[deliverable/linux.git] / drivers / mmc / core / host.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);
	mutex_destroy(&host->slot.lock);
	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);

	mutex_init(&host->slot.lock);
	host->slot.cd_irq = -EINVAL;

	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);
Commit	Line	Data
b93931a6 PO	1	/*
	2	* linux/drivers/mmc/core/host.c
	3	*
	4	* Copyright (C) 2003 Russell King, All Rights Reserved.
ff3112f5	5	* Copyright (C) 2007-2008 Pierre Ossman
04566831	6	* Copyright (C) 2010 Linus Walleij
b93931a6 PO	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* MMC host class device management
	13	*/
	14
	15	#include <linux/device.h>
	16	#include <linux/err.h>
	17	#include <linux/idr.h>
	18	#include <linux/pagemap.h>
3ef77af1	19	#include <linux/export.h>
af8350c7	20	#include <linux/leds.h>
5a0e3ad6	21	#include <linux/slab.h>
4c2ef25f	22	#include <linux/suspend.h>
b93931a6 PO	23
b93931a6 PO	24	#include <linux/mmc/host.h>
04566831	25	#include <linux/mmc/card.h>
b93931a6 PO	26
	27	#include "core.h"
	28	#include "host.h"
	29
	30	#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
	31
	32	static void mmc_host_classdev_release(struct device *dev)
	33	{
	34	struct mmc_host *host = cls_dev_to_mmc_host(dev);
a7d1a1eb	35	mutex_destroy(&host->slot.lock);
b93931a6 PO	36	kfree(host);
	37	}
	38
	39	static struct class mmc_host_class = {
	40	.name = "mmc_host",
	41	.dev_release = mmc_host_classdev_release,
	42	};
	43
	44	int mmc_register_host_class(void)
	45	{
	46	return class_register(&mmc_host_class);
	47	}
	48
	49	void mmc_unregister_host_class(void)
	50	{
	51	class_unregister(&mmc_host_class);
	52	}
	53
	54	static DEFINE_IDR(mmc_host_idr);
	55	static DEFINE_SPINLOCK(mmc_host_lock);
	56
04566831	57	#ifdef CONFIG_MMC_CLKGATE
597dd9d7 SRT	58	static ssize_t clkgate_delay_show(struct device *dev,
	59	struct device_attribute attr, char buf)
	60	{
	61	struct mmc_host *host = cls_dev_to_mmc_host(dev);
4137e504	62	return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
597dd9d7 SRT	63	}
	64
	65	static ssize_t clkgate_delay_store(struct device *dev,
	66	struct device_attribute attr, const char buf, size_t count)
	67	{
	68	struct mmc_host *host = cls_dev_to_mmc_host(dev);
	69	unsigned long flags, value;
	70
	71	if (kstrtoul(buf, 0, &value))
	72	return -EINVAL;
	73
	74	spin_lock_irqsave(&host->clk_lock, flags);
	75	host->clkgate_delay = value;
	76	spin_unlock_irqrestore(&host->clk_lock, flags);
597dd9d7 SRT	77	return count;
597dd9d7 SRT	78	}
04566831 LW	79
	80	/*
	81	* Enabling clock gating will make the core call out to the host
	82	* once up and once down when it performs a request or card operation
	83	* intermingled in any fashion. The driver will see this through
	84	* set_ios() operations with ios.clock field set to 0 to gate (disable)
	85	* the block clock, and to the old frequency to enable it again.
	86	*/
	87	static void mmc_host_clk_gate_delayed(struct mmc_host *host)
	88	{
	89	unsigned long tick_ns;
	90	unsigned long freq = host->ios.clock;
	91	unsigned long flags;
	92
	93	if (!freq) {
	94	pr_debug("%s: frequency set to 0 in disable function, "
	95	"this means the clock is already disabled.\n",
	96	mmc_hostname(host));
	97	return;
	98	}
	99	/*
	100	* New requests may have appeared while we were scheduling,
	101	* then there is no reason to delay the check before
	102	* clk_disable().
	103	*/
	104	spin_lock_irqsave(&host->clk_lock, flags);
	105
	106	/*
	107	* Delay n bus cycles (at least 8 from MMC spec) before attempting
	108	* to disable the MCI block clock. The reference count may have
	109	* gone up again after this delay due to rescheduling!
	110	*/
	111	if (!host->clk_requests) {
	112	spin_unlock_irqrestore(&host->clk_lock, flags);
	113	tick_ns = DIV_ROUND_UP(1000000000, freq);
	114	ndelay(host->clk_delay * tick_ns);
	115	} else {
	116	/* New users appeared while waiting for this work */
	117	spin_unlock_irqrestore(&host->clk_lock, flags);
	118	return;
	119	}
86f315bb	120	mutex_lock(&host->clk_gate_mutex);
04566831 LW	121	spin_lock_irqsave(&host->clk_lock, flags);
	122	if (!host->clk_requests) {
	123	spin_unlock_irqrestore(&host->clk_lock, flags);
	124	/* This will set host->ios.clock to 0 */
	125	mmc_gate_clock(host);
	126	spin_lock_irqsave(&host->clk_lock, flags);
	127	pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
	128	}
	129	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	130	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	131	}
	132
	133	/*
	134	* Internal work. Work to disable the clock at some later point.
	135	*/
	136	static void mmc_host_clk_gate_work(struct work_struct *work)
	137	{
	138	struct mmc_host *host = container_of(work, struct mmc_host,
597dd9d7	139	clk_gate_work.work);
04566831 LW	140
	141	mmc_host_clk_gate_delayed(host);
	142	}
	143
	144	/**
08c14071	145	* mmc_host_clk_hold - ungate hardware MCI clocks
04566831 LW	146	* @host: host to ungate.
	147	*
	148	* Makes sure the host ios.clock is restored to a non-zero value
	149	* past this call. Increase clock reference count and ungate clock
	150	* if we're the first user.
	151	*/
08c14071	152	void mmc_host_clk_hold(struct mmc_host *host)
04566831 LW	153	{
	154	unsigned long flags;
	155
597dd9d7 SRT	156	/* cancel any clock gating work scheduled by mmc_host_clk_release() */
597dd9d7 SRT	157	cancel_delayed_work_sync(&host->clk_gate_work);
86f315bb	158	mutex_lock(&host->clk_gate_mutex);
04566831 LW	159	spin_lock_irqsave(&host->clk_lock, flags);
	160	if (host->clk_gated) {
	161	spin_unlock_irqrestore(&host->clk_lock, flags);
	162	mmc_ungate_clock(host);
	163	spin_lock_irqsave(&host->clk_lock, flags);
	164	pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
	165	}
	166	host->clk_requests++;
	167	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	168	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	169	}
	170
	171	/**
	172	* mmc_host_may_gate_card - check if this card may be gated
	173	* @card: card to check.
	174	*/
	175	static bool mmc_host_may_gate_card(struct mmc_card *card)
	176	{
	177	/* If there is no card we may gate it */
	178	if (!card)
	179	return true;
	180	/*
	181	* Don't gate SDIO cards! These need to be clocked at all times
	182	* since they may be independent systems generating interrupts
	183	* and other events. The clock requests counter from the core will
	184	* go down to zero since the core does not need it, but we will not
	185	* gate the clock, because there is somebody out there that may still
	186	* be using it.
	187	*/
db993500	188	return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
04566831 LW	189	}
	190
	191	/**
08c14071	192	* mmc_host_clk_release - gate off hardware MCI clocks
04566831 LW	193	* @host: host to gate.
	194	*
	195	* Calls the host driver with ios.clock set to zero as often as possible
	196	* in order to gate off hardware MCI clocks. Decrease clock reference
	197	* count and schedule disabling of clock.
	198	*/
08c14071	199	void mmc_host_clk_release(struct mmc_host *host)
04566831 LW	200	{
	201	unsigned long flags;
	202
	203	spin_lock_irqsave(&host->clk_lock, flags);
	204	host->clk_requests--;
	205	if (mmc_host_may_gate_card(host->card) &&
	206	!host->clk_requests)
597dd9d7 SRT	207	queue_delayed_work(system_nrt_wq, &host->clk_gate_work,
597dd9d7 SRT	208	msecs_to_jiffies(host->clkgate_delay));
04566831 LW	209	spin_unlock_irqrestore(&host->clk_lock, flags);
	210	}
	211
	212	/**
	213	* mmc_host_clk_rate - get current clock frequency setting
	214	* @host: host to get the clock frequency for.
	215	*
	216	* Returns current clock frequency regardless of gating.
	217	*/
	218	unsigned int mmc_host_clk_rate(struct mmc_host *host)
	219	{
	220	unsigned long freq;
	221	unsigned long flags;
	222
	223	spin_lock_irqsave(&host->clk_lock, flags);
	224	if (host->clk_gated)
	225	freq = host->clk_old;
	226	else
	227	freq = host->ios.clock;
	228	spin_unlock_irqrestore(&host->clk_lock, flags);
	229	return freq;
	230	}
	231
	232	/**
	233	* mmc_host_clk_init - set up clock gating code
	234	* @host: host with potential clock to control
	235	*/
	236	static inline void mmc_host_clk_init(struct mmc_host *host)
	237	{
	238	host->clk_requests = 0;
	239	/* Hold MCI clock for 8 cycles by default */
	240	host->clk_delay = 8;
597dd9d7	241	/*
c84f15ae	242	* Default clock gating delay is 0ms to avoid wasting power.
597dd9d7 SRT	243	* This value can be tuned by writing into sysfs entry.
597dd9d7 SRT	244	*/
c84f15ae	245	host->clkgate_delay = 0;
04566831	246	host->clk_gated = false;
597dd9d7	247	INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
04566831	248	spin_lock_init(&host->clk_lock);
86f315bb	249	mutex_init(&host->clk_gate_mutex);
04566831 LW	250	}
	251
	252	/**
	253	* mmc_host_clk_exit - shut down clock gating code
	254	* @host: host with potential clock to control
	255	*/
	256	static inline void mmc_host_clk_exit(struct mmc_host *host)
	257	{
	258	/*
	259	* Wait for any outstanding gate and then make sure we're
	260	* ungated before exiting.
	261	*/
597dd9d7	262	if (cancel_delayed_work_sync(&host->clk_gate_work))
04566831 LW	263	mmc_host_clk_gate_delayed(host);
04566831 LW	264	if (host->clk_gated)
08c14071	265	mmc_host_clk_hold(host);
c288b855 LW	266	/* There should be only one user now */
c288b855 LW	267	WARN_ON(host->clk_requests > 1);
04566831 LW	268	}
04566831 LW	269
597dd9d7 SRT	270	static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
	271	{
	272	host->clkgate_delay_attr.show = clkgate_delay_show;
	273	host->clkgate_delay_attr.store = clkgate_delay_store;
	274	sysfs_attr_init(&host->clkgate_delay_attr.attr);
	275	host->clkgate_delay_attr.attr.name = "clkgate_delay";
	276	host->clkgate_delay_attr.attr.mode = S_IRUGO \| S_IWUSR;
	277	if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
	278	pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
	279	mmc_hostname(host));
	280	}
04566831 LW	281	#else
	282
	283	static inline void mmc_host_clk_init(struct mmc_host *host)
	284	{
	285	}
	286
	287	static inline void mmc_host_clk_exit(struct mmc_host *host)
	288	{
	289	}
	290
597dd9d7 SRT	291	static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
	292	{
	293	}
	294
04566831 LW	295	#endif
04566831 LW	296
b93931a6 PO	297	/**
	298	* mmc_alloc_host - initialise the per-host structure.
	299	* @extra: sizeof private data structure
	300	* @dev: pointer to host device model structure
	301	*
	302	* Initialise the per-host structure.
	303	*/
	304	struct mmc_host mmc_alloc_host(int extra, struct device dev)
	305	{
ff3112f5	306	int err;
b93931a6 PO	307	struct mmc_host *host;
b93931a6 PO	308
ff3112f5 PO	309	if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
	310	return NULL;
	311
be760a9d	312	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
b93931a6 PO	313	if (!host)
	314	return NULL;
	315
ff3112f5 PO	316	spin_lock(&mmc_host_lock);
	317	err = idr_get_new(&mmc_host_idr, host, &host->index);
	318	spin_unlock(&mmc_host_lock);
	319	if (err)
	320	goto free;
	321
d1b26863	322	dev_set_name(&host->class_dev, "mmc%d", host->index);
ff3112f5	323
b93931a6 PO	324	host->parent = dev;
	325	host->class_dev.parent = dev;
	326	host->class_dev.class = &mmc_host_class;
	327	device_initialize(&host->class_dev);
	328
04566831 LW	329	mmc_host_clk_init(host);
04566831 LW	330
a7d1a1eb	331	mutex_init(&host->slot.lock);
27410ee7 GL	332	host->slot.cd_irq = -EINVAL;
27410ee7 GL	333
b93931a6 PO	334	spin_lock_init(&host->lock);
	335	init_waitqueue_head(&host->wq);
	336	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
81ca03a0	337	#ifdef CONFIG_PM
4c2ef25f	338	host->pm_notify.notifier_call = mmc_pm_notify;
81ca03a0	339	#endif
b93931a6 PO	340
	341	/*
	342	* By default, hosts do not support SGIO or large requests.
	343	* They have to set these according to their abilities.
	344	*/
a36274e0	345	host->max_segs = 1;
b93931a6 PO	346	host->max_seg_size = PAGE_CACHE_SIZE;
	347
	348	host->max_req_size = PAGE_CACHE_SIZE;
	349	host->max_blk_size = 512;
	350	host->max_blk_count = PAGE_CACHE_SIZE / 512;
	351
	352	return host;
ff3112f5 PO	353
	354	free:
	355	kfree(host);
	356	return NULL;
b93931a6 PO	357	}
	358
	359	EXPORT_SYMBOL(mmc_alloc_host);
	360
	361	/**
	362	* mmc_add_host - initialise host hardware
	363	* @host: mmc host
67a61c48 PO	364	*
	365	* Register the host with the driver model. The host must be
	366	* prepared to start servicing requests before this function
	367	* completes.
b93931a6 PO	368	*/
	369	int mmc_add_host(struct mmc_host *host)
	370	{
	371	int err;
	372
17b759af NP	373	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
	374	!host->ops->enable_sdio_irq);
	375
b93931a6 PO	376	err = device_add(&host->class_dev);
	377	if (err)
	378	return err;
	379
f317dfeb WS	380	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
f317dfeb WS	381
6edd8ee6 HS	382	#ifdef CONFIG_DEBUG_FS
	383	mmc_add_host_debugfs(host);
	384	#endif
597dd9d7	385	mmc_host_clk_sysfs_init(host);
6edd8ee6	386
b93931a6	387	mmc_start_host(host);
4c2ef25f	388	register_pm_notifier(&host->pm_notify);
b93931a6 PO	389
	390	return 0;
	391	}
	392
	393	EXPORT_SYMBOL(mmc_add_host);
	394
	395	/**
	396	* mmc_remove_host - remove host hardware
	397	* @host: mmc host
	398	*
	399	* Unregister and remove all cards associated with this host,
67a61c48 PO	400	* and power down the MMC bus. No new requests will be issued
67a61c48 PO	401	* after this function has returned.
b93931a6 PO	402	*/
	403	void mmc_remove_host(struct mmc_host *host)
	404	{
4c2ef25f	405	unregister_pm_notifier(&host->pm_notify);
b93931a6 PO	406	mmc_stop_host(host);
b93931a6 PO	407
6edd8ee6 HS	408	#ifdef CONFIG_DEBUG_FS
	409	mmc_remove_host_debugfs(host);
	410	#endif
	411
b93931a6 PO	412	device_del(&host->class_dev);
b93931a6 PO	413
77f1fd6e	414	led_trigger_unregister_simple(host->led);
04566831 LW	415
04566831 LW	416	mmc_host_clk_exit(host);
b93931a6 PO	417	}
	418
	419	EXPORT_SYMBOL(mmc_remove_host);
	420
	421	/**
	422	* mmc_free_host - free the host structure
	423	* @host: mmc host
	424	*
	425	* Free the host once all references to it have been dropped.
	426	*/
	427	void mmc_free_host(struct mmc_host *host)
	428	{
ff3112f5 PO	429	spin_lock(&mmc_host_lock);
	430	idr_remove(&mmc_host_idr, host->index);
	431	spin_unlock(&mmc_host_lock);
	432
b93931a6 PO	433	put_device(&host->class_dev);
	434	}
	435
	436	EXPORT_SYMBOL(mmc_free_host);