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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> | |
19 | #include <linux/wait.h> | |
20 | #include <linux/delay.h> | |
21 | ||
22 | #include <linux/mmc/core.h> | |
23 | #include <linux/mmc/host.h> | |
24 | #include <linux/mmc/card.h> | |
25 | #include <linux/mmc/sdio.h> | |
26 | #include <linux/mmc/sdio_func.h> | |
27 | ||
28 | #include "sdio_ops.h" | |
29 | ||
30 | static int process_sdio_pending_irqs(struct mmc_card *card) | |
31 | { | |
6f4285d1 | 32 | int i, ret, count; |
d1496c39 NP |
33 | unsigned char pending; |
34 | ||
35 | ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); | |
36 | if (ret) { | |
37 | printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n", | |
38 | mmc_card_id(card), ret); | |
39 | return ret; | |
40 | } | |
41 | ||
6f4285d1 | 42 | count = 0; |
d1496c39 NP |
43 | for (i = 1; i <= 7; i++) { |
44 | if (pending & (1 << i)) { | |
45 | struct sdio_func *func = card->sdio_func[i - 1]; | |
46 | if (!func) { | |
47 | printk(KERN_WARNING "%s: pending IRQ for " | |
25985edc | 48 | "non-existent function\n", |
3e01e4bc | 49 | mmc_card_id(card)); |
599473cf | 50 | ret = -EINVAL; |
d1496c39 NP |
51 | } else if (func->irq_handler) { |
52 | func->irq_handler(func); | |
6f4285d1 | 53 | count++; |
599473cf | 54 | } else { |
d1496c39 NP |
55 | printk(KERN_WARNING "%s: pending IRQ with no handler\n", |
56 | sdio_func_id(func)); | |
599473cf NP |
57 | ret = -EINVAL; |
58 | } | |
d1496c39 NP |
59 | } |
60 | } | |
61 | ||
599473cf NP |
62 | if (count) |
63 | return count; | |
64 | ||
65 | return ret; | |
d1496c39 NP |
66 | } |
67 | ||
68 | static int sdio_irq_thread(void *_host) | |
69 | { | |
70 | struct mmc_host *host = _host; | |
71 | struct sched_param param = { .sched_priority = 1 }; | |
6f4285d1 | 72 | unsigned long period, idle_period; |
d1496c39 NP |
73 | int ret; |
74 | ||
75 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
76 | ||
77 | /* | |
78 | * We want to allow for SDIO cards to work even on non SDIO | |
79 | * aware hosts. One thing that non SDIO host cannot do is | |
80 | * asynchronous notification of pending SDIO card interrupts | |
81 | * hence we poll for them in that case. | |
82 | */ | |
6f4285d1 | 83 | idle_period = msecs_to_jiffies(10); |
17b759af | 84 | period = (host->caps & MMC_CAP_SDIO_IRQ) ? |
6f4285d1 | 85 | MAX_SCHEDULE_TIMEOUT : idle_period; |
d1496c39 NP |
86 | |
87 | pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", | |
88 | mmc_hostname(host), period); | |
89 | ||
90 | do { | |
91 | /* | |
92 | * We claim the host here on drivers behalf for a couple | |
93 | * reasons: | |
94 | * | |
95 | * 1) it is already needed to retrieve the CCCR_INTx; | |
96 | * 2) we want the driver(s) to clear the IRQ condition ASAP; | |
97 | * 3) we need to control the abort condition locally. | |
98 | * | |
99 | * Just like traditional hard IRQ handlers, we expect SDIO | |
100 | * IRQ handlers to be quick and to the point, so that the | |
101 | * holding of the host lock does not cover too much work | |
102 | * that doesn't require that lock to be held. | |
103 | */ | |
104 | ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); | |
105 | if (ret) | |
106 | break; | |
107 | ret = process_sdio_pending_irqs(host->card); | |
108 | mmc_release_host(host); | |
109 | ||
110 | /* | |
111 | * Give other threads a chance to run in the presence of | |
e633b7bc | 112 | * errors. |
d1496c39 | 113 | */ |
e633b7bc PO |
114 | if (ret < 0) { |
115 | set_current_state(TASK_INTERRUPTIBLE); | |
116 | if (!kthread_should_stop()) | |
117 | schedule_timeout(HZ); | |
118 | set_current_state(TASK_RUNNING); | |
119 | } | |
d1496c39 | 120 | |
6f4285d1 PO |
121 | /* |
122 | * Adaptive polling frequency based on the assumption | |
123 | * that an interrupt will be closely followed by more. | |
124 | * This has a substantial benefit for network devices. | |
125 | */ | |
126 | if (!(host->caps & MMC_CAP_SDIO_IRQ)) { | |
127 | if (ret > 0) | |
128 | period /= 2; | |
129 | else { | |
130 | period++; | |
131 | if (period > idle_period) | |
132 | period = idle_period; | |
133 | } | |
134 | } | |
135 | ||
6fee65cf | 136 | set_current_state(TASK_INTERRUPTIBLE); |
17b759af NP |
137 | if (host->caps & MMC_CAP_SDIO_IRQ) |
138 | host->ops->enable_sdio_irq(host, 1); | |
d1496c39 NP |
139 | if (!kthread_should_stop()) |
140 | schedule_timeout(period); | |
6fee65cf | 141 | set_current_state(TASK_RUNNING); |
d1496c39 NP |
142 | } while (!kthread_should_stop()); |
143 | ||
17b759af NP |
144 | if (host->caps & MMC_CAP_SDIO_IRQ) |
145 | host->ops->enable_sdio_irq(host, 0); | |
146 | ||
d1496c39 NP |
147 | pr_debug("%s: IRQ thread exiting with code %d\n", |
148 | mmc_hostname(host), ret); | |
149 | ||
150 | return ret; | |
151 | } | |
152 | ||
153 | static int sdio_card_irq_get(struct mmc_card *card) | |
154 | { | |
155 | struct mmc_host *host = card->host; | |
156 | ||
d84075c8 | 157 | WARN_ON(!host->claimed); |
d1496c39 NP |
158 | |
159 | if (!host->sdio_irqs++) { | |
160 | atomic_set(&host->sdio_irq_thread_abort, 0); | |
161 | host->sdio_irq_thread = | |
6501ff60 PO |
162 | kthread_run(sdio_irq_thread, host, "ksdioirqd/%s", |
163 | mmc_hostname(host)); | |
d1496c39 NP |
164 | if (IS_ERR(host->sdio_irq_thread)) { |
165 | int err = PTR_ERR(host->sdio_irq_thread); | |
166 | host->sdio_irqs--; | |
167 | return err; | |
168 | } | |
169 | } | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | static int sdio_card_irq_put(struct mmc_card *card) | |
175 | { | |
176 | struct mmc_host *host = card->host; | |
177 | ||
d84075c8 | 178 | WARN_ON(!host->claimed); |
d1496c39 NP |
179 | BUG_ON(host->sdio_irqs < 1); |
180 | ||
181 | if (!--host->sdio_irqs) { | |
182 | atomic_set(&host->sdio_irq_thread_abort, 1); | |
183 | kthread_stop(host->sdio_irq_thread); | |
184 | } | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | /** | |
190 | * sdio_claim_irq - claim the IRQ for a SDIO function | |
191 | * @func: SDIO function | |
192 | * @handler: IRQ handler callback | |
193 | * | |
194 | * Claim and activate the IRQ for the given SDIO function. The provided | |
195 | * handler will be called when that IRQ is asserted. The host is always | |
196 | * claimed already when the handler is called so the handler must not | |
197 | * call sdio_claim_host() nor sdio_release_host(). | |
198 | */ | |
199 | int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) | |
200 | { | |
201 | int ret; | |
202 | unsigned char reg; | |
203 | ||
204 | BUG_ON(!func); | |
205 | BUG_ON(!func->card); | |
206 | ||
207 | pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); | |
208 | ||
209 | if (func->irq_handler) { | |
210 | pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); | |
211 | return -EBUSY; | |
212 | } | |
213 | ||
214 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
215 | if (ret) | |
216 | return ret; | |
217 | ||
218 | reg |= 1 << func->num; | |
219 | ||
220 | reg |= 1; /* Master interrupt enable */ | |
221 | ||
222 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
223 | if (ret) | |
224 | return ret; | |
225 | ||
226 | func->irq_handler = handler; | |
227 | ret = sdio_card_irq_get(func->card); | |
228 | if (ret) | |
229 | func->irq_handler = NULL; | |
230 | ||
231 | return ret; | |
232 | } | |
233 | EXPORT_SYMBOL_GPL(sdio_claim_irq); | |
234 | ||
235 | /** | |
236 | * sdio_release_irq - release the IRQ for a SDIO function | |
237 | * @func: SDIO function | |
238 | * | |
239 | * Disable and release the IRQ for the given SDIO function. | |
240 | */ | |
241 | int sdio_release_irq(struct sdio_func *func) | |
242 | { | |
243 | int ret; | |
244 | unsigned char reg; | |
245 | ||
246 | BUG_ON(!func); | |
247 | BUG_ON(!func->card); | |
248 | ||
249 | pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); | |
250 | ||
251 | if (func->irq_handler) { | |
252 | func->irq_handler = NULL; | |
253 | sdio_card_irq_put(func->card); | |
254 | } | |
255 | ||
256 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
257 | if (ret) | |
258 | return ret; | |
259 | ||
260 | reg &= ~(1 << func->num); | |
261 | ||
262 | /* Disable master interrupt with the last function interrupt */ | |
263 | if (!(reg & 0xFE)) | |
264 | reg = 0; | |
265 | ||
266 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
267 | if (ret) | |
268 | return ret; | |
269 | ||
270 | return 0; | |
271 | } | |
272 | EXPORT_SYMBOL_GPL(sdio_release_irq); | |
273 |