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