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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 <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