blob: c7fa876c351be18ee664d7faeb355f2f380c3dcd [file] [log] [blame]
/*
* 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
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* 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/pm_runtime.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->wlock_name);
kfree(host);
}
static int mmc_host_runtime_suspend(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int ret = 0;
if (!mmc_use_core_runtime_pm(host))
return 0;
ret = mmc_suspend_host(host);
if (ret < 0)
pr_err("%s: %s: suspend host failed: %d\n", mmc_hostname(host),
__func__, ret);
return ret;
}
static int mmc_host_runtime_resume(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int ret = 0;
if (!mmc_use_core_runtime_pm(host))
return 0;
ret = mmc_resume_host(host);
if (ret < 0) {
pr_err("%s: %s: resume host: failed: ret: %d\n",
mmc_hostname(host), __func__, ret);
if (pm_runtime_suspended(dev))
BUG_ON(1);
}
return ret;
}
static int mmc_host_suspend(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int ret = 0;
if (!mmc_use_core_pm(host))
return 0;
if (!pm_runtime_suspended(dev)) {
ret = mmc_suspend_host(host);
if (ret < 0)
pr_err("%s: %s: failed: ret: %d\n", mmc_hostname(host),
__func__, ret);
}
return ret;
}
static int mmc_host_resume(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int ret = 0;
if (!mmc_use_core_pm(host))
return 0;
if (!pm_runtime_suspended(dev)) {
ret = mmc_resume_host(host);
if (ret < 0)
pr_err("%s: %s: failed: ret: %d\n", mmc_hostname(host),
__func__, ret);
}
return ret;
}
static const struct dev_pm_ops mmc_host_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(mmc_host_suspend, mmc_host_resume)
SET_RUNTIME_PM_OPS(mmc_host_runtime_suspend, mmc_host_runtime_resume,
pm_generic_runtime_idle)
};
static struct class mmc_host_class = {
.name = "mmc_host",
.dev_release = mmc_host_classdev_release,
.pm = &mmc_host_pm_ops,
};
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);
/* Reset clock scaling stats as host is out of idle */
mmc_reset_clk_scale_stats(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.
*/
bool mmc_host_may_gate_card(struct mmc_card *card)
{
/* If there is no card we may gate it */
if (!card)
return true;
/*
* SDIO3.0 card allows the clock to be gated off so check if
* that is the case or not.
*/
if (mmc_card_sdio(card) && card->cccr.async_intr_sup)
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);
host->wlock_name = kasprintf(GFP_KERNEL,
"%s_detect", mmc_hostname(host));
wake_lock_init(&host->detect_wake_lock, WAKE_LOCK_SUSPEND,
host->wlock_name);
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);
static ssize_t show_enable(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
if (!host)
return -EINVAL;
return snprintf(buf, PAGE_SIZE, "%d\n", mmc_can_scale_clk(host));
}
static ssize_t store_enable(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 value, freq;
int retval = -EINVAL;
if (!host)
goto out;
mmc_claim_host(host);
if (!host->card || kstrtoul(buf, 0, &value))
goto err;
if (value && !mmc_can_scale_clk(host)) {
host->caps2 |= MMC_CAP2_CLK_SCALE;
mmc_init_clk_scaling(host);
if (!mmc_can_scale_clk(host)) {
host->caps2 &= ~MMC_CAP2_CLK_SCALE;
goto err;
}
} else if (!value && mmc_can_scale_clk(host)) {
host->caps2 &= ~MMC_CAP2_CLK_SCALE;
mmc_disable_clk_scaling(host);
/* Set to max. frequency, since we are disabling */
if (host->bus_ops && host->bus_ops->change_bus_speed) {
freq = mmc_get_max_frequency(host);
if (host->bus_ops->change_bus_speed(host, &freq))
goto err;
}
if (host->ops->notify_load &&
host->ops->notify_load(host, MMC_LOAD_HIGH))
goto err;
host->clk_scaling.state = MMC_LOAD_HIGH;
host->clk_scaling.initialized = false;
}
retval = count;
err:
mmc_release_host(host);
out:
return retval;
}
static ssize_t show_up_threshold(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
if (!host)
return -EINVAL;
return snprintf(buf, PAGE_SIZE, "%d\n", host->clk_scaling.up_threshold);
}
#define MAX_PERCENTAGE 100
static ssize_t store_up_threshold(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 value;
if (!host || kstrtoul(buf, 0, &value) || (value > MAX_PERCENTAGE))
return -EINVAL;
host->clk_scaling.up_threshold = value;
pr_debug("%s: clkscale_up_thresh set to %lu\n",
mmc_hostname(host), value);
return count;
}
static ssize_t show_down_threshold(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
if (!host)
return -EINVAL;
return snprintf(buf, PAGE_SIZE, "%d\n",
host->clk_scaling.down_threshold);
}
static ssize_t store_down_threshold(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 value;
if (!host || kstrtoul(buf, 0, &value) || (value > MAX_PERCENTAGE))
return -EINVAL;
host->clk_scaling.down_threshold = value;
pr_debug("%s: clkscale_down_thresh set to %lu\n",
mmc_hostname(host), value);
return count;
}
static ssize_t show_polling(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
if (!host)
return -EINVAL;
return snprintf(buf, PAGE_SIZE, "%lu milliseconds\n",
host->clk_scaling.polling_delay_ms);
}
static ssize_t store_polling(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 value;
if (!host || kstrtoul(buf, 0, &value))
return -EINVAL;
host->clk_scaling.polling_delay_ms = value;
pr_debug("%s: clkscale_polling_delay_ms set to %lu\n",
mmc_hostname(host), value);
return count;
}
DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
show_enable, store_enable);
DEVICE_ATTR(polling_interval, S_IRUGO | S_IWUSR,
show_polling, store_polling);
DEVICE_ATTR(up_threshold, S_IRUGO | S_IWUSR,
show_up_threshold, store_up_threshold);
DEVICE_ATTR(down_threshold, S_IRUGO | S_IWUSR,
show_down_threshold, store_down_threshold);
static struct attribute *clk_scaling_attrs[] = {
&dev_attr_enable.attr,
&dev_attr_up_threshold.attr,
&dev_attr_down_threshold.attr,
&dev_attr_polling_interval.attr,
NULL,
};
static struct attribute_group clk_scaling_attr_grp = {
.name = "clk_scaling",
.attrs = clk_scaling_attrs,
};
#ifdef CONFIG_MMC_PERF_PROFILING
static ssize_t
show_perf(struct device *dev, struct device_attribute *attr, char *buf)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int64_t rtime_drv, wtime_drv;
unsigned long rbytes_drv, wbytes_drv;
spin_lock(&host->lock);
rbytes_drv = host->perf.rbytes_drv;
wbytes_drv = host->perf.wbytes_drv;
rtime_drv = ktime_to_us(host->perf.rtime_drv);
wtime_drv = ktime_to_us(host->perf.wtime_drv);
spin_unlock(&host->lock);
return snprintf(buf, PAGE_SIZE, "Write performance at driver Level:"
"%lu bytes in %lld microseconds\n"
"Read performance at driver Level:"
"%lu bytes in %lld microseconds\n",
wbytes_drv, wtime_drv,
rbytes_drv, rtime_drv);
}
static ssize_t
set_perf(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
int64_t value;
sscanf(buf, "%lld", &value);
spin_lock(&host->lock);
if (!value) {
memset(&host->perf, 0, sizeof(host->perf));
host->perf_enable = false;
} else {
host->perf_enable = true;
}
spin_unlock(&host->lock);
return count;
}
static DEVICE_ATTR(perf, S_IRUGO | S_IWUSR,
show_perf, set_perf);
#endif
static struct attribute *dev_attrs[] = {
#ifdef CONFIG_MMC_PERF_PROFILING
&dev_attr_perf.attr,
#endif
NULL,
};
static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
/**
* 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 = pm_runtime_set_active(&host->class_dev);
if (err)
pr_err("%s: %s: failed setting runtime active: err: %d\n",
mmc_hostname(host), __func__, err);
else if (mmc_use_core_runtime_pm(host))
pm_runtime_enable(&host->class_dev);
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);
host->clk_scaling.up_threshold = 35;
host->clk_scaling.down_threshold = 5;
host->clk_scaling.polling_delay_ms = 100;
err = sysfs_create_group(&host->class_dev.kobj, &clk_scaling_attr_grp);
if (err)
pr_err("%s: failed to create clk scale sysfs group with err %d\n",
__func__, err);
err = sysfs_create_group(&host->class_dev.kobj, &dev_attr_grp);
if (err)
pr_err("%s: failed to create sysfs group with err %d\n",
__func__, err);
mmc_start_host(host);
if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
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)
{
if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
unregister_pm_notifier(&host->pm_notify);
mmc_stop_host(host);
#ifdef CONFIG_DEBUG_FS
mmc_remove_host_debugfs(host);
#endif
sysfs_remove_group(&host->parent->kobj, &dev_attr_grp);
sysfs_remove_group(&host->class_dev.kobj, &clk_scaling_attr_grp);
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);
wake_lock_destroy(&host->detect_wake_lock);
put_device(&host->class_dev);
}
EXPORT_SYMBOL(mmc_free_host);