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