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_card *card)
34 unsigned char pending;
35 struct sdio_func *func;
38 * Optimization, if there is only 1 function interrupt registered
39 * call irq handler directly
41 func = card->sdio_single_irq;
43 func->irq_handler(func);
47 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
49 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
50 mmc_card_id(card), ret);
55 for (i = 1; i <= 7; i++) {
56 if (pending & (1 << i)) {
57 func = card->sdio_func[i - 1];
59 pr_warning("%s: pending IRQ for "
60 "non-existent function\n",
63 } else if (func->irq_handler) {
64 func->irq_handler(func);
67 pr_warning("%s: pending IRQ with no handler\n",
80 static int sdio_irq_thread(void *_host)
82 struct mmc_host *host = _host;
83 struct sched_param param = { .sched_priority = 1 };
84 unsigned long period, idle_period;
87 sched_setscheduler(current, SCHED_FIFO, ¶m);
90 * We want to allow for SDIO cards to work even on non SDIO
91 * aware hosts. One thing that non SDIO host cannot do is
92 * asynchronous notification of pending SDIO card interrupts
93 * hence we poll for them in that case.
95 idle_period = msecs_to_jiffies(10);
96 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
97 MAX_SCHEDULE_TIMEOUT : idle_period;
99 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
100 mmc_hostname(host), period);
104 * We claim the host here on drivers behalf for a couple
107 * 1) it is already needed to retrieve the CCCR_INTx;
108 * 2) we want the driver(s) to clear the IRQ condition ASAP;
109 * 3) we need to control the abort condition locally.
111 * Just like traditional hard IRQ handlers, we expect SDIO
112 * IRQ handlers to be quick and to the point, so that the
113 * holding of the host lock does not cover too much work
114 * that doesn't require that lock to be held.
116 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
119 ret = process_sdio_pending_irqs(host->card);
120 mmc_release_host(host);
123 * Give other threads a chance to run in the presence of
127 set_current_state(TASK_INTERRUPTIBLE);
128 if (!kthread_should_stop())
129 schedule_timeout(HZ);
130 set_current_state(TASK_RUNNING);
134 * Adaptive polling frequency based on the assumption
135 * that an interrupt will be closely followed by more.
136 * This has a substantial benefit for network devices.
138 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
143 if (period > idle_period)
144 period = idle_period;
148 set_current_state(TASK_INTERRUPTIBLE);
149 if (host->caps & MMC_CAP_SDIO_IRQ)
150 host->ops->enable_sdio_irq(host, 1);
151 if (!kthread_should_stop())
152 schedule_timeout(period);
153 set_current_state(TASK_RUNNING);
154 } while (!kthread_should_stop());
156 if (host->caps & MMC_CAP_SDIO_IRQ)
157 host->ops->enable_sdio_irq(host, 0);
159 pr_debug("%s: IRQ thread exiting with code %d\n",
160 mmc_hostname(host), ret);
165 static int sdio_card_irq_get(struct mmc_card *card)
167 struct mmc_host *host = card->host;
169 WARN_ON(!host->claimed);
171 if (!host->sdio_irqs++) {
172 atomic_set(&host->sdio_irq_thread_abort, 0);
173 host->sdio_irq_thread =
174 kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
176 if (IS_ERR(host->sdio_irq_thread)) {
177 int err = PTR_ERR(host->sdio_irq_thread);
186 static int sdio_card_irq_put(struct mmc_card *card)
188 struct mmc_host *host = card->host;
190 WARN_ON(!host->claimed);
191 BUG_ON(host->sdio_irqs < 1);
193 if (!--host->sdio_irqs) {
194 atomic_set(&host->sdio_irq_thread_abort, 1);
195 kthread_stop(host->sdio_irq_thread);
201 /* If there is only 1 function registered set sdio_single_irq */
202 static void sdio_single_irq_set(struct mmc_card *card)
204 struct sdio_func *func;
207 card->sdio_single_irq = NULL;
208 if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
209 card->host->sdio_irqs == 1)
210 for (i = 0; i < card->sdio_funcs; i++) {
211 func = card->sdio_func[i];
212 if (func && func->irq_handler) {
213 card->sdio_single_irq = func;
220 * sdio_claim_irq - claim the IRQ for a SDIO function
221 * @func: SDIO function
222 * @handler: IRQ handler callback
224 * Claim and activate the IRQ for the given SDIO function. The provided
225 * handler will be called when that IRQ is asserted. The host is always
226 * claimed already when the handler is called so the handler must not
227 * call sdio_claim_host() nor sdio_release_host().
229 int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
237 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
239 if (func->irq_handler) {
240 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
244 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
248 reg |= 1 << func->num;
250 reg |= 1; /* Master interrupt enable */
252 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
256 func->irq_handler = handler;
257 ret = sdio_card_irq_get(func->card);
259 func->irq_handler = NULL;
260 sdio_single_irq_set(func->card);
264 EXPORT_SYMBOL_GPL(sdio_claim_irq);
267 * sdio_release_irq - release the IRQ for a SDIO function
268 * @func: SDIO function
270 * Disable and release the IRQ for the given SDIO function.
272 int sdio_release_irq(struct sdio_func *func)
280 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
282 if (func->irq_handler) {
283 func->irq_handler = NULL;
284 sdio_card_irq_put(func->card);
285 sdio_single_irq_set(func->card);
288 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
292 reg &= ~(1 << func->num);
294 /* Disable master interrupt with the last function interrupt */
298 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
304 EXPORT_SYMBOL_GPL(sdio_release_irq);