![Adrian Hunter](/assets/img/avatar_default.png)
Most parts of the enable / disable API are no longer used and can be removed. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Venkatraman S <svenkatr@ti.com> Tested-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Chris Ball <cjb@laptop.org>
433 lines
11 KiB
C
433 lines
11 KiB
C
/*
|
|
* linux/drivers/mmc/core/host.c
|
|
*
|
|
* Copyright (C) 2003 Russell King, All Rights Reserved.
|
|
* Copyright (C) 2007-2008 Pierre Ossman
|
|
* Copyright (C) 2010 Linus Walleij
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* MMC host class device management
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/export.h>
|
|
#include <linux/leds.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/suspend.h>
|
|
|
|
#include <linux/mmc/host.h>
|
|
#include <linux/mmc/card.h>
|
|
|
|
#include "core.h"
|
|
#include "host.h"
|
|
|
|
#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
|
|
|
|
static void mmc_host_classdev_release(struct device *dev)
|
|
{
|
|
struct mmc_host *host = cls_dev_to_mmc_host(dev);
|
|
kfree(host);
|
|
}
|
|
|
|
static struct class mmc_host_class = {
|
|
.name = "mmc_host",
|
|
.dev_release = mmc_host_classdev_release,
|
|
};
|
|
|
|
int mmc_register_host_class(void)
|
|
{
|
|
return class_register(&mmc_host_class);
|
|
}
|
|
|
|
void mmc_unregister_host_class(void)
|
|
{
|
|
class_unregister(&mmc_host_class);
|
|
}
|
|
|
|
static DEFINE_IDR(mmc_host_idr);
|
|
static DEFINE_SPINLOCK(mmc_host_lock);
|
|
|
|
#ifdef CONFIG_MMC_CLKGATE
|
|
static ssize_t clkgate_delay_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct mmc_host *host = cls_dev_to_mmc_host(dev);
|
|
return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
|
|
}
|
|
|
|
static ssize_t clkgate_delay_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
struct mmc_host *host = cls_dev_to_mmc_host(dev);
|
|
unsigned long flags, value;
|
|
|
|
if (kstrtoul(buf, 0, &value))
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
host->clkgate_delay = value;
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* Enabling clock gating will make the core call out to the host
|
|
* once up and once down when it performs a request or card operation
|
|
* intermingled in any fashion. The driver will see this through
|
|
* set_ios() operations with ios.clock field set to 0 to gate (disable)
|
|
* the block clock, and to the old frequency to enable it again.
|
|
*/
|
|
static void mmc_host_clk_gate_delayed(struct mmc_host *host)
|
|
{
|
|
unsigned long tick_ns;
|
|
unsigned long freq = host->ios.clock;
|
|
unsigned long flags;
|
|
|
|
if (!freq) {
|
|
pr_debug("%s: frequency set to 0 in disable function, "
|
|
"this means the clock is already disabled.\n",
|
|
mmc_hostname(host));
|
|
return;
|
|
}
|
|
/*
|
|
* New requests may have appeared while we were scheduling,
|
|
* then there is no reason to delay the check before
|
|
* clk_disable().
|
|
*/
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
|
|
/*
|
|
* Delay n bus cycles (at least 8 from MMC spec) before attempting
|
|
* to disable the MCI block clock. The reference count may have
|
|
* gone up again after this delay due to rescheduling!
|
|
*/
|
|
if (!host->clk_requests) {
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
tick_ns = DIV_ROUND_UP(1000000000, freq);
|
|
ndelay(host->clk_delay * tick_ns);
|
|
} else {
|
|
/* New users appeared while waiting for this work */
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
return;
|
|
}
|
|
mutex_lock(&host->clk_gate_mutex);
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
if (!host->clk_requests) {
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
/* This will set host->ios.clock to 0 */
|
|
mmc_gate_clock(host);
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
|
|
}
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
mutex_unlock(&host->clk_gate_mutex);
|
|
}
|
|
|
|
/*
|
|
* Internal work. Work to disable the clock at some later point.
|
|
*/
|
|
static void mmc_host_clk_gate_work(struct work_struct *work)
|
|
{
|
|
struct mmc_host *host = container_of(work, struct mmc_host,
|
|
clk_gate_work.work);
|
|
|
|
mmc_host_clk_gate_delayed(host);
|
|
}
|
|
|
|
/**
|
|
* mmc_host_clk_hold - ungate hardware MCI clocks
|
|
* @host: host to ungate.
|
|
*
|
|
* Makes sure the host ios.clock is restored to a non-zero value
|
|
* past this call. Increase clock reference count and ungate clock
|
|
* if we're the first user.
|
|
*/
|
|
void mmc_host_clk_hold(struct mmc_host *host)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* cancel any clock gating work scheduled by mmc_host_clk_release() */
|
|
cancel_delayed_work_sync(&host->clk_gate_work);
|
|
mutex_lock(&host->clk_gate_mutex);
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
if (host->clk_gated) {
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
mmc_ungate_clock(host);
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
|
|
}
|
|
host->clk_requests++;
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
mutex_unlock(&host->clk_gate_mutex);
|
|
}
|
|
|
|
/**
|
|
* mmc_host_may_gate_card - check if this card may be gated
|
|
* @card: card to check.
|
|
*/
|
|
static bool mmc_host_may_gate_card(struct mmc_card *card)
|
|
{
|
|
/* If there is no card we may gate it */
|
|
if (!card)
|
|
return true;
|
|
/*
|
|
* Don't gate SDIO cards! These need to be clocked at all times
|
|
* since they may be independent systems generating interrupts
|
|
* and other events. The clock requests counter from the core will
|
|
* go down to zero since the core does not need it, but we will not
|
|
* gate the clock, because there is somebody out there that may still
|
|
* be using it.
|
|
*/
|
|
return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
|
|
}
|
|
|
|
/**
|
|
* mmc_host_clk_release - gate off hardware MCI clocks
|
|
* @host: host to gate.
|
|
*
|
|
* Calls the host driver with ios.clock set to zero as often as possible
|
|
* in order to gate off hardware MCI clocks. Decrease clock reference
|
|
* count and schedule disabling of clock.
|
|
*/
|
|
void mmc_host_clk_release(struct mmc_host *host)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
host->clk_requests--;
|
|
if (mmc_host_may_gate_card(host->card) &&
|
|
!host->clk_requests)
|
|
queue_delayed_work(system_nrt_wq, &host->clk_gate_work,
|
|
msecs_to_jiffies(host->clkgate_delay));
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
}
|
|
|
|
/**
|
|
* mmc_host_clk_rate - get current clock frequency setting
|
|
* @host: host to get the clock frequency for.
|
|
*
|
|
* Returns current clock frequency regardless of gating.
|
|
*/
|
|
unsigned int mmc_host_clk_rate(struct mmc_host *host)
|
|
{
|
|
unsigned long freq;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&host->clk_lock, flags);
|
|
if (host->clk_gated)
|
|
freq = host->clk_old;
|
|
else
|
|
freq = host->ios.clock;
|
|
spin_unlock_irqrestore(&host->clk_lock, flags);
|
|
return freq;
|
|
}
|
|
|
|
/**
|
|
* mmc_host_clk_init - set up clock gating code
|
|
* @host: host with potential clock to control
|
|
*/
|
|
static inline void mmc_host_clk_init(struct mmc_host *host)
|
|
{
|
|
host->clk_requests = 0;
|
|
/* Hold MCI clock for 8 cycles by default */
|
|
host->clk_delay = 8;
|
|
/*
|
|
* Default clock gating delay is 0ms to avoid wasting power.
|
|
* This value can be tuned by writing into sysfs entry.
|
|
*/
|
|
host->clkgate_delay = 0;
|
|
host->clk_gated = false;
|
|
INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
|
|
spin_lock_init(&host->clk_lock);
|
|
mutex_init(&host->clk_gate_mutex);
|
|
}
|
|
|
|
/**
|
|
* mmc_host_clk_exit - shut down clock gating code
|
|
* @host: host with potential clock to control
|
|
*/
|
|
static inline void mmc_host_clk_exit(struct mmc_host *host)
|
|
{
|
|
/*
|
|
* Wait for any outstanding gate and then make sure we're
|
|
* ungated before exiting.
|
|
*/
|
|
if (cancel_delayed_work_sync(&host->clk_gate_work))
|
|
mmc_host_clk_gate_delayed(host);
|
|
if (host->clk_gated)
|
|
mmc_host_clk_hold(host);
|
|
/* There should be only one user now */
|
|
WARN_ON(host->clk_requests > 1);
|
|
}
|
|
|
|
static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
|
|
{
|
|
host->clkgate_delay_attr.show = clkgate_delay_show;
|
|
host->clkgate_delay_attr.store = clkgate_delay_store;
|
|
sysfs_attr_init(&host->clkgate_delay_attr.attr);
|
|
host->clkgate_delay_attr.attr.name = "clkgate_delay";
|
|
host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
|
|
if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
|
|
pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
|
|
mmc_hostname(host));
|
|
}
|
|
#else
|
|
|
|
static inline void mmc_host_clk_init(struct mmc_host *host)
|
|
{
|
|
}
|
|
|
|
static inline void mmc_host_clk_exit(struct mmc_host *host)
|
|
{
|
|
}
|
|
|
|
static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
* mmc_alloc_host - initialise the per-host structure.
|
|
* @extra: sizeof private data structure
|
|
* @dev: pointer to host device model structure
|
|
*
|
|
* Initialise the per-host structure.
|
|
*/
|
|
struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
|
|
{
|
|
int err;
|
|
struct mmc_host *host;
|
|
|
|
if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
|
|
return NULL;
|
|
|
|
host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
|
|
if (!host)
|
|
return NULL;
|
|
|
|
spin_lock(&mmc_host_lock);
|
|
err = idr_get_new(&mmc_host_idr, host, &host->index);
|
|
spin_unlock(&mmc_host_lock);
|
|
if (err)
|
|
goto free;
|
|
|
|
dev_set_name(&host->class_dev, "mmc%d", host->index);
|
|
|
|
host->parent = dev;
|
|
host->class_dev.parent = dev;
|
|
host->class_dev.class = &mmc_host_class;
|
|
device_initialize(&host->class_dev);
|
|
|
|
mmc_host_clk_init(host);
|
|
|
|
spin_lock_init(&host->lock);
|
|
init_waitqueue_head(&host->wq);
|
|
INIT_DELAYED_WORK(&host->detect, mmc_rescan);
|
|
#ifdef CONFIG_PM
|
|
host->pm_notify.notifier_call = mmc_pm_notify;
|
|
#endif
|
|
|
|
/*
|
|
* By default, hosts do not support SGIO or large requests.
|
|
* They have to set these according to their abilities.
|
|
*/
|
|
host->max_segs = 1;
|
|
host->max_seg_size = PAGE_CACHE_SIZE;
|
|
|
|
host->max_req_size = PAGE_CACHE_SIZE;
|
|
host->max_blk_size = 512;
|
|
host->max_blk_count = PAGE_CACHE_SIZE / 512;
|
|
|
|
return host;
|
|
|
|
free:
|
|
kfree(host);
|
|
return NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL(mmc_alloc_host);
|
|
|
|
/**
|
|
* mmc_add_host - initialise host hardware
|
|
* @host: mmc host
|
|
*
|
|
* Register the host with the driver model. The host must be
|
|
* prepared to start servicing requests before this function
|
|
* completes.
|
|
*/
|
|
int mmc_add_host(struct mmc_host *host)
|
|
{
|
|
int err;
|
|
|
|
WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
|
|
!host->ops->enable_sdio_irq);
|
|
|
|
err = device_add(&host->class_dev);
|
|
if (err)
|
|
return err;
|
|
|
|
led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
mmc_add_host_debugfs(host);
|
|
#endif
|
|
mmc_host_clk_sysfs_init(host);
|
|
|
|
mmc_start_host(host);
|
|
register_pm_notifier(&host->pm_notify);
|
|
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(mmc_add_host);
|
|
|
|
/**
|
|
* mmc_remove_host - remove host hardware
|
|
* @host: mmc host
|
|
*
|
|
* Unregister and remove all cards associated with this host,
|
|
* and power down the MMC bus. No new requests will be issued
|
|
* after this function has returned.
|
|
*/
|
|
void mmc_remove_host(struct mmc_host *host)
|
|
{
|
|
unregister_pm_notifier(&host->pm_notify);
|
|
mmc_stop_host(host);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
mmc_remove_host_debugfs(host);
|
|
#endif
|
|
|
|
device_del(&host->class_dev);
|
|
|
|
led_trigger_unregister_simple(host->led);
|
|
|
|
mmc_host_clk_exit(host);
|
|
}
|
|
|
|
EXPORT_SYMBOL(mmc_remove_host);
|
|
|
|
/**
|
|
* mmc_free_host - free the host structure
|
|
* @host: mmc host
|
|
*
|
|
* Free the host once all references to it have been dropped.
|
|
*/
|
|
void mmc_free_host(struct mmc_host *host)
|
|
{
|
|
spin_lock(&mmc_host_lock);
|
|
idr_remove(&mmc_host_idr, host->index);
|
|
spin_unlock(&mmc_host_lock);
|
|
|
|
put_device(&host->class_dev);
|
|
}
|
|
|
|
EXPORT_SYMBOL(mmc_free_host);
|