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