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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 | ||
6f4285d1 | 56 | count = 0; |
d1496c39 NP |
57 | for (i = 1; i <= 7; i++) { |
58 | if (pending & (1 << i)) { | |
06e8935f | 59 | func = card->sdio_func[i - 1]; |
d1496c39 | 60 | if (!func) { |
a3c76eb9 | 61 | pr_warning("%s: pending IRQ for " |
25985edc | 62 | "non-existent function\n", |
3e01e4bc | 63 | mmc_card_id(card)); |
599473cf | 64 | ret = -EINVAL; |
d1496c39 NP |
65 | } else if (func->irq_handler) { |
66 | func->irq_handler(func); | |
6f4285d1 | 67 | count++; |
599473cf | 68 | } else { |
a3c76eb9 | 69 | pr_warning("%s: pending IRQ with no handler\n", |
d1496c39 | 70 | sdio_func_id(func)); |
599473cf NP |
71 | ret = -EINVAL; |
72 | } | |
d1496c39 NP |
73 | } |
74 | } | |
75 | ||
599473cf NP |
76 | if (count) |
77 | return count; | |
78 | ||
79 | return ret; | |
d1496c39 NP |
80 | } |
81 | ||
82 | static int sdio_irq_thread(void *_host) | |
83 | { | |
84 | struct mmc_host *host = _host; | |
85 | struct sched_param param = { .sched_priority = 1 }; | |
6f4285d1 | 86 | unsigned long period, idle_period; |
d1496c39 NP |
87 | int ret; |
88 | ||
89 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
90 | ||
91 | /* | |
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. | |
96 | */ | |
6f4285d1 | 97 | idle_period = msecs_to_jiffies(10); |
17b759af | 98 | period = (host->caps & MMC_CAP_SDIO_IRQ) ? |
6f4285d1 | 99 | MAX_SCHEDULE_TIMEOUT : idle_period; |
d1496c39 NP |
100 | |
101 | pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", | |
102 | mmc_hostname(host), period); | |
103 | ||
104 | do { | |
105 | /* | |
106 | * We claim the host here on drivers behalf for a couple | |
107 | * reasons: | |
108 | * | |
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. | |
112 | * | |
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. | |
117 | */ | |
118 | ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); | |
119 | if (ret) | |
120 | break; | |
bbbc4c4d NP |
121 | ret = process_sdio_pending_irqs(host); |
122 | host->sdio_irq_pending = false; | |
d1496c39 NP |
123 | mmc_release_host(host); |
124 | ||
125 | /* | |
126 | * Give other threads a chance to run in the presence of | |
e633b7bc | 127 | * errors. |
d1496c39 | 128 | */ |
e633b7bc PO |
129 | if (ret < 0) { |
130 | set_current_state(TASK_INTERRUPTIBLE); | |
131 | if (!kthread_should_stop()) | |
132 | schedule_timeout(HZ); | |
133 | set_current_state(TASK_RUNNING); | |
134 | } | |
d1496c39 | 135 | |
6f4285d1 PO |
136 | /* |
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. | |
140 | */ | |
141 | if (!(host->caps & MMC_CAP_SDIO_IRQ)) { | |
142 | if (ret > 0) | |
143 | period /= 2; | |
144 | else { | |
145 | period++; | |
146 | if (period > idle_period) | |
147 | period = idle_period; | |
148 | } | |
149 | } | |
150 | ||
6fee65cf | 151 | set_current_state(TASK_INTERRUPTIBLE); |
2c4967f7 SRT |
152 | if (host->caps & MMC_CAP_SDIO_IRQ) { |
153 | mmc_host_clk_hold(host); | |
17b759af | 154 | host->ops->enable_sdio_irq(host, 1); |
2c4967f7 SRT |
155 | mmc_host_clk_release(host); |
156 | } | |
d1496c39 NP |
157 | if (!kthread_should_stop()) |
158 | schedule_timeout(period); | |
6fee65cf | 159 | set_current_state(TASK_RUNNING); |
d1496c39 NP |
160 | } while (!kthread_should_stop()); |
161 | ||
2c4967f7 SRT |
162 | if (host->caps & MMC_CAP_SDIO_IRQ) { |
163 | mmc_host_clk_hold(host); | |
17b759af | 164 | host->ops->enable_sdio_irq(host, 0); |
2c4967f7 SRT |
165 | mmc_host_clk_release(host); |
166 | } | |
17b759af | 167 | |
d1496c39 NP |
168 | pr_debug("%s: IRQ thread exiting with code %d\n", |
169 | mmc_hostname(host), ret); | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | static int sdio_card_irq_get(struct mmc_card *card) | |
175 | { | |
176 | struct mmc_host *host = card->host; | |
177 | ||
d84075c8 | 178 | WARN_ON(!host->claimed); |
d1496c39 NP |
179 | |
180 | if (!host->sdio_irqs++) { | |
181 | atomic_set(&host->sdio_irq_thread_abort, 0); | |
182 | host->sdio_irq_thread = | |
6501ff60 PO |
183 | kthread_run(sdio_irq_thread, host, "ksdioirqd/%s", |
184 | mmc_hostname(host)); | |
d1496c39 NP |
185 | if (IS_ERR(host->sdio_irq_thread)) { |
186 | int err = PTR_ERR(host->sdio_irq_thread); | |
187 | host->sdio_irqs--; | |
188 | return err; | |
189 | } | |
190 | } | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | static int sdio_card_irq_put(struct mmc_card *card) | |
196 | { | |
197 | struct mmc_host *host = card->host; | |
198 | ||
d84075c8 | 199 | WARN_ON(!host->claimed); |
d1496c39 NP |
200 | BUG_ON(host->sdio_irqs < 1); |
201 | ||
202 | if (!--host->sdio_irqs) { | |
203 | atomic_set(&host->sdio_irq_thread_abort, 1); | |
204 | kthread_stop(host->sdio_irq_thread); | |
205 | } | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
06e8935f SNX |
210 | /* If there is only 1 function registered set sdio_single_irq */ |
211 | static void sdio_single_irq_set(struct mmc_card *card) | |
212 | { | |
213 | struct sdio_func *func; | |
214 | int i; | |
215 | ||
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; | |
223 | break; | |
224 | } | |
225 | } | |
226 | } | |
227 | ||
d1496c39 NP |
228 | /** |
229 | * sdio_claim_irq - claim the IRQ for a SDIO function | |
230 | * @func: SDIO function | |
231 | * @handler: IRQ handler callback | |
232 | * | |
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(). | |
237 | */ | |
238 | int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) | |
239 | { | |
240 | int ret; | |
241 | unsigned char reg; | |
242 | ||
243 | BUG_ON(!func); | |
244 | BUG_ON(!func->card); | |
245 | ||
246 | pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); | |
247 | ||
248 | if (func->irq_handler) { | |
249 | pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); | |
250 | return -EBUSY; | |
251 | } | |
252 | ||
253 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
254 | if (ret) | |
255 | return ret; | |
256 | ||
257 | reg |= 1 << func->num; | |
258 | ||
259 | reg |= 1; /* Master interrupt enable */ | |
260 | ||
261 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
262 | if (ret) | |
263 | return ret; | |
264 | ||
265 | func->irq_handler = handler; | |
266 | ret = sdio_card_irq_get(func->card); | |
267 | if (ret) | |
268 | func->irq_handler = NULL; | |
06e8935f | 269 | sdio_single_irq_set(func->card); |
d1496c39 NP |
270 | |
271 | return ret; | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(sdio_claim_irq); | |
274 | ||
275 | /** | |
276 | * sdio_release_irq - release the IRQ for a SDIO function | |
277 | * @func: SDIO function | |
278 | * | |
279 | * Disable and release the IRQ for the given SDIO function. | |
280 | */ | |
281 | int sdio_release_irq(struct sdio_func *func) | |
282 | { | |
283 | int ret; | |
284 | unsigned char reg; | |
285 | ||
286 | BUG_ON(!func); | |
287 | BUG_ON(!func->card); | |
288 | ||
289 | pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); | |
290 | ||
291 | if (func->irq_handler) { | |
292 | func->irq_handler = NULL; | |
293 | sdio_card_irq_put(func->card); | |
06e8935f | 294 | sdio_single_irq_set(func->card); |
d1496c39 NP |
295 | } |
296 | ||
297 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
298 | if (ret) | |
299 | return ret; | |
300 | ||
301 | reg &= ~(1 << func->num); | |
302 | ||
303 | /* Disable master interrupt with the last function interrupt */ | |
304 | if (!(reg & 0xFE)) | |
305 | reg = 0; | |
306 | ||
307 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
308 | if (ret) | |
309 | return ret; | |
310 | ||
311 | return 0; | |
312 | } | |
313 | EXPORT_SYMBOL_GPL(sdio_release_irq); | |
314 |