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