2 * linux/drivers/mmc/core/sdio_irq.c
4 * Author: Nicolas Pitre
5 * Created: June 18, 2007
6 * Copyright: MontaVista Software Inc.
8 * Copyright 2008 Pierre Ossman
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.
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>
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>
31 static int process_sdio_pending_irqs(struct mmc_host *host)
33 struct mmc_card *card = host->card;
35 unsigned char pending;
36 struct sdio_func *func;
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.
43 func = card->sdio_single_irq;
44 if (func && host->sdio_irq_pending) {
45 func->irq_handler(func);
49 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
51 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
52 mmc_card_id(card), ret);
56 if (pending && mmc_card_broken_irq_polling(card) &&
57 !(host->caps & MMC_CAP_SDIO_IRQ)) {
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.
64 mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
68 for (i = 1; i <= 7; i++) {
69 if (pending & (1 << i)) {
70 func = card->sdio_func[i - 1];
72 pr_warning("%s: pending IRQ for "
73 "non-existent function\n",
76 } else if (func->irq_handler) {
77 func->irq_handler(func);
80 pr_warning("%s: pending IRQ with no handler\n",
93 void sdio_run_irqs(struct mmc_host *host)
96 host->sdio_irq_pending = true;
97 process_sdio_pending_irqs(host);
98 mmc_release_host(host);
100 EXPORT_SYMBOL_GPL(sdio_run_irqs);
102 static int sdio_irq_thread(void *_host)
104 struct mmc_host *host = _host;
105 struct sched_param param = { .sched_priority = 1 };
106 unsigned long period, idle_period;
109 sched_setscheduler(current, SCHED_FIFO, ¶m);
112 * We want to allow for SDIO cards to work even on non SDIO
113 * aware hosts. One thing that non SDIO host cannot do is
114 * asynchronous notification of pending SDIO card interrupts
115 * hence we poll for them in that case.
117 idle_period = msecs_to_jiffies(10);
118 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
119 MAX_SCHEDULE_TIMEOUT : idle_period;
121 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
122 mmc_hostname(host), period);
126 * We claim the host here on drivers behalf for a couple
129 * 1) it is already needed to retrieve the CCCR_INTx;
130 * 2) we want the driver(s) to clear the IRQ condition ASAP;
131 * 3) we need to control the abort condition locally.
133 * Just like traditional hard IRQ handlers, we expect SDIO
134 * IRQ handlers to be quick and to the point, so that the
135 * holding of the host lock does not cover too much work
136 * that doesn't require that lock to be held.
138 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
141 ret = process_sdio_pending_irqs(host);
142 host->sdio_irq_pending = false;
143 mmc_release_host(host);
146 * Give other threads a chance to run in the presence of
150 set_current_state(TASK_INTERRUPTIBLE);
151 if (!kthread_should_stop())
152 schedule_timeout(HZ);
153 set_current_state(TASK_RUNNING);
157 * Adaptive polling frequency based on the assumption
158 * that an interrupt will be closely followed by more.
159 * This has a substantial benefit for network devices.
161 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
166 if (period > idle_period)
167 period = idle_period;
171 set_current_state(TASK_INTERRUPTIBLE);
172 if (host->caps & MMC_CAP_SDIO_IRQ) {
173 mmc_host_clk_hold(host);
174 host->ops->enable_sdio_irq(host, 1);
175 mmc_host_clk_release(host);
177 if (!kthread_should_stop())
178 schedule_timeout(period);
179 set_current_state(TASK_RUNNING);
180 } while (!kthread_should_stop());
182 if (host->caps & MMC_CAP_SDIO_IRQ) {
183 mmc_host_clk_hold(host);
184 host->ops->enable_sdio_irq(host, 0);
185 mmc_host_clk_release(host);
188 pr_debug("%s: IRQ thread exiting with code %d\n",
189 mmc_hostname(host), ret);
194 static int sdio_card_irq_get(struct mmc_card *card)
196 struct mmc_host *host = card->host;
198 WARN_ON(!host->claimed);
200 if (!host->sdio_irqs++) {
201 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
202 atomic_set(&host->sdio_irq_thread_abort, 0);
203 host->sdio_irq_thread =
204 kthread_run(sdio_irq_thread, host,
205 "ksdioirqd/%s", mmc_hostname(host));
206 if (IS_ERR(host->sdio_irq_thread)) {
207 int err = PTR_ERR(host->sdio_irq_thread);
212 mmc_host_clk_hold(host);
213 host->ops->enable_sdio_irq(host, 1);
214 mmc_host_clk_release(host);
221 static int sdio_card_irq_put(struct mmc_card *card)
223 struct mmc_host *host = card->host;
225 WARN_ON(!host->claimed);
226 BUG_ON(host->sdio_irqs < 1);
228 if (!--host->sdio_irqs) {
229 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
230 atomic_set(&host->sdio_irq_thread_abort, 1);
231 kthread_stop(host->sdio_irq_thread);
233 mmc_host_clk_hold(host);
234 host->ops->enable_sdio_irq(host, 0);
235 mmc_host_clk_release(host);
242 /* If there is only 1 function registered set sdio_single_irq */
243 static void sdio_single_irq_set(struct mmc_card *card)
245 struct sdio_func *func;
248 card->sdio_single_irq = NULL;
249 if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
250 card->host->sdio_irqs == 1)
251 for (i = 0; i < card->sdio_funcs; i++) {
252 func = card->sdio_func[i];
253 if (func && func->irq_handler) {
254 card->sdio_single_irq = func;
261 * sdio_claim_irq - claim the IRQ for a SDIO function
262 * @func: SDIO function
263 * @handler: IRQ handler callback
265 * Claim and activate the IRQ for the given SDIO function. The provided
266 * handler will be called when that IRQ is asserted. The host is always
267 * claimed already when the handler is called so the handler must not
268 * call sdio_claim_host() nor sdio_release_host().
270 int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
278 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
280 if (func->irq_handler) {
281 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
285 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
289 reg |= 1 << func->num;
291 reg |= 1; /* Master interrupt enable */
293 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
297 func->irq_handler = handler;
298 ret = sdio_card_irq_get(func->card);
300 func->irq_handler = NULL;
301 sdio_single_irq_set(func->card);
305 EXPORT_SYMBOL_GPL(sdio_claim_irq);
308 * sdio_release_irq - release the IRQ for a SDIO function
309 * @func: SDIO function
311 * Disable and release the IRQ for the given SDIO function.
313 int sdio_release_irq(struct sdio_func *func)
321 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
323 if (func->irq_handler) {
324 func->irq_handler = NULL;
325 sdio_card_irq_put(func->card);
326 sdio_single_irq_set(func->card);
329 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
333 reg &= ~(1 << func->num);
335 /* Disable master interrupt with the last function interrupt */
339 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
345 EXPORT_SYMBOL_GPL(sdio_release_irq);