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Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +02001/*
2 * Generic GPIO card-detect helper
3 *
4 * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/err.h>
12#include <linux/gpio.h>
Adrian Hunter842f4bd2014-03-10 15:02:39 +020013#include <linux/gpio/consumer.h>
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +020014#include <linux/interrupt.h>
15#include <linux/jiffies.h>
16#include <linux/mmc/host.h>
17#include <linux/mmc/slot-gpio.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20
21struct mmc_gpio {
Adrian Hunter842f4bd2014-03-10 15:02:39 +020022 struct gpio_desc *ro_gpio;
23 struct gpio_desc *cd_gpio;
24 bool override_ro_active_level;
25 bool override_cd_active_level;
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020026 char *ro_label;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +020027 char cd_label[0];
28};
29
30static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
31{
32 /* Schedule a card detection after a debounce timeout */
Guennadi Liakhovetski451c8952012-12-04 16:51:36 +010033 struct mmc_host *host = dev_id;
34
Markus Mayerfa372a52014-04-08 15:19:43 -070035 host->trigger_card_event = true;
Guennadi Liakhovetski451c8952012-12-04 16:51:36 +010036 mmc_detect_change(host, msecs_to_jiffies(200));
37
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +020038 return IRQ_HANDLED;
39}
40
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +020041static int mmc_gpio_alloc(struct mmc_host *host)
42{
43 size_t len = strlen(dev_name(host->parent)) + 4;
44 struct mmc_gpio *ctx;
45
46 mutex_lock(&host->slot.lock);
47
48 ctx = host->slot.handler_priv;
49 if (!ctx) {
50 /*
51 * devm_kzalloc() can be called after device_initialize(), even
52 * before device_add(), i.e., between mmc_alloc_host() and
53 * mmc_add_host()
54 */
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020055 ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +020056 GFP_KERNEL);
57 if (ctx) {
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020058 ctx->ro_label = ctx->cd_label + len;
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +020059 snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020060 snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +020061 host->slot.handler_priv = ctx;
62 }
63 }
64
65 mutex_unlock(&host->slot.lock);
66
67 return ctx ? 0 : -ENOMEM;
68}
69
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020070int mmc_gpio_get_ro(struct mmc_host *host)
71{
72 struct mmc_gpio *ctx = host->slot.handler_priv;
73
Adrian Hunter842f4bd2014-03-10 15:02:39 +020074 if (!ctx || !ctx->ro_gpio)
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020075 return -ENOSYS;
76
Adrian Hunter842f4bd2014-03-10 15:02:39 +020077 if (ctx->override_ro_active_level)
78 return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
79 !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
80
81 return gpiod_get_value_cansleep(ctx->ro_gpio);
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +020082}
83EXPORT_SYMBOL(mmc_gpio_get_ro);
84
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +020085int mmc_gpio_get_cd(struct mmc_host *host)
86{
87 struct mmc_gpio *ctx = host->slot.handler_priv;
88
Adrian Hunter842f4bd2014-03-10 15:02:39 +020089 if (!ctx || !ctx->cd_gpio)
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +020090 return -ENOSYS;
91
Adrian Hunter842f4bd2014-03-10 15:02:39 +020092 if (ctx->override_cd_active_level)
93 return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
94 !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
95
96 return gpiod_get_value_cansleep(ctx->cd_gpio);
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +020097}
98EXPORT_SYMBOL(mmc_gpio_get_cd);
99
Shawn Guod65b5ae2012-12-11 22:32:18 +0800100/**
101 * mmc_gpio_request_ro - request a gpio for write-protection
102 * @host: mmc host
103 * @gpio: gpio number requested
104 *
105 * As devm_* managed functions are used in mmc_gpio_request_ro(), client
106 * drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up,
107 * if the requesting and freeing are only needed at probing and unbinding time
108 * for once. However, if client drivers do something special like runtime
109 * switching for write-protection, they are responsible for calling
110 * mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own.
111 *
112 * Returns zero on success, else an error.
113 */
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200114int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
115{
116 struct mmc_gpio *ctx;
117 int ret;
118
119 if (!gpio_is_valid(gpio))
120 return -EINVAL;
121
122 ret = mmc_gpio_alloc(host);
123 if (ret < 0)
124 return ret;
125
126 ctx = host->slot.handler_priv;
127
Shawn Guod65b5ae2012-12-11 22:32:18 +0800128 ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
129 ctx->ro_label);
Chris Ball15e8a8e2012-09-09 22:56:48 -0400130 if (ret < 0)
131 return ret;
132
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200133 ctx->override_ro_active_level = true;
134 ctx->ro_gpio = gpio_to_desc(gpio);
Chris Ball15e8a8e2012-09-09 22:56:48 -0400135
136 return 0;
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200137}
138EXPORT_SYMBOL(mmc_gpio_request_ro);
139
Adrian Hunter740a2212014-03-10 15:02:41 +0200140void mmc_gpiod_request_cd_irq(struct mmc_host *host)
Adrian Hunter26652672014-03-10 15:02:40 +0200141{
142 struct mmc_gpio *ctx = host->slot.handler_priv;
143 int ret, irq;
144
145 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
146 return;
147
148 irq = gpiod_to_irq(ctx->cd_gpio);
149
150 /*
151 * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
152 * still prefer to poll, e.g., because that IRQ number is already used
153 * by another unit and cannot be shared.
154 */
155 if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
156 irq = -EINVAL;
157
158 if (irq >= 0) {
159 ret = devm_request_threaded_irq(&host->class_dev, irq,
160 NULL, mmc_gpio_cd_irqt,
161 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
162 ctx->cd_label, host);
163 if (ret < 0)
164 irq = ret;
165 }
166
167 host->slot.cd_irq = irq;
168
169 if (irq < 0)
170 host->caps |= MMC_CAP_NEEDS_POLL;
171}
Adrian Hunter740a2212014-03-10 15:02:41 +0200172EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
Adrian Hunter26652672014-03-10 15:02:40 +0200173
Shawn Guod65b5ae2012-12-11 22:32:18 +0800174/**
175 * mmc_gpio_request_cd - request a gpio for card-detection
176 * @host: mmc host
177 * @gpio: gpio number requested
Laurent Pinchart214fc302013-08-08 12:38:31 +0200178 * @debounce: debounce time in microseconds
Shawn Guod65b5ae2012-12-11 22:32:18 +0800179 *
180 * As devm_* managed functions are used in mmc_gpio_request_cd(), client
181 * drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up,
182 * if the requesting and freeing are only needed at probing and unbinding time
183 * for once. However, if client drivers do something special like runtime
184 * switching for card-detection, they are responsible for calling
185 * mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own.
186 *
Laurent Pinchart214fc302013-08-08 12:38:31 +0200187 * If GPIO debouncing is desired, set the debounce parameter to a non-zero
188 * value. The caller is responsible for ensuring that the GPIO driver associated
189 * with the GPIO supports debouncing, otherwise an error will be returned.
190 *
Shawn Guod65b5ae2012-12-11 22:32:18 +0800191 * Returns zero on success, else an error.
192 */
Laurent Pinchart214fc302013-08-08 12:38:31 +0200193int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
194 unsigned int debounce)
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200195{
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200196 struct mmc_gpio *ctx;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200197 int ret;
198
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +0200199 ret = mmc_gpio_alloc(host);
200 if (ret < 0)
201 return ret;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200202
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +0200203 ctx = host->slot.handler_priv;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200204
Shawn Guod65b5ae2012-12-11 22:32:18 +0800205 ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
206 ctx->cd_label);
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200207 if (ret < 0)
Guennadi Liakhovetskia7d1a1e2012-05-01 16:51:38 +0200208 /*
209 * don't bother freeing memory. It might still get used by other
210 * slot functions, in any case it will be freed, when the device
211 * is destroyed.
212 */
213 return ret;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200214
Laurent Pinchart214fc302013-08-08 12:38:31 +0200215 if (debounce) {
216 ret = gpio_set_debounce(gpio, debounce);
217 if (ret < 0)
218 return ret;
219 }
220
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200221 ctx->override_cd_active_level = true;
222 ctx->cd_gpio = gpio_to_desc(gpio);
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200223
Adrian Hunter26652672014-03-10 15:02:40 +0200224 mmc_gpiod_request_cd_irq(host);
225
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200226 return 0;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200227}
228EXPORT_SYMBOL(mmc_gpio_request_cd);
229
Shawn Guod65b5ae2012-12-11 22:32:18 +0800230/**
231 * mmc_gpio_free_ro - free the write-protection gpio
232 * @host: mmc host
233 *
234 * It's provided only for cases that client drivers need to manually free
235 * up the write-protection gpio requested by mmc_gpio_request_ro().
236 */
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200237void mmc_gpio_free_ro(struct mmc_host *host)
238{
239 struct mmc_gpio *ctx = host->slot.handler_priv;
240 int gpio;
241
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200242 if (!ctx || !ctx->ro_gpio)
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200243 return;
244
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200245 gpio = desc_to_gpio(ctx->ro_gpio);
246 ctx->ro_gpio = NULL;
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200247
Shawn Guod65b5ae2012-12-11 22:32:18 +0800248 devm_gpio_free(&host->class_dev, gpio);
Guennadi Liakhovetski5aa7dad2012-05-01 16:59:38 +0200249}
250EXPORT_SYMBOL(mmc_gpio_free_ro);
251
Shawn Guod65b5ae2012-12-11 22:32:18 +0800252/**
253 * mmc_gpio_free_cd - free the card-detection gpio
254 * @host: mmc host
255 *
256 * It's provided only for cases that client drivers need to manually free
257 * up the card-detection gpio requested by mmc_gpio_request_cd().
258 */
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200259void mmc_gpio_free_cd(struct mmc_host *host)
260{
Guennadi Liakhovetski27410ee2012-05-01 15:40:15 +0200261 struct mmc_gpio *ctx = host->slot.handler_priv;
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +0200262 int gpio;
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200263
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200264 if (!ctx || !ctx->cd_gpio)
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200265 return;
266
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +0200267 if (host->slot.cd_irq >= 0) {
Shawn Guod65b5ae2012-12-11 22:32:18 +0800268 devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +0200269 host->slot.cd_irq = -EINVAL;
270 }
271
Adrian Hunter842f4bd2014-03-10 15:02:39 +0200272 gpio = desc_to_gpio(ctx->cd_gpio);
273 ctx->cd_gpio = NULL;
Guennadi Liakhovetskibefe4042012-05-01 16:27:25 +0200274
Shawn Guod65b5ae2012-12-11 22:32:18 +0800275 devm_gpio_free(&host->class_dev, gpio);
Guennadi Liakhovetskifd0ea652012-04-30 23:31:57 +0200276}
277EXPORT_SYMBOL(mmc_gpio_free_cd);
Adrian Hunter740a2212014-03-10 15:02:41 +0200278
279/**
280 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
281 * @host: mmc host
282 * @con_id: function within the GPIO consumer
283 * @idx: index of the GPIO to obtain in the consumer
284 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
285 * @debounce: debounce time in microseconds
286 *
287 * Use this function in place of mmc_gpio_request_cd() to use the GPIO
288 * descriptor API. Note that it is paired with mmc_gpiod_free_cd() not
289 * mmc_gpio_free_cd(). Note also that it must be called prior to mmc_add_host()
290 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
291 *
292 * Returns zero on success, else an error.
293 */
294int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
295 unsigned int idx, bool override_active_level,
296 unsigned int debounce)
297{
298 struct mmc_gpio *ctx;
299 struct gpio_desc *desc;
300 int ret;
301
302 ret = mmc_gpio_alloc(host);
303 if (ret < 0)
304 return ret;
305
306 ctx = host->slot.handler_priv;
307
308 if (!con_id)
309 con_id = ctx->cd_label;
310
Linus Walleij9fbc6952014-08-27 13:00:50 +0200311 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
Adrian Hunter740a2212014-03-10 15:02:41 +0200312 if (IS_ERR(desc))
313 return PTR_ERR(desc);
314
Adrian Hunter740a2212014-03-10 15:02:41 +0200315 if (debounce) {
316 ret = gpiod_set_debounce(desc, debounce);
317 if (ret < 0)
318 return ret;
319 }
320
321 ctx->override_cd_active_level = override_active_level;
322 ctx->cd_gpio = desc;
323
324 return 0;
325}
326EXPORT_SYMBOL(mmc_gpiod_request_cd);
327
328/**
Linus Walleij9d2fa242014-08-27 13:00:51 +0200329 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
330 * @host: mmc host
331 * @con_id: function within the GPIO consumer
332 * @idx: index of the GPIO to obtain in the consumer
333 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
334 * @debounce: debounce time in microseconds
335 *
336 * Use this function in place of mmc_gpio_request_ro() to use the GPIO
337 * descriptor API. Note that it is paired with mmc_gpiod_free_ro() not
338 * mmc_gpio_free_ro().
339 *
340 * Returns zero on success, else an error.
341 */
342int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
343 unsigned int idx, bool override_active_level,
344 unsigned int debounce)
345{
346 struct mmc_gpio *ctx;
347 struct gpio_desc *desc;
348 int ret;
349
350 ret = mmc_gpio_alloc(host);
351 if (ret < 0)
352 return ret;
353
354 ctx = host->slot.handler_priv;
355
356 if (!con_id)
357 con_id = ctx->ro_label;
358
359 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
360 if (IS_ERR(desc))
361 return PTR_ERR(desc);
362
363 if (debounce) {
364 ret = gpiod_set_debounce(desc, debounce);
365 if (ret < 0)
366 return ret;
367 }
368
369 ctx->override_ro_active_level = override_active_level;
370 ctx->ro_gpio = desc;
371
372 return 0;
373}
374EXPORT_SYMBOL(mmc_gpiod_request_ro);
375
376/**
Adrian Hunter740a2212014-03-10 15:02:41 +0200377 * mmc_gpiod_free_cd - free the card-detection gpio descriptor
378 * @host: mmc host
379 *
380 * It's provided only for cases that client drivers need to manually free
381 * up the card-detection gpio requested by mmc_gpiod_request_cd().
382 */
383void mmc_gpiod_free_cd(struct mmc_host *host)
384{
385 struct mmc_gpio *ctx = host->slot.handler_priv;
386
387 if (!ctx || !ctx->cd_gpio)
388 return;
389
390 if (host->slot.cd_irq >= 0) {
391 devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
392 host->slot.cd_irq = -EINVAL;
393 }
394
395 devm_gpiod_put(&host->class_dev, ctx->cd_gpio);
396
397 ctx->cd_gpio = NULL;
398}
399EXPORT_SYMBOL(mmc_gpiod_free_cd);