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);
57 for (i = 1; i <= 7; i++) {
58 if (pending & (1 << i)) {
59 func = card->sdio_func[i - 1];
61 pr_warning("%s: pending IRQ for "
62 "non-existent function\n",
65 } else if (func->irq_handler) {
66 func->irq_handler(func);
69 pr_warning("%s: pending IRQ with no handler\n",
82 static int sdio_irq_thread(void *_host)
84 struct mmc_host *host = _host;
85 struct sched_param param = { .sched_priority = 1 };
86 unsigned long period, idle_period;
89 sched_setscheduler(current, SCHED_FIFO, ¶m);
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.
97 idle_period = msecs_to_jiffies(10);
98 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
99 MAX_SCHEDULE_TIMEOUT : idle_period;
101 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
102 mmc_hostname(host), period);
106 * We claim the host here on drivers behalf for a couple
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.
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.
118 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
121 ret = process_sdio_pending_irqs(host);
122 host->sdio_irq_pending = false;
123 mmc_release_host(host);
126 * Give other threads a chance to run in the presence of
130 set_current_state(TASK_INTERRUPTIBLE);
131 if (!kthread_should_stop())
132 schedule_timeout(HZ);
133 set_current_state(TASK_RUNNING);
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.
141 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
146 if (period > idle_period)
147 period = idle_period;
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);
157 if (!kthread_should_stop())
158 schedule_timeout(period);
159 set_current_state(TASK_RUNNING);
160 } while (!kthread_should_stop());
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);
168 pr_debug("%s: IRQ thread exiting with code %d\n",
169 mmc_hostname(host), ret);
174 static int sdio_card_irq_get(struct mmc_card *card)
176 struct mmc_host *host = card->host;
178 WARN_ON(!host->claimed);
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",
185 if (IS_ERR(host->sdio_irq_thread)) {
186 int err = PTR_ERR(host->sdio_irq_thread);
195 static int sdio_card_irq_put(struct mmc_card *card)
197 struct mmc_host *host = card->host;
199 WARN_ON(!host->claimed);
200 BUG_ON(host->sdio_irqs < 1);
202 if (!--host->sdio_irqs) {
203 atomic_set(&host->sdio_irq_thread_abort, 1);
204 kthread_stop(host->sdio_irq_thread);
210 /* If there is only 1 function registered set sdio_single_irq */
211 static void sdio_single_irq_set(struct mmc_card *card)
213 struct sdio_func *func;
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;
229 * sdio_claim_irq - claim the IRQ for a SDIO function
230 * @func: SDIO function
231 * @handler: IRQ handler callback
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().
238 int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
246 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
248 if (func->irq_handler) {
249 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
253 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
257 reg |= 1 << func->num;
259 reg |= 1; /* Master interrupt enable */
261 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
265 func->irq_handler = handler;
266 ret = sdio_card_irq_get(func->card);
268 func->irq_handler = NULL;
269 sdio_single_irq_set(func->card);
273 EXPORT_SYMBOL_GPL(sdio_claim_irq);
276 * sdio_release_irq - release the IRQ for a SDIO function
277 * @func: SDIO function
279 * Disable and release the IRQ for the given SDIO function.
281 int sdio_release_irq(struct sdio_func *func)
289 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
291 if (func->irq_handler) {
292 func->irq_handler = NULL;
293 sdio_card_irq_put(func->card);
294 sdio_single_irq_set(func->card);
297 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
301 reg &= ~(1 << func->num);
303 /* Disable master interrupt with the last function interrupt */
307 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
313 EXPORT_SYMBOL_GPL(sdio_release_irq);