[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"
#include "core.h"
#include "card.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_warn("%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_warn("%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)
			host->ops->enable_sdio_irq(host, 1);
		if (!kthread_should_stop())
			schedule_timeout(period);
		set_current_state(TASK_RUNNING);
	} while (!kthread_should_stop());

	if (host->caps & MMC_CAP_SDIO_IRQ)
		host->ops->enable_sdio_irq(host, 0);

	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 if (host->caps & MMC_CAP_SDIO_IRQ) {
			host->ops->enable_sdio_irq(host, 1);
		}
	}

	return 0;
}

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

	WARN_ON(!host->claimed);

	if (host->sdio_irqs < 1)
		return -EINVAL;

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

	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;

	if (!func)
		return -EINVAL;

	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;

	if (!func)
		return -EINVAL;

	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"
55244c56	30	#include "core.h"
4facdde1	31	#include "card.h"
d1496c39	32
bbbc4c4d	33	static int process_sdio_pending_irqs(struct mmc_host *host)
d1496c39	34	{
bbbc4c4d	35	struct mmc_card *card = host->card;
6f4285d1	36	int i, ret, count;
d1496c39	37	unsigned char pending;
06e8935f SNX	38	struct sdio_func *func;
	39
	40	/*
	41	* Optimization, if there is only 1 function interrupt registered
bbbc4c4d NP	42	* and we know an IRQ was signaled then call irq handler directly.
bbbc4c4d NP	43	* Otherwise do the full probe.
06e8935f SNX	44	*/
06e8935f SNX	45	func = card->sdio_single_irq;
bbbc4c4d	46	if (func && host->sdio_irq_pending) {
06e8935f SNX	47	func->irq_handler(func);
	48	return 1;
	49	}
d1496c39 NP	50
	51	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
	52	if (ret) {
a3c76eb9	53	pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
d1496c39 NP	54	mmc_card_id(card), ret);
	55	return ret;
	56	}
	57
e5624054 BZ	58	if (pending && mmc_card_broken_irq_polling(card) &&
	59	!(host->caps & MMC_CAP_SDIO_IRQ)) {
	60	unsigned char dummy;
	61
	62	/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
	63	* register with a Marvell SD8797 card. A dummy CMD52 read to
	64	* function 0 register 0xff can avoid this.
	65	*/
	66	mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
	67	}
	68
6f4285d1	69	count = 0;
d1496c39 NP	70	for (i = 1; i <= 7; i++) {
d1496c39 NP	71	if (pending & (1 << i)) {
06e8935f	72	func = card->sdio_func[i - 1];
d1496c39	73	if (!func) {
6606110d	74	pr_warn("%s: pending IRQ for non-existent function\n",
3e01e4bc	75	mmc_card_id(card));
599473cf	76	ret = -EINVAL;
d1496c39 NP	77	} else if (func->irq_handler) {
d1496c39 NP	78	func->irq_handler(func);
6f4285d1	79	count++;
599473cf	80	} else {
6606110d JP	81	pr_warn("%s: pending IRQ with no handler\n",
6606110d JP	82	sdio_func_id(func));
599473cf NP	83	ret = -EINVAL;
599473cf NP	84	}
d1496c39 NP	85	}
	86	}
	87
599473cf NP	88	if (count)
	89	return count;
	90
	91	return ret;
d1496c39 NP	92	}
d1496c39 NP	93
bf3b5ec6 RK	94	void sdio_run_irqs(struct mmc_host *host)
	95	{
	96	mmc_claim_host(host);
	97	host->sdio_irq_pending = true;
	98	process_sdio_pending_irqs(host);
	99	mmc_release_host(host);
	100	}
	101	EXPORT_SYMBOL_GPL(sdio_run_irqs);
	102
d1496c39 NP	103	static int sdio_irq_thread(void *_host)
	104	{
	105	struct mmc_host *host = _host;
	106	struct sched_param param = { .sched_priority = 1 };
6f4285d1	107	unsigned long period, idle_period;
d1496c39 NP	108	int ret;
	109
	110	sched_setscheduler(current, SCHED_FIFO, &param);
	111
	112	/*
	113	* We want to allow for SDIO cards to work even on non SDIO
	114	* aware hosts. One thing that non SDIO host cannot do is
	115	* asynchronous notification of pending SDIO card interrupts
	116	* hence we poll for them in that case.
	117	*/
6f4285d1	118	idle_period = msecs_to_jiffies(10);
17b759af	119	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
6f4285d1	120	MAX_SCHEDULE_TIMEOUT : idle_period;
d1496c39 NP	121
	122	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
	123	mmc_hostname(host), period);
	124
	125	do {
	126	/*
	127	* We claim the host here on drivers behalf for a couple
	128	* reasons:
	129	*
	130	* 1) it is already needed to retrieve the CCCR_INTx;
	131	* 2) we want the driver(s) to clear the IRQ condition ASAP;
	132	* 3) we need to control the abort condition locally.
	133	*
	134	* Just like traditional hard IRQ handlers, we expect SDIO
	135	* IRQ handlers to be quick and to the point, so that the
	136	* holding of the host lock does not cover too much work
	137	* that doesn't require that lock to be held.
	138	*/
	139	ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
	140	if (ret)
	141	break;
bbbc4c4d NP	142	ret = process_sdio_pending_irqs(host);
bbbc4c4d NP	143	host->sdio_irq_pending = false;
d1496c39 NP	144	mmc_release_host(host);
	145
	146	/*
	147	* Give other threads a chance to run in the presence of
e633b7bc	148	* errors.
d1496c39	149	*/
e633b7bc PO	150	if (ret < 0) {
	151	set_current_state(TASK_INTERRUPTIBLE);
	152	if (!kthread_should_stop())
	153	schedule_timeout(HZ);
	154	set_current_state(TASK_RUNNING);
	155	}
d1496c39	156
6f4285d1 PO	157	/*
	158	* Adaptive polling frequency based on the assumption
	159	* that an interrupt will be closely followed by more.
	160	* This has a substantial benefit for network devices.
	161	*/
	162	if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
	163	if (ret > 0)
	164	period /= 2;
	165	else {
	166	period++;
	167	if (period > idle_period)
	168	period = idle_period;
	169	}
	170	}
	171
6fee65cf	172	set_current_state(TASK_INTERRUPTIBLE);
9eadcc05	173	if (host->caps & MMC_CAP_SDIO_IRQ)
17b759af	174	host->ops->enable_sdio_irq(host, 1);
d1496c39 NP	175	if (!kthread_should_stop())
d1496c39 NP	176	schedule_timeout(period);
6fee65cf	177	set_current_state(TASK_RUNNING);
d1496c39 NP	178	} while (!kthread_should_stop());
d1496c39 NP	179
9eadcc05	180	if (host->caps & MMC_CAP_SDIO_IRQ)
17b759af NP	181	host->ops->enable_sdio_irq(host, 0);
17b759af NP	182
d1496c39 NP	183	pr_debug("%s: IRQ thread exiting with code %d\n",
	184	mmc_hostname(host), ret);
	185
	186	return ret;
	187	}
	188
	189	static int sdio_card_irq_get(struct mmc_card *card)
	190	{
	191	struct mmc_host *host = card->host;
	192
d84075c8	193	WARN_ON(!host->claimed);
d1496c39 NP	194
d1496c39 NP	195	if (!host->sdio_irqs++) {
bf3b5ec6 RK	196	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	197	atomic_set(&host->sdio_irq_thread_abort, 0);
	198	host->sdio_irq_thread =
	199	kthread_run(sdio_irq_thread, host,
	200	"ksdioirqd/%s", mmc_hostname(host));
	201	if (IS_ERR(host->sdio_irq_thread)) {
	202	int err = PTR_ERR(host->sdio_irq_thread);
	203	host->sdio_irqs--;
	204	return err;
	205	}
dea67c4e	206	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
bf3b5ec6	207	host->ops->enable_sdio_irq(host, 1);
d1496c39 NP	208	}
	209	}
	210
	211	return 0;
	212	}
	213
	214	static int sdio_card_irq_put(struct mmc_card *card)
	215	{
	216	struct mmc_host *host = card->host;
	217
d84075c8	218	WARN_ON(!host->claimed);
5df0e823 SL	219
	220	if (host->sdio_irqs < 1)
	221	return -EINVAL;
d1496c39 NP	222
d1496c39 NP	223	if (!--host->sdio_irqs) {
bf3b5ec6 RK	224	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	225	atomic_set(&host->sdio_irq_thread_abort, 1);
	226	kthread_stop(host->sdio_irq_thread);
dea67c4e	227	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
bf3b5ec6	228	host->ops->enable_sdio_irq(host, 0);
bf3b5ec6	229	}
d1496c39 NP	230	}
	231
	232	return 0;
	233	}
	234
06e8935f SNX	235	/* If there is only 1 function registered set sdio_single_irq */
	236	static void sdio_single_irq_set(struct mmc_card *card)
	237	{
	238	struct sdio_func *func;
	239	int i;
	240
	241	card->sdio_single_irq = NULL;
	242	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
	243	card->host->sdio_irqs == 1)
	244	for (i = 0; i < card->sdio_funcs; i++) {
	245	func = card->sdio_func[i];
	246	if (func && func->irq_handler) {
	247	card->sdio_single_irq = func;
	248	break;
	249	}
	250	}
	251	}
	252
d1496c39 NP	253	/**
	254	* sdio_claim_irq - claim the IRQ for a SDIO function
	255	* @func: SDIO function
	256	* @handler: IRQ handler callback
	257	*
	258	* Claim and activate the IRQ for the given SDIO function. The provided
	259	* handler will be called when that IRQ is asserted. The host is always
	260	* claimed already when the handler is called so the handler must not
	261	* call sdio_claim_host() nor sdio_release_host().
	262	*/
	263	int sdio_claim_irq(struct sdio_func func, sdio_irq_handler_t handler)
	264	{
	265	int ret;
	266	unsigned char reg;
	267
5df0e823 SL	268	if (!func)
5df0e823 SL	269	return -EINVAL;
d1496c39 NP	270
	271	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
	272
	273	if (func->irq_handler) {
	274	pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
	275	return -EBUSY;
	276	}
	277
	278	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	279	if (ret)
	280	return ret;
	281
	282	reg \|= 1 << func->num;
	283
	284	reg \|= 1; /* Master interrupt enable */
	285
	286	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	287	if (ret)
	288	return ret;
	289
	290	func->irq_handler = handler;
	291	ret = sdio_card_irq_get(func->card);
	292	if (ret)
	293	func->irq_handler = NULL;
06e8935f	294	sdio_single_irq_set(func->card);
d1496c39 NP	295
	296	return ret;
	297	}
	298	EXPORT_SYMBOL_GPL(sdio_claim_irq);
	299
	300	/**
	301	* sdio_release_irq - release the IRQ for a SDIO function
	302	* @func: SDIO function
	303	*
	304	* Disable and release the IRQ for the given SDIO function.
	305	*/
	306	int sdio_release_irq(struct sdio_func *func)
	307	{
	308	int ret;
	309	unsigned char reg;
	310
5df0e823 SL	311	if (!func)
5df0e823 SL	312	return -EINVAL;
d1496c39 NP	313
	314	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
	315
	316	if (func->irq_handler) {
	317	func->irq_handler = NULL;
	318	sdio_card_irq_put(func->card);
06e8935f	319	sdio_single_irq_set(func->card);
d1496c39 NP	320	}
	321
	322	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	323	if (ret)
	324	return ret;
	325
	326	reg &= ~(1 << func->num);
	327
	328	/* Disable master interrupt with the last function interrupt */
	329	if (!(reg & 0xFE))
	330	reg = 0;
	331
	332	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	333	if (ret)
	334	return ret;
	335
	336	return 0;
	337	}
	338	EXPORT_SYMBOL_GPL(sdio_release_irq);
	339