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
 30static 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
 58static 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
113static 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
124void 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
132void sdio_signal_irq(struct mmc_host *host)
133{
134	host->sdio_irq_pending = true;
135	schedule_work(&host->sdio_irq_work);
136}
137EXPORT_SYMBOL_GPL(sdio_signal_irq);
138
139static 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
224static 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
249static 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 */
271static 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 */
299int 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}
334EXPORT_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 */
342int 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}
374EXPORT_SYMBOL_GPL(sdio_release_irq);
375

  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
 30static 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
 58static 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
113static 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
124void sdio_irq_work(struct work_struct *work)
125{
126	struct mmc_host *host =
127		container_of(work, struct mmc_host, sdio_irq_work.work);
128
129	sdio_run_irqs(host);
130}
131
132void sdio_signal_irq(struct mmc_host *host)
133{
134	host->sdio_irq_pending = true;
135	queue_delayed_work(system_wq, &host->sdio_irq_work, 0);
136}
137EXPORT_SYMBOL_GPL(sdio_signal_irq);
138
139static int sdio_irq_thread(void *_host)
140{
141	struct mmc_host *host = _host;
142	struct sched_param param = { .sched_priority = 1 };
143	unsigned long period, idle_period;
144	int ret;
145
146	sched_setscheduler(current, SCHED_FIFO, &param);
147
148	/*
149	 * We want to allow for SDIO cards to work even on non SDIO
150	 * aware hosts.  One thing that non SDIO host cannot do is
151	 * asynchronous notification of pending SDIO card interrupts
152	 * hence we poll for them in that case.
153	 */
154	idle_period = msecs_to_jiffies(10);
155	period = (host->caps & MMC_CAP_SDIO_IRQ) ?
156		MAX_SCHEDULE_TIMEOUT : idle_period;
157
158	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
159		 mmc_hostname(host), period);
160
161	do {
162		/*
163		 * We claim the host here on drivers behalf for a couple
164		 * reasons:
165		 *
166		 * 1) it is already needed to retrieve the CCCR_INTx;
167		 * 2) we want the driver(s) to clear the IRQ condition ASAP;
168		 * 3) we need to control the abort condition locally.
169		 *
170		 * Just like traditional hard IRQ handlers, we expect SDIO
171		 * IRQ handlers to be quick and to the point, so that the
172		 * holding of the host lock does not cover too much work
173		 * that doesn't require that lock to be held.
174		 */
175		ret = __mmc_claim_host(host, NULL,
176				       &host->sdio_irq_thread_abort);
177		if (ret)
178			break;
179		ret = process_sdio_pending_irqs(host);
180		mmc_release_host(host);
181
182		/*
183		 * Give other threads a chance to run in the presence of
184		 * errors.
185		 */
186		if (ret < 0) {
187			set_current_state(TASK_INTERRUPTIBLE);
188			if (!kthread_should_stop())
189				schedule_timeout(HZ);
190			set_current_state(TASK_RUNNING);
191		}
192
193		/*
194		 * Adaptive polling frequency based on the assumption
195		 * that an interrupt will be closely followed by more.
196		 * This has a substantial benefit for network devices.
197		 */
198		if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
199			if (ret > 0)
200				period /= 2;
201			else {
202				period++;
203				if (period > idle_period)
204					period = idle_period;
205			}
206		}
207
208		set_current_state(TASK_INTERRUPTIBLE);
209		if (host->caps & MMC_CAP_SDIO_IRQ)
210			host->ops->enable_sdio_irq(host, 1);
211		if (!kthread_should_stop())
212			schedule_timeout(period);
213		set_current_state(TASK_RUNNING);
214	} while (!kthread_should_stop());
215
216	if (host->caps & MMC_CAP_SDIO_IRQ)
217		host->ops->enable_sdio_irq(host, 0);
218
219	pr_debug("%s: IRQ thread exiting with code %d\n",
220		 mmc_hostname(host), ret);
221
222	return ret;
223}
224
225static int sdio_card_irq_get(struct mmc_card *card)
226{
227	struct mmc_host *host = card->host;
228
229	WARN_ON(!host->claimed);
230
231	if (!host->sdio_irqs++) {
232		if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
233			atomic_set(&host->sdio_irq_thread_abort, 0);
234			host->sdio_irq_thread =
235				kthread_run(sdio_irq_thread, host,
236					    "ksdioirqd/%s", mmc_hostname(host));
237			if (IS_ERR(host->sdio_irq_thread)) {
238				int err = PTR_ERR(host->sdio_irq_thread);
239				host->sdio_irqs--;
240				return err;
241			}
242		} else if (host->caps & MMC_CAP_SDIO_IRQ) {
243			host->ops->enable_sdio_irq(host, 1);
244		}
245	}
246
247	return 0;
248}
249
250static int sdio_card_irq_put(struct mmc_card *card)
251{
252	struct mmc_host *host = card->host;
253
254	WARN_ON(!host->claimed);
255
256	if (host->sdio_irqs < 1)
257		return -EINVAL;
258
259	if (!--host->sdio_irqs) {
260		if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
261			atomic_set(&host->sdio_irq_thread_abort, 1);
262			kthread_stop(host->sdio_irq_thread);
263		} else if (host->caps & MMC_CAP_SDIO_IRQ) {
264			host->ops->enable_sdio_irq(host, 0);
265		}
266	}
267
268	return 0;
269}
270
271/* If there is only 1 function registered set sdio_single_irq */
272static void sdio_single_irq_set(struct mmc_card *card)
273{
274	struct sdio_func *func;
275	int i;
276
277	card->sdio_single_irq = NULL;
278	if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
279	    card->host->sdio_irqs == 1)
280		for (i = 0; i < card->sdio_funcs; i++) {
281		       func = card->sdio_func[i];
282		       if (func && func->irq_handler) {
283			       card->sdio_single_irq = func;
284			       break;
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 */
299int 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}
334EXPORT_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 */
342int 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}
374EXPORT_SYMBOL_GPL(sdio_release_irq);
375