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1/*
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>
13#include <linux/gpio/consumer.h>
14#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 {
22 struct gpio_desc *ro_gpio;
23 struct gpio_desc *cd_gpio;
24 bool override_ro_active_level;
25 bool override_cd_active_level;
26 char *ro_label;
27 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 */
33 struct mmc_host *host = dev_id;
34
35 if (host->ops->card_event)
36 host->ops->card_event(host);
37
38 mmc_detect_change(host, msecs_to_jiffies(200));
39
40 return IRQ_HANDLED;
41}
42
43static int mmc_gpio_alloc(struct mmc_host *host)
44{
45 size_t len = strlen(dev_name(host->parent)) + 4;
46 struct mmc_gpio *ctx;
47
48 mutex_lock(&host->slot.lock);
49
50 ctx = host->slot.handler_priv;
51 if (!ctx) {
52 /*
53 * devm_kzalloc() can be called after device_initialize(), even
54 * before device_add(), i.e., between mmc_alloc_host() and
55 * mmc_add_host()
56 */
57 ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
58 GFP_KERNEL);
59 if (ctx) {
60 ctx->ro_label = ctx->cd_label + len;
61 snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
62 snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
63 host->slot.handler_priv = ctx;
64 }
65 }
66
67 mutex_unlock(&host->slot.lock);
68
69 return ctx ? 0 : -ENOMEM;
70}
71
72int mmc_gpio_get_ro(struct mmc_host *host)
73{
74 struct mmc_gpio *ctx = host->slot.handler_priv;
75
76 if (!ctx || !ctx->ro_gpio)
77 return -ENOSYS;
78
79 if (ctx->override_ro_active_level)
80 return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
81 !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
82
83 return gpiod_get_value_cansleep(ctx->ro_gpio);
84}
85EXPORT_SYMBOL(mmc_gpio_get_ro);
86
87int mmc_gpio_get_cd(struct mmc_host *host)
88{
89 struct mmc_gpio *ctx = host->slot.handler_priv;
90
91 if (!ctx || !ctx->cd_gpio)
92 return -ENOSYS;
93
94 if (ctx->override_cd_active_level)
95 return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
96 !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
97
98 return gpiod_get_value_cansleep(ctx->cd_gpio);
99}
100EXPORT_SYMBOL(mmc_gpio_get_cd);
101
102/**
103 * mmc_gpio_request_ro - request a gpio for write-protection
104 * @host: mmc host
105 * @gpio: gpio number requested
106 *
107 * As devm_* managed functions are used in mmc_gpio_request_ro(), client
108 * drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up,
109 * if the requesting and freeing are only needed at probing and unbinding time
110 * for once. However, if client drivers do something special like runtime
111 * switching for write-protection, they are responsible for calling
112 * mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own.
113 *
114 * Returns zero on success, else an error.
115 */
116int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
117{
118 struct mmc_gpio *ctx;
119 int ret;
120
121 if (!gpio_is_valid(gpio))
122 return -EINVAL;
123
124 ret = mmc_gpio_alloc(host);
125 if (ret < 0)
126 return ret;
127
128 ctx = host->slot.handler_priv;
129
130 ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
131 ctx->ro_label);
132 if (ret < 0)
133 return ret;
134
135 ctx->override_ro_active_level = true;
136 ctx->ro_gpio = gpio_to_desc(gpio);
137
138 return 0;
139}
140EXPORT_SYMBOL(mmc_gpio_request_ro);
141
142void mmc_gpiod_request_cd_irq(struct mmc_host *host)
143{
144 struct mmc_gpio *ctx = host->slot.handler_priv;
145 int ret, irq;
146
147 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
148 return;
149
150 irq = gpiod_to_irq(ctx->cd_gpio);
151
152 /*
153 * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
154 * still prefer to poll, e.g., because that IRQ number is already used
155 * by another unit and cannot be shared.
156 */
157 if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
158 irq = -EINVAL;
159
160 if (irq >= 0) {
161 ret = devm_request_threaded_irq(&host->class_dev, irq,
162 NULL, mmc_gpio_cd_irqt,
163 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
164 ctx->cd_label, host);
165 if (ret < 0)
166 irq = ret;
167 }
168
169 host->slot.cd_irq = irq;
170
171 if (irq < 0)
172 host->caps |= MMC_CAP_NEEDS_POLL;
173}
174EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
175
176/**
177 * mmc_gpio_request_cd - request a gpio for card-detection
178 * @host: mmc host
179 * @gpio: gpio number requested
180 * @debounce: debounce time in microseconds
181 *
182 * As devm_* managed functions are used in mmc_gpio_request_cd(), client
183 * drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up,
184 * if the requesting and freeing are only needed at probing and unbinding time
185 * for once. However, if client drivers do something special like runtime
186 * switching for card-detection, they are responsible for calling
187 * mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own.
188 *
189 * If GPIO debouncing is desired, set the debounce parameter to a non-zero
190 * value. The caller is responsible for ensuring that the GPIO driver associated
191 * with the GPIO supports debouncing, otherwise an error will be returned.
192 *
193 * Returns zero on success, else an error.
194 */
195int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
196 unsigned int debounce)
197{
198 struct mmc_gpio *ctx;
199 int ret;
200
201 ret = mmc_gpio_alloc(host);
202 if (ret < 0)
203 return ret;
204
205 ctx = host->slot.handler_priv;
206
207 ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
208 ctx->cd_label);
209 if (ret < 0)
210 /*
211 * don't bother freeing memory. It might still get used by other
212 * slot functions, in any case it will be freed, when the device
213 * is destroyed.
214 */
215 return ret;
216
217 if (debounce) {
218 ret = gpio_set_debounce(gpio, debounce);
219 if (ret < 0)
220 return ret;
221 }
222
223 ctx->override_cd_active_level = true;
224 ctx->cd_gpio = gpio_to_desc(gpio);
225
226 mmc_gpiod_request_cd_irq(host);
227
228 return 0;
229}
230EXPORT_SYMBOL(mmc_gpio_request_cd);
231
232/**
233 * mmc_gpio_free_ro - free the write-protection gpio
234 * @host: mmc host
235 *
236 * It's provided only for cases that client drivers need to manually free
237 * up the write-protection gpio requested by mmc_gpio_request_ro().
238 */
239void mmc_gpio_free_ro(struct mmc_host *host)
240{
241 struct mmc_gpio *ctx = host->slot.handler_priv;
242 int gpio;
243
244 if (!ctx || !ctx->ro_gpio)
245 return;
246
247 gpio = desc_to_gpio(ctx->ro_gpio);
248 ctx->ro_gpio = NULL;
249
250 devm_gpio_free(&host->class_dev, gpio);
251}
252EXPORT_SYMBOL(mmc_gpio_free_ro);
253
254/**
255 * mmc_gpio_free_cd - free the card-detection gpio
256 * @host: mmc host
257 *
258 * It's provided only for cases that client drivers need to manually free
259 * up the card-detection gpio requested by mmc_gpio_request_cd().
260 */
261void mmc_gpio_free_cd(struct mmc_host *host)
262{
263 struct mmc_gpio *ctx = host->slot.handler_priv;
264 int gpio;
265
266 if (!ctx || !ctx->cd_gpio)
267 return;
268
269 if (host->slot.cd_irq >= 0) {
270 devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
271 host->slot.cd_irq = -EINVAL;
272 }
273
274 gpio = desc_to_gpio(ctx->cd_gpio);
275 ctx->cd_gpio = NULL;
276
277 devm_gpio_free(&host->class_dev, gpio);
278}
279EXPORT_SYMBOL(mmc_gpio_free_cd);
280
281/**
282 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
283 * @host: mmc host
284 * @con_id: function within the GPIO consumer
285 * @idx: index of the GPIO to obtain in the consumer
286 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
287 * @debounce: debounce time in microseconds
288 *
289 * Use this function in place of mmc_gpio_request_cd() to use the GPIO
290 * descriptor API. Note that it is paired with mmc_gpiod_free_cd() not
291 * mmc_gpio_free_cd(). Note also that it must be called prior to mmc_add_host()
292 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
293 *
294 * Returns zero on success, else an error.
295 */
296int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
297 unsigned int idx, bool override_active_level,
298 unsigned int debounce)
299{
300 struct mmc_gpio *ctx;
301 struct gpio_desc *desc;
302 int ret;
303
304 ret = mmc_gpio_alloc(host);
305 if (ret < 0)
306 return ret;
307
308 ctx = host->slot.handler_priv;
309
310 if (!con_id)
311 con_id = ctx->cd_label;
312
313 desc = devm_gpiod_get_index(host->parent, con_id, idx);
314 if (IS_ERR(desc))
315 return PTR_ERR(desc);
316
317 ret = gpiod_direction_input(desc);
318 if (ret < 0)
319 return ret;
320
321 if (debounce) {
322 ret = gpiod_set_debounce(desc, debounce);
323 if (ret < 0)
324 return ret;
325 }
326
327 ctx->override_cd_active_level = override_active_level;
328 ctx->cd_gpio = desc;
329
330 return 0;
331}
332EXPORT_SYMBOL(mmc_gpiod_request_cd);
333
334/**
335 * mmc_gpiod_free_cd - free the card-detection gpio descriptor
336 * @host: mmc host
337 *
338 * It's provided only for cases that client drivers need to manually free
339 * up the card-detection gpio requested by mmc_gpiod_request_cd().
340 */
341void mmc_gpiod_free_cd(struct mmc_host *host)
342{
343 struct mmc_gpio *ctx = host->slot.handler_priv;
344
345 if (!ctx || !ctx->cd_gpio)
346 return;
347
348 if (host->slot.cd_irq >= 0) {
349 devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
350 host->slot.cd_irq = -EINVAL;
351 }
352
353 devm_gpiod_put(&host->class_dev, ctx->cd_gpio);
354
355 ctx->cd_gpio = NULL;
356}
357EXPORT_SYMBOL(mmc_gpiod_free_cd);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic GPIO card-detect helper
4 *
5 * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
6 */
7
8#include <linux/err.h>
9#include <linux/gpio/consumer.h>
10#include <linux/interrupt.h>
11#include <linux/jiffies.h>
12#include <linux/mmc/host.h>
13#include <linux/mmc/slot-gpio.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16
17#include "slot-gpio.h"
18
19struct mmc_gpio {
20 struct gpio_desc *ro_gpio;
21 struct gpio_desc *cd_gpio;
22 irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
23 char *ro_label;
24 char *cd_label;
25 u32 cd_debounce_delay_ms;
26 int cd_irq;
27};
28
29static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
30{
31 /* Schedule a card detection after a debounce timeout */
32 struct mmc_host *host = dev_id;
33 struct mmc_gpio *ctx = host->slot.handler_priv;
34
35 host->trigger_card_event = true;
36 mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
37
38 return IRQ_HANDLED;
39}
40
41int mmc_gpio_alloc(struct mmc_host *host)
42{
43 const char *devname = dev_name(host->parent);
44 struct mmc_gpio *ctx;
45
46 ctx = devm_kzalloc(host->parent, sizeof(*ctx), GFP_KERNEL);
47 if (!ctx)
48 return -ENOMEM;
49
50 ctx->cd_debounce_delay_ms = 200;
51 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s cd", devname);
52 if (!ctx->cd_label)
53 return -ENOMEM;
54 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s ro", devname);
55 if (!ctx->ro_label)
56 return -ENOMEM;
57 ctx->cd_irq = -EINVAL;
58 host->slot.handler_priv = ctx;
59 host->slot.cd_irq = -EINVAL;
60
61 return 0;
62}
63
64void mmc_gpio_set_cd_irq(struct mmc_host *host, int irq)
65{
66 struct mmc_gpio *ctx = host->slot.handler_priv;
67
68 if (!ctx || irq < 0)
69 return;
70
71 ctx->cd_irq = irq;
72}
73EXPORT_SYMBOL(mmc_gpio_set_cd_irq);
74
75int mmc_gpio_get_ro(struct mmc_host *host)
76{
77 struct mmc_gpio *ctx = host->slot.handler_priv;
78 int cansleep;
79
80 if (!ctx || !ctx->ro_gpio)
81 return -ENOSYS;
82
83 cansleep = gpiod_cansleep(ctx->ro_gpio);
84 return cansleep ?
85 gpiod_get_value_cansleep(ctx->ro_gpio) :
86 gpiod_get_value(ctx->ro_gpio);
87}
88EXPORT_SYMBOL(mmc_gpio_get_ro);
89
90int mmc_gpio_get_cd(struct mmc_host *host)
91{
92 struct mmc_gpio *ctx = host->slot.handler_priv;
93 int cansleep;
94
95 if (!ctx || !ctx->cd_gpio)
96 return -ENOSYS;
97
98 cansleep = gpiod_cansleep(ctx->cd_gpio);
99 return cansleep ?
100 gpiod_get_value_cansleep(ctx->cd_gpio) :
101 gpiod_get_value(ctx->cd_gpio);
102}
103EXPORT_SYMBOL(mmc_gpio_get_cd);
104
105void mmc_gpiod_request_cd_irq(struct mmc_host *host)
106{
107 struct mmc_gpio *ctx = host->slot.handler_priv;
108 int irq = -EINVAL;
109 int ret;
110
111 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
112 return;
113
114 /*
115 * Do not use IRQ if the platform prefers to poll, e.g., because that
116 * IRQ number is already used by another unit and cannot be shared.
117 */
118 if (ctx->cd_irq >= 0)
119 irq = ctx->cd_irq;
120 else if (!(host->caps & MMC_CAP_NEEDS_POLL))
121 irq = gpiod_to_irq(ctx->cd_gpio);
122
123 if (irq >= 0) {
124 if (!ctx->cd_gpio_isr)
125 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
126 ret = devm_request_threaded_irq(host->parent, irq,
127 NULL, ctx->cd_gpio_isr,
128 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
129 ctx->cd_label, host);
130 if (ret < 0)
131 irq = ret;
132 }
133
134 host->slot.cd_irq = irq;
135
136 if (irq < 0)
137 host->caps |= MMC_CAP_NEEDS_POLL;
138}
139EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
140
141int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
142{
143 int ret = 0;
144
145 if (!(host->caps & MMC_CAP_CD_WAKE) ||
146 host->slot.cd_irq < 0 ||
147 on == host->slot.cd_wake_enabled)
148 return 0;
149
150 if (on) {
151 ret = enable_irq_wake(host->slot.cd_irq);
152 host->slot.cd_wake_enabled = !ret;
153 } else {
154 disable_irq_wake(host->slot.cd_irq);
155 host->slot.cd_wake_enabled = false;
156 }
157
158 return ret;
159}
160EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
161
162/* Register an alternate interrupt service routine for
163 * the card-detect GPIO.
164 */
165void mmc_gpio_set_cd_isr(struct mmc_host *host,
166 irqreturn_t (*isr)(int irq, void *dev_id))
167{
168 struct mmc_gpio *ctx = host->slot.handler_priv;
169
170 WARN_ON(ctx->cd_gpio_isr);
171 ctx->cd_gpio_isr = isr;
172}
173EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
174
175/**
176 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
177 * @host: mmc host
178 * @con_id: function within the GPIO consumer
179 * @idx: index of the GPIO to obtain in the consumer
180 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
181 * @debounce: debounce time in microseconds
182 *
183 * Note that this must be called prior to mmc_add_host()
184 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
185 *
186 * Returns zero on success, else an error.
187 */
188int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
189 unsigned int idx, bool override_active_level,
190 unsigned int debounce)
191{
192 struct mmc_gpio *ctx = host->slot.handler_priv;
193 struct gpio_desc *desc;
194 int ret;
195
196 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
197 if (IS_ERR(desc))
198 return PTR_ERR(desc);
199
200 /* Update default label if no con_id provided */
201 if (!con_id)
202 gpiod_set_consumer_name(desc, ctx->cd_label);
203
204 if (debounce) {
205 ret = gpiod_set_debounce(desc, debounce);
206 if (ret < 0)
207 ctx->cd_debounce_delay_ms = debounce / 1000;
208 }
209
210 /* override forces default (active-low) polarity ... */
211 if (override_active_level && !gpiod_is_active_low(desc))
212 gpiod_toggle_active_low(desc);
213
214 /* ... or active-high */
215 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
216 gpiod_toggle_active_low(desc);
217
218 ctx->cd_gpio = desc;
219
220 return 0;
221}
222EXPORT_SYMBOL(mmc_gpiod_request_cd);
223
224bool mmc_can_gpio_cd(struct mmc_host *host)
225{
226 struct mmc_gpio *ctx = host->slot.handler_priv;
227
228 return ctx->cd_gpio ? true : false;
229}
230EXPORT_SYMBOL(mmc_can_gpio_cd);
231
232/**
233 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
234 * @host: mmc host
235 * @con_id: function within the GPIO consumer
236 * @idx: index of the GPIO to obtain in the consumer
237 * @debounce: debounce time in microseconds
238 *
239 * Returns zero on success, else an error.
240 */
241int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
242 unsigned int idx, unsigned int debounce)
243{
244 struct mmc_gpio *ctx = host->slot.handler_priv;
245 struct gpio_desc *desc;
246 int ret;
247
248 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
249 if (IS_ERR(desc))
250 return PTR_ERR(desc);
251
252 /* Update default label if no con_id provided */
253 if (!con_id)
254 gpiod_set_consumer_name(desc, ctx->ro_label);
255
256 if (debounce) {
257 ret = gpiod_set_debounce(desc, debounce);
258 if (ret < 0)
259 return ret;
260 }
261
262 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
263 gpiod_toggle_active_low(desc);
264
265 ctx->ro_gpio = desc;
266
267 return 0;
268}
269EXPORT_SYMBOL(mmc_gpiod_request_ro);
270
271bool mmc_can_gpio_ro(struct mmc_host *host)
272{
273 struct mmc_gpio *ctx = host->slot.handler_priv;
274
275 return ctx->ro_gpio ? true : false;
276}
277EXPORT_SYMBOL(mmc_can_gpio_ro);