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d1496c39 NP |
1 | /* |
2 | * linux/drivers/mmc/core/sdio_irq.c | |
3 | * | |
4 | * Author: Nicolas Pitre | |
5 | * Created: June 18, 2007 | |
6 | * Copyright: MontaVista Software Inc. | |
7 | * | |
e633b7bc PO |
8 | * Copyright 2008 Pierre Ossman |
9 | * | |
d1496c39 NP |
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. | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
17 | #include <linux/sched.h> | |
18 | #include <linux/kthread.h> | |
3ef77af1 | 19 | #include <linux/export.h> |
d1496c39 NP |
20 | #include <linux/wait.h> |
21 | #include <linux/delay.h> | |
22 | ||
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> | |
28 | ||
29 | #include "sdio_ops.h" | |
30 | ||
bbbc4c4d | 31 | static int process_sdio_pending_irqs(struct mmc_host *host) |
d1496c39 | 32 | { |
bbbc4c4d | 33 | struct mmc_card *card = host->card; |
6f4285d1 | 34 | int i, ret, count; |
d1496c39 | 35 | unsigned char pending; |
06e8935f SNX |
36 | struct sdio_func *func; |
37 | ||
38 | /* | |
39 | * Optimization, if there is only 1 function interrupt registered | |
bbbc4c4d NP |
40 | * and we know an IRQ was signaled then call irq handler directly. |
41 | * Otherwise do the full probe. | |
06e8935f SNX |
42 | */ |
43 | func = card->sdio_single_irq; | |
bbbc4c4d | 44 | if (func && host->sdio_irq_pending) { |
06e8935f SNX |
45 | func->irq_handler(func); |
46 | return 1; | |
47 | } | |
d1496c39 NP |
48 | |
49 | ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); | |
50 | if (ret) { | |
a3c76eb9 | 51 | pr_debug("%s: error %d reading SDIO_CCCR_INTx\n", |
d1496c39 NP |
52 | mmc_card_id(card), ret); |
53 | return ret; | |
54 | } | |
55 | ||
e5624054 BZ |
56 | if (pending && mmc_card_broken_irq_polling(card) && |
57 | !(host->caps & MMC_CAP_SDIO_IRQ)) { | |
58 | unsigned char dummy; | |
59 | ||
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. | |
63 | */ | |
64 | mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy); | |
65 | } | |
66 | ||
6f4285d1 | 67 | count = 0; |
d1496c39 NP |
68 | for (i = 1; i <= 7; i++) { |
69 | if (pending & (1 << i)) { | |
06e8935f | 70 | func = card->sdio_func[i - 1]; |
d1496c39 | 71 | if (!func) { |
6606110d | 72 | pr_warn("%s: pending IRQ for non-existent function\n", |
3e01e4bc | 73 | mmc_card_id(card)); |
599473cf | 74 | ret = -EINVAL; |
d1496c39 NP |
75 | } else if (func->irq_handler) { |
76 | func->irq_handler(func); | |
6f4285d1 | 77 | count++; |
599473cf | 78 | } else { |
6606110d JP |
79 | pr_warn("%s: pending IRQ with no handler\n", |
80 | sdio_func_id(func)); | |
599473cf NP |
81 | ret = -EINVAL; |
82 | } | |
d1496c39 NP |
83 | } |
84 | } | |
85 | ||
599473cf NP |
86 | if (count) |
87 | return count; | |
88 | ||
89 | return ret; | |
d1496c39 NP |
90 | } |
91 | ||
bf3b5ec6 RK |
92 | void sdio_run_irqs(struct mmc_host *host) |
93 | { | |
94 | mmc_claim_host(host); | |
95 | host->sdio_irq_pending = true; | |
96 | process_sdio_pending_irqs(host); | |
97 | mmc_release_host(host); | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(sdio_run_irqs); | |
100 | ||
d1496c39 NP |
101 | static int sdio_irq_thread(void *_host) |
102 | { | |
103 | struct mmc_host *host = _host; | |
104 | struct sched_param param = { .sched_priority = 1 }; | |
6f4285d1 | 105 | unsigned long period, idle_period; |
d1496c39 NP |
106 | int ret; |
107 | ||
108 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
109 | ||
110 | /* | |
111 | * We want to allow for SDIO cards to work even on non SDIO | |
112 | * aware hosts. One thing that non SDIO host cannot do is | |
113 | * asynchronous notification of pending SDIO card interrupts | |
114 | * hence we poll for them in that case. | |
115 | */ | |
6f4285d1 | 116 | idle_period = msecs_to_jiffies(10); |
17b759af | 117 | period = (host->caps & MMC_CAP_SDIO_IRQ) ? |
6f4285d1 | 118 | MAX_SCHEDULE_TIMEOUT : idle_period; |
d1496c39 NP |
119 | |
120 | pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", | |
121 | mmc_hostname(host), period); | |
122 | ||
123 | do { | |
124 | /* | |
125 | * We claim the host here on drivers behalf for a couple | |
126 | * reasons: | |
127 | * | |
128 | * 1) it is already needed to retrieve the CCCR_INTx; | |
129 | * 2) we want the driver(s) to clear the IRQ condition ASAP; | |
130 | * 3) we need to control the abort condition locally. | |
131 | * | |
132 | * Just like traditional hard IRQ handlers, we expect SDIO | |
133 | * IRQ handlers to be quick and to the point, so that the | |
134 | * holding of the host lock does not cover too much work | |
135 | * that doesn't require that lock to be held. | |
136 | */ | |
137 | ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); | |
138 | if (ret) | |
139 | break; | |
bbbc4c4d NP |
140 | ret = process_sdio_pending_irqs(host); |
141 | host->sdio_irq_pending = false; | |
d1496c39 NP |
142 | mmc_release_host(host); |
143 | ||
144 | /* | |
145 | * Give other threads a chance to run in the presence of | |
e633b7bc | 146 | * errors. |
d1496c39 | 147 | */ |
e633b7bc PO |
148 | if (ret < 0) { |
149 | set_current_state(TASK_INTERRUPTIBLE); | |
150 | if (!kthread_should_stop()) | |
151 | schedule_timeout(HZ); | |
152 | set_current_state(TASK_RUNNING); | |
153 | } | |
d1496c39 | 154 | |
6f4285d1 PO |
155 | /* |
156 | * Adaptive polling frequency based on the assumption | |
157 | * that an interrupt will be closely followed by more. | |
158 | * This has a substantial benefit for network devices. | |
159 | */ | |
160 | if (!(host->caps & MMC_CAP_SDIO_IRQ)) { | |
161 | if (ret > 0) | |
162 | period /= 2; | |
163 | else { | |
164 | period++; | |
165 | if (period > idle_period) | |
166 | period = idle_period; | |
167 | } | |
168 | } | |
169 | ||
6fee65cf | 170 | set_current_state(TASK_INTERRUPTIBLE); |
2c4967f7 SRT |
171 | if (host->caps & MMC_CAP_SDIO_IRQ) { |
172 | mmc_host_clk_hold(host); | |
17b759af | 173 | host->ops->enable_sdio_irq(host, 1); |
2c4967f7 SRT |
174 | mmc_host_clk_release(host); |
175 | } | |
d1496c39 NP |
176 | if (!kthread_should_stop()) |
177 | schedule_timeout(period); | |
6fee65cf | 178 | set_current_state(TASK_RUNNING); |
d1496c39 NP |
179 | } while (!kthread_should_stop()); |
180 | ||
2c4967f7 SRT |
181 | if (host->caps & MMC_CAP_SDIO_IRQ) { |
182 | mmc_host_clk_hold(host); | |
17b759af | 183 | host->ops->enable_sdio_irq(host, 0); |
2c4967f7 SRT |
184 | mmc_host_clk_release(host); |
185 | } | |
17b759af | 186 | |
d1496c39 NP |
187 | pr_debug("%s: IRQ thread exiting with code %d\n", |
188 | mmc_hostname(host), ret); | |
189 | ||
190 | return ret; | |
191 | } | |
192 | ||
193 | static int sdio_card_irq_get(struct mmc_card *card) | |
194 | { | |
195 | struct mmc_host *host = card->host; | |
196 | ||
d84075c8 | 197 | WARN_ON(!host->claimed); |
d1496c39 NP |
198 | |
199 | if (!host->sdio_irqs++) { | |
bf3b5ec6 RK |
200 | if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { |
201 | atomic_set(&host->sdio_irq_thread_abort, 0); | |
202 | host->sdio_irq_thread = | |
203 | kthread_run(sdio_irq_thread, host, | |
204 | "ksdioirqd/%s", mmc_hostname(host)); | |
205 | if (IS_ERR(host->sdio_irq_thread)) { | |
206 | int err = PTR_ERR(host->sdio_irq_thread); | |
207 | host->sdio_irqs--; | |
208 | return err; | |
209 | } | |
dea67c4e | 210 | } else if (host->caps & MMC_CAP_SDIO_IRQ) { |
bf3b5ec6 RK |
211 | mmc_host_clk_hold(host); |
212 | host->ops->enable_sdio_irq(host, 1); | |
213 | mmc_host_clk_release(host); | |
d1496c39 NP |
214 | } |
215 | } | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | static int sdio_card_irq_put(struct mmc_card *card) | |
221 | { | |
222 | struct mmc_host *host = card->host; | |
223 | ||
d84075c8 | 224 | WARN_ON(!host->claimed); |
d1496c39 NP |
225 | BUG_ON(host->sdio_irqs < 1); |
226 | ||
227 | if (!--host->sdio_irqs) { | |
bf3b5ec6 RK |
228 | if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { |
229 | atomic_set(&host->sdio_irq_thread_abort, 1); | |
230 | kthread_stop(host->sdio_irq_thread); | |
dea67c4e | 231 | } else if (host->caps & MMC_CAP_SDIO_IRQ) { |
bf3b5ec6 RK |
232 | mmc_host_clk_hold(host); |
233 | host->ops->enable_sdio_irq(host, 0); | |
234 | mmc_host_clk_release(host); | |
235 | } | |
d1496c39 NP |
236 | } |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
06e8935f SNX |
241 | /* If there is only 1 function registered set sdio_single_irq */ |
242 | static void sdio_single_irq_set(struct mmc_card *card) | |
243 | { | |
244 | struct sdio_func *func; | |
245 | int i; | |
246 | ||
247 | card->sdio_single_irq = NULL; | |
248 | if ((card->host->caps & MMC_CAP_SDIO_IRQ) && | |
249 | card->host->sdio_irqs == 1) | |
250 | for (i = 0; i < card->sdio_funcs; i++) { | |
251 | func = card->sdio_func[i]; | |
252 | if (func && func->irq_handler) { | |
253 | card->sdio_single_irq = func; | |
254 | break; | |
255 | } | |
256 | } | |
257 | } | |
258 | ||
d1496c39 NP |
259 | /** |
260 | * sdio_claim_irq - claim the IRQ for a SDIO function | |
261 | * @func: SDIO function | |
262 | * @handler: IRQ handler callback | |
263 | * | |
264 | * Claim and activate the IRQ for the given SDIO function. The provided | |
265 | * handler will be called when that IRQ is asserted. The host is always | |
266 | * claimed already when the handler is called so the handler must not | |
267 | * call sdio_claim_host() nor sdio_release_host(). | |
268 | */ | |
269 | int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) | |
270 | { | |
271 | int ret; | |
272 | unsigned char reg; | |
273 | ||
274 | BUG_ON(!func); | |
275 | BUG_ON(!func->card); | |
276 | ||
277 | pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); | |
278 | ||
279 | if (func->irq_handler) { | |
280 | pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); | |
281 | return -EBUSY; | |
282 | } | |
283 | ||
284 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
285 | if (ret) | |
286 | return ret; | |
287 | ||
288 | reg |= 1 << func->num; | |
289 | ||
290 | reg |= 1; /* Master interrupt enable */ | |
291 | ||
292 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
293 | if (ret) | |
294 | return ret; | |
295 | ||
296 | func->irq_handler = handler; | |
297 | ret = sdio_card_irq_get(func->card); | |
298 | if (ret) | |
299 | func->irq_handler = NULL; | |
06e8935f | 300 | sdio_single_irq_set(func->card); |
d1496c39 NP |
301 | |
302 | return ret; | |
303 | } | |
304 | EXPORT_SYMBOL_GPL(sdio_claim_irq); | |
305 | ||
306 | /** | |
307 | * sdio_release_irq - release the IRQ for a SDIO function | |
308 | * @func: SDIO function | |
309 | * | |
310 | * Disable and release the IRQ for the given SDIO function. | |
311 | */ | |
312 | int sdio_release_irq(struct sdio_func *func) | |
313 | { | |
314 | int ret; | |
315 | unsigned char reg; | |
316 | ||
317 | BUG_ON(!func); | |
318 | BUG_ON(!func->card); | |
319 | ||
320 | pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); | |
321 | ||
322 | if (func->irq_handler) { | |
323 | func->irq_handler = NULL; | |
324 | sdio_card_irq_put(func->card); | |
06e8935f | 325 | sdio_single_irq_set(func->card); |
d1496c39 NP |
326 | } |
327 | ||
328 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
329 | if (ret) | |
330 | return ret; | |
331 | ||
332 | reg &= ~(1 << func->num); | |
333 | ||
334 | /* Disable master interrupt with the last function interrupt */ | |
335 | if (!(reg & 0xFE)) | |
336 | reg = 0; | |
337 | ||
338 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
339 | if (ret) | |
340 | return ret; | |
341 | ||
342 | return 0; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(sdio_release_irq); | |
345 |