[linux-2.6-block.git] / drivers / mmc / core / sdio_irq.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * linux/drivers/mmc/core/sdio_irq.c
 *
 * Author:      Nicolas Pitre
 * Created:     June 18, 2007
 * Copyright:   MontaVista Software Inc.
 *
 * Copyright 2008 Pierre Ossman
 */

#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 sdio_get_pending_irqs(struct mmc_host *host, u8 *pending)
{
	struct mmc_card *card = host->card;
	int ret;

	WARN_ON(!host->claimed);

	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);
	}

	return 0;
}

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

	/* Don't process SDIO IRQs if the card is suspended. */
	if (mmc_card_suspended(card))
		return 0;

	/* Clear the flag to indicate that we have processed the IRQ. */
	host->sdio_irq_pending = false;

	/*
	 * 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 && sdio_irq_pending) {
		func->irq_handler(func);
		return 1;
	}

	ret = sdio_get_pending_irqs(host, &pending);
	if (ret)
		return ret;

	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;
}

static void sdio_run_irqs(struct mmc_host *host)
{
	mmc_claim_host(host);
	if (host->sdio_irqs) {
		process_sdio_pending_irqs(host);
		if (!host->sdio_irq_pending)
			host->ops->ack_sdio_irq(host);
	}
	mmc_release_host(host);
}

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

	sdio_run_irqs(host);
}

void sdio_signal_irq(struct mmc_host *host)
{
	host->sdio_irq_pending = true;
	schedule_work(&host->sdio_irq_work);
}
EXPORT_SYMBOL_GPL(sdio_signal_irq);

static int sdio_irq_thread(void *_host)
{
	struct mmc_host *host = _host;
	unsigned long period, idle_period;
	int ret;

	sched_set_fifo_low(current);

	/*
	 * 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, NULL,
				       &host->sdio_irq_thread_abort);
		if (ret)
			break;
		ret = process_sdio_pending_irqs(host);
		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 should not
 *	call sdio_claim_host() or 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	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* linux/drivers/mmc/core/sdio_irq.c
	4	*
	5	* Author: Nicolas Pitre
	6	* Created: June 18, 2007
	7	* Copyright: MontaVista Software Inc.
	8	*
	9	* Copyright 2008 Pierre Ossman
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/sched.h>
	14	#include <uapi/linux/sched/types.h>
	15	#include <linux/kthread.h>
	16	#include <linux/export.h>
	17	#include <linux/wait.h>
	18	#include <linux/delay.h>
	19
	20	#include <linux/mmc/core.h>
	21	#include <linux/mmc/host.h>
	22	#include <linux/mmc/card.h>
	23	#include <linux/mmc/sdio.h>
	24	#include <linux/mmc/sdio_func.h>
	25
	26	#include "sdio_ops.h"
	27	#include "core.h"
	28	#include "card.h"
	29
	30	static int sdio_get_pending_irqs(struct mmc_host host, u8 pending)
	31	{
	32	struct mmc_card *card = host->card;
	33	int ret;
	34
	35	WARN_ON(!host->claimed);
	36
	37	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, pending);
	38	if (ret) {
	39	pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
	40	mmc_card_id(card), ret);
	41	return ret;
	42	}
	43
	44	if (*pending && mmc_card_broken_irq_polling(card) &&
	45	!(host->caps & MMC_CAP_SDIO_IRQ)) {
	46	unsigned char dummy;
	47
	48	/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
	49	* register with a Marvell SD8797 card. A dummy CMD52 read to
	50	* function 0 register 0xff can avoid this.
	51	*/
	52	mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
	53	}
	54
	55	return 0;
	56	}
	57
	58	static int process_sdio_pending_irqs(struct mmc_host *host)
	59	{
	60	struct mmc_card *card = host->card;
	61	int i, ret, count;
	62	bool sdio_irq_pending = host->sdio_irq_pending;
	63	unsigned char pending;
	64	struct sdio_func *func;
	65
	66	/* Don't process SDIO IRQs if the card is suspended. */
	67	if (mmc_card_suspended(card))
	68	return 0;
	69
	70	/* Clear the flag to indicate that we have processed the IRQ. */
	71	host->sdio_irq_pending = false;
	72
	73	/*
	74	* Optimization, if there is only 1 function interrupt registered
	75	* and we know an IRQ was signaled then call irq handler directly.
	76	* Otherwise do the full probe.
	77	*/
	78	func = card->sdio_single_irq;
	79	if (func && sdio_irq_pending) {
	80	func->irq_handler(func);
	81	return 1;
	82	}
	83
	84	ret = sdio_get_pending_irqs(host, &pending);
	85	if (ret)
	86	return ret;
	87
	88	count = 0;
	89	for (i = 1; i <= 7; i++) {
	90	if (pending & (1 << i)) {
	91	func = card->sdio_func[i - 1];
	92	if (!func) {
	93	pr_warn("%s: pending IRQ for non-existent function\n",
	94	mmc_card_id(card));
	95	ret = -EINVAL;
	96	} else if (func->irq_handler) {
	97	func->irq_handler(func);
	98	count++;
	99	} else {
	100	pr_warn("%s: pending IRQ with no handler\n",
	101	sdio_func_id(func));
	102	ret = -EINVAL;
	103	}
	104	}
	105	}
	106
	107	if (count)
	108	return count;
	109
	110	return ret;
	111	}
	112
	113	static void sdio_run_irqs(struct mmc_host *host)
	114	{
	115	mmc_claim_host(host);
	116	if (host->sdio_irqs) {
	117	process_sdio_pending_irqs(host);
	118	if (!host->sdio_irq_pending)
	119	host->ops->ack_sdio_irq(host);
	120	}
	121	mmc_release_host(host);
	122	}
	123
	124	void sdio_irq_work(struct work_struct *work)
	125	{
	126	struct mmc_host *host =
	127	container_of(work, struct mmc_host, sdio_irq_work);
	128
	129	sdio_run_irqs(host);
	130	}
	131
	132	void sdio_signal_irq(struct mmc_host *host)
	133	{
	134	host->sdio_irq_pending = true;
	135	schedule_work(&host->sdio_irq_work);
	136	}
	137	EXPORT_SYMBOL_GPL(sdio_signal_irq);
	138
	139	static int sdio_irq_thread(void *_host)
	140	{
	141	struct mmc_host *host = _host;
	142	unsigned long period, idle_period;
	143	int ret;
	144
	145	sched_set_fifo_low(current);
	146
	147	/*
	148	* We want to allow for SDIO cards to work even on non SDIO
	149	* aware hosts. One thing that non SDIO host cannot do is
	150	* asynchronous notification of pending SDIO card interrupts
	151	* hence we poll for them in that case.
	152	*/
	153	idle_period = msecs_to_jiffies(10);
	154	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
	155	MAX_SCHEDULE_TIMEOUT : idle_period;
	156
	157	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
	158	mmc_hostname(host), period);
	159
	160	do {
	161	/*
	162	* We claim the host here on drivers behalf for a couple
	163	* reasons:
	164	*
	165	* 1) it is already needed to retrieve the CCCR_INTx;
	166	* 2) we want the driver(s) to clear the IRQ condition ASAP;
	167	* 3) we need to control the abort condition locally.
	168	*
	169	* Just like traditional hard IRQ handlers, we expect SDIO
	170	* IRQ handlers to be quick and to the point, so that the
	171	* holding of the host lock does not cover too much work
	172	* that doesn't require that lock to be held.
	173	*/
	174	ret = __mmc_claim_host(host, NULL,
	175	&host->sdio_irq_thread_abort);
	176	if (ret)
	177	break;
	178	ret = process_sdio_pending_irqs(host);
	179	mmc_release_host(host);
	180
	181	/*
	182	* Give other threads a chance to run in the presence of
	183	* errors.
	184	*/
	185	if (ret < 0) {
	186	set_current_state(TASK_INTERRUPTIBLE);
	187	if (!kthread_should_stop())
	188	schedule_timeout(HZ);
	189	set_current_state(TASK_RUNNING);
	190	}
	191
	192	/*
	193	* Adaptive polling frequency based on the assumption
	194	* that an interrupt will be closely followed by more.
	195	* This has a substantial benefit for network devices.
	196	*/
	197	if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
	198	if (ret > 0)
	199	period /= 2;
	200	else {
	201	period++;
	202	if (period > idle_period)
	203	period = idle_period;
	204	}
	205	}
	206
	207	set_current_state(TASK_INTERRUPTIBLE);
	208	if (host->caps & MMC_CAP_SDIO_IRQ)
	209	host->ops->enable_sdio_irq(host, 1);
	210	if (!kthread_should_stop())
	211	schedule_timeout(period);
	212	set_current_state(TASK_RUNNING);
	213	} while (!kthread_should_stop());
	214
	215	if (host->caps & MMC_CAP_SDIO_IRQ)
	216	host->ops->enable_sdio_irq(host, 0);
	217
	218	pr_debug("%s: IRQ thread exiting with code %d\n",
	219	mmc_hostname(host), ret);
	220
	221	return ret;
	222	}
	223
	224	static int sdio_card_irq_get(struct mmc_card *card)
	225	{
	226	struct mmc_host *host = card->host;
	227
	228	WARN_ON(!host->claimed);
	229
	230	if (!host->sdio_irqs++) {
	231	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	232	atomic_set(&host->sdio_irq_thread_abort, 0);
	233	host->sdio_irq_thread =
	234	kthread_run(sdio_irq_thread, host,
	235	"ksdioirqd/%s", mmc_hostname(host));
	236	if (IS_ERR(host->sdio_irq_thread)) {
	237	int err = PTR_ERR(host->sdio_irq_thread);
	238	host->sdio_irqs--;
	239	return err;
	240	}
	241	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
	242	host->ops->enable_sdio_irq(host, 1);
	243	}
	244	}
	245
	246	return 0;
	247	}
	248
	249	static int sdio_card_irq_put(struct mmc_card *card)
	250	{
	251	struct mmc_host *host = card->host;
	252
	253	WARN_ON(!host->claimed);
	254
	255	if (host->sdio_irqs < 1)
	256	return -EINVAL;
	257
	258	if (!--host->sdio_irqs) {
	259	if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
	260	atomic_set(&host->sdio_irq_thread_abort, 1);
	261	kthread_stop(host->sdio_irq_thread);
	262	} else if (host->caps & MMC_CAP_SDIO_IRQ) {
	263	host->ops->enable_sdio_irq(host, 0);
	264	}
	265	}
	266
	267	return 0;
	268	}
	269
	270	/* If there is only 1 function registered set sdio_single_irq */
	271	static void sdio_single_irq_set(struct mmc_card *card)
	272	{
	273	struct sdio_func *func;
	274	int i;
	275
	276	card->sdio_single_irq = NULL;
	277	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
	278	card->host->sdio_irqs == 1) {
	279	for (i = 0; i < card->sdio_funcs; i++) {
	280	func = card->sdio_func[i];
	281	if (func && func->irq_handler) {
	282	card->sdio_single_irq = func;
	283	break;
	284	}
	285	}
	286	}
	287	}
	288
	289	/**
	290	* sdio_claim_irq - claim the IRQ for a SDIO function
	291	* @func: SDIO function
	292	* @handler: IRQ handler callback
	293	*
	294	* Claim and activate the IRQ for the given SDIO function. The provided
	295	* handler will be called when that IRQ is asserted. The host is always
	296	* claimed already when the handler is called so the handler should not
	297	* call sdio_claim_host() or sdio_release_host().
	298	*/
	299	int sdio_claim_irq(struct sdio_func func, sdio_irq_handler_t handler)
	300	{
	301	int ret;
	302	unsigned char reg;
	303
	304	if (!func)
	305	return -EINVAL;
	306
	307	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
	308
	309	if (func->irq_handler) {
	310	pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
	311	return -EBUSY;
	312	}
	313
	314	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	315	if (ret)
	316	return ret;
	317
	318	reg \|= 1 << func->num;
	319
	320	reg \|= 1; /* Master interrupt enable */
	321
	322	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	323	if (ret)
	324	return ret;
	325
	326	func->irq_handler = handler;
	327	ret = sdio_card_irq_get(func->card);
	328	if (ret)
	329	func->irq_handler = NULL;
	330	sdio_single_irq_set(func->card);
	331
	332	return ret;
	333	}
	334	EXPORT_SYMBOL_GPL(sdio_claim_irq);
	335
	336	/**
	337	* sdio_release_irq - release the IRQ for a SDIO function
	338	* @func: SDIO function
	339	*
	340	* Disable and release the IRQ for the given SDIO function.
	341	*/
	342	int sdio_release_irq(struct sdio_func *func)
	343	{
	344	int ret;
	345	unsigned char reg;
	346
	347	if (!func)
	348	return -EINVAL;
	349
	350	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
	351
	352	if (func->irq_handler) {
	353	func->irq_handler = NULL;
	354	sdio_card_irq_put(func->card);
	355	sdio_single_irq_set(func->card);
	356	}
	357
	358	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	359	if (ret)
	360	return ret;
	361
	362	reg &= ~(1 << func->num);
	363
	364	/* Disable master interrupt with the last function interrupt */
	365	if (!(reg & 0xFE))
	366	reg = 0;
	367
	368	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	369	if (ret)
	370	return ret;
	371
	372	return 0;
	373	}
	374	EXPORT_SYMBOL_GPL(sdio_release_irq);
	375