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>
33 static int process_sdio_pending_irqs(struct mmc_host
*host
)
35 struct mmc_card
*card
= host
->card
;
37 unsigned char pending
;
38 struct sdio_func
*func
;
41 * Optimization, if there is only 1 function interrupt registered
42 * and we know an IRQ was signaled then call irq handler directly.
43 * Otherwise do the full probe.
45 func
= card
->sdio_single_irq
;
46 if (func
&& host
->sdio_irq_pending
) {
47 func
->irq_handler(func
);
51 ret
= mmc_io_rw_direct(card
, 0, 0, SDIO_CCCR_INTx
, 0, &pending
);
53 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
54 mmc_card_id(card
), ret
);
58 if (pending
&& mmc_card_broken_irq_polling(card
) &&
59 !(host
->caps
& MMC_CAP_SDIO_IRQ
)) {
62 /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
63 * register with a Marvell SD8797 card. A dummy CMD52 read to
64 * function 0 register 0xff can avoid this.
66 mmc_io_rw_direct(card
, 0, 0, 0xff, 0, &dummy
);
70 for (i
= 1; i
<= 7; i
++) {
71 if (pending
& (1 << i
)) {
72 func
= card
->sdio_func
[i
- 1];
74 pr_warn("%s: pending IRQ for non-existent function\n",
77 } else if (func
->irq_handler
) {
78 func
->irq_handler(func
);
81 pr_warn("%s: pending IRQ with no handler\n",
94 void sdio_run_irqs(struct mmc_host
*host
)
97 host
->sdio_irq_pending
= true;
98 process_sdio_pending_irqs(host
);
99 mmc_release_host(host
);
101 EXPORT_SYMBOL_GPL(sdio_run_irqs
);
103 static int sdio_irq_thread(void *_host
)
105 struct mmc_host
*host
= _host
;
106 struct sched_param param
= { .sched_priority
= 1 };
107 unsigned long period
, idle_period
;
110 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
113 * We want to allow for SDIO cards to work even on non SDIO
114 * aware hosts. One thing that non SDIO host cannot do is
115 * asynchronous notification of pending SDIO card interrupts
116 * hence we poll for them in that case.
118 idle_period
= msecs_to_jiffies(10);
119 period
= (host
->caps
& MMC_CAP_SDIO_IRQ
) ?
120 MAX_SCHEDULE_TIMEOUT
: idle_period
;
122 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
123 mmc_hostname(host
), period
);
127 * We claim the host here on drivers behalf for a couple
130 * 1) it is already needed to retrieve the CCCR_INTx;
131 * 2) we want the driver(s) to clear the IRQ condition ASAP;
132 * 3) we need to control the abort condition locally.
134 * Just like traditional hard IRQ handlers, we expect SDIO
135 * IRQ handlers to be quick and to the point, so that the
136 * holding of the host lock does not cover too much work
137 * that doesn't require that lock to be held.
139 ret
= __mmc_claim_host(host
, &host
->sdio_irq_thread_abort
);
142 ret
= process_sdio_pending_irqs(host
);
143 host
->sdio_irq_pending
= false;
144 mmc_release_host(host
);
147 * Give other threads a chance to run in the presence of
151 set_current_state(TASK_INTERRUPTIBLE
);
152 if (!kthread_should_stop())
153 schedule_timeout(HZ
);
154 set_current_state(TASK_RUNNING
);
158 * Adaptive polling frequency based on the assumption
159 * that an interrupt will be closely followed by more.
160 * This has a substantial benefit for network devices.
162 if (!(host
->caps
& MMC_CAP_SDIO_IRQ
)) {
167 if (period
> idle_period
)
168 period
= idle_period
;
172 set_current_state(TASK_INTERRUPTIBLE
);
173 if (host
->caps
& MMC_CAP_SDIO_IRQ
)
174 host
->ops
->enable_sdio_irq(host
, 1);
175 if (!kthread_should_stop())
176 schedule_timeout(period
);
177 set_current_state(TASK_RUNNING
);
178 } while (!kthread_should_stop());
180 if (host
->caps
& MMC_CAP_SDIO_IRQ
)
181 host
->ops
->enable_sdio_irq(host
, 0);
183 pr_debug("%s: IRQ thread exiting with code %d\n",
184 mmc_hostname(host
), ret
);
189 static int sdio_card_irq_get(struct mmc_card
*card
)
191 struct mmc_host
*host
= card
->host
;
193 WARN_ON(!host
->claimed
);
195 if (!host
->sdio_irqs
++) {
196 if (!(host
->caps2
& MMC_CAP2_SDIO_IRQ_NOTHREAD
)) {
197 atomic_set(&host
->sdio_irq_thread_abort
, 0);
198 host
->sdio_irq_thread
=
199 kthread_run(sdio_irq_thread
, host
,
200 "ksdioirqd/%s", mmc_hostname(host
));
201 if (IS_ERR(host
->sdio_irq_thread
)) {
202 int err
= PTR_ERR(host
->sdio_irq_thread
);
206 } else if (host
->caps
& MMC_CAP_SDIO_IRQ
) {
207 host
->ops
->enable_sdio_irq(host
, 1);
214 static int sdio_card_irq_put(struct mmc_card
*card
)
216 struct mmc_host
*host
= card
->host
;
218 WARN_ON(!host
->claimed
);
220 if (host
->sdio_irqs
< 1)
223 if (!--host
->sdio_irqs
) {
224 if (!(host
->caps2
& MMC_CAP2_SDIO_IRQ_NOTHREAD
)) {
225 atomic_set(&host
->sdio_irq_thread_abort
, 1);
226 kthread_stop(host
->sdio_irq_thread
);
227 } else if (host
->caps
& MMC_CAP_SDIO_IRQ
) {
228 host
->ops
->enable_sdio_irq(host
, 0);
235 /* If there is only 1 function registered set sdio_single_irq */
236 static void sdio_single_irq_set(struct mmc_card
*card
)
238 struct sdio_func
*func
;
241 card
->sdio_single_irq
= NULL
;
242 if ((card
->host
->caps
& MMC_CAP_SDIO_IRQ
) &&
243 card
->host
->sdio_irqs
== 1)
244 for (i
= 0; i
< card
->sdio_funcs
; i
++) {
245 func
= card
->sdio_func
[i
];
246 if (func
&& func
->irq_handler
) {
247 card
->sdio_single_irq
= func
;
254 * sdio_claim_irq - claim the IRQ for a SDIO function
255 * @func: SDIO function
256 * @handler: IRQ handler callback
258 * Claim and activate the IRQ for the given SDIO function. The provided
259 * handler will be called when that IRQ is asserted. The host is always
260 * claimed already when the handler is called so the handler must not
261 * call sdio_claim_host() nor sdio_release_host().
263 int sdio_claim_irq(struct sdio_func
*func
, sdio_irq_handler_t
*handler
)
271 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func
));
273 if (func
->irq_handler
) {
274 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func
));
278 ret
= mmc_io_rw_direct(func
->card
, 0, 0, SDIO_CCCR_IENx
, 0, ®
);
282 reg
|= 1 << func
->num
;
284 reg
|= 1; /* Master interrupt enable */
286 ret
= mmc_io_rw_direct(func
->card
, 1, 0, SDIO_CCCR_IENx
, reg
, NULL
);
290 func
->irq_handler
= handler
;
291 ret
= sdio_card_irq_get(func
->card
);
293 func
->irq_handler
= NULL
;
294 sdio_single_irq_set(func
->card
);
298 EXPORT_SYMBOL_GPL(sdio_claim_irq
);
301 * sdio_release_irq - release the IRQ for a SDIO function
302 * @func: SDIO function
304 * Disable and release the IRQ for the given SDIO function.
306 int sdio_release_irq(struct sdio_func
*func
)
314 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func
));
316 if (func
->irq_handler
) {
317 func
->irq_handler
= NULL
;
318 sdio_card_irq_put(func
->card
);
319 sdio_single_irq_set(func
->card
);
322 ret
= mmc_io_rw_direct(func
->card
, 0, 0, SDIO_CCCR_IENx
, 0, ®
);
326 reg
&= ~(1 << func
->num
);
328 /* Disable master interrupt with the last function interrupt */
332 ret
= mmc_io_rw_direct(func
->card
, 1, 0, SDIO_CCCR_IENx
, reg
, NULL
);
338 EXPORT_SYMBOL_GPL(sdio_release_irq
);