Loading...
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
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