[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 <uapi/linux/sched/types.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);
	if (host->sdio_irqs) {
		host->sdio_irq_pending = true;
		process_sdio_pending_irqs(host);
		if (host->ops->ack_sdio_irq)
			host->ops->ack_sdio_irq(host);
	}
	mmc_release_host(host);
}
EXPORT_SYMBOL_GPL(sdio_run_irqs);

void sdio_irq_work(struct work_struct *work)
{
	struct mmc_host *host =
		container_of(work, struct mmc_host, sdio_irq_work.work);

	sdio_run_irqs(host);
}

void sdio_signal_irq(struct mmc_host *host)
{
	queue_delayed_work(system_wq, &host->sdio_irq_work, 0);
}
EXPORT_SYMBOL_GPL(sdio_signal_irq);

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
	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	*
	8	* Copyright 2008 Pierre Ossman
	9	*
	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 <uapi/linux/sched/types.h>
	19	#include <linux/kthread.h>
	20	#include <linux/export.h>
	21	#include <linux/wait.h>
	22	#include <linux/delay.h>
	23
	24	#include <linux/mmc/core.h>
	25	#include <linux/mmc/host.h>
	26	#include <linux/mmc/card.h>
	27	#include <linux/mmc/sdio.h>
	28	#include <linux/mmc/sdio_func.h>
	29
	30	#include "sdio_ops.h"
	31	#include "core.h"
	32	#include "card.h"
	33
	34	static int process_sdio_pending_irqs(struct mmc_host *host)
	35	{
	36	struct mmc_card *card = host->card;
	37	int i, ret, count;
	38	unsigned char pending;
	39	struct sdio_func *func;
	40
	41	/*
	42	* Optimization, if there is only 1 function interrupt registered
	43	* and we know an IRQ was signaled then call irq handler directly.
	44	* Otherwise do the full probe.
	45	*/
	46	func = card->sdio_single_irq;
	47	if (func && host->sdio_irq_pending) {
	48	func->irq_handler(func);
	49	return 1;
	50	}
	51
	52	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
	53	if (ret) {
	54	pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
	55	mmc_card_id(card), ret);
	56	return ret;
	57	}
	58
	59	if (pending && mmc_card_broken_irq_polling(card) &&
	60	!(host->caps & MMC_CAP_SDIO_IRQ)) {
	61	unsigned char dummy;
	62
	63	/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
	64	* register with a Marvell SD8797 card. A dummy CMD52 read to
	65	* function 0 register 0xff can avoid this.
	66	*/
	67	mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
	68	}
	69
	70	count = 0;
	71	for (i = 1; i <= 7; i++) {
	72	if (pending & (1 << i)) {
	73	func = card->sdio_func[i - 1];
	74	if (!func) {
	75	pr_warn("%s: pending IRQ for non-existent function\n",
	76	mmc_card_id(card));
	77	ret = -EINVAL;
	78	} else if (func->irq_handler) {
	79	func->irq_handler(func);
	80	count++;
	81	} else {
	82	pr_warn("%s: pending IRQ with no handler\n",
	83	sdio_func_id(func));
	84	ret = -EINVAL;
	85	}
	86	}
	87	}
	88
	89	if (count)
	90	return count;
	91
	92	return ret;
	93	}
	94
	95	void sdio_run_irqs(struct mmc_host *host)
	96	{
	97	mmc_claim_host(host);
	98	if (host->sdio_irqs) {
	99	host->sdio_irq_pending = true;
	100	process_sdio_pending_irqs(host);
	101	if (host->ops->ack_sdio_irq)
	102	host->ops->ack_sdio_irq(host);
	103	}
	104	mmc_release_host(host);
	105	}
	106	EXPORT_SYMBOL_GPL(sdio_run_irqs);
	107
	108	void sdio_irq_work(struct work_struct *work)
	109	{
	110	struct mmc_host *host =
	111	container_of(work, struct mmc_host, sdio_irq_work.work);
	112
	113	sdio_run_irqs(host);
	114	}
	115
	116	void sdio_signal_irq(struct mmc_host *host)
	117	{
	118	queue_delayed_work(system_wq, &host->sdio_irq_work, 0);
	119	}
	120	EXPORT_SYMBOL_GPL(sdio_signal_irq);
	121
	122	static int sdio_irq_thread(void *_host)
	123	{
	124	struct mmc_host *host = _host;
	125	struct sched_param param = { .sched_priority = 1 };
	126	unsigned long period, idle_period;
	127	int ret;
	128
	129	sched_setscheduler(current, SCHED_FIFO, &param);
	130
	131	/*
	132	* We want to allow for SDIO cards to work even on non SDIO
	133	* aware hosts. One thing that non SDIO host cannot do is
	134	* asynchronous notification of pending SDIO card interrupts
	135	* hence we poll for them in that case.
	136	*/
	137	idle_period = msecs_to_jiffies(10);
	138	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
	139	MAX_SCHEDULE_TIMEOUT : idle_period;
	140
	141	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
	142	mmc_hostname(host), period);
	143
	144	do {
	145	/*
	146	* We claim the host here on drivers behalf for a couple
	147	* reasons:
	148	*
	149	* 1) it is already needed to retrieve the CCCR_INTx;
	150	* 2) we want the driver(s) to clear the IRQ condition ASAP;
	151	* 3) we need to control the abort condition locally.
	152	*
	153	* Just like traditional hard IRQ handlers, we expect SDIO
	154	* IRQ handlers to be quick and to the point, so that the
	155	* holding of the host lock does not cover too much work
	156	* that doesn't require that lock to be held.
	157	*/
	158	ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
	159	if (ret)
	160	break;
	161	ret = process_sdio_pending_irqs(host);
	162	host->sdio_irq_pending = false;
	163	mmc_release_host(host);
	164
	165	/*
	166	* Give other threads a chance to run in the presence of
	167	* errors.
	168	*/
	169	if (ret < 0) {
	170	set_current_state(TASK_INTERRUPTIBLE);
	171	if (!kthread_should_stop())
	172	schedule_timeout(HZ);
	173	set_current_state(TASK_RUNNING);
	174	}
	175
	176	/*
	177	* Adaptive polling frequency based on the assumption
	178	* that an interrupt will be closely followed by more.
	179	* This has a substantial benefit for network devices.
	180	*/
	181	if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
	182	if (ret > 0)
	183	period /= 2;
	184	else {
	185	period++;
	186	if (period > idle_period)
	187	period = idle_period;
	188	}
	189	}
	190
	191	set_current_state(TASK_INTERRUPTIBLE);
	192	if (host->caps & MMC_CAP_SDIO_IRQ)
	193	host->ops->enable_sdio_irq(host, 1);
	194	if (!kthread_should_stop())
	195	schedule_timeout(period);
	196	set_current_state(TASK_RUNNING);
	197	} while (!kthread_should_stop());
	198
	199	if (host->caps & MMC_CAP_SDIO_IRQ)
	200	host->ops->enable_sdio_irq(host, 0);
	201
	202	pr_debug("%s: IRQ thread exiting with code %d\n",
	203	mmc_hostname(host), ret);
	204
	205	return ret;
	206	}
	207
	208	static int sdio_card_irq_get(struct mmc_card *card)
	209	{
	210	struct mmc_host *host = card->host;
	211
	212	WARN_ON(!host->claimed);
	213
	214	if (!host->sdio_irqs++) {
	215	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	216	atomic_set(&host->sdio_irq_thread_abort, 0);
	217	host->sdio_irq_thread =
	218	kthread_run(sdio_irq_thread, host,
	219	"ksdioirqd/%s", mmc_hostname(host));
	220	if (IS_ERR(host->sdio_irq_thread)) {
	221	int err = PTR_ERR(host->sdio_irq_thread);
	222	host->sdio_irqs--;
	223	return err;
	224	}
	225	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
	226	host->ops->enable_sdio_irq(host, 1);
	227	}
	228	}
	229
	230	return 0;
	231	}
	232
	233	static int sdio_card_irq_put(struct mmc_card *card)
	234	{
	235	struct mmc_host *host = card->host;
	236
	237	WARN_ON(!host->claimed);
	238
	239	if (host->sdio_irqs < 1)
	240	return -EINVAL;
	241
	242	if (!--host->sdio_irqs) {
	243	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	244	atomic_set(&host->sdio_irq_thread_abort, 1);
	245	kthread_stop(host->sdio_irq_thread);
	246	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
	247	host->ops->enable_sdio_irq(host, 0);
	248	}
	249	}
	250
	251	return 0;
	252	}
	253
	254	/* If there is only 1 function registered set sdio_single_irq */
	255	static void sdio_single_irq_set(struct mmc_card *card)
	256	{
	257	struct sdio_func *func;
	258	int i;
	259
	260	card->sdio_single_irq = NULL;
	261	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
	262	card->host->sdio_irqs == 1)
	263	for (i = 0; i < card->sdio_funcs; i++) {
	264	func = card->sdio_func[i];
	265	if (func && func->irq_handler) {
	266	card->sdio_single_irq = func;
	267	break;
	268	}
	269	}
	270	}
	271
	272	/**
	273	* sdio_claim_irq - claim the IRQ for a SDIO function
	274	* @func: SDIO function
	275	* @handler: IRQ handler callback
	276	*
	277	* Claim and activate the IRQ for the given SDIO function. The provided
	278	* handler will be called when that IRQ is asserted. The host is always
	279	* claimed already when the handler is called so the handler must not
	280	* call sdio_claim_host() nor sdio_release_host().
	281	*/
	282	int sdio_claim_irq(struct sdio_func func, sdio_irq_handler_t handler)
	283	{
	284	int ret;
	285	unsigned char reg;
	286
	287	if (!func)
	288	return -EINVAL;
	289
	290	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
	291
	292	if (func->irq_handler) {
	293	pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
	294	return -EBUSY;
	295	}
	296
	297	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	298	if (ret)
	299	return ret;
	300
	301	reg \|= 1 << func->num;
	302
	303	reg \|= 1; /* Master interrupt enable */
	304
	305	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	306	if (ret)
	307	return ret;
	308
	309	func->irq_handler = handler;
	310	ret = sdio_card_irq_get(func->card);
	311	if (ret)
	312	func->irq_handler = NULL;
	313	sdio_single_irq_set(func->card);
	314
	315	return ret;
	316	}
	317	EXPORT_SYMBOL_GPL(sdio_claim_irq);
	318
	319	/**
	320	* sdio_release_irq - release the IRQ for a SDIO function
	321	* @func: SDIO function
	322	*
	323	* Disable and release the IRQ for the given SDIO function.
	324	*/
	325	int sdio_release_irq(struct sdio_func *func)
	326	{
	327	int ret;
	328	unsigned char reg;
	329
	330	if (!func)
	331	return -EINVAL;
	332
	333	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
	334
	335	if (func->irq_handler) {
	336	func->irq_handler = NULL;
	337	sdio_card_irq_put(func->card);
	338	sdio_single_irq_set(func->card);
	339	}
	340
	341	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	342	if (ret)
	343	return ret;
	344
	345	reg &= ~(1 << func->num);
	346
	347	/* Disable master interrupt with the last function interrupt */
	348	if (!(reg & 0xFE))
	349	reg = 0;
	350
	351	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	352	if (ret)
	353	return ret;
	354
	355	return 0;
	356	}
	357	EXPORT_SYMBOL_GPL(sdio_release_irq);
	358