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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 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or (at | |
11 | * your option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/kthread.h> | |
17 | #include <linux/wait.h> | |
18 | #include <linux/delay.h> | |
19 | ||
20 | #include <linux/mmc/core.h> | |
21 | #include <linux/mmc/host.h> | |
22 | #include <linux/mmc/card.h> | |
23 | #include <linux/mmc/sdio.h> | |
24 | #include <linux/mmc/sdio_func.h> | |
25 | ||
26 | #include "sdio_ops.h" | |
27 | ||
28 | static int process_sdio_pending_irqs(struct mmc_card *card) | |
29 | { | |
6f4285d1 | 30 | int i, ret, count; |
d1496c39 NP |
31 | unsigned char pending; |
32 | ||
33 | ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); | |
34 | if (ret) { | |
35 | printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n", | |
36 | mmc_card_id(card), ret); | |
37 | return ret; | |
38 | } | |
39 | ||
6f4285d1 | 40 | count = 0; |
d1496c39 NP |
41 | for (i = 1; i <= 7; i++) { |
42 | if (pending & (1 << i)) { | |
43 | struct sdio_func *func = card->sdio_func[i - 1]; | |
44 | if (!func) { | |
45 | printk(KERN_WARNING "%s: pending IRQ for " | |
46 | "non-existant function\n", | |
3e01e4bc | 47 | mmc_card_id(card)); |
d1496c39 NP |
48 | } else if (func->irq_handler) { |
49 | func->irq_handler(func); | |
6f4285d1 | 50 | count++; |
d1496c39 NP |
51 | } else |
52 | printk(KERN_WARNING "%s: pending IRQ with no handler\n", | |
53 | sdio_func_id(func)); | |
54 | } | |
55 | } | |
56 | ||
6f4285d1 | 57 | return count; |
d1496c39 NP |
58 | } |
59 | ||
60 | static int sdio_irq_thread(void *_host) | |
61 | { | |
62 | struct mmc_host *host = _host; | |
63 | struct sched_param param = { .sched_priority = 1 }; | |
6f4285d1 | 64 | unsigned long period, idle_period; |
d1496c39 NP |
65 | int ret; |
66 | ||
67 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
68 | ||
69 | /* | |
70 | * We want to allow for SDIO cards to work even on non SDIO | |
71 | * aware hosts. One thing that non SDIO host cannot do is | |
72 | * asynchronous notification of pending SDIO card interrupts | |
73 | * hence we poll for them in that case. | |
74 | */ | |
6f4285d1 | 75 | idle_period = msecs_to_jiffies(10); |
17b759af | 76 | period = (host->caps & MMC_CAP_SDIO_IRQ) ? |
6f4285d1 | 77 | MAX_SCHEDULE_TIMEOUT : idle_period; |
d1496c39 NP |
78 | |
79 | pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", | |
80 | mmc_hostname(host), period); | |
81 | ||
82 | do { | |
83 | /* | |
84 | * We claim the host here on drivers behalf for a couple | |
85 | * reasons: | |
86 | * | |
87 | * 1) it is already needed to retrieve the CCCR_INTx; | |
88 | * 2) we want the driver(s) to clear the IRQ condition ASAP; | |
89 | * 3) we need to control the abort condition locally. | |
90 | * | |
91 | * Just like traditional hard IRQ handlers, we expect SDIO | |
92 | * IRQ handlers to be quick and to the point, so that the | |
93 | * holding of the host lock does not cover too much work | |
94 | * that doesn't require that lock to be held. | |
95 | */ | |
96 | ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); | |
97 | if (ret) | |
98 | break; | |
99 | ret = process_sdio_pending_irqs(host->card); | |
100 | mmc_release_host(host); | |
101 | ||
102 | /* | |
103 | * Give other threads a chance to run in the presence of | |
104 | * errors. FIXME: determine if due to card removal and | |
105 | * possibly exit this thread if so. | |
106 | */ | |
6f4285d1 | 107 | if (ret < 0) |
d1496c39 NP |
108 | ssleep(1); |
109 | ||
6f4285d1 PO |
110 | /* |
111 | * Adaptive polling frequency based on the assumption | |
112 | * that an interrupt will be closely followed by more. | |
113 | * This has a substantial benefit for network devices. | |
114 | */ | |
115 | if (!(host->caps & MMC_CAP_SDIO_IRQ)) { | |
116 | if (ret > 0) | |
117 | period /= 2; | |
118 | else { | |
119 | period++; | |
120 | if (period > idle_period) | |
121 | period = idle_period; | |
122 | } | |
123 | } | |
124 | ||
d1496c39 | 125 | set_task_state(current, TASK_INTERRUPTIBLE); |
17b759af NP |
126 | if (host->caps & MMC_CAP_SDIO_IRQ) |
127 | host->ops->enable_sdio_irq(host, 1); | |
d1496c39 NP |
128 | if (!kthread_should_stop()) |
129 | schedule_timeout(period); | |
130 | set_task_state(current, TASK_RUNNING); | |
131 | } while (!kthread_should_stop()); | |
132 | ||
17b759af NP |
133 | if (host->caps & MMC_CAP_SDIO_IRQ) |
134 | host->ops->enable_sdio_irq(host, 0); | |
135 | ||
d1496c39 NP |
136 | pr_debug("%s: IRQ thread exiting with code %d\n", |
137 | mmc_hostname(host), ret); | |
138 | ||
139 | return ret; | |
140 | } | |
141 | ||
142 | static int sdio_card_irq_get(struct mmc_card *card) | |
143 | { | |
144 | struct mmc_host *host = card->host; | |
145 | ||
d84075c8 | 146 | WARN_ON(!host->claimed); |
d1496c39 NP |
147 | |
148 | if (!host->sdio_irqs++) { | |
149 | atomic_set(&host->sdio_irq_thread_abort, 0); | |
150 | host->sdio_irq_thread = | |
151 | kthread_run(sdio_irq_thread, host, "ksdiorqd"); | |
152 | if (IS_ERR(host->sdio_irq_thread)) { | |
153 | int err = PTR_ERR(host->sdio_irq_thread); | |
154 | host->sdio_irqs--; | |
155 | return err; | |
156 | } | |
157 | } | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
162 | static int sdio_card_irq_put(struct mmc_card *card) | |
163 | { | |
164 | struct mmc_host *host = card->host; | |
165 | ||
d84075c8 | 166 | WARN_ON(!host->claimed); |
d1496c39 NP |
167 | BUG_ON(host->sdio_irqs < 1); |
168 | ||
169 | if (!--host->sdio_irqs) { | |
170 | atomic_set(&host->sdio_irq_thread_abort, 1); | |
171 | kthread_stop(host->sdio_irq_thread); | |
172 | } | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | /** | |
178 | * sdio_claim_irq - claim the IRQ for a SDIO function | |
179 | * @func: SDIO function | |
180 | * @handler: IRQ handler callback | |
181 | * | |
182 | * Claim and activate the IRQ for the given SDIO function. The provided | |
183 | * handler will be called when that IRQ is asserted. The host is always | |
184 | * claimed already when the handler is called so the handler must not | |
185 | * call sdio_claim_host() nor sdio_release_host(). | |
186 | */ | |
187 | int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) | |
188 | { | |
189 | int ret; | |
190 | unsigned char reg; | |
191 | ||
192 | BUG_ON(!func); | |
193 | BUG_ON(!func->card); | |
194 | ||
195 | pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); | |
196 | ||
197 | if (func->irq_handler) { | |
198 | pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); | |
199 | return -EBUSY; | |
200 | } | |
201 | ||
202 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
203 | if (ret) | |
204 | return ret; | |
205 | ||
206 | reg |= 1 << func->num; | |
207 | ||
208 | reg |= 1; /* Master interrupt enable */ | |
209 | ||
210 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
211 | if (ret) | |
212 | return ret; | |
213 | ||
214 | func->irq_handler = handler; | |
215 | ret = sdio_card_irq_get(func->card); | |
216 | if (ret) | |
217 | func->irq_handler = NULL; | |
218 | ||
219 | return ret; | |
220 | } | |
221 | EXPORT_SYMBOL_GPL(sdio_claim_irq); | |
222 | ||
223 | /** | |
224 | * sdio_release_irq - release the IRQ for a SDIO function | |
225 | * @func: SDIO function | |
226 | * | |
227 | * Disable and release the IRQ for the given SDIO function. | |
228 | */ | |
229 | int sdio_release_irq(struct sdio_func *func) | |
230 | { | |
231 | int ret; | |
232 | unsigned char reg; | |
233 | ||
234 | BUG_ON(!func); | |
235 | BUG_ON(!func->card); | |
236 | ||
237 | pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); | |
238 | ||
239 | if (func->irq_handler) { | |
240 | func->irq_handler = NULL; | |
241 | sdio_card_irq_put(func->card); | |
242 | } | |
243 | ||
244 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); | |
245 | if (ret) | |
246 | return ret; | |
247 | ||
248 | reg &= ~(1 << func->num); | |
249 | ||
250 | /* Disable master interrupt with the last function interrupt */ | |
251 | if (!(reg & 0xFE)) | |
252 | reg = 0; | |
253 | ||
254 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); | |
255 | if (ret) | |
256 | return ret; | |
257 | ||
258 | return 0; | |
259 | } | |
260 | EXPORT_SYMBOL_GPL(sdio_release_irq); | |
261 |