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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};
27
28static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
29{
30 /* Schedule a card detection after a debounce timeout */
31 struct mmc_host *host = dev_id;
32 struct mmc_gpio *ctx = host->slot.handler_priv;
33
34 host->trigger_card_event = true;
35 mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
36
37 return IRQ_HANDLED;
38}
39
40int mmc_gpio_alloc(struct mmc_host *host)
41{
42 const char *devname = dev_name(host->parent);
43 struct mmc_gpio *ctx;
44
45 ctx = devm_kzalloc(host->parent, sizeof(*ctx), GFP_KERNEL);
46 if (!ctx)
47 return -ENOMEM;
48
49 ctx->cd_debounce_delay_ms = 200;
50 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s cd", devname);
51 if (!ctx->cd_label)
52 return -ENOMEM;
53 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s ro", devname);
54 if (!ctx->ro_label)
55 return -ENOMEM;
56 host->slot.handler_priv = ctx;
57 host->slot.cd_irq = -EINVAL;
58
59 return 0;
60}
61
62int mmc_gpio_get_ro(struct mmc_host *host)
63{
64 struct mmc_gpio *ctx = host->slot.handler_priv;
65
66 if (!ctx || !ctx->ro_gpio)
67 return -ENOSYS;
68
69 return gpiod_get_value_cansleep(ctx->ro_gpio);
70}
71EXPORT_SYMBOL(mmc_gpio_get_ro);
72
73int mmc_gpio_get_cd(struct mmc_host *host)
74{
75 struct mmc_gpio *ctx = host->slot.handler_priv;
76 int cansleep;
77
78 if (!ctx || !ctx->cd_gpio)
79 return -ENOSYS;
80
81 cansleep = gpiod_cansleep(ctx->cd_gpio);
82 return cansleep ?
83 gpiod_get_value_cansleep(ctx->cd_gpio) :
84 gpiod_get_value(ctx->cd_gpio);
85}
86EXPORT_SYMBOL(mmc_gpio_get_cd);
87
88void mmc_gpiod_request_cd_irq(struct mmc_host *host)
89{
90 struct mmc_gpio *ctx = host->slot.handler_priv;
91 int irq = -EINVAL;
92 int ret;
93
94 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
95 return;
96
97 /*
98 * Do not use IRQ if the platform prefers to poll, e.g., because that
99 * IRQ number is already used by another unit and cannot be shared.
100 */
101 if (!(host->caps & MMC_CAP_NEEDS_POLL))
102 irq = gpiod_to_irq(ctx->cd_gpio);
103
104 if (irq >= 0) {
105 if (!ctx->cd_gpio_isr)
106 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
107 ret = devm_request_threaded_irq(host->parent, irq,
108 NULL, ctx->cd_gpio_isr,
109 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
110 ctx->cd_label, host);
111 if (ret < 0)
112 irq = ret;
113 }
114
115 host->slot.cd_irq = irq;
116
117 if (irq < 0)
118 host->caps |= MMC_CAP_NEEDS_POLL;
119}
120EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
121
122int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
123{
124 int ret = 0;
125
126 if (!(host->caps & MMC_CAP_CD_WAKE) ||
127 host->slot.cd_irq < 0 ||
128 on == host->slot.cd_wake_enabled)
129 return 0;
130
131 if (on) {
132 ret = enable_irq_wake(host->slot.cd_irq);
133 host->slot.cd_wake_enabled = !ret;
134 } else {
135 disable_irq_wake(host->slot.cd_irq);
136 host->slot.cd_wake_enabled = false;
137 }
138
139 return ret;
140}
141EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
142
143/* Register an alternate interrupt service routine for
144 * the card-detect GPIO.
145 */
146void mmc_gpio_set_cd_isr(struct mmc_host *host,
147 irqreturn_t (*isr)(int irq, void *dev_id))
148{
149 struct mmc_gpio *ctx = host->slot.handler_priv;
150
151 WARN_ON(ctx->cd_gpio_isr);
152 ctx->cd_gpio_isr = isr;
153}
154EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
155
156/**
157 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
158 * @host: mmc host
159 * @con_id: function within the GPIO consumer
160 * @idx: index of the GPIO to obtain in the consumer
161 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
162 * @debounce: debounce time in microseconds
163 *
164 * Note that this must be called prior to mmc_add_host()
165 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
166 *
167 * Returns zero on success, else an error.
168 */
169int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
170 unsigned int idx, bool override_active_level,
171 unsigned int debounce)
172{
173 struct mmc_gpio *ctx = host->slot.handler_priv;
174 struct gpio_desc *desc;
175 int ret;
176
177 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
178 if (IS_ERR(desc))
179 return PTR_ERR(desc);
180
181 /* Update default label if no con_id provided */
182 if (!con_id)
183 gpiod_set_consumer_name(desc, ctx->cd_label);
184
185 if (debounce) {
186 ret = gpiod_set_debounce(desc, debounce);
187 if (ret < 0)
188 ctx->cd_debounce_delay_ms = debounce / 1000;
189 }
190
191 /* override forces default (active-low) polarity ... */
192 if (override_active_level && !gpiod_is_active_low(desc))
193 gpiod_toggle_active_low(desc);
194
195 /* ... or active-high */
196 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
197 gpiod_toggle_active_low(desc);
198
199 ctx->cd_gpio = desc;
200
201 return 0;
202}
203EXPORT_SYMBOL(mmc_gpiod_request_cd);
204
205bool mmc_can_gpio_cd(struct mmc_host *host)
206{
207 struct mmc_gpio *ctx = host->slot.handler_priv;
208
209 return ctx->cd_gpio ? true : false;
210}
211EXPORT_SYMBOL(mmc_can_gpio_cd);
212
213/**
214 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
215 * @host: mmc host
216 * @con_id: function within the GPIO consumer
217 * @idx: index of the GPIO to obtain in the consumer
218 * @debounce: debounce time in microseconds
219 *
220 * Returns zero on success, else an error.
221 */
222int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
223 unsigned int idx, unsigned int debounce)
224{
225 struct mmc_gpio *ctx = host->slot.handler_priv;
226 struct gpio_desc *desc;
227 int ret;
228
229 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
230 if (IS_ERR(desc))
231 return PTR_ERR(desc);
232
233 /* Update default label if no con_id provided */
234 if (!con_id)
235 gpiod_set_consumer_name(desc, ctx->ro_label);
236
237 if (debounce) {
238 ret = gpiod_set_debounce(desc, debounce);
239 if (ret < 0)
240 return ret;
241 }
242
243 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
244 gpiod_toggle_active_low(desc);
245
246 ctx->ro_gpio = desc;
247
248 return 0;
249}
250EXPORT_SYMBOL(mmc_gpiod_request_ro);
251
252bool mmc_can_gpio_ro(struct mmc_host *host)
253{
254 struct mmc_gpio *ctx = host->slot.handler_priv;
255
256 return ctx->ro_gpio ? true : false;
257}
258EXPORT_SYMBOL(mmc_can_gpio_ro);