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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 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