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
);