXIO;
|
|
}
|
|
|
|
static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
|
|
{
|
|
return -ENXIO;
|
|
}
|
|
|
|
static const struct clk_ops clk_nodrv_ops = {
|
|
.enable = clk_nodrv_prepare_enable,
|
|
.disable = clk_nodrv_disable_unprepare,
|
|
.prepare = clk_nodrv_prepare_enable,
|
|
.unprepare = clk_nodrv_disable_unprepare,
|
|
.set_rate = clk_nodrv_set_rate,
|
|
.set_parent = clk_nodrv_set_parent,
|
|
};
|
|
|
|
/**
|
|
* clk_unregister - unregister a currently registered clock
|
|
* @clk: clock to unregister
|
|
*/
|
|
void clk_unregister(struct clk *clk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
|
|
return;
|
|
|
|
clk_debug_unregister(clk->core);
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk->core->ops == &clk_nodrv_ops) {
|
|
pr_err("%s: unregistered clock: %s\n", __func__,
|
|
clk->core->name);
|
|
goto unlock;
|
|
}
|
|
/*
|
|
* Assign empty clock ops for consumers that might still hold
|
|
* a reference to this clock.
|
|
*/
|
|
flags = clk_enable_lock();
|
|
clk->core->ops = &clk_nodrv_ops;
|
|
clk_enable_unlock(flags);
|
|
|
|
if (!hlist_empty(&clk->core->children)) {
|
|
struct clk_core *child;
|
|
struct hlist_node *t;
|
|
|
|
/* Reparent all children to the orphan list. */
|
|
hlist_for_each_entry_safe(child, t, &clk->core->children,
|
|
child_node)
|
|
clk_core_set_parent_nolock(child, NULL);
|
|
}
|
|
|
|
hlist_del_init(&clk->core->child_node);
|
|
|
|
if (clk->core->prepare_count)
|
|
pr_warn("%s: unregistering prepared clock: %s\n",
|
|
__func__, clk->core->name);
|
|
|
|
if (clk->core->protect_count)
|
|
pr_warn("%s: unregistering protected clock: %s\n",
|
|
__func__, clk->core->name);
|
|
|
|
kref_put(&clk->core->ref, __clk_release);
|
|
unlock:
|
|
clk_prepare_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_unregister);
|
|
|
|
/**
|
|
* clk_hw_unregister - unregister a currently registered clk_hw
|
|
* @hw: hardware-specific clock data to unregister
|
|
*/
|
|
void clk_hw_unregister(struct clk_hw *hw)
|
|
{
|
|
clk_unregister(hw->clk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_hw_unregister);
|
|
|
|
static void devm_clk_release(struct device *dev, void *res)
|
|
{
|
|
clk_unregister(*(struct clk **)res);
|
|
}
|
|
|
|
static void devm_clk_hw_release(struct device *dev, void *res)
|
|
{
|
|
clk_hw_unregister(*(struct clk_hw **)res);
|
|
}
|
|
|
|
/**
|
|
* devm_clk_register - resource managed clk_register()
|
|
* @dev: device that is registering this clock
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
|
|
*
|
|
* Clocks returned from this function are automatically clk_unregister()ed on
|
|
* driver detach. See clk_register() for more information.
|
|
*/
|
|
struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
|
|
{
|
|
struct clk *clk;
|
|
struct clk **clkp;
|
|
|
|
clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
|
|
if (!clkp)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
clk = clk_register(dev, hw);
|
|
if (!IS_ERR(clk)) {
|
|
*clkp = clk;
|
|
devres_add(dev, clkp);
|
|
} else {
|
|
devres_free(clkp);
|
|
}
|
|
|
|
return clk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_clk_register);
|
|
|
|
/**
|
|
* devm_clk_hw_register - resource managed clk_hw_register()
|
|
* @dev: device that is registering this clock
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* Managed clk_hw_register(). Clocks registered by this function are
|
|
* automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
|
|
* for more information.
|
|
*/
|
|
int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
|
|
{
|
|
struct clk_hw **hwp;
|
|
int ret;
|
|
|
|
hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
|
|
if (!hwp)
|
|
return -ENOMEM;
|
|
|
|
ret = clk_hw_register(dev, hw);
|
|
if (!ret) {
|
|
*hwp = hw;
|
|
devres_add(dev, hwp);
|
|
} else {
|
|
devres_free(hwp);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_clk_hw_register);
|
|
|
|
static int devm_clk_match(struct device *dev, void *res, void *data)
|
|
{
|
|
struct clk *c = res;
|
|
if (WARN_ON(!c))
|
|
return 0;
|
|
return c == data;
|
|
}
|
|
|
|
static int devm_clk_hw_match(struct device *dev, void *res, void *data)
|
|
{
|
|
struct clk_hw *hw = res;
|
|
|
|
if (WARN_ON(!hw))
|
|
return 0;
|
|
return hw == data;
|
|
}
|
|
|
|
/**
|
|
* devm_clk_unregister - resource managed clk_unregister()
|
|
* @clk: clock to unregister
|
|
*
|
|
* Deallocate a clock allocated with devm_clk_register(). Normally
|
|
* this function will not need to be called and the resource management
|
|
* code will ensure that the resource is freed.
|
|
*/
|
|
void devm_clk_unregister(struct device *dev, struct clk *clk)
|
|
{
|
|
WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_clk_unregister);
|
|
|
|
/**
|
|
* devm_clk_hw_unregister - resource managed clk_hw_unregister()
|
|
* @dev: device that is unregistering the hardware-specific clock data
|
|
* @hw: link to hardware-specific clock data
|
|
*
|
|
* Unregister a clk_hw registered with devm_clk_hw_register(). Normally
|
|
* this function will not need to be called and the resource management
|
|
* code will ensure that the resource is freed.
|
|
*/
|
|
void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
|
|
{
|
|
WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
|
|
hw));
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
|
|
|
|
/*
|
|
* clkdev helpers
|
|
*/
|
|
|
|
void __clk_put(struct clk *clk)
|
|
{
|
|
struct module *owner;
|
|
|
|
if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
|
|
return;
|
|
|
|
clk_prepare_lock();
|
|
|
|
/*
|
|
* Before calling clk_put, all calls to clk_rate_exclusive_get() from a
|
|
* given user should be balanced with calls to clk_rate_exclusive_put()
|
|
* and by that same consumer
|
|
*/
|
|
if (WARN_ON(clk->exclusive_count)) {
|
|
/* We voiced our concern, let's sanitize the situation */
|
|
clk->core->protect_count -= (clk->exclusive_count - 1);
|
|
clk_core_rate_unprotect(clk->core);
|
|
clk->exclusive_count = 0;
|
|
}
|
|
|
|
hlist_del(&clk->clks_node);
|
|
if (clk->min_rate > clk->core->req_rate ||
|
|
clk->max_rate < clk->core->req_rate)
|
|
clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
|
|
|
|
owner = clk->core->owner;
|
|
kref_put(&clk->core->ref, __clk_release);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
module_put(owner);
|
|
|
|
free_clk(clk);
|
|
}
|
|
|
|
/*** clk rate change notifiers ***/
|
|
|
|
/**
|
|
* clk_notifier_register - add a clk rate change notifier
|
|
* @clk: struct clk * to watch
|
|
* @nb: struct notifier_block * with callback info
|
|
*
|
|
* Request notification when clk's rate changes. This uses an SRCU
|
|
* notifier because we want it to block and notifier unregistrations are
|
|
* uncommon. The callbacks associated with the notifier must not
|
|
* re-enter into the clk framework by calling any top-level clk APIs;
|
|
* this will cause a nested prepare_lock mutex.
|
|
*
|
|
* In all notification cases (pre, post and abort rate change) the original
|
|
* clock rate is passed to the callback via struct clk_notifier_data.old_rate
|
|
* and the new frequency is passed via struct clk_notifier_data.new_rate.
|
|
*
|
|
* clk_notifier_register() must be called from non-atomic context.
|
|
* Returns -EINVAL if called with null arguments, -ENOMEM upon
|
|
* allocation failure; otherwise, passes along the return value of
|
|
* srcu_notifier_chain_register().
|
|
*/
|
|
int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
|
|
{
|
|
struct clk_notifier *cn;
|
|
int ret = -ENOMEM;
|
|
|
|
if (!clk || !nb)
|
|
return -EINVAL;
|
|
|
|
clk_prepare_lock();
|
|
|
|
/* search the list of notifiers for this clk */
|
|
list_for_each_entry(cn, &clk_notifier_list, node)
|
|
if (cn->clk == clk)
|
|
break;
|
|
|
|
/* if clk wasn't in the notifier list, allocate new clk_notifier */
|
|
if (cn->clk != clk) {
|
|
cn = kzalloc(sizeof(*cn), GFP_KERNEL);
|
|
if (!cn)
|
|
goto out;
|
|
|
|
cn->clk = clk;
|
|
srcu_init_notifier_head(&cn->notifier_head);
|
|
|
|
list_add(&cn->node, &clk_notifier_list);
|
|
}
|
|
|
|
ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
|
|
|
|
clk->core->notifier_count++;
|
|
|
|
out:
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_notifier_register);
|
|
|
|
/**
|
|
* clk_notifier_unregister - remove a clk rate change notifier
|
|
* @clk: struct clk *
|
|
* @nb: struct notifier_block * with callback info
|
|
*
|
|
* Request no further notification for changes to 'clk' and frees memory
|
|
* allocated in clk_notifier_register.
|
|
*
|
|
* Returns -EINVAL if called with null arguments; otherwise, passes
|
|
* along the return value of srcu_notifier_chain_unregister().
|
|
*/
|
|
int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
|
|
{
|
|
struct clk_notifier *cn = NULL;
|
|
int ret = -EINVAL;
|
|
|
|
if (!clk || !nb)
|
|
return -EINVAL;
|
|
|
|
clk_prepare_lock();
|
|
|
|
list_for_each_entry(cn, &clk_notifier_list, node)
|
|
if (cn->clk == clk)
|
|
break;
|
|
|
|
if (cn->clk == clk) {
|
|
ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
|
|
|
|
clk->core->notifier_count--;
|
|
|
|
/* XXX the notifier code should handle this better */
|
|
if (!cn->notifier_head.head) {
|
|
srcu_cleanup_notifier_head(&cn->notifier_head);
|
|
list_del(&cn->node);
|
|
kfree(cn);
|
|
}
|
|
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_notifier_unregister);
|
|
|
|
#ifdef CONFIG_OF
|
|
/**
|
|
* struct of_clk_provider - Clock provider registration structure
|
|
* @link: Entry in global list of clock providers
|
|
* @node: Pointer to device tree node of clock provider
|
|
* @get: Get clock callback. Returns NULL or a struct clk for the
|
|
* given clock specifier
|
|
* @data: context pointer to be passed into @get callback
|
|
*/
|
|
struct of_clk_provider {
|
|
struct list_head link;
|
|
|
|
struct device_node *node;
|
|
struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
|
|
struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
|
|
void *data;
|
|
};
|
|
|
|
static const struct of_device_id __clk_of_table_sentinel
|
|
__used __section(__clk_of_table_end);
|
|
|
|
static LIST_HEAD(of_clk_providers);
|
|
static DEFINE_MUTEX(of_clk_mutex);
|
|
|
|
struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
|
|
void *data)
|
|
{
|
|
return data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
|
|
|
|
struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
|
|
{
|
|
return data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
|
|
|
|
struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
|
|
{
|
|
struct clk_onecell_data *clk_data = data;
|
|
unsigned int idx = clkspec->args[0];
|
|
|
|
if (idx >= clk_data->clk_num) {
|
|
pr_err("%s: invalid clock index %u\n", __func__, idx);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return clk_data->clks[idx];
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
|
|
|
|
struct clk_hw *
|
|
of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
|
|
{
|
|
struct clk_hw_onecell_data *hw_data = data;
|
|
unsigned int idx = clkspec->args[0];
|
|
|
|
if (idx >= hw_data->num) {
|
|
pr_err("%s: invalid index %u\n", __func__, idx);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return hw_data->hws[idx];
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
|
|
|
|
/**
|
|
* of_clk_add_provider() - Register a clock provider for a node
|
|
* @np: Device node pointer associated with clock provider
|
|
* @clk_src_get: callback for decoding clock
|
|
* @data: context pointer for @clk_src_get callback.
|
|
*
|
|
* This function is *deprecated*. Use of_clk_add_hw_provider() instead.
|
|
*/
|
|
int of_clk_add_provider(struct device_node *np,
|
|
struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
|
|
void *data),
|
|
void *data)
|
|
{
|
|
struct of_clk_provider *cp;
|
|
int ret;
|
|
|
|
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
|
|
if (!cp)
|
|
return -ENOMEM;
|
|
|
|
cp->node = of_node_get(np);
|
|
cp->data = data;
|
|
cp->get = clk_src_get;
|
|
|
|
mutex_lock(&of_clk_mutex);
|
|
list_add(&cp->link, &of_clk_providers);
|
|
mutex_unlock(&of_clk_mutex);
|
|
pr_debug("Added clock from %pOF\n", np);
|
|
|
|
ret = of_clk_set_defaults(np, true);
|
|
if (ret < 0)
|
|
of_clk_del_provider(np);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_add_provider);
|
|
|
|
/**
|
|
* of_clk_add_hw_provider() - Register a clock provider for a node
|
|
* @np: Device node pointer associated with clock provider
|
|
* @get: callback for decoding clk_hw
|
|
* @data: context pointer for @get callback.
|
|
*/
|
|
int of_clk_add_hw_provider(struct device_node *np,
|
|
struct clk_hw *(*get)(struct of_phandle_args *clkspec,
|
|
void *data),
|
|
void *data)
|
|
{
|
|
struct of_clk_provider *cp;
|
|
int ret;
|
|
|
|
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
|
|
if (!cp)
|
|
return -ENOMEM;
|
|
|
|
cp->node = of_node_get(np);
|
|
cp->data = data;
|
|
cp->get_hw = get;
|
|
|
|
mutex_lock(&of_clk_mutex);
|
|
list_add(&cp->link, &of_clk_providers);
|
|
mutex_unlock(&of_clk_mutex);
|
|
pr_debug("Added clk_hw provider from %pOF\n", np);
|
|
|
|
ret = of_clk_set_defaults(np, true);
|
|
if (ret < 0)
|
|
of_clk_del_provider(np);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
|
|
|
|
static void devm_of_clk_release_provider(struct device *dev, void *res)
|
|
{
|
|
of_clk_del_provider(*(struct device_node **)res);
|
|
}
|
|
|
|
/*
|
|
* We allow a child device to use its parent device as the clock provider node
|
|
* for cases like MFD sub-devices where the child device driver wants to use
|
|
* devm_*() APIs but not list the device in DT as a sub-node.
|
|
*/
|
|
static struct device_node *get_clk_provider_node(struct device *dev)
|
|
{
|
|
struct device_node *np, *parent_np;
|
|
|
|
np = dev->of_node;
|
|
parent_np = dev->parent ? dev->parent->of_node : NULL;
|
|
|
|
if (!of_find_property(np, "#clock-cells", NULL))
|
|
if (of_find_property(parent_np, "#clock-cells", NULL))
|
|
np = parent_np;
|
|
|
|
return np;
|
|
}
|
|
|
|
/**
|
|
* devm_of_clk_add_hw_provider() - Managed clk provider node registration
|
|
* @dev: Device acting as the clock provider (used for DT node and lifetime)
|
|
* @get: callback for decoding clk_hw
|
|
* @data: context pointer for @get callback
|
|
*
|
|
* Registers clock provider for given device's node. If the device has no DT
|
|
* node or if the device node lacks of clock provider information (#clock-cells)
|
|
* then the parent device's node is scanned for this information. If parent node
|
|
* has the #clock-cells then it is used in registration. Provider is
|
|
* automatically released at device exit.
|
|
*
|
|
* Return: 0 on success or an errno on failure.
|
|
*/
|
|
int devm_of_clk_add_hw_provider(struct device *dev,
|
|
struct clk_hw *(*get)(struct of_phandle_args *clkspec,
|
|
void *data),
|
|
void *data)
|
|
{
|
|
struct device_node **ptr, *np;
|
|
int ret;
|
|
|
|
ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
np = get_clk_provider_node(dev);
|
|
ret = of_clk_add_hw_provider(np, get, data);
|
|
if (!ret) {
|
|
*ptr = np;
|
|
devres_add(dev, ptr);
|
|
} else {
|
|
devres_free(ptr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
|
|
|
|
/**
|
|
* of_clk_del_provider() - Remove a previously registered clock provider
|
|
* @np: Device node pointer associated with clock provider
|
|
*/
|
|
void of_clk_del_provider(struct device_node *np)
|
|
{
|
|
struct of_clk_provider *cp;
|
|
|
|
mutex_lock(&of_clk_mutex);
|
|
list_for_each_entry(cp, &of_clk_providers, link) {
|
|
if (cp->node == np) {
|
|
list_del(&cp->link);
|
|
of_node_put(cp->node);
|
|
kfree(cp);
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&of_clk_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_del_provider);
|
|
|
|
static int devm_clk_provider_match(struct device *dev, void *res, void *data)
|
|
{
|
|
struct device_node **np = res;
|
|
|
|
if (WARN_ON(!np || !*np))
|
|
return 0;
|
|
|
|
return *np == data;
|
|
}
|
|
|
|
/**
|
|
* devm_of_clk_del_provider() - Remove clock provider registered using devm
|
|
* @dev: Device to whose lifetime the clock provider was bound
|
|
*/
|
|
void devm_of_clk_del_provider(struct device *dev)
|
|
{
|
|
int ret;
|
|
struct device_node *np = get_clk_provider_node(dev);
|
|
|
|
ret = devres_release(dev, devm_of_clk_release_provider,
|
|
devm_clk_provider_match, np);
|
|
|
|
WARN_ON(ret);
|
|
}
|
|
EXPORT_SYMBOL(devm_of_clk_del_provider);
|
|
|
|
/*
|
|
* Beware the return values when np is valid, but no clock provider is found.
|
|
* If name == NULL, the function returns -ENOENT.
|
|
* If name != NULL, the function returns -EINVAL. This is because
|
|
* of_parse_phandle_with_args() is called even if of_property_match_string()
|
|
* returns an error.
|
|
*/
|
|
static int of_parse_clkspec(const struct device_node *np, int index,
|
|
const char *name, struct of_phandle_args *out_args)
|
|
{
|
|
int ret = -ENOENT;
|
|
|
|
/* Walk up the tree of devices looking for a clock property that matches */
|
|
while (np) {
|
|
/*
|
|
* For named clocks, first look up the name in the
|
|
* "clock-names" property. If it cannot be found, then index
|
|
* will be an error code and of_parse_phandle_with_args() will
|
|
* return -EINVAL.
|
|
*/
|
|
if (name)
|
|
index = of_property_match_string(np, "clock-names", name);
|
|
ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
|
|
index, out_args);
|
|
if (!ret)
|
|
break;
|
|
if (name && index >= 0)
|
|
break;
|
|
|
|
/*
|
|
* No matching clock found on this node. If the parent node
|
|
* has a "clock-ranges" property, then we can try one of its
|
|
* clocks.
|
|
*/
|
|
np = np->parent;
|
|
if (np && !of_get_property(np, "clock-ranges", NULL))
|
|
break;
|
|
index = 0;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct clk_hw *
|
|
__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
|
|
struct of_phandle_args *clkspec)
|
|
{
|
|
struct clk *clk;
|
|
|
|
if (provider->get_hw)
|
|
return provider->get_hw(clkspec, provider->data);
|
|
|
|
clk = provider->get(clkspec, provider->data);
|
|
if (IS_ERR(clk))
|
|
return ERR_CAST(clk);
|
|
return __clk_get_hw(clk);
|
|
}
|
|
|
|
static struct clk_hw *
|
|
of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
|
|
{
|
|
struct of_clk_provider *provider;
|
|
struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
|
|
|
|
if (!clkspec)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
mutex_lock(&of_clk_mutex);
|
|
list_for_each_entry(provider, &of_clk_providers, link) {
|
|
if (provider->node == clkspec->np) {
|
|
hw = __of_clk_get_hw_from_provider(provider, clkspec);
|
|
if (!IS_ERR(hw))
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&of_clk_mutex);
|
|
|
|
return hw;
|
|
}
|
|
|
|
/**
|
|
* of_clk_get_from_provider() - Lookup a clock from a clock provider
|
|
* @clkspec: pointer to a clock specifier data structure
|
|
*
|
|
* This function looks up a struct clk from the registered list of clock
|
|
* providers, an input is a clock specifier data structure as returned
|
|
* from the of_parse_phandle_with_args() function call.
|
|
*/
|
|
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
|
|
{
|
|
struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
|
|
|
|
return clk_hw_create_clk(NULL, hw, NULL, __func__);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
|
|
|
|
struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
|
|
const char *con_id)
|
|
{
|
|
int ret;
|
|
struct clk_hw *hw;
|
|
struct of_phandle_args clkspec;
|
|
|
|
ret = of_parse_clkspec(np, index, con_id, &clkspec);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
|
|
hw = of_clk_get_hw_from_clkspec(&clkspec);
|
|
of_node_put(clkspec.np);
|
|
|
|
return hw;
|
|
}
|
|
|
|
static struct clk *__of_clk_get(struct device_node *np,
|
|
int index, const char *dev_id,
|
|
const char *con_id)
|
|
{
|
|
struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
|
|
|
|
return clk_hw_create_clk(NULL, hw, dev_id, con_id);
|
|
}
|
|
|
|
struct clk *of_clk_get(struct device_node *np, int index)
|
|
{
|
|
return __of_clk_get(np, index, np->full_name, NULL);
|
|
}
|
|
EXPORT_SYMBOL(of_clk_get);
|
|
|
|
/**
|
|
* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
|
|
* @np: pointer to clock consumer node
|
|
* @name: name of consumer's clock input, or NULL for the first clock reference
|
|
*
|
|
* This function parses the clocks and clock-names properties,
|
|
* and uses them to look up the struct clk from the registered list of clock
|
|
* providers.
|
|
*/
|
|
struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
|
|
{
|
|
if (!np)
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
return __of_clk_get(np, 0, np->full_name, name);
|
|
}
|
|
EXPORT_SYMBOL(of_clk_get_by_name);
|
|
|
|
/**
|
|
* of_clk_get_parent_count() - Count the number of clocks a device node has
|
|
* @np: device node to count
|
|
*
|
|
* Returns: The number of clocks that are possible parents of this node
|
|
*/
|
|
unsigned int of_clk_get_parent_count(struct device_node *np)
|
|
{
|
|
int count;
|
|
|
|
count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
|
|
if (count < 0)
|
|
return 0;
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
|
|
|
|
const char *of_clk_get_parent_name(struct device_node *np, int index)
|
|
{
|
|
struct of_phandle_args clkspec;
|
|
struct property *prop;
|
|
const char *clk_name;
|
|
const __be32 *vp;
|
|
u32 pv;
|
|
int rc;
|
|
int count;
|
|
struct clk *clk;
|
|
|
|
rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
|
|
&clkspec);
|
|
if (rc)
|
|
return NULL;
|
|
|
|
index = clkspec.args_count ? clkspec.args[0] : 0;
|
|
count = 0;
|
|
|
|
/* if there is an indices property, use it to transfer the index
|
|
* specified into an array offset for the clock-output-names property.
|
|
*/
|
|
of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
|
|
if (index == pv) {
|
|
index = count;
|
|
break;
|
|
}
|
|
count++;
|
|
}
|
|
/* We went off the end of 'clock-indices' without finding it */
|
|
if (prop && !vp)
|
|
return NULL;
|
|
|
|
if (of_property_read_string_index(clkspec.np, "clock-output-names",
|
|
index,
|
|
&clk_name) < 0) {
|
|
/*
|
|
* Best effort to get the name if the clock has been
|
|
* registered with the framework. If the clock isn't
|
|
* registered, we return the node name as the name of
|
|
* the clock as long as #clock-cells = 0.
|
|
*/
|
|
clk = of_clk_get_from_provider(&clkspec);
|
|
if (IS_ERR(clk)) {
|
|
if (clkspec.args_count == 0)
|
|
clk_name = clkspec.np->name;
|
|
else
|
|
clk_name = NULL;
|
|
} else {
|
|
clk_name = __clk_get_name(clk);
|
|
clk_put(clk);
|
|
}
|
|
}
|
|
|
|
|
|
of_node_put(clkspec.np);
|
|
return clk_name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
|
|
|
|
/**
|
|
* of_clk_parent_fill() - Fill @parents with names of @np's parents and return
|
|
* number of parents
|
|
* @np: Device node pointer associated with clock provider
|
|
* @parents: pointer to char array that hold the parents' names
|
|
* @size: size of the @parents array
|
|
*
|
|
* Return: number of parents for the clock node.
|
|
*/
|
|
int of_clk_parent_fill(struct device_node *np, const char **parents,
|
|
unsigned int size)
|
|
{
|
|
unsigned int i = 0;
|
|
|
|
while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
|
|
i++;
|
|
|
|
return i;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_parent_fill);
|
|
|
|
struct clock_provider {
|
|
void (*clk_init_cb)(struct device_node *);
|
|
struct device_node *np;
|
|
struct list_head node;
|
|
};
|
|
|
|
/*
|
|
* This function looks for a parent clock. If there is one, then it
|
|
* checks that the provider for this parent clock was initialized, in
|
|
* this case the parent clock will be ready.
|
|
*/
|
|
static int parent_ready(struct device_node *np)
|
|
{
|
|
int i = 0;
|
|
|
|
while (true) {
|
|
struct clk *clk = of_clk_get(np, i);
|
|
|
|
/* this parent is ready we can check the next one */
|
|
if (!IS_ERR(clk)) {
|
|
clk_put(clk);
|
|
i++;
|
|
continue;
|
|
}
|
|
|
|
/* at least one parent is not ready, we exit now */
|
|
if (PTR_ERR(clk) == -EPROBE_DEFER)
|
|
return 0;
|
|
|
|
/*
|
|
* Here we make assumption that the device tree is
|
|
* written correctly. So an error means that there is
|
|
* no more parent. As we didn't exit yet, then the
|
|
* previous parent are ready. If there is no clock
|
|
* parent, no need to wait for them, then we can
|
|
* consider their absence as being ready
|
|
*/
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
|
|
* @np: Device node pointer associated with clock provider
|
|
* @index: clock index
|
|
* @flags: pointer to top-level framework flags
|
|
*
|
|
* Detects if the clock-critical property exists and, if so, sets the
|
|
* corresponding CLK_IS_CRITICAL flag.
|
|
*
|
|
* Do not use this function. It exists only for legacy Device Tree
|
|
* bindings, such as the one-clock-per-node style that are outdated.
|
|
* Those bindings typically put all clock data into .dts and the Linux
|
|
* driver has no clock data, thus making it impossible to set this flag
|
|
* correctly from the driver. Only those drivers may call
|
|
* of_clk_detect_critical from their setup functions.
|
|
*
|
|
* Return: error code or zero on success
|
|
*/
|
|
int of_clk_detect_critical(struct device_node *np,
|
|
int index, unsigned long *flags)
|
|
{
|
|
struct property *prop;
|
|
const __be32 *cur;
|
|
uint32_t idx;
|
|
|
|
if (!np || !flags)
|
|
return -EINVAL;
|
|
|
|
of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
|
|
if (index == idx)
|
|
*flags |= CLK_IS_CRITICAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* of_clk_init() - Scan and init clock providers from the DT
|
|
* @matches: array of compatible values and init functions for providers.
|
|
*
|
|
* This function scans the device tree for matching clock providers
|
|
* and calls their initialization functions. It also does it by trying
|
|
* to follow the dependencies.
|
|
*/
|
|
void __init of_clk_init(const struct of_device_id *matches)
|
|
{
|
|
const struct of_device_id *match;
|
|
struct device_node *np;
|
|
struct clock_provider *clk_provider, *next;
|
|
bool is_init_done;
|
|
bool force = false;
|
|
LIST_HEAD(clk_provider_list);
|
|
|
|
if (!matches)
|
|
matches = &__clk_of_table;
|
|
|
|
/* First prepare the list of the clocks providers */
|
|
for_each_matching_node_and_match(np, matches, &match) {
|
|
struct clock_provider *parent;
|
|
|
|
if (!of_device_is_available(np))
|
|
continue;
|
|
|
|
parent = kzalloc(sizeof(*parent), GFP_KERNEL);
|
|
if (!parent) {
|
|
list_for_each_entry_safe(clk_provider, next,
|
|
&clk_provider_list, node) {
|
|
list_del(&clk_provider->node);
|
|
of_node_put(clk_provider->np);
|
|
kfree(clk_provider);
|
|
}
|
|
of_node_put(np);
|
|
return;
|
|
}
|
|
|
|
parent->clk_init_cb = match->data;
|
|
parent->np = of_node_get(np);
|
|
list_add_tail(&parent->node, &clk_provider_list);
|
|
}
|
|
|
|
while (!list_empty(&clk_provider_list)) {
|
|
is_init_done = false;
|
|
list_for_each_entry_safe(clk_provider, next,
|
|
&clk_provider_list, node) {
|
|
if (force || parent_ready(clk_provider->np)) {
|
|
|
|
/* Don't populate platform devices */
|
|
of_node_set_flag(clk_provider->np,
|
|
OF_POPULATED);
|
|
|
|
clk_provider->clk_init_cb(clk_provider->np);
|
|
of_clk_set_defaults(clk_provider->np, true);
|
|
|
|
list_del(&clk_provider->node);
|
|
of_node_put(clk_provider->np);
|
|
kfree(clk_provider);
|
|
is_init_done = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We didn't manage to initialize any of the
|
|
* remaining providers during the last loop, so now we
|
|
* initialize all the remaining ones unconditionally
|
|
* in case the clock parent was not mandatory
|
|
*/
|
|
if (!is_init_done)
|
|
force = true;
|
|
}
|
|
}
|
|
#endif
|