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[mirror_ubuntu-artful-kernel.git] / drivers / mmc / core / sdio_irq.c
CommitLineData
d1496c39
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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 *
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8 * Copyright 2008 Pierre Ossman
9 *
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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>
ae7e81c0 18#include <uapi/linux/sched/types.h>
d1496c39 19#include <linux/kthread.h>
3ef77af1 20#include <linux/export.h>
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21#include <linux/wait.h>
22#include <linux/delay.h>
23
24#include <linux/mmc/core.h>
25#include <linux/mmc/host.h>
26#include <linux/mmc/card.h>
27#include <linux/mmc/sdio.h>
28#include <linux/mmc/sdio_func.h>
29
30#include "sdio_ops.h"
55244c56 31#include "core.h"
4facdde1 32#include "card.h"
d1496c39 33
bbbc4c4d 34static int process_sdio_pending_irqs(struct mmc_host *host)
d1496c39 35{
bbbc4c4d 36 struct mmc_card *card = host->card;
6f4285d1 37 int i, ret, count;
d1496c39 38 unsigned char pending;
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39 struct sdio_func *func;
40
41 /*
42 * Optimization, if there is only 1 function interrupt registered
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43 * and we know an IRQ was signaled then call irq handler directly.
44 * Otherwise do the full probe.
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45 */
46 func = card->sdio_single_irq;
bbbc4c4d 47 if (func && host->sdio_irq_pending) {
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48 func->irq_handler(func);
49 return 1;
50 }
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51
52 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
53 if (ret) {
a3c76eb9 54 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
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55 mmc_card_id(card), ret);
56 return ret;
57 }
58
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59 if (pending && mmc_card_broken_irq_polling(card) &&
60 !(host->caps & MMC_CAP_SDIO_IRQ)) {
61 unsigned char dummy;
62
63 /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
64 * register with a Marvell SD8797 card. A dummy CMD52 read to
65 * function 0 register 0xff can avoid this.
66 */
67 mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
68 }
69
6f4285d1 70 count = 0;
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71 for (i = 1; i <= 7; i++) {
72 if (pending & (1 << i)) {
06e8935f 73 func = card->sdio_func[i - 1];
d1496c39 74 if (!func) {
6606110d 75 pr_warn("%s: pending IRQ for non-existent function\n",
3e01e4bc 76 mmc_card_id(card));
599473cf 77 ret = -EINVAL;
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78 } else if (func->irq_handler) {
79 func->irq_handler(func);
6f4285d1 80 count++;
599473cf 81 } else {
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82 pr_warn("%s: pending IRQ with no handler\n",
83 sdio_func_id(func));
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84 ret = -EINVAL;
85 }
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86 }
87 }
88
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89 if (count)
90 return count;
91
92 return ret;
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93}
94
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95void sdio_run_irqs(struct mmc_host *host)
96{
97 mmc_claim_host(host);
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98 if (host->sdio_irqs) {
99 host->sdio_irq_pending = true;
100 process_sdio_pending_irqs(host);
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101 if (host->ops->ack_sdio_irq)
102 host->ops->ack_sdio_irq(host);
e3a84267 103 }
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104 mmc_release_host(host);
105}
106EXPORT_SYMBOL_GPL(sdio_run_irqs);
107
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108void sdio_irq_work(struct work_struct *work)
109{
110 struct mmc_host *host =
111 container_of(work, struct mmc_host, sdio_irq_work.work);
112
113 sdio_run_irqs(host);
114}
115
116void sdio_signal_irq(struct mmc_host *host)
117{
118 queue_delayed_work(system_wq, &host->sdio_irq_work, 0);
119}
120EXPORT_SYMBOL_GPL(sdio_signal_irq);
121
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122static int sdio_irq_thread(void *_host)
123{
124 struct mmc_host *host = _host;
125 struct sched_param param = { .sched_priority = 1 };
6f4285d1 126 unsigned long period, idle_period;
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127 int ret;
128
129 sched_setscheduler(current, SCHED_FIFO, &param);
130
131 /*
132 * We want to allow for SDIO cards to work even on non SDIO
133 * aware hosts. One thing that non SDIO host cannot do is
134 * asynchronous notification of pending SDIO card interrupts
135 * hence we poll for them in that case.
136 */
6f4285d1 137 idle_period = msecs_to_jiffies(10);
17b759af 138 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
6f4285d1 139 MAX_SCHEDULE_TIMEOUT : idle_period;
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140
141 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
142 mmc_hostname(host), period);
143
144 do {
145 /*
146 * We claim the host here on drivers behalf for a couple
147 * reasons:
148 *
149 * 1) it is already needed to retrieve the CCCR_INTx;
150 * 2) we want the driver(s) to clear the IRQ condition ASAP;
151 * 3) we need to control the abort condition locally.
152 *
153 * Just like traditional hard IRQ handlers, we expect SDIO
154 * IRQ handlers to be quick and to the point, so that the
155 * holding of the host lock does not cover too much work
156 * that doesn't require that lock to be held.
157 */
158 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
159 if (ret)
160 break;
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161 ret = process_sdio_pending_irqs(host);
162 host->sdio_irq_pending = false;
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163 mmc_release_host(host);
164
165 /*
166 * Give other threads a chance to run in the presence of
e633b7bc 167 * errors.
d1496c39 168 */
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169 if (ret < 0) {
170 set_current_state(TASK_INTERRUPTIBLE);
171 if (!kthread_should_stop())
172 schedule_timeout(HZ);
173 set_current_state(TASK_RUNNING);
174 }
d1496c39 175
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176 /*
177 * Adaptive polling frequency based on the assumption
178 * that an interrupt will be closely followed by more.
179 * This has a substantial benefit for network devices.
180 */
181 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
182 if (ret > 0)
183 period /= 2;
184 else {
185 period++;
186 if (period > idle_period)
187 period = idle_period;
188 }
189 }
190
6fee65cf 191 set_current_state(TASK_INTERRUPTIBLE);
9eadcc05 192 if (host->caps & MMC_CAP_SDIO_IRQ)
17b759af 193 host->ops->enable_sdio_irq(host, 1);
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194 if (!kthread_should_stop())
195 schedule_timeout(period);
6fee65cf 196 set_current_state(TASK_RUNNING);
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197 } while (!kthread_should_stop());
198
9eadcc05 199 if (host->caps & MMC_CAP_SDIO_IRQ)
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200 host->ops->enable_sdio_irq(host, 0);
201
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202 pr_debug("%s: IRQ thread exiting with code %d\n",
203 mmc_hostname(host), ret);
204
205 return ret;
206}
207
208static int sdio_card_irq_get(struct mmc_card *card)
209{
210 struct mmc_host *host = card->host;
211
d84075c8 212 WARN_ON(!host->claimed);
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213
214 if (!host->sdio_irqs++) {
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215 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
216 atomic_set(&host->sdio_irq_thread_abort, 0);
217 host->sdio_irq_thread =
218 kthread_run(sdio_irq_thread, host,
219 "ksdioirqd/%s", mmc_hostname(host));
220 if (IS_ERR(host->sdio_irq_thread)) {
221 int err = PTR_ERR(host->sdio_irq_thread);
222 host->sdio_irqs--;
223 return err;
224 }
dea67c4e 225 } else if (host->caps & MMC_CAP_SDIO_IRQ) {
bf3b5ec6 226 host->ops->enable_sdio_irq(host, 1);
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227 }
228 }
229
230 return 0;
231}
232
233static int sdio_card_irq_put(struct mmc_card *card)
234{
235 struct mmc_host *host = card->host;
236
d84075c8 237 WARN_ON(!host->claimed);
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238
239 if (host->sdio_irqs < 1)
240 return -EINVAL;
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241
242 if (!--host->sdio_irqs) {
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243 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
244 atomic_set(&host->sdio_irq_thread_abort, 1);
245 kthread_stop(host->sdio_irq_thread);
dea67c4e 246 } else if (host->caps & MMC_CAP_SDIO_IRQ) {
bf3b5ec6 247 host->ops->enable_sdio_irq(host, 0);
bf3b5ec6 248 }
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249 }
250
251 return 0;
252}
253
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254/* If there is only 1 function registered set sdio_single_irq */
255static void sdio_single_irq_set(struct mmc_card *card)
256{
257 struct sdio_func *func;
258 int i;
259
260 card->sdio_single_irq = NULL;
261 if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
262 card->host->sdio_irqs == 1)
263 for (i = 0; i < card->sdio_funcs; i++) {
264 func = card->sdio_func[i];
265 if (func && func->irq_handler) {
266 card->sdio_single_irq = func;
267 break;
268 }
269 }
270}
271
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272/**
273 * sdio_claim_irq - claim the IRQ for a SDIO function
274 * @func: SDIO function
275 * @handler: IRQ handler callback
276 *
277 * Claim and activate the IRQ for the given SDIO function. The provided
278 * handler will be called when that IRQ is asserted. The host is always
279 * claimed already when the handler is called so the handler must not
280 * call sdio_claim_host() nor sdio_release_host().
281 */
282int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
283{
284 int ret;
285 unsigned char reg;
286
5df0e823
SL
287 if (!func)
288 return -EINVAL;
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289
290 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
291
292 if (func->irq_handler) {
293 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
294 return -EBUSY;
295 }
296
297 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
298 if (ret)
299 return ret;
300
301 reg |= 1 << func->num;
302
303 reg |= 1; /* Master interrupt enable */
304
305 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
306 if (ret)
307 return ret;
308
309 func->irq_handler = handler;
310 ret = sdio_card_irq_get(func->card);
311 if (ret)
312 func->irq_handler = NULL;
06e8935f 313 sdio_single_irq_set(func->card);
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314
315 return ret;
316}
317EXPORT_SYMBOL_GPL(sdio_claim_irq);
318
319/**
320 * sdio_release_irq - release the IRQ for a SDIO function
321 * @func: SDIO function
322 *
323 * Disable and release the IRQ for the given SDIO function.
324 */
325int sdio_release_irq(struct sdio_func *func)
326{
327 int ret;
328 unsigned char reg;
329
5df0e823
SL
330 if (!func)
331 return -EINVAL;
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332
333 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
334
335 if (func->irq_handler) {
336 func->irq_handler = NULL;
337 sdio_card_irq_put(func->card);
06e8935f 338 sdio_single_irq_set(func->card);
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339 }
340
341 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
342 if (ret)
343 return ret;
344
345 reg &= ~(1 << func->num);
346
347 /* Disable master interrupt with the last function interrupt */
348 if (!(reg & 0xFE))
349 reg = 0;
350
351 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
352 if (ret)
353 return ret;
354
355 return 0;
356}
357EXPORT_SYMBOL_GPL(sdio_release_irq);
358