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