[GitHub/mt8127/android_kernel_alcatel_ttab.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/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

/*
 * 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);

	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;

	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_work(system_nrt_wq, &host->clk_gate_work);
	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;
	host->clk_gated = false;
	INIT_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_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);
}

#else

static inline void mmc_host_clk_init(struct mmc_host *host)
{
}

static inline void mmc_host_clk_exit(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);
	INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
#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_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>
af8350c7	19	#include <linux/leds.h>
5a0e3ad6	20	#include <linux/slab.h>
4c2ef25f	21	#include <linux/suspend.h>
b93931a6 PO	22
b93931a6 PO	23	#include <linux/mmc/host.h>
04566831	24	#include <linux/mmc/card.h>
b93931a6 PO	25
	26	#include "core.h"
	27	#include "host.h"
	28
	29	#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
	30
	31	static void mmc_host_classdev_release(struct device *dev)
	32	{
	33	struct mmc_host *host = cls_dev_to_mmc_host(dev);
	34	kfree(host);
	35	}
	36
	37	static struct class mmc_host_class = {
	38	.name = "mmc_host",
	39	.dev_release = mmc_host_classdev_release,
	40	};
	41
	42	int mmc_register_host_class(void)
	43	{
	44	return class_register(&mmc_host_class);
	45	}
	46
	47	void mmc_unregister_host_class(void)
	48	{
	49	class_unregister(&mmc_host_class);
	50	}
	51
	52	static DEFINE_IDR(mmc_host_idr);
	53	static DEFINE_SPINLOCK(mmc_host_lock);
	54
04566831 LW	55	#ifdef CONFIG_MMC_CLKGATE
	56
	57	/*
	58	* Enabling clock gating will make the core call out to the host
	59	* once up and once down when it performs a request or card operation
	60	* intermingled in any fashion. The driver will see this through
	61	* set_ios() operations with ios.clock field set to 0 to gate (disable)
	62	* the block clock, and to the old frequency to enable it again.
	63	*/
	64	static void mmc_host_clk_gate_delayed(struct mmc_host *host)
	65	{
	66	unsigned long tick_ns;
	67	unsigned long freq = host->ios.clock;
	68	unsigned long flags;
	69
	70	if (!freq) {
	71	pr_debug("%s: frequency set to 0 in disable function, "
	72	"this means the clock is already disabled.\n",
	73	mmc_hostname(host));
	74	return;
	75	}
	76	/*
	77	* New requests may have appeared while we were scheduling,
	78	* then there is no reason to delay the check before
	79	* clk_disable().
	80	*/
	81	spin_lock_irqsave(&host->clk_lock, flags);
	82
	83	/*
	84	* Delay n bus cycles (at least 8 from MMC spec) before attempting
	85	* to disable the MCI block clock. The reference count may have
	86	* gone up again after this delay due to rescheduling!
	87	*/
	88	if (!host->clk_requests) {
	89	spin_unlock_irqrestore(&host->clk_lock, flags);
	90	tick_ns = DIV_ROUND_UP(1000000000, freq);
	91	ndelay(host->clk_delay * tick_ns);
	92	} else {
	93	/* New users appeared while waiting for this work */
	94	spin_unlock_irqrestore(&host->clk_lock, flags);
	95	return;
	96	}
86f315bb	97	mutex_lock(&host->clk_gate_mutex);
04566831 LW	98	spin_lock_irqsave(&host->clk_lock, flags);
	99	if (!host->clk_requests) {
	100	spin_unlock_irqrestore(&host->clk_lock, flags);
	101	/* This will set host->ios.clock to 0 */
	102	mmc_gate_clock(host);
	103	spin_lock_irqsave(&host->clk_lock, flags);
	104	pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
	105	}
	106	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	107	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	108	}
	109
	110	/*
	111	* Internal work. Work to disable the clock at some later point.
	112	*/
	113	static void mmc_host_clk_gate_work(struct work_struct *work)
	114	{
	115	struct mmc_host *host = container_of(work, struct mmc_host,
	116	clk_gate_work);
	117
	118	mmc_host_clk_gate_delayed(host);
	119	}
	120
	121	/**
08c14071	122	* mmc_host_clk_hold - ungate hardware MCI clocks
04566831 LW	123	* @host: host to ungate.
	124	*
	125	* Makes sure the host ios.clock is restored to a non-zero value
	126	* past this call. Increase clock reference count and ungate clock
	127	* if we're the first user.
	128	*/
08c14071	129	void mmc_host_clk_hold(struct mmc_host *host)
04566831 LW	130	{
	131	unsigned long flags;
	132
86f315bb	133	mutex_lock(&host->clk_gate_mutex);
04566831 LW	134	spin_lock_irqsave(&host->clk_lock, flags);
	135	if (host->clk_gated) {
	136	spin_unlock_irqrestore(&host->clk_lock, flags);
	137	mmc_ungate_clock(host);
	138	spin_lock_irqsave(&host->clk_lock, flags);
	139	pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
	140	}
	141	host->clk_requests++;
	142	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	143	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	144	}
	145
	146	/**
	147	* mmc_host_may_gate_card - check if this card may be gated
	148	* @card: card to check.
	149	*/
	150	static bool mmc_host_may_gate_card(struct mmc_card *card)
	151	{
	152	/* If there is no card we may gate it */
	153	if (!card)
	154	return true;
	155	/*
	156	* Don't gate SDIO cards! These need to be clocked at all times
	157	* since they may be independent systems generating interrupts
	158	* and other events. The clock requests counter from the core will
	159	* go down to zero since the core does not need it, but we will not
	160	* gate the clock, because there is somebody out there that may still
	161	* be using it.
	162	*/
db993500	163	return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
04566831 LW	164	}
	165
	166	/**
08c14071	167	* mmc_host_clk_release - gate off hardware MCI clocks
04566831 LW	168	* @host: host to gate.
	169	*
	170	* Calls the host driver with ios.clock set to zero as often as possible
	171	* in order to gate off hardware MCI clocks. Decrease clock reference
	172	* count and schedule disabling of clock.
	173	*/
08c14071	174	void mmc_host_clk_release(struct mmc_host *host)
04566831 LW	175	{
	176	unsigned long flags;
	177
	178	spin_lock_irqsave(&host->clk_lock, flags);
	179	host->clk_requests--;
	180	if (mmc_host_may_gate_card(host->card) &&
	181	!host->clk_requests)
50a50f92	182	queue_work(system_nrt_wq, &host->clk_gate_work);
04566831 LW	183	spin_unlock_irqrestore(&host->clk_lock, flags);
	184	}
	185
	186	/**
	187	* mmc_host_clk_rate - get current clock frequency setting
	188	* @host: host to get the clock frequency for.
	189	*
	190	* Returns current clock frequency regardless of gating.
	191	*/
	192	unsigned int mmc_host_clk_rate(struct mmc_host *host)
	193	{
	194	unsigned long freq;
	195	unsigned long flags;
	196
	197	spin_lock_irqsave(&host->clk_lock, flags);
	198	if (host->clk_gated)
	199	freq = host->clk_old;
	200	else
	201	freq = host->ios.clock;
	202	spin_unlock_irqrestore(&host->clk_lock, flags);
	203	return freq;
	204	}
	205
	206	/**
	207	* mmc_host_clk_init - set up clock gating code
	208	* @host: host with potential clock to control
	209	*/
	210	static inline void mmc_host_clk_init(struct mmc_host *host)
	211	{
	212	host->clk_requests = 0;
	213	/* Hold MCI clock for 8 cycles by default */
	214	host->clk_delay = 8;
	215	host->clk_gated = false;
	216	INIT_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
	217	spin_lock_init(&host->clk_lock);
86f315bb	218	mutex_init(&host->clk_gate_mutex);
04566831 LW	219	}
	220
	221	/**
	222	* mmc_host_clk_exit - shut down clock gating code
	223	* @host: host with potential clock to control
	224	*/
	225	static inline void mmc_host_clk_exit(struct mmc_host *host)
	226	{
	227	/*
	228	* Wait for any outstanding gate and then make sure we're
	229	* ungated before exiting.
	230	*/
	231	if (cancel_work_sync(&host->clk_gate_work))
	232	mmc_host_clk_gate_delayed(host);
	233	if (host->clk_gated)
08c14071	234	mmc_host_clk_hold(host);
c288b855 LW	235	/* There should be only one user now */
c288b855 LW	236	WARN_ON(host->clk_requests > 1);
04566831 LW	237	}
	238
	239	#else
	240
	241	static inline void mmc_host_clk_init(struct mmc_host *host)
	242	{
	243	}
	244
	245	static inline void mmc_host_clk_exit(struct mmc_host *host)
	246	{
	247	}
	248
	249	#endif
	250
b93931a6 PO	251	/**
	252	* mmc_alloc_host - initialise the per-host structure.
	253	* @extra: sizeof private data structure
	254	* @dev: pointer to host device model structure
	255	*
	256	* Initialise the per-host structure.
	257	*/
	258	struct mmc_host mmc_alloc_host(int extra, struct device dev)
	259	{
ff3112f5	260	int err;
b93931a6 PO	261	struct mmc_host *host;
b93931a6 PO	262
ff3112f5 PO	263	if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
	264	return NULL;
	265
be760a9d	266	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
b93931a6 PO	267	if (!host)
	268	return NULL;
	269
ff3112f5 PO	270	spin_lock(&mmc_host_lock);
	271	err = idr_get_new(&mmc_host_idr, host, &host->index);
	272	spin_unlock(&mmc_host_lock);
	273	if (err)
	274	goto free;
	275
d1b26863	276	dev_set_name(&host->class_dev, "mmc%d", host->index);
ff3112f5	277
b93931a6 PO	278	host->parent = dev;
	279	host->class_dev.parent = dev;
	280	host->class_dev.class = &mmc_host_class;
	281	device_initialize(&host->class_dev);
	282
04566831 LW	283	mmc_host_clk_init(host);
04566831 LW	284
b93931a6 PO	285	spin_lock_init(&host->lock);
	286	init_waitqueue_head(&host->wq);
	287	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
8ea926b2	288	INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
81ca03a0	289	#ifdef CONFIG_PM
4c2ef25f	290	host->pm_notify.notifier_call = mmc_pm_notify;
81ca03a0	291	#endif
b93931a6 PO	292
	293	/*
	294	* By default, hosts do not support SGIO or large requests.
	295	* They have to set these according to their abilities.
	296	*/
a36274e0	297	host->max_segs = 1;
b93931a6 PO	298	host->max_seg_size = PAGE_CACHE_SIZE;
	299
	300	host->max_req_size = PAGE_CACHE_SIZE;
	301	host->max_blk_size = 512;
	302	host->max_blk_count = PAGE_CACHE_SIZE / 512;
	303
	304	return host;
ff3112f5 PO	305
	306	free:
	307	kfree(host);
	308	return NULL;
b93931a6 PO	309	}
	310
	311	EXPORT_SYMBOL(mmc_alloc_host);
	312
	313	/**
	314	* mmc_add_host - initialise host hardware
	315	* @host: mmc host
67a61c48 PO	316	*
	317	* Register the host with the driver model. The host must be
	318	* prepared to start servicing requests before this function
	319	* completes.
b93931a6 PO	320	*/
	321	int mmc_add_host(struct mmc_host *host)
	322	{
	323	int err;
	324
17b759af NP	325	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
	326	!host->ops->enable_sdio_irq);
	327
b93931a6 PO	328	err = device_add(&host->class_dev);
	329	if (err)
	330	return err;
	331
f317dfeb WS	332	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
f317dfeb WS	333
6edd8ee6 HS	334	#ifdef CONFIG_DEBUG_FS
	335	mmc_add_host_debugfs(host);
	336	#endif
	337
b93931a6	338	mmc_start_host(host);
4c2ef25f	339	register_pm_notifier(&host->pm_notify);
b93931a6 PO	340
	341	return 0;
	342	}
	343
	344	EXPORT_SYMBOL(mmc_add_host);
	345
	346	/**
	347	* mmc_remove_host - remove host hardware
	348	* @host: mmc host
	349	*
	350	* Unregister and remove all cards associated with this host,
67a61c48 PO	351	* and power down the MMC bus. No new requests will be issued
67a61c48 PO	352	* after this function has returned.
b93931a6 PO	353	*/
	354	void mmc_remove_host(struct mmc_host *host)
	355	{
4c2ef25f	356	unregister_pm_notifier(&host->pm_notify);
b93931a6 PO	357	mmc_stop_host(host);
b93931a6 PO	358
6edd8ee6 HS	359	#ifdef CONFIG_DEBUG_FS
	360	mmc_remove_host_debugfs(host);
	361	#endif
	362
b93931a6 PO	363	device_del(&host->class_dev);
b93931a6 PO	364
77f1fd6e	365	led_trigger_unregister_simple(host->led);
04566831 LW	366
04566831 LW	367	mmc_host_clk_exit(host);
b93931a6 PO	368	}
	369
	370	EXPORT_SYMBOL(mmc_remove_host);
	371
	372	/**
	373	* mmc_free_host - free the host structure
	374	* @host: mmc host
	375	*
	376	* Free the host once all references to it have been dropped.
	377	*/
	378	void mmc_free_host(struct mmc_host *host)
	379	{
ff3112f5 PO	380	spin_lock(&mmc_host_lock);
	381	idr_remove(&mmc_host_idr, host->index);
	382	spin_unlock(&mmc_host_lock);
	383
b93931a6 PO	384	put_device(&host->class_dev);
	385	}
	386
	387	EXPORT_SYMBOL(mmc_free_host);