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/wait.h>
20 #include <linux/delay.h>
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>
30 static int process_sdio_pending_irqs(struct mmc_card *card)
33 unsigned char pending;
34 struct sdio_func *func;
37 * Optimization, if there is only 1 function interrupt registered
38 * call irq handler directly
40 func = card->sdio_single_irq;
42 func->irq_handler(func);
46 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
48 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
49 mmc_card_id(card), ret);
54 for (i = 1; i <= 7; i++) {
55 if (pending & (1 << i)) {
56 func = card->sdio_func[i - 1];
58 pr_warning("%s: pending IRQ for "
59 "non-existent function\n",
62 } else if (func->irq_handler) {
63 func->irq_handler(func);
66 pr_warning("%s: pending IRQ with no handler\n",
79 static int sdio_irq_thread(void *_host)
81 struct mmc_host *host = _host;
82 struct sched_param param = { .sched_priority = 1 };
83 unsigned long period, idle_period;
86 sched_setscheduler(current, SCHED_FIFO, ¶m);
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.
94 idle_period = msecs_to_jiffies(10);
95 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
96 MAX_SCHEDULE_TIMEOUT : idle_period;
98 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
99 mmc_hostname(host), period);
103 * We claim the host here on drivers behalf for a couple
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.
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.
115 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
118 ret = process_sdio_pending_irqs(host->card);
119 mmc_release_host(host);
122 * Give other threads a chance to run in the presence of
126 set_current_state(TASK_INTERRUPTIBLE);
127 if (!kthread_should_stop())
128 schedule_timeout(HZ);
129 set_current_state(TASK_RUNNING);
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.
137 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
142 if (period > idle_period)
143 period = idle_period;
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());
155 if (host->caps & MMC_CAP_SDIO_IRQ)
156 host->ops->enable_sdio_irq(host, 0);
158 pr_debug("%s: IRQ thread exiting with code %d\n",
159 mmc_hostname(host), ret);
164 static int sdio_card_irq_get(struct mmc_card *card)
166 struct mmc_host *host = card->host;
168 WARN_ON(!host->claimed);
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",
175 if (IS_ERR(host->sdio_irq_thread)) {
176 int err = PTR_ERR(host->sdio_irq_thread);
185 static int sdio_card_irq_put(struct mmc_card *card)
187 struct mmc_host *host = card->host;
189 WARN_ON(!host->claimed);
190 BUG_ON(host->sdio_irqs < 1);
192 if (!--host->sdio_irqs) {
193 atomic_set(&host->sdio_irq_thread_abort, 1);
194 kthread_stop(host->sdio_irq_thread);
200 /* If there is only 1 function registered set sdio_single_irq */
201 static void sdio_single_irq_set(struct mmc_card *card)
203 struct sdio_func *func;
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;
219 * sdio_claim_irq - claim the IRQ for a SDIO function
220 * @func: SDIO function
221 * @handler: IRQ handler callback
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().
228 int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
236 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
238 if (func->irq_handler) {
239 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
243 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
247 reg |= 1 << func->num;
249 reg |= 1; /* Master interrupt enable */
251 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
255 func->irq_handler = handler;
256 ret = sdio_card_irq_get(func->card);
258 func->irq_handler = NULL;
259 sdio_single_irq_set(func->card);
263 EXPORT_SYMBOL_GPL(sdio_claim_irq);
266 * sdio_release_irq - release the IRQ for a SDIO function
267 * @func: SDIO function
269 * Disable and release the IRQ for the given SDIO function.
271 int sdio_release_irq(struct sdio_func *func)
279 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
281 if (func->irq_handler) {
282 func->irq_handler = NULL;
283 sdio_card_irq_put(func->card);
284 sdio_single_irq_set(func->card);
287 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
291 reg &= ~(1 << func->num);
293 /* Disable master interrupt with the last function interrupt */
297 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
303 EXPORT_SYMBOL_GPL(sdio_release_irq);