[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
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);

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