[linux-2.6-block.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 millisecs\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);

	pr_info("%s: clock gate delay set to %lu ms\n",
			mmc_hostname(host), value);
	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 200ms.
	 * This value can be tuned by writing into sysfs entry.
	 */
	host->clkgate_delay = 200;
	host->clk_gated = false;
	INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
	spin_lock_init(&host->clk_lock);
	mutex_init(&host->clk_gate_mutex);
}

/**
 *	mmc_host_clk_exit - shut down clock gating code
 *	@host: host with potential clock to control
 */
static inline void mmc_host_clk_exit(struct mmc_host *host)
{
	/*
	 * Wait for any outstanding gate and then make sure we're
	 * ungated before exiting.
	 */
	if (cancel_delayed_work_sync(&host->clk_gate_work))
		mmc_host_clk_gate_delayed(host);
	if (host->clk_gated)
		mmc_host_clk_hold(host);
	/* There should be only one user now */
	WARN_ON(host->clk_requests > 1);
}

static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
{
	host->clkgate_delay_attr.show = clkgate_delay_show;
	host->clkgate_delay_attr.store = clkgate_delay_store;
	sysfs_attr_init(&host->clkgate_delay_attr.attr);
	host->clkgate_delay_attr.attr.name = "clkgate_delay";
	host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
	if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
		pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
				mmc_hostname(host));
}
#else

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

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

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

#endif

/**
 *	mmc_alloc_host - initialise the per-host structure.
 *	@extra: sizeof private data structure
 *	@dev: pointer to host device model structure
 *
 *	Initialise the per-host structure.
 */
struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
{
	int err;
	struct mmc_host *host;

	if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
		return NULL;

	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
	if (!host)
		return NULL;

	spin_lock(&mmc_host_lock);
	err = idr_get_new(&mmc_host_idr, host, &host->index);
	spin_unlock(&mmc_host_lock);
	if (err)
		goto free;

	dev_set_name(&host->class_dev, "mmc%d", host->index);

	host->parent = dev;
	host->class_dev.parent = dev;
	host->class_dev.class = &mmc_host_class;
	device_initialize(&host->class_dev);

	mmc_host_clk_init(host);

	spin_lock_init(&host->lock);
	init_waitqueue_head(&host->wq);
	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_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);
	61	return snprintf(buf, PAGE_SIZE, "%lu millisecs\n",
	62	host->clkgate_delay);
	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);
	77
	78	pr_info("%s: clock gate delay set to %lu ms\n",
	79	mmc_hostname(host), value);
	80	return count;
	81	}
04566831 LW	82
	83	/*
	84	* Enabling clock gating will make the core call out to the host
	85	* once up and once down when it performs a request or card operation
	86	* intermingled in any fashion. The driver will see this through
	87	* set_ios() operations with ios.clock field set to 0 to gate (disable)
	88	* the block clock, and to the old frequency to enable it again.
	89	*/
	90	static void mmc_host_clk_gate_delayed(struct mmc_host *host)
	91	{
	92	unsigned long tick_ns;
	93	unsigned long freq = host->ios.clock;
	94	unsigned long flags;
	95
	96	if (!freq) {
	97	pr_debug("%s: frequency set to 0 in disable function, "
	98	"this means the clock is already disabled.\n",
	99	mmc_hostname(host));
	100	return;
	101	}
	102	/*
	103	* New requests may have appeared while we were scheduling,
	104	* then there is no reason to delay the check before
	105	* clk_disable().
	106	*/
	107	spin_lock_irqsave(&host->clk_lock, flags);
	108
	109	/*
	110	* Delay n bus cycles (at least 8 from MMC spec) before attempting
	111	* to disable the MCI block clock. The reference count may have
	112	* gone up again after this delay due to rescheduling!
	113	*/
	114	if (!host->clk_requests) {
	115	spin_unlock_irqrestore(&host->clk_lock, flags);
	116	tick_ns = DIV_ROUND_UP(1000000000, freq);
	117	ndelay(host->clk_delay * tick_ns);
	118	} else {
	119	/* New users appeared while waiting for this work */
	120	spin_unlock_irqrestore(&host->clk_lock, flags);
	121	return;
	122	}
86f315bb	123	mutex_lock(&host->clk_gate_mutex);
04566831 LW	124	spin_lock_irqsave(&host->clk_lock, flags);
	125	if (!host->clk_requests) {
	126	spin_unlock_irqrestore(&host->clk_lock, flags);
	127	/* This will set host->ios.clock to 0 */
	128	mmc_gate_clock(host);
	129	spin_lock_irqsave(&host->clk_lock, flags);
	130	pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
	131	}
	132	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	133	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	134	}
	135
	136	/*
	137	* Internal work. Work to disable the clock at some later point.
	138	*/
	139	static void mmc_host_clk_gate_work(struct work_struct *work)
	140	{
	141	struct mmc_host *host = container_of(work, struct mmc_host,
597dd9d7	142	clk_gate_work.work);
04566831 LW	143
	144	mmc_host_clk_gate_delayed(host);
	145	}
	146
	147	/**
08c14071	148	* mmc_host_clk_hold - ungate hardware MCI clocks
04566831 LW	149	* @host: host to ungate.
	150	*
	151	* Makes sure the host ios.clock is restored to a non-zero value
	152	* past this call. Increase clock reference count and ungate clock
	153	* if we're the first user.
	154	*/
08c14071	155	void mmc_host_clk_hold(struct mmc_host *host)
04566831 LW	156	{
	157	unsigned long flags;
	158
597dd9d7 SRT	159	/* cancel any clock gating work scheduled by mmc_host_clk_release() */
597dd9d7 SRT	160	cancel_delayed_work_sync(&host->clk_gate_work);
86f315bb	161	mutex_lock(&host->clk_gate_mutex);
04566831 LW	162	spin_lock_irqsave(&host->clk_lock, flags);
	163	if (host->clk_gated) {
	164	spin_unlock_irqrestore(&host->clk_lock, flags);
	165	mmc_ungate_clock(host);
	166	spin_lock_irqsave(&host->clk_lock, flags);
	167	pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
	168	}
	169	host->clk_requests++;
	170	spin_unlock_irqrestore(&host->clk_lock, flags);
86f315bb	171	mutex_unlock(&host->clk_gate_mutex);
04566831 LW	172	}
	173
	174	/**
	175	* mmc_host_may_gate_card - check if this card may be gated
	176	* @card: card to check.
	177	*/
	178	static bool mmc_host_may_gate_card(struct mmc_card *card)
	179	{
	180	/* If there is no card we may gate it */
	181	if (!card)
	182	return true;
	183	/*
	184	* Don't gate SDIO cards! These need to be clocked at all times
	185	* since they may be independent systems generating interrupts
	186	* and other events. The clock requests counter from the core will
	187	* go down to zero since the core does not need it, but we will not
	188	* gate the clock, because there is somebody out there that may still
	189	* be using it.
	190	*/
db993500	191	return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
04566831 LW	192	}
	193
	194	/**
08c14071	195	* mmc_host_clk_release - gate off hardware MCI clocks
04566831 LW	196	* @host: host to gate.
	197	*
	198	* Calls the host driver with ios.clock set to zero as often as possible
	199	* in order to gate off hardware MCI clocks. Decrease clock reference
	200	* count and schedule disabling of clock.
	201	*/
08c14071	202	void mmc_host_clk_release(struct mmc_host *host)
04566831 LW	203	{
	204	unsigned long flags;
	205
	206	spin_lock_irqsave(&host->clk_lock, flags);
	207	host->clk_requests--;
	208	if (mmc_host_may_gate_card(host->card) &&
	209	!host->clk_requests)
597dd9d7 SRT	210	queue_delayed_work(system_nrt_wq, &host->clk_gate_work,
597dd9d7 SRT	211	msecs_to_jiffies(host->clkgate_delay));
04566831 LW	212	spin_unlock_irqrestore(&host->clk_lock, flags);
	213	}
	214
	215	/**
	216	* mmc_host_clk_rate - get current clock frequency setting
	217	* @host: host to get the clock frequency for.
	218	*
	219	* Returns current clock frequency regardless of gating.
	220	*/
	221	unsigned int mmc_host_clk_rate(struct mmc_host *host)
	222	{
	223	unsigned long freq;
	224	unsigned long flags;
	225
	226	spin_lock_irqsave(&host->clk_lock, flags);
	227	if (host->clk_gated)
	228	freq = host->clk_old;
	229	else
	230	freq = host->ios.clock;
	231	spin_unlock_irqrestore(&host->clk_lock, flags);
	232	return freq;
	233	}
	234
	235	/**
	236	* mmc_host_clk_init - set up clock gating code
	237	* @host: host with potential clock to control
	238	*/
	239	static inline void mmc_host_clk_init(struct mmc_host *host)
	240	{
	241	host->clk_requests = 0;
	242	/* Hold MCI clock for 8 cycles by default */
	243	host->clk_delay = 8;
597dd9d7 SRT	244	/*
	245	* Default clock gating delay is 200ms.
	246	* This value can be tuned by writing into sysfs entry.
	247	*/
	248	host->clkgate_delay = 200;
04566831	249	host->clk_gated = false;
597dd9d7	250	INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
04566831	251	spin_lock_init(&host->clk_lock);
86f315bb	252	mutex_init(&host->clk_gate_mutex);
04566831 LW	253	}
	254
	255	/**
	256	* mmc_host_clk_exit - shut down clock gating code
	257	* @host: host with potential clock to control
	258	*/
	259	static inline void mmc_host_clk_exit(struct mmc_host *host)
	260	{
	261	/*
	262	* Wait for any outstanding gate and then make sure we're
	263	* ungated before exiting.
	264	*/
597dd9d7	265	if (cancel_delayed_work_sync(&host->clk_gate_work))
04566831 LW	266	mmc_host_clk_gate_delayed(host);
04566831 LW	267	if (host->clk_gated)
08c14071	268	mmc_host_clk_hold(host);
c288b855 LW	269	/* There should be only one user now */
c288b855 LW	270	WARN_ON(host->clk_requests > 1);
04566831 LW	271	}
04566831 LW	272
597dd9d7 SRT	273	static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
	274	{
	275	host->clkgate_delay_attr.show = clkgate_delay_show;
	276	host->clkgate_delay_attr.store = clkgate_delay_store;
	277	sysfs_attr_init(&host->clkgate_delay_attr.attr);
	278	host->clkgate_delay_attr.attr.name = "clkgate_delay";
	279	host->clkgate_delay_attr.attr.mode = S_IRUGO \| S_IWUSR;
	280	if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
	281	pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
	282	mmc_hostname(host));
	283	}
04566831 LW	284	#else
	285
	286	static inline void mmc_host_clk_init(struct mmc_host *host)
	287	{
	288	}
	289
	290	static inline void mmc_host_clk_exit(struct mmc_host *host)
	291	{
	292	}
	293
597dd9d7 SRT	294	static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
	295	{
	296	}
	297
04566831 LW	298	#endif
04566831 LW	299
b93931a6 PO	300	/**
	301	* mmc_alloc_host - initialise the per-host structure.
	302	* @extra: sizeof private data structure
	303	* @dev: pointer to host device model structure
	304	*
	305	* Initialise the per-host structure.
	306	*/
	307	struct mmc_host mmc_alloc_host(int extra, struct device dev)
	308	{
ff3112f5	309	int err;
b93931a6 PO	310	struct mmc_host *host;
b93931a6 PO	311
ff3112f5 PO	312	if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
	313	return NULL;
	314
be760a9d	315	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
b93931a6 PO	316	if (!host)
	317	return NULL;
	318
ff3112f5 PO	319	spin_lock(&mmc_host_lock);
	320	err = idr_get_new(&mmc_host_idr, host, &host->index);
	321	spin_unlock(&mmc_host_lock);
	322	if (err)
	323	goto free;
	324
d1b26863	325	dev_set_name(&host->class_dev, "mmc%d", host->index);
ff3112f5	326
b93931a6 PO	327	host->parent = dev;
	328	host->class_dev.parent = dev;
	329	host->class_dev.class = &mmc_host_class;
	330	device_initialize(&host->class_dev);
	331
04566831 LW	332	mmc_host_clk_init(host);
04566831 LW	333
b93931a6 PO	334	spin_lock_init(&host->lock);
	335	init_waitqueue_head(&host->wq);
	336	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
8ea926b2	337	INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
81ca03a0	338	#ifdef CONFIG_PM
4c2ef25f	339	host->pm_notify.notifier_call = mmc_pm_notify;
81ca03a0	340	#endif
b93931a6 PO	341
	342	/*
	343	* By default, hosts do not support SGIO or large requests.
	344	* They have to set these according to their abilities.
	345	*/
a36274e0	346	host->max_segs = 1;
b93931a6 PO	347	host->max_seg_size = PAGE_CACHE_SIZE;
	348
	349	host->max_req_size = PAGE_CACHE_SIZE;
	350	host->max_blk_size = 512;
	351	host->max_blk_count = PAGE_CACHE_SIZE / 512;
	352
	353	return host;
ff3112f5 PO	354
	355	free:
	356	kfree(host);
	357	return NULL;
b93931a6 PO	358	}
	359
	360	EXPORT_SYMBOL(mmc_alloc_host);
	361
	362	/**
	363	* mmc_add_host - initialise host hardware
	364	* @host: mmc host
67a61c48 PO	365	*
	366	* Register the host with the driver model. The host must be
	367	* prepared to start servicing requests before this function
	368	* completes.
b93931a6 PO	369	*/
	370	int mmc_add_host(struct mmc_host *host)
	371	{
	372	int err;
	373
17b759af NP	374	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
	375	!host->ops->enable_sdio_irq);
	376
b93931a6 PO	377	err = device_add(&host->class_dev);
	378	if (err)
	379	return err;
	380
f317dfeb WS	381	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
f317dfeb WS	382
6edd8ee6 HS	383	#ifdef CONFIG_DEBUG_FS
	384	mmc_add_host_debugfs(host);
	385	#endif
597dd9d7	386	mmc_host_clk_sysfs_init(host);
6edd8ee6	387
b93931a6	388	mmc_start_host(host);
4c2ef25f	389	register_pm_notifier(&host->pm_notify);
b93931a6 PO	390
	391	return 0;
	392	}
	393
	394	EXPORT_SYMBOL(mmc_add_host);
	395
	396	/**
	397	* mmc_remove_host - remove host hardware
	398	* @host: mmc host
	399	*
	400	* Unregister and remove all cards associated with this host,
67a61c48 PO	401	* and power down the MMC bus. No new requests will be issued
67a61c48 PO	402	* after this function has returned.
b93931a6 PO	403	*/
	404	void mmc_remove_host(struct mmc_host *host)
	405	{
4c2ef25f	406	unregister_pm_notifier(&host->pm_notify);
b93931a6 PO	407	mmc_stop_host(host);
b93931a6 PO	408
6edd8ee6 HS	409	#ifdef CONFIG_DEBUG_FS
	410	mmc_remove_host_debugfs(host);
	411	#endif
	412
b93931a6 PO	413	device_del(&host->class_dev);
b93931a6 PO	414
77f1fd6e	415	led_trigger_unregister_simple(host->led);
04566831 LW	416
04566831 LW	417	mmc_host_clk_exit(host);
b93931a6 PO	418	}
	419
	420	EXPORT_SYMBOL(mmc_remove_host);
	421
	422	/**
	423	* mmc_free_host - free the host structure
	424	* @host: mmc host
	425	*
	426	* Free the host once all references to it have been dropped.
	427	*/
	428	void mmc_free_host(struct mmc_host *host)
	429	{
ff3112f5 PO	430	spin_lock(&mmc_host_lock);
	431	idr_remove(&mmc_host_idr, host->index);
	432	spin_unlock(&mmc_host_lock);
	433
b93931a6 PO	434	put_device(&host->class_dev);
	435	}
	436
	437	EXPORT_SYMBOL(mmc_free_host);