[mirror_ubuntu-artful-kernel.git] / drivers / mmc / core / sdio_irq.c

/*
 * linux/drivers/mmc/core/sdio_irq.c
 *
 * Author:      Nicolas Pitre
 * Created:     June 18, 2007
 * Copyright:   MontaVista Software Inc.
 *
 * Copyright 2008 Pierre Ossman
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/export.h>
#include <linux/wait.h>
#include <linux/delay.h>

#include <linux/mmc/core.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>

#include "sdio_ops.h"

static int process_sdio_pending_irqs(struct mmc_host *host)
{
	struct mmc_card *card = host->card;
	int i, ret, count;
	unsigned char pending;
	struct sdio_func *func;

	/*
	 * Optimization, if there is only 1 function interrupt registered
	 * and we know an IRQ was signaled then call irq handler directly.
	 * Otherwise do the full probe.
	 */
	func = card->sdio_single_irq;
	if (func && host->sdio_irq_pending) {
		func->irq_handler(func);
		return 1;
	}

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
	if (ret) {
		pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
		       mmc_card_id(card), ret);
		return ret;
	}

	if (pending && mmc_card_broken_irq_polling(card) &&
	    !(host->caps & MMC_CAP_SDIO_IRQ)) {
		unsigned char dummy;

		/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
		 * register with a Marvell SD8797 card. A dummy CMD52 read to
		 * function 0 register 0xff can avoid this.
		 */
		mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
	}

	count = 0;
	for (i = 1; i <= 7; i++) {
		if (pending & (1 << i)) {
			func = card->sdio_func[i - 1];
			if (!func) {
				pr_warning("%s: pending IRQ for "
					"non-existent function\n",
					mmc_card_id(card));
				ret = -EINVAL;
			} else if (func->irq_handler) {
				func->irq_handler(func);
				count++;
			} else {
				pr_warning("%s: pending IRQ with no handler\n",
				       sdio_func_id(func));
				ret = -EINVAL;
			}
		}
	}

	if (count)
		return count;

	return ret;
}

void sdio_run_irqs(struct mmc_host *host)
{
	mmc_claim_host(host);
	host->sdio_irq_pending = true;
	process_sdio_pending_irqs(host);
	mmc_release_host(host);
}
EXPORT_SYMBOL_GPL(sdio_run_irqs);

static int sdio_irq_thread(void *_host)
{
	struct mmc_host *host = _host;
	struct sched_param param = { .sched_priority = 1 };
	unsigned long period, idle_period;
	int ret;

	sched_setscheduler(current, SCHED_FIFO, &param);

	/*
	 * We want to allow for SDIO cards to work even on non SDIO
	 * aware hosts.  One thing that non SDIO host cannot do is
	 * asynchronous notification of pending SDIO card interrupts
	 * hence we poll for them in that case.
	 */
	idle_period = msecs_to_jiffies(10);
	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
		MAX_SCHEDULE_TIMEOUT : idle_period;

	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
		 mmc_hostname(host), period);

	do {
		/*
		 * We claim the host here on drivers behalf for a couple
		 * reasons:
		 *
		 * 1) it is already needed to retrieve the CCCR_INTx;
		 * 2) we want the driver(s) to clear the IRQ condition ASAP;
		 * 3) we need to control the abort condition locally.
		 *
		 * Just like traditional hard IRQ handlers, we expect SDIO
		 * IRQ handlers to be quick and to the point, so that the
		 * holding of the host lock does not cover too much work
		 * that doesn't require that lock to be held.
		 */
		ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
		if (ret)
			break;
		ret = process_sdio_pending_irqs(host);
		host->sdio_irq_pending = false;
		mmc_release_host(host);

		/*
		 * Give other threads a chance to run in the presence of
		 * errors.
		 */
		if (ret < 0) {
			set_current_state(TASK_INTERRUPTIBLE);
			if (!kthread_should_stop())
				schedule_timeout(HZ);
			set_current_state(TASK_RUNNING);
		}

		/*
		 * Adaptive polling frequency based on the assumption
		 * that an interrupt will be closely followed by more.
		 * This has a substantial benefit for network devices.
		 */
		if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
			if (ret > 0)
				period /= 2;
			else {
				period++;
				if (period > idle_period)
					period = idle_period;
			}
		}

		set_current_state(TASK_INTERRUPTIBLE);
		if (host->caps & MMC_CAP_SDIO_IRQ) {
			mmc_host_clk_hold(host);
			host->ops->enable_sdio_irq(host, 1);
			mmc_host_clk_release(host);
		}
		if (!kthread_should_stop())
			schedule_timeout(period);
		set_current_state(TASK_RUNNING);
	} while (!kthread_should_stop());

	if (host->caps & MMC_CAP_SDIO_IRQ) {
		mmc_host_clk_hold(host);
		host->ops->enable_sdio_irq(host, 0);
		mmc_host_clk_release(host);
	}

	pr_debug("%s: IRQ thread exiting with code %d\n",
		 mmc_hostname(host), ret);

	return ret;
}

static int sdio_card_irq_get(struct mmc_card *card)
{
	struct mmc_host *host = card->host;

	WARN_ON(!host->claimed);

	if (!host->sdio_irqs++) {
		if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
			atomic_set(&host->sdio_irq_thread_abort, 0);
			host->sdio_irq_thread =
				kthread_run(sdio_irq_thread, host,
					    "ksdioirqd/%s", mmc_hostname(host));
			if (IS_ERR(host->sdio_irq_thread)) {
				int err = PTR_ERR(host->sdio_irq_thread);
				host->sdio_irqs--;
				return err;
			}
		} else {
			mmc_host_clk_hold(host);
			host->ops->enable_sdio_irq(host, 1);
			mmc_host_clk_release(host);
		}
	}

	return 0;
}

static int sdio_card_irq_put(struct mmc_card *card)
{
	struct mmc_host *host = card->host;

	WARN_ON(!host->claimed);
	BUG_ON(host->sdio_irqs < 1);

	if (!--host->sdio_irqs) {
		if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
			atomic_set(&host->sdio_irq_thread_abort, 1);
			kthread_stop(host->sdio_irq_thread);
		} else {
			mmc_host_clk_hold(host);
			host->ops->enable_sdio_irq(host, 0);
			mmc_host_clk_release(host);
		}
	}

	return 0;
}

/* If there is only 1 function registered set sdio_single_irq */
static void sdio_single_irq_set(struct mmc_card *card)
{
	struct sdio_func *func;
	int i;

	card->sdio_single_irq = NULL;
	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
	    card->host->sdio_irqs == 1)
		for (i = 0; i < card->sdio_funcs; i++) {
		       func = card->sdio_func[i];
		       if (func && func->irq_handler) {
			       card->sdio_single_irq = func;
			       break;
		       }
	       }
}

/**
 *	sdio_claim_irq - claim the IRQ for a SDIO function
 *	@func: SDIO function
 *	@handler: IRQ handler callback
 *
 *	Claim and activate the IRQ for the given SDIO function. The provided
 *	handler will be called when that IRQ is asserted.  The host is always
 *	claimed already when the handler is called so the handler must not
 *	call sdio_claim_host() nor sdio_release_host().
 */
int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
{
	int ret;
	unsigned char reg;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));

	if (func->irq_handler) {
		pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
		return -EBUSY;
	}

	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	if (ret)
		return ret;

	reg |= 1 << func->num;

	reg |= 1; /* Master interrupt enable */

	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	if (ret)
		return ret;

	func->irq_handler = handler;
	ret = sdio_card_irq_get(func->card);
	if (ret)
		func->irq_handler = NULL;
	sdio_single_irq_set(func->card);

	return ret;
}
EXPORT_SYMBOL_GPL(sdio_claim_irq);

/**
 *	sdio_release_irq - release the IRQ for a SDIO function
 *	@func: SDIO function
 *
 *	Disable and release the IRQ for the given SDIO function.
 */
int sdio_release_irq(struct sdio_func *func)
{
	int ret;
	unsigned char reg;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));

	if (func->irq_handler) {
		func->irq_handler = NULL;
		sdio_card_irq_put(func->card);
		sdio_single_irq_set(func->card);
	}

	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	if (ret)
		return ret;

	reg &= ~(1 << func->num);

	/* Disable master interrupt with the last function interrupt */
	if (!(reg & 0xFE))
		reg = 0;

	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	if (ret)
		return ret;

	return 0;
}
EXPORT_SYMBOL_GPL(sdio_release_irq);
Commit	Line	Data
d1496c39 NP	1	/*
	2	* linux/drivers/mmc/core/sdio_irq.c
	3	*
	4	* Author: Nicolas Pitre
	5	* Created: June 18, 2007
	6	* Copyright: MontaVista Software Inc.
	7	*
e633b7bc PO	8	* Copyright 2008 Pierre Ossman
e633b7bc PO	9	*
d1496c39 NP	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or (at
	13	* your option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/sched.h>
	18	#include <linux/kthread.h>
3ef77af1	19	#include <linux/export.h>
d1496c39 NP	20	#include <linux/wait.h>
	21	#include <linux/delay.h>
	22
	23	#include <linux/mmc/core.h>
	24	#include <linux/mmc/host.h>
	25	#include <linux/mmc/card.h>
	26	#include <linux/mmc/sdio.h>
	27	#include <linux/mmc/sdio_func.h>
	28
	29	#include "sdio_ops.h"
	30
bbbc4c4d	31	static int process_sdio_pending_irqs(struct mmc_host *host)
d1496c39	32	{
bbbc4c4d	33	struct mmc_card *card = host->card;
6f4285d1	34	int i, ret, count;
d1496c39	35	unsigned char pending;
06e8935f SNX	36	struct sdio_func *func;
	37
	38	/*
	39	* Optimization, if there is only 1 function interrupt registered
bbbc4c4d NP	40	* and we know an IRQ was signaled then call irq handler directly.
bbbc4c4d NP	41	* Otherwise do the full probe.
06e8935f SNX	42	*/
06e8935f SNX	43	func = card->sdio_single_irq;
bbbc4c4d	44	if (func && host->sdio_irq_pending) {
06e8935f SNX	45	func->irq_handler(func);
	46	return 1;
	47	}
d1496c39 NP	48
	49	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
	50	if (ret) {
a3c76eb9	51	pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
d1496c39 NP	52	mmc_card_id(card), ret);
	53	return ret;
	54	}
	55
e5624054 BZ	56	if (pending && mmc_card_broken_irq_polling(card) &&
	57	!(host->caps & MMC_CAP_SDIO_IRQ)) {
	58	unsigned char dummy;
	59
	60	/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
	61	* register with a Marvell SD8797 card. A dummy CMD52 read to
	62	* function 0 register 0xff can avoid this.
	63	*/
	64	mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
	65	}
	66
6f4285d1	67	count = 0;
d1496c39 NP	68	for (i = 1; i <= 7; i++) {
d1496c39 NP	69	if (pending & (1 << i)) {
06e8935f	70	func = card->sdio_func[i - 1];
d1496c39	71	if (!func) {
a3c76eb9	72	pr_warning("%s: pending IRQ for "
25985edc	73	"non-existent function\n",
3e01e4bc	74	mmc_card_id(card));
599473cf	75	ret = -EINVAL;
d1496c39 NP	76	} else if (func->irq_handler) {
d1496c39 NP	77	func->irq_handler(func);
6f4285d1	78	count++;
599473cf	79	} else {
a3c76eb9	80	pr_warning("%s: pending IRQ with no handler\n",
d1496c39	81	sdio_func_id(func));
599473cf NP	82	ret = -EINVAL;
599473cf NP	83	}
d1496c39 NP	84	}
	85	}
	86
599473cf NP	87	if (count)
	88	return count;
	89
	90	return ret;
d1496c39 NP	91	}
d1496c39 NP	92
bf3b5ec6 RK	93	void sdio_run_irqs(struct mmc_host *host)
	94	{
	95	mmc_claim_host(host);
	96	host->sdio_irq_pending = true;
	97	process_sdio_pending_irqs(host);
	98	mmc_release_host(host);
	99	}
	100	EXPORT_SYMBOL_GPL(sdio_run_irqs);
	101
d1496c39 NP	102	static int sdio_irq_thread(void *_host)
	103	{
	104	struct mmc_host *host = _host;
	105	struct sched_param param = { .sched_priority = 1 };
6f4285d1	106	unsigned long period, idle_period;
d1496c39 NP	107	int ret;
	108
	109	sched_setscheduler(current, SCHED_FIFO, &param);
	110
	111	/*
	112	* We want to allow for SDIO cards to work even on non SDIO
	113	* aware hosts. One thing that non SDIO host cannot do is
	114	* asynchronous notification of pending SDIO card interrupts
	115	* hence we poll for them in that case.
	116	*/
6f4285d1	117	idle_period = msecs_to_jiffies(10);
17b759af	118	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
6f4285d1	119	MAX_SCHEDULE_TIMEOUT : idle_period;
d1496c39 NP	120
	121	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
	122	mmc_hostname(host), period);
	123
	124	do {
	125	/*
	126	* We claim the host here on drivers behalf for a couple
	127	* reasons:
	128	*
	129	* 1) it is already needed to retrieve the CCCR_INTx;
	130	* 2) we want the driver(s) to clear the IRQ condition ASAP;
	131	* 3) we need to control the abort condition locally.
	132	*
	133	* Just like traditional hard IRQ handlers, we expect SDIO
	134	* IRQ handlers to be quick and to the point, so that the
	135	* holding of the host lock does not cover too much work
	136	* that doesn't require that lock to be held.
	137	*/
	138	ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
	139	if (ret)
	140	break;
bbbc4c4d NP	141	ret = process_sdio_pending_irqs(host);
bbbc4c4d NP	142	host->sdio_irq_pending = false;
d1496c39 NP	143	mmc_release_host(host);
	144
	145	/*
	146	* Give other threads a chance to run in the presence of
e633b7bc	147	* errors.
d1496c39	148	*/
e633b7bc PO	149	if (ret < 0) {
	150	set_current_state(TASK_INTERRUPTIBLE);
	151	if (!kthread_should_stop())
	152	schedule_timeout(HZ);
	153	set_current_state(TASK_RUNNING);
	154	}
d1496c39	155
6f4285d1 PO	156	/*
	157	* Adaptive polling frequency based on the assumption
	158	* that an interrupt will be closely followed by more.
	159	* This has a substantial benefit for network devices.
	160	*/
	161	if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
	162	if (ret > 0)
	163	period /= 2;
	164	else {
	165	period++;
	166	if (period > idle_period)
	167	period = idle_period;
	168	}
	169	}
	170
6fee65cf	171	set_current_state(TASK_INTERRUPTIBLE);
2c4967f7 SRT	172	if (host->caps & MMC_CAP_SDIO_IRQ) {
2c4967f7 SRT	173	mmc_host_clk_hold(host);
17b759af	174	host->ops->enable_sdio_irq(host, 1);
2c4967f7 SRT	175	mmc_host_clk_release(host);
2c4967f7 SRT	176	}
d1496c39 NP	177	if (!kthread_should_stop())
d1496c39 NP	178	schedule_timeout(period);
6fee65cf	179	set_current_state(TASK_RUNNING);
d1496c39 NP	180	} while (!kthread_should_stop());
d1496c39 NP	181
2c4967f7 SRT	182	if (host->caps & MMC_CAP_SDIO_IRQ) {
2c4967f7 SRT	183	mmc_host_clk_hold(host);
17b759af	184	host->ops->enable_sdio_irq(host, 0);
2c4967f7 SRT	185	mmc_host_clk_release(host);
2c4967f7 SRT	186	}
17b759af	187
d1496c39 NP	188	pr_debug("%s: IRQ thread exiting with code %d\n",
	189	mmc_hostname(host), ret);
	190
	191	return ret;
	192	}
	193
	194	static int sdio_card_irq_get(struct mmc_card *card)
	195	{
	196	struct mmc_host *host = card->host;
	197
d84075c8	198	WARN_ON(!host->claimed);
d1496c39 NP	199
d1496c39 NP	200	if (!host->sdio_irqs++) {
bf3b5ec6 RK	201	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	202	atomic_set(&host->sdio_irq_thread_abort, 0);
	203	host->sdio_irq_thread =
	204	kthread_run(sdio_irq_thread, host,
	205	"ksdioirqd/%s", mmc_hostname(host));
	206	if (IS_ERR(host->sdio_irq_thread)) {
	207	int err = PTR_ERR(host->sdio_irq_thread);
	208	host->sdio_irqs--;
	209	return err;
	210	}
	211	} else {
	212	mmc_host_clk_hold(host);
	213	host->ops->enable_sdio_irq(host, 1);
	214	mmc_host_clk_release(host);
d1496c39 NP	215	}
	216	}
	217
	218	return 0;
	219	}
	220
	221	static int sdio_card_irq_put(struct mmc_card *card)
	222	{
	223	struct mmc_host *host = card->host;
	224
d84075c8	225	WARN_ON(!host->claimed);
d1496c39 NP	226	BUG_ON(host->sdio_irqs < 1);
	227
	228	if (!--host->sdio_irqs) {
bf3b5ec6 RK	229	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	230	atomic_set(&host->sdio_irq_thread_abort, 1);
	231	kthread_stop(host->sdio_irq_thread);
	232	} else {
	233	mmc_host_clk_hold(host);
	234	host->ops->enable_sdio_irq(host, 0);
	235	mmc_host_clk_release(host);
	236	}
d1496c39 NP	237	}
	238
	239	return 0;
	240	}
	241
06e8935f SNX	242	/* If there is only 1 function registered set sdio_single_irq */
	243	static void sdio_single_irq_set(struct mmc_card *card)
	244	{
	245	struct sdio_func *func;
	246	int i;
	247
	248	card->sdio_single_irq = NULL;
	249	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
	250	card->host->sdio_irqs == 1)
	251	for (i = 0; i < card->sdio_funcs; i++) {
	252	func = card->sdio_func[i];
	253	if (func && func->irq_handler) {
	254	card->sdio_single_irq = func;
	255	break;
	256	}
	257	}
	258	}
	259
d1496c39 NP	260	/**
	261	* sdio_claim_irq - claim the IRQ for a SDIO function
	262	* @func: SDIO function
	263	* @handler: IRQ handler callback
	264	*
	265	* Claim and activate the IRQ for the given SDIO function. The provided
	266	* handler will be called when that IRQ is asserted. The host is always
	267	* claimed already when the handler is called so the handler must not
	268	* call sdio_claim_host() nor sdio_release_host().
	269	*/
	270	int sdio_claim_irq(struct sdio_func func, sdio_irq_handler_t handler)
	271	{
	272	int ret;
	273	unsigned char reg;
	274
	275	BUG_ON(!func);
	276	BUG_ON(!func->card);
	277
	278	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
	279
	280	if (func->irq_handler) {
	281	pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
	282	return -EBUSY;
	283	}
	284
	285	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	286	if (ret)
	287	return ret;
	288
	289	reg \|= 1 << func->num;
	290
	291	reg \|= 1; /* Master interrupt enable */
	292
	293	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	294	if (ret)
	295	return ret;
	296
	297	func->irq_handler = handler;
	298	ret = sdio_card_irq_get(func->card);
	299	if (ret)
	300	func->irq_handler = NULL;
06e8935f	301	sdio_single_irq_set(func->card);
d1496c39 NP	302
	303	return ret;
	304	}
	305	EXPORT_SYMBOL_GPL(sdio_claim_irq);
	306
	307	/**
	308	* sdio_release_irq - release the IRQ for a SDIO function
	309	* @func: SDIO function
	310	*
	311	* Disable and release the IRQ for the given SDIO function.
	312	*/
	313	int sdio_release_irq(struct sdio_func *func)
	314	{
	315	int ret;
	316	unsigned char reg;
	317
	318	BUG_ON(!func);
	319	BUG_ON(!func->card);
	320
	321	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
	322
	323	if (func->irq_handler) {
	324	func->irq_handler = NULL;
	325	sdio_card_irq_put(func->card);
06e8935f	326	sdio_single_irq_set(func->card);
d1496c39 NP	327	}
	328
	329	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	330	if (ret)
	331	return ret;
	332
	333	reg &= ~(1 << func->num);
	334
	335	/* Disable master interrupt with the last function interrupt */
	336	if (!(reg & 0xFE))
	337	reg = 0;
	338
	339	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	340	if (ret)
	341	return ret;
	342
	343	return 0;
	344	}
	345	EXPORT_SYMBOL_GPL(sdio_release_irq);
	346