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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
21#include "slot-gpio.h"
22
23struct mmc_gpio {
24 struct gpio_desc *ro_gpio;
25 struct gpio_desc *cd_gpio;
26 bool override_ro_active_level;
27 bool override_cd_active_level;
28 irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
29 char *ro_label;
30 char cd_label[0];
31};
32
33static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
34{
35 /* Schedule a card detection after a debounce timeout */
36 struct mmc_host *host = dev_id;
37
38 host->trigger_card_event = true;
39 mmc_detect_change(host, msecs_to_jiffies(200));
40
41 return IRQ_HANDLED;
42}
43
44int mmc_gpio_alloc(struct mmc_host *host)
45{
46 size_t len = strlen(dev_name(host->parent)) + 4;
47 struct mmc_gpio *ctx = devm_kzalloc(host->parent,
48 sizeof(*ctx) + 2 * len, GFP_KERNEL);
49
50 if (ctx) {
51 ctx->ro_label = ctx->cd_label + len;
52 snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
53 snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
54 host->slot.handler_priv = ctx;
55 host->slot.cd_irq = -EINVAL;
56 }
57
58 return ctx ? 0 : -ENOMEM;
59}
60
61int mmc_gpio_get_ro(struct mmc_host *host)
62{
63 struct mmc_gpio *ctx = host->slot.handler_priv;
64
65 if (!ctx || !ctx->ro_gpio)
66 return -ENOSYS;
67
68 if (ctx->override_ro_active_level)
69 return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
70 !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
71
72 return gpiod_get_value_cansleep(ctx->ro_gpio);
73}
74EXPORT_SYMBOL(mmc_gpio_get_ro);
75
76int mmc_gpio_get_cd(struct mmc_host *host)
77{
78 struct mmc_gpio *ctx = host->slot.handler_priv;
79
80 if (!ctx || !ctx->cd_gpio)
81 return -ENOSYS;
82
83 if (ctx->override_cd_active_level)
84 return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
85 !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
86
87 return gpiod_get_value_cansleep(ctx->cd_gpio);
88}
89EXPORT_SYMBOL(mmc_gpio_get_cd);
90
91/**
92 * mmc_gpio_request_ro - request a gpio for write-protection
93 * @host: mmc host
94 * @gpio: gpio number requested
95 *
96 * As devm_* managed functions are used in mmc_gpio_request_ro(), client
97 * drivers do not need to worry about freeing up memory.
98 *
99 * Returns zero on success, else an error.
100 */
101int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
102{
103 struct mmc_gpio *ctx = host->slot.handler_priv;
104 int ret;
105
106 if (!gpio_is_valid(gpio))
107 return -EINVAL;
108
109 ret = devm_gpio_request_one(host->parent, gpio, GPIOF_DIR_IN,
110 ctx->ro_label);
111 if (ret < 0)
112 return ret;
113
114 ctx->override_ro_active_level = true;
115 ctx->ro_gpio = gpio_to_desc(gpio);
116
117 return 0;
118}
119EXPORT_SYMBOL(mmc_gpio_request_ro);
120
121void mmc_gpiod_request_cd_irq(struct mmc_host *host)
122{
123 struct mmc_gpio *ctx = host->slot.handler_priv;
124 int ret, irq;
125
126 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
127 return;
128
129 irq = gpiod_to_irq(ctx->cd_gpio);
130
131 /*
132 * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
133 * still prefer to poll, e.g., because that IRQ number is already used
134 * by another unit and cannot be shared.
135 */
136 if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
137 irq = -EINVAL;
138
139 if (irq >= 0) {
140 if (!ctx->cd_gpio_isr)
141 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
142 ret = devm_request_threaded_irq(host->parent, irq,
143 NULL, ctx->cd_gpio_isr,
144 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
145 ctx->cd_label, host);
146 if (ret < 0)
147 irq = ret;
148 }
149
150 host->slot.cd_irq = irq;
151
152 if (irq < 0)
153 host->caps |= MMC_CAP_NEEDS_POLL;
154}
155EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
156
157/* Register an alternate interrupt service routine for
158 * the card-detect GPIO.
159 */
160void mmc_gpio_set_cd_isr(struct mmc_host *host,
161 irqreturn_t (*isr)(int irq, void *dev_id))
162{
163 struct mmc_gpio *ctx = host->slot.handler_priv;
164
165 WARN_ON(ctx->cd_gpio_isr);
166 ctx->cd_gpio_isr = isr;
167}
168EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
169
170/**
171 * mmc_gpio_request_cd - request a gpio for card-detection
172 * @host: mmc host
173 * @gpio: gpio number requested
174 * @debounce: debounce time in microseconds
175 *
176 * As devm_* managed functions are used in mmc_gpio_request_cd(), client
177 * drivers do not need to worry about freeing up memory.
178 *
179 * If GPIO debouncing is desired, set the debounce parameter to a non-zero
180 * value. The caller is responsible for ensuring that the GPIO driver associated
181 * with the GPIO supports debouncing, otherwise an error will be returned.
182 *
183 * Returns zero on success, else an error.
184 */
185int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
186 unsigned int debounce)
187{
188 struct mmc_gpio *ctx = host->slot.handler_priv;
189 int ret;
190
191 ret = devm_gpio_request_one(host->parent, gpio, GPIOF_DIR_IN,
192 ctx->cd_label);
193 if (ret < 0)
194 /*
195 * don't bother freeing memory. It might still get used by other
196 * slot functions, in any case it will be freed, when the device
197 * is destroyed.
198 */
199 return ret;
200
201 if (debounce) {
202 ret = gpio_set_debounce(gpio, debounce);
203 if (ret < 0)
204 return ret;
205 }
206
207 ctx->override_cd_active_level = true;
208 ctx->cd_gpio = gpio_to_desc(gpio);
209
210 return 0;
211}
212EXPORT_SYMBOL(mmc_gpio_request_cd);
213
214/**
215 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
216 * @host: mmc host
217 * @con_id: function within the GPIO consumer
218 * @idx: index of the GPIO to obtain in the consumer
219 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
220 * @debounce: debounce time in microseconds
221 * @gpio_invert: will return whether the GPIO line is inverted or not, set
222 * to NULL to ignore
223 *
224 * Use this function in place of mmc_gpio_request_cd() to use the GPIO
225 * descriptor API. Note that it must be called prior to mmc_add_host()
226 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
227 *
228 * Returns zero on success, else an error.
229 */
230int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
231 unsigned int idx, bool override_active_level,
232 unsigned int debounce, bool *gpio_invert)
233{
234 struct mmc_gpio *ctx = host->slot.handler_priv;
235 struct gpio_desc *desc;
236 int ret;
237
238 if (!con_id)
239 con_id = ctx->cd_label;
240
241 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
242 if (IS_ERR(desc))
243 return PTR_ERR(desc);
244
245 if (debounce) {
246 ret = gpiod_set_debounce(desc, debounce);
247 if (ret < 0)
248 return ret;
249 }
250
251 if (gpio_invert)
252 *gpio_invert = !gpiod_is_active_low(desc);
253
254 ctx->override_cd_active_level = override_active_level;
255 ctx->cd_gpio = desc;
256
257 return 0;
258}
259EXPORT_SYMBOL(mmc_gpiod_request_cd);
260
261/**
262 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
263 * @host: mmc host
264 * @con_id: function within the GPIO consumer
265 * @idx: index of the GPIO to obtain in the consumer
266 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
267 * @debounce: debounce time in microseconds
268 * @gpio_invert: will return whether the GPIO line is inverted or not,
269 * set to NULL to ignore
270 *
271 * Use this function in place of mmc_gpio_request_ro() to use the GPIO
272 * descriptor API.
273 *
274 * Returns zero on success, else an error.
275 */
276int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
277 unsigned int idx, bool override_active_level,
278 unsigned int debounce, bool *gpio_invert)
279{
280 struct mmc_gpio *ctx = host->slot.handler_priv;
281 struct gpio_desc *desc;
282 int ret;
283
284 if (!con_id)
285 con_id = ctx->ro_label;
286
287 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
288 if (IS_ERR(desc))
289 return PTR_ERR(desc);
290
291 if (debounce) {
292 ret = gpiod_set_debounce(desc, debounce);
293 if (ret < 0)
294 return ret;
295 }
296
297 if (gpio_invert)
298 *gpio_invert = !gpiod_is_active_low(desc);
299
300 ctx->override_ro_active_level = override_active_level;
301 ctx->ro_gpio = desc;
302
303 return 0;
304}
305EXPORT_SYMBOL(mmc_gpiod_request_ro);
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);