![Michael Turquette](/assets/img/avatar_default.png)
Some drivers compare struct clk pointers as a means of knowing
if the two pointers reference the same clock hardware. This behavior is
dubious (drivers must not dereference struct clk), but did not cause any
regressions until the per-user struct clk patch was merged. Now the test
for matching clk's will always fail with per-user struct clk's.
clk_is_match is introduced to fix the regression and prevent drivers
from comparing the pointers manually.
Fixes: 035a61c314
("clk: Make clk API return per-user struct clk instances")
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: const arguments to clk_is_match() and
remove unnecessary ternary operation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
3108 lines
75 KiB
C
3108 lines
75 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Standard functionality for the common clock API. See Documentation/clk.txt
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*/
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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/sched.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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static long clk_core_get_accuracy(struct clk_core *clk);
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static unsigned long clk_core_get_rate(struct clk_core *clk);
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static int clk_core_get_phase(struct clk_core *clk);
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static bool clk_core_is_prepared(struct clk_core *clk);
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static bool clk_core_is_enabled(struct clk_core *clk);
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static struct clk_core *clk_core_lookup(const char *name);
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/*** private data structures ***/
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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 clk_core *parent;
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const char **parent_names;
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struct clk_core **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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unsigned int enable_count;
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unsigned int prepare_count;
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unsigned long accuracy;
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int phase;
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struct hlist_head children;
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struct hlist_node child_node;
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struct hlist_node debug_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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#endif
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struct kref ref;
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};
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struct clk {
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struct clk_core *core;
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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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struct hlist_node child_node;
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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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{
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unsigned long flags;
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if (!spin_trylock_irqsave(&enable_lock, flags)) {
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if (enable_owner == current) {
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enable_refcnt++;
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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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{
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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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return;
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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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/*** debugfs support ***/
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#ifdef CONFIG_DEBUG_FS
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#include <linux/debugfs.h>
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static struct dentry *rootdir;
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static int inited = 0;
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static DEFINE_MUTEX(clk_debug_lock);
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static HLIST_HEAD(clk_debug_list);
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static struct hlist_head *all_lists[] = {
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&clk_root_list,
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&clk_orphan_list,
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NULL,
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};
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static struct hlist_head *orphan_list[] = {
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&clk_orphan_list,
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NULL,
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};
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static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
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int level)
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{
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if (!c)
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return;
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seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
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level * 3 + 1, "",
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30 - level * 3, c->name,
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c->enable_count, c->prepare_count, clk_core_get_rate(c),
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clk_core_get_accuracy(c), clk_core_get_phase(c));
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}
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static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
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int level)
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{
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struct clk_core *child;
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if (!c)
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return;
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clk_summary_show_one(s, c, level);
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hlist_for_each_entry(child, &c->children, child_node)
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clk_summary_show_subtree(s, child, level + 1);
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}
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static int clk_summary_show(struct seq_file *s, void *data)
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{
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struct clk_core *c;
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struct hlist_head **lists = (struct hlist_head **)s->private;
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seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
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seq_puts(s, "----------------------------------------------------------------------------------------\n");
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clk_prepare_lock();
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for (; *lists; lists++)
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hlist_for_each_entry(c, *lists, child_node)
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clk_summary_show_subtree(s, c, 0);
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clk_prepare_unlock();
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return 0;
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}
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static int clk_summary_open(struct inode *inode, struct file *file)
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{
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return single_open(file, clk_summary_show, inode->i_private);
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}
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static const struct file_operations clk_summary_fops = {
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.open = clk_summary_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
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{
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if (!c)
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return;
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seq_printf(s, "\"%s\": { ", c->name);
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seq_printf(s, "\"enable_count\": %d,", c->enable_count);
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seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
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seq_printf(s, "\"rate\": %lu", clk_core_get_rate(c));
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seq_printf(s, "\"accuracy\": %lu", clk_core_get_accuracy(c));
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seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
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}
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static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
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{
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struct clk_core *child;
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if (!c)
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return;
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clk_dump_one(s, c, level);
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hlist_for_each_entry(child, &c->children, child_node) {
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seq_printf(s, ",");
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clk_dump_subtree(s, child, level + 1);
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}
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seq_printf(s, "}");
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}
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static int clk_dump(struct seq_file *s, void *data)
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{
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struct clk_core *c;
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bool first_node = true;
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struct hlist_head **lists = (struct hlist_head **)s->private;
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seq_printf(s, "{");
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clk_prepare_lock();
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for (; *lists; lists++) {
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hlist_for_each_entry(c, *lists, child_node) {
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if (!first_node)
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seq_puts(s, ",");
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first_node = false;
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clk_dump_subtree(s, c, 0);
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}
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}
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clk_prepare_unlock();
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seq_printf(s, "}");
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return 0;
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}
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static int clk_dump_open(struct inode *inode, struct file *file)
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{
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return single_open(file, clk_dump, inode->i_private);
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}
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static const struct file_operations clk_dump_fops = {
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.open = clk_dump_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int clk_debug_create_one(struct clk_core *clk, struct dentry *pdentry)
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{
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struct dentry *d;
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int ret = -ENOMEM;
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if (!clk || !pdentry) {
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ret = -EINVAL;
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goto out;
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}
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d = debugfs_create_dir(clk->name, pdentry);
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if (!d)
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goto out;
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clk->dentry = d;
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d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
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(u32 *)&clk->rate);
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if (!d)
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goto err_out;
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d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
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(u32 *)&clk->accuracy);
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if (!d)
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goto err_out;
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d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry,
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(u32 *)&clk->phase);
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if (!d)
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goto err_out;
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d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
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(u32 *)&clk->flags);
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if (!d)
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goto err_out;
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d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
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(u32 *)&clk->prepare_count);
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if (!d)
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goto err_out;
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d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
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(u32 *)&clk->enable_count);
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if (!d)
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goto err_out;
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d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
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(u32 *)&clk->notifier_count);
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if (!d)
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goto err_out;
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if (clk->ops->debug_init) {
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ret = clk->ops->debug_init(clk->hw, clk->dentry);
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if (ret)
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goto err_out;
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}
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ret = 0;
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goto out;
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err_out:
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debugfs_remove_recursive(clk->dentry);
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clk->dentry = NULL;
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out:
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return ret;
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}
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/**
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* clk_debug_register - add a clk node to the debugfs clk tree
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* @clk: the clk being added to the debugfs clk tree
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*
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* Dynamically adds a clk to the debugfs clk tree if debugfs has been
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* initialized. Otherwise it bails out early since the debugfs clk tree
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* will be created lazily by clk_debug_init as part of a late_initcall.
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*/
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static int clk_debug_register(struct clk_core *clk)
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{
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int ret = 0;
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mutex_lock(&clk_debug_lock);
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hlist_add_head(&clk->debug_node, &clk_debug_list);
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if (!inited)
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goto unlock;
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ret = clk_debug_create_one(clk, rootdir);
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unlock:
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mutex_unlock(&clk_debug_lock);
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return ret;
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}
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/**
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* clk_debug_unregister - remove a clk node from the debugfs clk tree
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* @clk: the clk being removed from the debugfs clk tree
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*
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* Dynamically removes a clk and all it's children clk nodes from the
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* debugfs clk tree if clk->dentry points to debugfs created by
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* clk_debug_register in __clk_init.
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*/
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static void clk_debug_unregister(struct clk_core *clk)
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{
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mutex_lock(&clk_debug_lock);
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hlist_del_init(&clk->debug_node);
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debugfs_remove_recursive(clk->dentry);
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clk->dentry = NULL;
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mutex_unlock(&clk_debug_lock);
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}
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struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
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void *data, const struct file_operations *fops)
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{
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struct dentry *d = NULL;
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if (hw->core->dentry)
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d = debugfs_create_file(name, mode, hw->core->dentry, data,
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fops);
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return d;
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}
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EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
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/**
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* clk_debug_init - lazily create the debugfs clk tree visualization
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*
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* clks are often initialized very early during boot before memory can
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* be dynamically allocated and well before debugfs is setup.
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* clk_debug_init walks the clk tree hierarchy while holding
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* prepare_lock and creates the topology as part of a late_initcall,
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* thus insuring that clks initialized very early will still be
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* represented in the debugfs clk tree. This function should only be
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* called once at boot-time, and all other clks added dynamically will
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* be done so with clk_debug_register.
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*/
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static int __init clk_debug_init(void)
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{
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struct clk_core *clk;
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struct dentry *d;
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rootdir = debugfs_create_dir("clk", NULL);
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if (!rootdir)
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return -ENOMEM;
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d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
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&clk_summary_fops);
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if (!d)
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return -ENOMEM;
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d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
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&clk_dump_fops);
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if (!d)
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return -ENOMEM;
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d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
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&orphan_list, &clk_summary_fops);
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if (!d)
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return -ENOMEM;
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d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
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&orphan_list, &clk_dump_fops);
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if (!d)
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return -ENOMEM;
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mutex_lock(&clk_debug_lock);
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hlist_for_each_entry(clk, &clk_debug_list, debug_node)
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clk_debug_create_one(clk, rootdir);
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inited = 1;
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mutex_unlock(&clk_debug_lock);
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return 0;
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}
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late_initcall(clk_debug_init);
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#else
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static inline int clk_debug_register(struct clk_core *clk) { return 0; }
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static inline void clk_debug_reparent(struct clk_core *clk,
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struct clk_core *new_parent)
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{
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}
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static inline void clk_debug_unregister(struct clk_core *clk)
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{
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}
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#endif
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/* caller must hold prepare_lock */
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static void clk_unprepare_unused_subtree(struct clk_core *clk)
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{
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struct clk_core *child;
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hlist_for_each_entry(child, &clk->children, child_node)
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clk_unprepare_unused_subtree(child);
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if (clk->prepare_count)
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return;
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if (clk->flags & CLK_IGNORE_UNUSED)
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return;
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if (clk_core_is_prepared(clk)) {
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if (clk->ops->unprepare_unused)
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clk->ops->unprepare_unused(clk->hw);
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else if (clk->ops->unprepare)
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clk->ops->unprepare(clk->hw);
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}
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}
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/* caller must hold prepare_lock */
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static void clk_disable_unused_subtree(struct clk_core *clk)
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{
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struct clk_core *child;
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unsigned long flags;
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hlist_for_each_entry(child, &clk->children, child_node)
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clk_disable_unused_subtree(child);
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flags = clk_enable_lock();
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if (clk->enable_count)
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goto unlock_out;
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if (clk->flags & CLK_IGNORE_UNUSED)
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goto unlock_out;
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/*
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* some gate clocks have special needs during the disable-unused
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* sequence. call .disable_unused if available, otherwise fall
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* back to .disable
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*/
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if (clk_core_is_enabled(clk)) {
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if (clk->ops->disable_unused)
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clk->ops->disable_unused(clk->hw);
|
|
else if (clk->ops->disable)
|
|
clk->ops->disable(clk->hw);
|
|
}
|
|
|
|
unlock_out:
|
|
clk_enable_unlock(flags);
|
|
}
|
|
|
|
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 *clk;
|
|
|
|
if (clk_ignore_unused) {
|
|
pr_warn("clk: Not disabling unused clocks\n");
|
|
return 0;
|
|
}
|
|
|
|
clk_prepare_lock();
|
|
|
|
hlist_for_each_entry(clk, &clk_root_list, child_node)
|
|
clk_disable_unused_subtree(clk);
|
|
|
|
hlist_for_each_entry(clk, &clk_orphan_list, child_node)
|
|
clk_disable_unused_subtree(clk);
|
|
|
|
hlist_for_each_entry(clk, &clk_root_list, child_node)
|
|
clk_unprepare_unused_subtree(clk);
|
|
|
|
hlist_for_each_entry(clk, &clk_orphan_list, child_node)
|
|
clk_unprepare_unused_subtree(clk);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return 0;
|
|
}
|
|
late_initcall_sync(clk_disable_unused);
|
|
|
|
/*** helper functions ***/
|
|
|
|
const char *__clk_get_name(struct clk *clk)
|
|
{
|
|
return !clk ? NULL : clk->core->name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_name);
|
|
|
|
struct clk_hw *__clk_get_hw(struct clk *clk)
|
|
{
|
|
return !clk ? NULL : clk->core->hw;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_hw);
|
|
|
|
u8 __clk_get_num_parents(struct clk *clk)
|
|
{
|
|
return !clk ? 0 : clk->core->num_parents;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_num_parents);
|
|
|
|
struct clk *__clk_get_parent(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return NULL;
|
|
|
|
/* TODO: Create a per-user clk and change callers to call clk_put */
|
|
return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_parent);
|
|
|
|
static struct clk_core *clk_core_get_parent_by_index(struct clk_core *clk,
|
|
u8 index)
|
|
{
|
|
if (!clk || index >= clk->num_parents)
|
|
return NULL;
|
|
else if (!clk->parents)
|
|
return clk_core_lookup(clk->parent_names[index]);
|
|
else if (!clk->parents[index])
|
|
return clk->parents[index] =
|
|
clk_core_lookup(clk->parent_names[index]);
|
|
else
|
|
return clk->parents[index];
|
|
}
|
|
|
|
struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
|
|
{
|
|
struct clk_core *parent;
|
|
|
|
if (!clk)
|
|
return NULL;
|
|
|
|
parent = clk_core_get_parent_by_index(clk->core, index);
|
|
|
|
return !parent ? NULL : parent->hw->clk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
|
|
|
|
unsigned int __clk_get_enable_count(struct clk *clk)
|
|
{
|
|
return !clk ? 0 : clk->core->enable_count;
|
|
}
|
|
|
|
static unsigned long clk_core_get_rate_nolock(struct clk_core *clk)
|
|
{
|
|
unsigned long ret;
|
|
|
|
if (!clk) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = clk->rate;
|
|
|
|
if (clk->flags & CLK_IS_ROOT)
|
|
goto out;
|
|
|
|
if (!clk->parent)
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
unsigned long __clk_get_rate(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_get_rate_nolock(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_rate);
|
|
|
|
static unsigned long __clk_get_accuracy(struct clk_core *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk->accuracy;
|
|
}
|
|
|
|
unsigned long __clk_get_flags(struct clk *clk)
|
|
{
|
|
return !clk ? 0 : clk->core->flags;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_get_flags);
|
|
|
|
static bool clk_core_is_prepared(struct clk_core *clk)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return false;
|
|
|
|
/*
|
|
* .is_prepared is optional for clocks that can prepare
|
|
* fall back to software usage counter if it is missing
|
|
*/
|
|
if (!clk->ops->is_prepared) {
|
|
ret = clk->prepare_count ? 1 : 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = clk->ops->is_prepared(clk->hw);
|
|
out:
|
|
return !!ret;
|
|
}
|
|
|
|
bool __clk_is_prepared(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return false;
|
|
|
|
return clk_core_is_prepared(clk->core);
|
|
}
|
|
|
|
static bool clk_core_is_enabled(struct clk_core *clk)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return false;
|
|
|
|
/*
|
|
* .is_enabled is only mandatory for clocks that gate
|
|
* fall back to software usage counter if .is_enabled is missing
|
|
*/
|
|
if (!clk->ops->is_enabled) {
|
|
ret = clk->enable_count ? 1 : 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = clk->ops->is_enabled(clk->hw);
|
|
out:
|
|
return !!ret;
|
|
}
|
|
|
|
bool __clk_is_enabled(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return false;
|
|
|
|
return clk_core_is_enabled(clk->core);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_is_enabled);
|
|
|
|
static struct clk_core *__clk_lookup_subtree(const char *name,
|
|
struct clk_core *clk)
|
|
{
|
|
struct clk_core *child;
|
|
struct clk_core *ret;
|
|
|
|
if (!strcmp(clk->name, name))
|
|
return clk;
|
|
|
|
hlist_for_each_entry(child, &clk->children, child_node) {
|
|
ret = __clk_lookup_subtree(name, child);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct clk_core *clk_core_lookup(const char *name)
|
|
{
|
|
struct clk_core *root_clk;
|
|
struct clk_core *ret;
|
|
|
|
if (!name)
|
|
return NULL;
|
|
|
|
/* search the 'proper' clk tree first */
|
|
hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
|
|
ret = __clk_lookup_subtree(name, root_clk);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/* if not found, then search the orphan tree */
|
|
hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
|
|
ret = __clk_lookup_subtree(name, root_clk);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static bool mux_is_better_rate(unsigned long rate, unsigned long now,
|
|
unsigned long best, unsigned long flags)
|
|
{
|
|
if (flags & CLK_MUX_ROUND_CLOSEST)
|
|
return abs(now - rate) < abs(best - rate);
|
|
|
|
return now <= rate && now > best;
|
|
}
|
|
|
|
static long
|
|
clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long min_rate,
|
|
unsigned long max_rate,
|
|
unsigned long *best_parent_rate,
|
|
struct clk_hw **best_parent_p,
|
|
unsigned long flags)
|
|
{
|
|
struct clk_core *core = hw->core, *parent, *best_parent = NULL;
|
|
int i, num_parents;
|
|
unsigned long parent_rate, best = 0;
|
|
|
|
/* if NO_REPARENT flag set, pass through to current parent */
|
|
if (core->flags & CLK_SET_RATE_NO_REPARENT) {
|
|
parent = core->parent;
|
|
if (core->flags & CLK_SET_RATE_PARENT)
|
|
best = __clk_determine_rate(parent ? parent->hw : NULL,
|
|
rate, min_rate, max_rate);
|
|
else if (parent)
|
|
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_rate = __clk_determine_rate(parent->hw, rate,
|
|
min_rate,
|
|
max_rate);
|
|
else
|
|
parent_rate = clk_core_get_rate_nolock(parent);
|
|
if (mux_is_better_rate(rate, parent_rate, best, flags)) {
|
|
best_parent = parent;
|
|
best = parent_rate;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (best_parent)
|
|
*best_parent_p = best_parent->hw;
|
|
*best_parent_rate = best;
|
|
|
|
return best;
|
|
}
|
|
|
|
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 *clk,
|
|
unsigned long *min_rate,
|
|
unsigned long *max_rate)
|
|
{
|
|
struct clk *clk_user;
|
|
|
|
*min_rate = 0;
|
|
*max_rate = ULONG_MAX;
|
|
|
|
hlist_for_each_entry(clk_user, &clk->clks, child_node)
|
|
*min_rate = max(*min_rate, clk_user->min_rate);
|
|
|
|
hlist_for_each_entry(clk_user, &clk->clks, child_node)
|
|
*max_rate = min(*max_rate, clk_user->max_rate);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long min_rate,
|
|
unsigned long max_rate,
|
|
unsigned long *best_parent_rate,
|
|
struct clk_hw **best_parent_p)
|
|
{
|
|
return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
|
|
best_parent_rate,
|
|
best_parent_p, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
|
|
|
|
long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long min_rate,
|
|
unsigned long max_rate,
|
|
unsigned long *best_parent_rate,
|
|
struct clk_hw **best_parent_p)
|
|
{
|
|
return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
|
|
best_parent_rate,
|
|
best_parent_p,
|
|
CLK_MUX_ROUND_CLOSEST);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
|
|
|
|
/*** clk api ***/
|
|
|
|
static void clk_core_unprepare(struct clk_core *clk)
|
|
{
|
|
if (!clk)
|
|
return;
|
|
|
|
if (WARN_ON(clk->prepare_count == 0))
|
|
return;
|
|
|
|
if (--clk->prepare_count > 0)
|
|
return;
|
|
|
|
WARN_ON(clk->enable_count > 0);
|
|
|
|
if (clk->ops->unprepare)
|
|
clk->ops->unprepare(clk->hw);
|
|
|
|
clk_core_unprepare(clk->parent);
|
|
}
|
|
|
|
/**
|
|
* 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_prepare_lock();
|
|
clk_core_unprepare(clk->core);
|
|
clk_prepare_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_unprepare);
|
|
|
|
static int clk_core_prepare(struct clk_core *clk)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
if (clk->prepare_count == 0) {
|
|
ret = clk_core_prepare(clk->parent);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (clk->ops->prepare) {
|
|
ret = clk->ops->prepare(clk->hw);
|
|
if (ret) {
|
|
clk_core_unprepare(clk->parent);
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
clk->prepare_count++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
int ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_prepare_lock();
|
|
ret = clk_core_prepare(clk->core);
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_prepare);
|
|
|
|
static void clk_core_disable(struct clk_core *clk)
|
|
{
|
|
if (!clk)
|
|
return;
|
|
|
|
if (WARN_ON(clk->enable_count == 0))
|
|
return;
|
|
|
|
if (--clk->enable_count > 0)
|
|
return;
|
|
|
|
if (clk->ops->disable)
|
|
clk->ops->disable(clk->hw);
|
|
|
|
clk_core_disable(clk->parent);
|
|
}
|
|
|
|
static void __clk_disable(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return;
|
|
|
|
clk_core_disable(clk->core);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (IS_ERR_OR_NULL(clk))
|
|
return;
|
|
|
|
flags = clk_enable_lock();
|
|
__clk_disable(clk);
|
|
clk_enable_unlock(flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_disable);
|
|
|
|
static int clk_core_enable(struct clk_core *clk)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
if (WARN_ON(clk->prepare_count == 0))
|
|
return -ESHUTDOWN;
|
|
|
|
if (clk->enable_count == 0) {
|
|
ret = clk_core_enable(clk->parent);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (clk->ops->enable) {
|
|
ret = clk->ops->enable(clk->hw);
|
|
if (ret) {
|
|
clk_core_disable(clk->parent);
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
clk->enable_count++;
|
|
return 0;
|
|
}
|
|
|
|
static int __clk_enable(struct clk *clk)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_enable(clk->core);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
flags = clk_enable_lock();
|
|
ret = __clk_enable(clk);
|
|
clk_enable_unlock(flags);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_enable);
|
|
|
|
static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
|
|
unsigned long rate,
|
|
unsigned long min_rate,
|
|
unsigned long max_rate)
|
|
{
|
|
unsigned long parent_rate = 0;
|
|
struct clk_core *parent;
|
|
struct clk_hw *parent_hw;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
parent = clk->parent;
|
|
if (parent)
|
|
parent_rate = parent->rate;
|
|
|
|
if (clk->ops->determine_rate) {
|
|
parent_hw = parent ? parent->hw : NULL;
|
|
return clk->ops->determine_rate(clk->hw, rate,
|
|
min_rate, max_rate,
|
|
&parent_rate, &parent_hw);
|
|
} else if (clk->ops->round_rate)
|
|
return clk->ops->round_rate(clk->hw, rate, &parent_rate);
|
|
else if (clk->flags & CLK_SET_RATE_PARENT)
|
|
return clk_core_round_rate_nolock(clk->parent, rate, min_rate,
|
|
max_rate);
|
|
else
|
|
return clk->rate;
|
|
}
|
|
|
|
/**
|
|
* __clk_determine_rate - get the closest rate actually supported by a clock
|
|
* @hw: determine the rate of this clock
|
|
* @rate: target rate
|
|
* @min_rate: returned rate must be greater than this rate
|
|
* @max_rate: returned rate must be less than this rate
|
|
*
|
|
* Caller must hold prepare_lock. Useful for clk_ops such as .set_rate and
|
|
* .determine_rate.
|
|
*/
|
|
unsigned long __clk_determine_rate(struct clk_hw *hw,
|
|
unsigned long rate,
|
|
unsigned long min_rate,
|
|
unsigned long max_rate)
|
|
{
|
|
if (!hw)
|
|
return 0;
|
|
|
|
return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_determine_rate);
|
|
|
|
/**
|
|
* __clk_round_rate - round the given rate for a clk
|
|
* @clk: round the rate of this clock
|
|
* @rate: the rate which is to be rounded
|
|
*
|
|
* Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
|
|
*/
|
|
unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
|
|
{
|
|
unsigned long min_rate;
|
|
unsigned long max_rate;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
|
|
|
|
return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__clk_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)
|
|
{
|
|
unsigned long ret;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
clk_prepare_lock();
|
|
ret = __clk_round_rate(clk, rate);
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_round_rate);
|
|
|
|
/**
|
|
* __clk_notify - call clk notifier chain
|
|
* @clk: struct 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 *clk, 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 == clk) {
|
|
cnd.clk = cn->clk;
|
|
ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
|
|
&cnd);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __clk_recalc_accuracies
|
|
* @clk: 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 it's
|
|
* parent.
|
|
*
|
|
* Caller must hold prepare_lock.
|
|
*/
|
|
static void __clk_recalc_accuracies(struct clk_core *clk)
|
|
{
|
|
unsigned long parent_accuracy = 0;
|
|
struct clk_core *child;
|
|
|
|
if (clk->parent)
|
|
parent_accuracy = clk->parent->accuracy;
|
|
|
|
if (clk->ops->recalc_accuracy)
|
|
clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
|
|
parent_accuracy);
|
|
else
|
|
clk->accuracy = parent_accuracy;
|
|
|
|
hlist_for_each_entry(child, &clk->children, child_node)
|
|
__clk_recalc_accuracies(child);
|
|
}
|
|
|
|
static long clk_core_get_accuracy(struct clk_core *clk)
|
|
{
|
|
unsigned long accuracy;
|
|
|
|
clk_prepare_lock();
|
|
if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
|
|
__clk_recalc_accuracies(clk);
|
|
|
|
accuracy = __clk_get_accuracy(clk);
|
|
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 *clk,
|
|
unsigned long parent_rate)
|
|
{
|
|
if (clk->ops->recalc_rate)
|
|
return clk->ops->recalc_rate(clk->hw, parent_rate);
|
|
return parent_rate;
|
|
}
|
|
|
|
/**
|
|
* __clk_recalc_rates
|
|
* @clk: 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.
|
|
*
|
|
* Caller must hold prepare_lock.
|
|
*/
|
|
static void __clk_recalc_rates(struct clk_core *clk, unsigned long msg)
|
|
{
|
|
unsigned long old_rate;
|
|
unsigned long parent_rate = 0;
|
|
struct clk_core *child;
|
|
|
|
old_rate = clk->rate;
|
|
|
|
if (clk->parent)
|
|
parent_rate = clk->parent->rate;
|
|
|
|
clk->rate = clk_recalc(clk, parent_rate);
|
|
|
|
/*
|
|
* ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
|
|
* & ABORT_RATE_CHANGE notifiers
|
|
*/
|
|
if (clk->notifier_count && msg)
|
|
__clk_notify(clk, msg, old_rate, clk->rate);
|
|
|
|
hlist_for_each_entry(child, &clk->children, child_node)
|
|
__clk_recalc_rates(child, msg);
|
|
}
|
|
|
|
static unsigned long clk_core_get_rate(struct clk_core *clk)
|
|
{
|
|
unsigned long rate;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
|
|
__clk_recalc_rates(clk, 0);
|
|
|
|
rate = clk_core_get_rate_nolock(clk);
|
|
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 *clk,
|
|
struct clk_core *parent)
|
|
{
|
|
int i;
|
|
|
|
if (!clk->parents) {
|
|
clk->parents = kcalloc(clk->num_parents,
|
|
sizeof(struct clk *), GFP_KERNEL);
|
|
if (!clk->parents)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* find index of new parent clock using cached parent ptrs,
|
|
* or if not yet cached, use string name comparison and cache
|
|
* them now to avoid future calls to clk_core_lookup.
|
|
*/
|
|
for (i = 0; i < clk->num_parents; i++) {
|
|
if (clk->parents[i] == parent)
|
|
return i;
|
|
|
|
if (clk->parents[i])
|
|
continue;
|
|
|
|
if (!strcmp(clk->parent_names[i], parent->name)) {
|
|
clk->parents[i] = clk_core_lookup(parent->name);
|
|
return i;
|
|
}
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void clk_reparent(struct clk_core *clk, struct clk_core *new_parent)
|
|
{
|
|
hlist_del(&clk->child_node);
|
|
|
|
if (new_parent) {
|
|
/* avoid duplicate POST_RATE_CHANGE notifications */
|
|
if (new_parent->new_child == clk)
|
|
new_parent->new_child = NULL;
|
|
|
|
hlist_add_head(&clk->child_node, &new_parent->children);
|
|
} else {
|
|
hlist_add_head(&clk->child_node, &clk_orphan_list);
|
|
}
|
|
|
|
clk->parent = new_parent;
|
|
}
|
|
|
|
static struct clk_core *__clk_set_parent_before(struct clk_core *clk,
|
|
struct clk_core *parent)
|
|
{
|
|
unsigned long flags;
|
|
struct clk_core *old_parent = clk->parent;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (clk->prepare_count) {
|
|
clk_core_prepare(parent);
|
|
clk_core_enable(parent);
|
|
clk_core_enable(clk);
|
|
}
|
|
|
|
/* update the clk tree topology */
|
|
flags = clk_enable_lock();
|
|
clk_reparent(clk, 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(core);
|
|
clk_core_disable(old_parent);
|
|
clk_core_unprepare(old_parent);
|
|
}
|
|
}
|
|
|
|
static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
|
|
u8 p_index)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
struct clk_core *old_parent;
|
|
|
|
old_parent = __clk_set_parent_before(clk, parent);
|
|
|
|
/* change clock input source */
|
|
if (parent && clk->ops->set_parent)
|
|
ret = clk->ops->set_parent(clk->hw, p_index);
|
|
|
|
if (ret) {
|
|
flags = clk_enable_lock();
|
|
clk_reparent(clk, old_parent);
|
|
clk_enable_unlock(flags);
|
|
|
|
if (clk->prepare_count) {
|
|
clk_core_disable(clk);
|
|
clk_core_disable(parent);
|
|
clk_core_unprepare(parent);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
__clk_set_parent_after(clk, parent, old_parent);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __clk_speculate_rates
|
|
* @clk: 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.
|
|
*
|
|
* Caller must hold prepare_lock.
|
|
*/
|
|
static int __clk_speculate_rates(struct clk_core *clk,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct clk_core *child;
|
|
unsigned long new_rate;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
new_rate = clk_recalc(clk, parent_rate);
|
|
|
|
/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
|
|
if (clk->notifier_count)
|
|
ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
|
|
|
|
if (ret & NOTIFY_STOP_MASK) {
|
|
pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
|
|
__func__, clk->name, ret);
|
|
goto out;
|
|
}
|
|
|
|
hlist_for_each_entry(child, &clk->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 *clk, unsigned long new_rate,
|
|
struct clk_core *new_parent, u8 p_index)
|
|
{
|
|
struct clk_core *child;
|
|
|
|
clk->new_rate = new_rate;
|
|
clk->new_parent = new_parent;
|
|
clk->new_parent_index = p_index;
|
|
/* include clk in new parent's PRE_RATE_CHANGE notifications */
|
|
clk->new_child = NULL;
|
|
if (new_parent && new_parent != clk->parent)
|
|
new_parent->new_child = clk;
|
|
|
|
hlist_for_each_entry(child, &clk->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 *clk,
|
|
unsigned long rate)
|
|
{
|
|
struct clk_core *top = clk;
|
|
struct clk_core *old_parent, *parent;
|
|
struct clk_hw *parent_hw;
|
|
unsigned long best_parent_rate = 0;
|
|
unsigned long new_rate;
|
|
unsigned long min_rate;
|
|
unsigned long max_rate;
|
|
int p_index = 0;
|
|
|
|
/* sanity */
|
|
if (IS_ERR_OR_NULL(clk))
|
|
return NULL;
|
|
|
|
/* save parent rate, if it exists */
|
|
parent = old_parent = clk->parent;
|
|
if (parent)
|
|
best_parent_rate = parent->rate;
|
|
|
|
clk_core_get_boundaries(clk, &min_rate, &max_rate);
|
|
|
|
/* find the closest rate and parent clk/rate */
|
|
if (clk->ops->determine_rate) {
|
|
parent_hw = parent ? parent->hw : NULL;
|
|
new_rate = clk->ops->determine_rate(clk->hw, rate,
|
|
min_rate,
|
|
max_rate,
|
|
&best_parent_rate,
|
|
&parent_hw);
|
|
parent = parent_hw ? parent_hw->core : NULL;
|
|
} else if (clk->ops->round_rate) {
|
|
new_rate = clk->ops->round_rate(clk->hw, rate,
|
|
&best_parent_rate);
|
|
if (new_rate < min_rate || new_rate > max_rate)
|
|
return NULL;
|
|
} else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
|
|
/* pass-through clock without adjustable parent */
|
|
clk->new_rate = clk->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 &&
|
|
(clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
|
|
pr_debug("%s: %s not gated but wants to reparent\n",
|
|
__func__, clk->name);
|
|
return NULL;
|
|
}
|
|
|
|
/* try finding the new parent index */
|
|
if (parent && clk->num_parents > 1) {
|
|
p_index = clk_fetch_parent_index(clk, parent);
|
|
if (p_index < 0) {
|
|
pr_debug("%s: clk %s can not be parent of clk %s\n",
|
|
__func__, parent->name, clk->name);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
|
|
best_parent_rate != parent->rate)
|
|
top = clk_calc_new_rates(parent, best_parent_rate);
|
|
|
|
out:
|
|
clk_calc_subtree(clk, 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 *clk,
|
|
unsigned long event)
|
|
{
|
|
struct clk_core *child, *tmp_clk, *fail_clk = NULL;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
if (clk->rate == clk->new_rate)
|
|
return NULL;
|
|
|
|
if (clk->notifier_count) {
|
|
ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
fail_clk = clk;
|
|
}
|
|
|
|
hlist_for_each_entry(child, &clk->children, child_node) {
|
|
/* Skip children who will be reparented to another clock */
|
|
if (child->new_parent && child->new_parent != clk)
|
|
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 clk->children yet */
|
|
if (clk->new_child) {
|
|
tmp_clk = clk_propagate_rate_change(clk->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 *clk)
|
|
{
|
|
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;
|
|
|
|
old_rate = clk->rate;
|
|
|
|
if (clk->new_parent)
|
|
best_parent_rate = clk->new_parent->rate;
|
|
else if (clk->parent)
|
|
best_parent_rate = clk->parent->rate;
|
|
|
|
if (clk->new_parent && clk->new_parent != clk->parent) {
|
|
old_parent = __clk_set_parent_before(clk, clk->new_parent);
|
|
|
|
if (clk->ops->set_rate_and_parent) {
|
|
skip_set_rate = true;
|
|
clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
|
|
best_parent_rate,
|
|
clk->new_parent_index);
|
|
} else if (clk->ops->set_parent) {
|
|
clk->ops->set_parent(clk->hw, clk->new_parent_index);
|
|
}
|
|
|
|
__clk_set_parent_after(clk, clk->new_parent, old_parent);
|
|
}
|
|
|
|
if (!skip_set_rate && clk->ops->set_rate)
|
|
clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
|
|
|
|
clk->rate = clk_recalc(clk, best_parent_rate);
|
|
|
|
if (clk->notifier_count && old_rate != clk->rate)
|
|
__clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
|
|
|
|
/*
|
|
* Use safe iteration, as change_rate can actually swap parents
|
|
* for certain clock types.
|
|
*/
|
|
hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) {
|
|
/* Skip children who will be reparented to another clock */
|
|
if (child->new_parent && child->new_parent != clk)
|
|
continue;
|
|
clk_change_rate(child);
|
|
}
|
|
|
|
/* handle the new child who might not be in clk->children yet */
|
|
if (clk->new_child)
|
|
clk_change_rate(clk->new_child);
|
|
}
|
|
|
|
static int clk_core_set_rate_nolock(struct clk_core *clk,
|
|
unsigned long req_rate)
|
|
{
|
|
struct clk_core *top, *fail_clk;
|
|
unsigned long rate = req_rate;
|
|
int ret = 0;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* bail early if nothing to do */
|
|
if (rate == clk_core_get_rate_nolock(clk))
|
|
return 0;
|
|
|
|
if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count)
|
|
return -EBUSY;
|
|
|
|
/* calculate new rates and get the topmost changed clock */
|
|
top = clk_calc_new_rates(clk, rate);
|
|
if (!top)
|
|
return -EINVAL;
|
|
|
|
/* 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);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* change the rates */
|
|
clk_change_rate(top);
|
|
|
|
clk->req_rate = req_rate;
|
|
|
|
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();
|
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate);
|
|
|
|
clk_prepare_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_rate);
|
|
|
|
/**
|
|
* 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;
|
|
|
|
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 (min != clk->min_rate || max != clk->max_rate) {
|
|
clk->min_rate = min;
|
|
clk->max_rate = max;
|
|
ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
|
|
}
|
|
|
|
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;
|
|
|
|
clk_prepare_lock();
|
|
parent = __clk_get_parent(clk);
|
|
clk_prepare_unlock();
|
|
|
|
return parent;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_parent);
|
|
|
|
/*
|
|
* .get_parent is mandatory for clocks with multiple possible parents. It is
|
|
* optional for single-parent clocks. Always call .get_parent if it is
|
|
* available and WARN if it is missing for multi-parent clocks.
|
|
*
|
|
* For single-parent clocks without .get_parent, first check to see if the
|
|
* .parents array exists, and if so use it to avoid an expensive tree
|
|
* traversal. If .parents does not exist then walk the tree.
|
|
*/
|
|
static struct clk_core *__clk_init_parent(struct clk_core *clk)
|
|
{
|
|
struct clk_core *ret = NULL;
|
|
u8 index;
|
|
|
|
/* handle the trivial cases */
|
|
|
|
if (!clk->num_parents)
|
|
goto out;
|
|
|
|
if (clk->num_parents == 1) {
|
|
if (IS_ERR_OR_NULL(clk->parent))
|
|
clk->parent = clk_core_lookup(clk->parent_names[0]);
|
|
ret = clk->parent;
|
|
goto out;
|
|
}
|
|
|
|
if (!clk->ops->get_parent) {
|
|
WARN(!clk->ops->get_parent,
|
|
"%s: multi-parent clocks must implement .get_parent\n",
|
|
__func__);
|
|
goto out;
|
|
};
|
|
|
|
/*
|
|
* Do our best to cache parent clocks in clk->parents. This prevents
|
|
* unnecessary and expensive lookups. We don't set clk->parent here;
|
|
* that is done by the calling function.
|
|
*/
|
|
|
|
index = clk->ops->get_parent(clk->hw);
|
|
|
|
if (!clk->parents)
|
|
clk->parents =
|
|
kcalloc(clk->num_parents, sizeof(struct clk *),
|
|
GFP_KERNEL);
|
|
|
|
ret = clk_core_get_parent_by_index(clk, index);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void clk_core_reparent(struct clk_core *clk,
|
|
struct clk_core *new_parent)
|
|
{
|
|
clk_reparent(clk, new_parent);
|
|
__clk_recalc_accuracies(clk);
|
|
__clk_recalc_rates(clk, POST_RATE_CHANGE);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
unsigned 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->parent_names[i], parent_core->name) == 0)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_has_parent);
|
|
|
|
static int clk_core_set_parent(struct clk_core *clk, struct clk_core *parent)
|
|
{
|
|
int ret = 0;
|
|
int p_index = 0;
|
|
unsigned long p_rate = 0;
|
|
|
|
if (!clk)
|
|
return 0;
|
|
|
|
/* verify ops for for multi-parent clks */
|
|
if ((clk->num_parents > 1) && (!clk->ops->set_parent))
|
|
return -ENOSYS;
|
|
|
|
/* prevent racing with updates to the clock topology */
|
|
clk_prepare_lock();
|
|
|
|
if (clk->parent == parent)
|
|
goto out;
|
|
|
|
/* check that we are allowed to re-parent if the clock is in use */
|
|
if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
/* try finding the new parent index */
|
|
if (parent) {
|
|
p_index = clk_fetch_parent_index(clk, parent);
|
|
p_rate = parent->rate;
|
|
if (p_index < 0) {
|
|
pr_debug("%s: clk %s can not be parent of clk %s\n",
|
|
__func__, parent->name, clk->name);
|
|
ret = p_index;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* propagate PRE_RATE_CHANGE notifications */
|
|
ret = __clk_speculate_rates(clk, p_rate);
|
|
|
|
/* abort if a driver objects */
|
|
if (ret & NOTIFY_STOP_MASK)
|
|
goto out;
|
|
|
|
/* do the re-parent */
|
|
ret = __clk_set_parent(clk, parent, p_index);
|
|
|
|
/* propagate rate an accuracy recalculation accordingly */
|
|
if (ret) {
|
|
__clk_recalc_rates(clk, ABORT_RATE_CHANGE);
|
|
} else {
|
|
__clk_recalc_rates(clk, POST_RATE_CHANGE);
|
|
__clk_recalc_accuracies(clk);
|
|
}
|
|
|
|
out:
|
|
clk_prepare_unlock();
|
|
|
|
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)
|
|
{
|
|
if (!clk)
|
|
return 0;
|
|
|
|
return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_parent);
|
|
|
|
/**
|
|
* 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 = 0;
|
|
|
|
if (!clk)
|
|
goto out;
|
|
|
|
/* sanity check degrees */
|
|
degrees %= 360;
|
|
if (degrees < 0)
|
|
degrees += 360;
|
|
|
|
clk_prepare_lock();
|
|
|
|
if (!clk->core->ops->set_phase)
|
|
goto out_unlock;
|
|
|
|
ret = clk->core->ops->set_phase(clk->core->hw, degrees);
|
|
|
|
if (!ret)
|
|
clk->core->phase = degrees;
|
|
|
|
out_unlock:
|
|
clk_prepare_unlock();
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_set_phase);
|
|
|
|
static int clk_core_get_phase(struct clk_core *clk)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!clk)
|
|
goto out;
|
|
|
|
clk_prepare_lock();
|
|
ret = clk->phase;
|
|
clk_prepare_unlock();
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_get_phase);
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
/**
|
|
* 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 derefing 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);
|
|
|
|
/**
|
|
* __clk_init - initialize the data structures in a struct clk
|
|
* @dev: device initializing this clk, placeholder for now
|
|
* @clk: clk being initialized
|
|
*
|
|
* Initializes the lists in struct clk_core, queries the hardware for the
|
|
* parent and rate and sets them both.
|
|
*/
|
|
static int __clk_init(struct device *dev, struct clk *clk_user)
|
|
{
|
|
int i, ret = 0;
|
|
struct clk_core *orphan;
|
|
struct hlist_node *tmp2;
|
|
struct clk_core *clk;
|
|
unsigned long rate;
|
|
|
|
if (!clk_user)
|
|
return -EINVAL;
|
|
|
|
clk = clk_user->core;
|
|
|
|
clk_prepare_lock();
|
|
|
|
/* check to see if a clock with this name is already registered */
|
|
if (clk_core_lookup(clk->name)) {
|
|
pr_debug("%s: clk %s already initialized\n",
|
|
__func__, clk->name);
|
|
ret = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
/* check that clk_ops are sane. See Documentation/clk.txt */
|
|
if (clk->ops->set_rate &&
|
|
!((clk->ops->round_rate || clk->ops->determine_rate) &&
|
|
clk->ops->recalc_rate)) {
|
|
pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
|
|
__func__, clk->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (clk->ops->set_parent && !clk->ops->get_parent) {
|
|
pr_warning("%s: %s must implement .get_parent & .set_parent\n",
|
|
__func__, clk->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (clk->ops->set_rate_and_parent &&
|
|
!(clk->ops->set_parent && clk->ops->set_rate)) {
|
|
pr_warn("%s: %s must implement .set_parent & .set_rate\n",
|
|
__func__, clk->name);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* throw a WARN if any entries in parent_names are NULL */
|
|
for (i = 0; i < clk->num_parents; i++)
|
|
WARN(!clk->parent_names[i],
|
|
"%s: invalid NULL in %s's .parent_names\n",
|
|
__func__, clk->name);
|
|
|
|
/*
|
|
* Allocate an array of struct clk *'s to avoid unnecessary string
|
|
* look-ups of clk's possible parents. This can fail for clocks passed
|
|
* in to clk_init during early boot; thus any access to clk->parents[]
|
|
* must always check for a NULL pointer and try to populate it if
|
|
* necessary.
|
|
*
|
|
* If clk->parents is not NULL we skip this entire block. This allows
|
|
* for clock drivers to statically initialize clk->parents.
|
|
*/
|
|
if (clk->num_parents > 1 && !clk->parents) {
|
|
clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
|
|
GFP_KERNEL);
|
|
/*
|
|
* clk_core_lookup returns NULL for parents that have not been
|
|
* clk_init'd; thus any access to clk->parents[] must check
|
|
* for a NULL pointer. We can always perform lazy lookups for
|
|
* missing parents later on.
|
|
*/
|
|
if (clk->parents)
|
|
for (i = 0; i < clk->num_parents; i++)
|
|
clk->parents[i] =
|
|
clk_core_lookup(clk->parent_names[i]);
|
|
}
|
|
|
|
clk->parent = __clk_init_parent(clk);
|
|
|
|
/*
|
|
* Populate clk->parent if parent has already been __clk_init'd. If
|
|
* parent has not yet been __clk_init'd then place clk in the orphan
|
|
* list. If clk has set the CLK_IS_ROOT flag 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 (clk->parent)
|
|
hlist_add_head(&clk->child_node,
|
|
&clk->parent->children);
|
|
else if (clk->flags & CLK_IS_ROOT)
|
|
hlist_add_head(&clk->child_node, &clk_root_list);
|
|
else
|
|
hlist_add_head(&clk->child_node, &clk_orphan_list);
|
|
|
|
/*
|
|
* 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 (clk->ops->recalc_accuracy)
|
|
clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
|
|
__clk_get_accuracy(clk->parent));
|
|
else if (clk->parent)
|
|
clk->accuracy = clk->parent->accuracy;
|
|
else
|
|
clk->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 (clk->ops->get_phase)
|
|
clk->phase = clk->ops->get_phase(clk->hw);
|
|
else
|
|
clk->phase = 0;
|
|
|
|
/*
|
|
* 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 (clk->ops->recalc_rate)
|
|
rate = clk->ops->recalc_rate(clk->hw,
|
|
clk_core_get_rate_nolock(clk->parent));
|
|
else if (clk->parent)
|
|
rate = clk->parent->rate;
|
|
else
|
|
rate = 0;
|
|
clk->rate = clk->req_rate = rate;
|
|
|
|
/*
|
|
* walk the list of orphan clocks and reparent any that are children of
|
|
* this clock
|
|
*/
|
|
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
|
|
if (orphan->num_parents && orphan->ops->get_parent) {
|
|
i = orphan->ops->get_parent(orphan->hw);
|
|
if (!strcmp(clk->name, orphan->parent_names[i]))
|
|
clk_core_reparent(orphan, clk);
|
|
continue;
|
|
}
|
|
|
|
for (i = 0; i < orphan->num_parents; i++)
|
|
if (!strcmp(clk->name, orphan->parent_names[i])) {
|
|
clk_core_reparent(orphan, clk);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 (clk->ops->init)
|
|
clk->ops->init(clk->hw);
|
|
|
|
kref_init(&clk->ref);
|
|
out:
|
|
clk_prepare_unlock();
|
|
|
|
if (!ret)
|
|
clk_debug_register(clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
|
|
const char *con_id)
|
|
{
|
|
struct clk *clk;
|
|
|
|
/* This is to allow this function to be chained to others */
|
|
if (!hw || IS_ERR(hw))
|
|
return (struct clk *) hw;
|
|
|
|
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
|
|
if (!clk)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
clk->core = hw->core;
|
|
clk->dev_id = dev_id;
|
|
clk->con_id = con_id;
|
|
clk->max_rate = ULONG_MAX;
|
|
|
|
clk_prepare_lock();
|
|
hlist_add_head(&clk->child_node, &hw->core->clks);
|
|
clk_prepare_unlock();
|
|
|
|
return clk;
|
|
}
|
|
|
|
void __clk_free_clk(struct clk *clk)
|
|
{
|
|
clk_prepare_lock();
|
|
hlist_del(&clk->child_node);
|
|
clk_prepare_unlock();
|
|
|
|
kfree(clk);
|
|
}
|
|
|
|
/**
|
|
* 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 primary interface for populating the clock tree with new
|
|
* clock nodes. It returns a pointer to the newly allocated struct clk which
|
|
* cannot be dereferenced by driver code but may be used in conjuction 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)
|
|
{
|
|
int i, ret;
|
|
struct clk_core *clk;
|
|
|
|
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
|
|
if (!clk) {
|
|
pr_err("%s: could not allocate clk\n", __func__);
|
|
ret = -ENOMEM;
|
|
goto fail_out;
|
|
}
|
|
|
|
clk->name = kstrdup_const(hw->init->name, GFP_KERNEL);
|
|
if (!clk->name) {
|
|
pr_err("%s: could not allocate clk->name\n", __func__);
|
|
ret = -ENOMEM;
|
|
goto fail_name;
|
|
}
|
|
clk->ops = hw->init->ops;
|
|
if (dev && dev->driver)
|
|
clk->owner = dev->driver->owner;
|
|
clk->hw = hw;
|
|
clk->flags = hw->init->flags;
|
|
clk->num_parents = hw->init->num_parents;
|
|
hw->core = clk;
|
|
|
|
/* allocate local copy in case parent_names is __initdata */
|
|
clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
|
|
GFP_KERNEL);
|
|
|
|
if (!clk->parent_names) {
|
|
pr_err("%s: could not allocate clk->parent_names\n", __func__);
|
|
ret = -ENOMEM;
|
|
goto fail_parent_names;
|
|
}
|
|
|
|
|
|
/* copy each string name in case parent_names is __initdata */
|
|
for (i = 0; i < clk->num_parents; i++) {
|
|
clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
|
|
GFP_KERNEL);
|
|
if (!clk->parent_names[i]) {
|
|
pr_err("%s: could not copy parent_names\n", __func__);
|
|
ret = -ENOMEM;
|
|
goto fail_parent_names_copy;
|
|
}
|
|
}
|
|
|
|
INIT_HLIST_HEAD(&clk->clks);
|
|
|
|
hw->clk = __clk_create_clk(hw, NULL, NULL);
|
|
if (IS_ERR(hw->clk)) {
|
|
pr_err("%s: could not allocate per-user clk\n", __func__);
|
|
ret = PTR_ERR(hw->clk);
|
|
goto fail_parent_names_copy;
|
|
}
|
|
|
|
ret = __clk_init(dev, hw->clk);
|
|
if (!ret)
|
|
return hw->clk;
|
|
|
|
__clk_free_clk(hw->clk);
|
|
hw->clk = NULL;
|
|
|
|
fail_parent_names_copy:
|
|
while (--i >= 0)
|
|
kfree_const(clk->parent_names[i]);
|
|
kfree(clk->parent_names);
|
|
fail_parent_names:
|
|
kfree_const(clk->name);
|
|
fail_name:
|
|
kfree(clk);
|
|
fail_out:
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_register);
|
|
|
|
/*
|
|
* Free memory allocated for a clock.
|
|
* Caller must hold prepare_lock.
|
|
*/
|
|
static void __clk_release(struct kref *ref)
|
|
{
|
|
struct clk_core *clk = container_of(ref, struct clk_core, ref);
|
|
int i = clk->num_parents;
|
|
|
|
kfree(clk->parents);
|
|
while (--i >= 0)
|
|
kfree_const(clk->parent_names[i]);
|
|
|
|
kfree(clk->parent_names);
|
|
kfree_const(clk->name);
|
|
kfree(clk);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
return;
|
|
}
|
|
/*
|
|
* 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(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);
|
|
kref_put(&clk->core->ref, __clk_release);
|
|
|
|
clk_prepare_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(clk_unregister);
|
|
|
|
static void devm_clk_release(struct device *dev, void *res)
|
|
{
|
|
clk_unregister(*(struct clk **)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(). 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);
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
|
|
/*
|
|
* clkdev helpers
|
|
*/
|
|
int __clk_get(struct clk *clk)
|
|
{
|
|
struct clk_core *core = !clk ? NULL : clk->core;
|
|
|
|
if (core) {
|
|
if (!try_module_get(core->owner))
|
|
return 0;
|
|
|
|
kref_get(&core->ref);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void __clk_put(struct clk *clk)
|
|
{
|
|
struct module *owner;
|
|
|
|
if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
|
|
return;
|
|
|
|
clk_prepare_lock();
|
|
|
|
hlist_del(&clk->child_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);
|
|
|
|
kfree(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 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(struct clk_notifier), 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);
|
|
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);
|
|
|
|
/* of_clk_provider list locking helpers */
|
|
void of_clk_lock(void)
|
|
{
|
|
mutex_lock(&of_clk_mutex);
|
|
}
|
|
|
|
void of_clk_unlock(void)
|
|
{
|
|
mutex_unlock(&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 *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 %d\n", __func__, idx);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return clk_data->clks[idx];
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_src_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.
|
|
*/
|
|
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(struct of_clk_provider), 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 %s\n", np->full_name);
|
|
|
|
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_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);
|
|
|
|
struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
|
|
const char *dev_id, const char *con_id)
|
|
{
|
|
struct of_clk_provider *provider;
|
|
struct clk *clk = ERR_PTR(-EPROBE_DEFER);
|
|
|
|
/* Check if we have such a provider in our array */
|
|
list_for_each_entry(provider, &of_clk_providers, link) {
|
|
if (provider->node == clkspec->np)
|
|
clk = provider->get(clkspec, provider->data);
|
|
if (!IS_ERR(clk)) {
|
|
clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
|
|
con_id);
|
|
|
|
if (!IS_ERR(clk) && !__clk_get(clk)) {
|
|
__clk_free_clk(clk);
|
|
clk = ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
return clk;
|
|
}
|
|
|
|
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
|
|
{
|
|
struct clk *clk;
|
|
|
|
mutex_lock(&of_clk_mutex);
|
|
clk = __of_clk_get_from_provider(clkspec, NULL, __func__);
|
|
mutex_unlock(&of_clk_mutex);
|
|
|
|
return clk;
|
|
}
|
|
|
|
int of_clk_get_parent_count(struct device_node *np)
|
|
{
|
|
return of_count_phandle_with_args(np, "clocks", "#clock-cells");
|
|
}
|
|
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;
|
|
|
|
if (index < 0)
|
|
return NULL;
|
|
|
|
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++;
|
|
}
|
|
|
|
if (of_property_read_string_index(clkspec.np, "clock-output-names",
|
|
index,
|
|
&clk_name) < 0)
|
|
clk_name = clkspec.np->name;
|
|
|
|
of_node_put(clkspec.np);
|
|
return clk_name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
|
|
|
|
struct clock_provider {
|
|
of_clk_init_cb_t clk_init_cb;
|
|
struct device_node *np;
|
|
struct list_head node;
|
|
};
|
|
|
|
static LIST_HEAD(clk_provider_list);
|
|
|
|
/*
|
|
* 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_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;
|
|
|
|
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 =
|
|
kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
|
|
|
|
parent->clk_init_cb = match->data;
|
|
parent->np = 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)) {
|
|
|
|
clk_provider->clk_init_cb(clk_provider->np);
|
|
of_clk_set_defaults(clk_provider->np, true);
|
|
|
|
list_del(&clk_provider->node);
|
|
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
|