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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 irq_handler_t cd_gpio_isr;
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, irq_handler_t isr)
166{
167 struct mmc_gpio *ctx = host->slot.handler_priv;
168
169 WARN_ON(ctx->cd_gpio_isr);
170 ctx->cd_gpio_isr = isr;
171}
172EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
173
174/**
175 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
176 * @host: mmc host
177 * @con_id: function within the GPIO consumer
178 * @idx: index of the GPIO to obtain in the consumer
179 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
180 * @debounce: debounce time in microseconds
181 *
182 * Note that this must be called prior to mmc_add_host()
183 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
184 *
185 * Returns zero on success, else an error.
186 */
187int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
188 unsigned int idx, bool override_active_level,
189 unsigned int debounce)
190{
191 struct mmc_gpio *ctx = host->slot.handler_priv;
192 struct gpio_desc *desc;
193 int ret;
194
195 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
196 if (IS_ERR(desc))
197 return PTR_ERR(desc);
198
199 /* Update default label if no con_id provided */
200 if (!con_id)
201 gpiod_set_consumer_name(desc, ctx->cd_label);
202
203 if (debounce) {
204 ret = gpiod_set_debounce(desc, debounce);
205 if (ret < 0)
206 ctx->cd_debounce_delay_ms = debounce / 1000;
207 }
208
209 /* override forces default (active-low) polarity ... */
210 if (override_active_level && !gpiod_is_active_low(desc))
211 gpiod_toggle_active_low(desc);
212
213 /* ... or active-high */
214 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
215 gpiod_toggle_active_low(desc);
216
217 ctx->cd_gpio = desc;
218
219 return 0;
220}
221EXPORT_SYMBOL(mmc_gpiod_request_cd);
222
223/**
224 * mmc_gpiod_set_cd_config - set config for card-detection GPIO
225 * @host: mmc host
226 * @config: Generic pinconf config (from pinconf_to_config_packed())
227 *
228 * This can be used by mmc host drivers to fixup a card-detection GPIO's config
229 * (e.g. set PIN_CONFIG_BIAS_PULL_UP) after acquiring the GPIO descriptor
230 * through mmc_gpiod_request_cd().
231 *
232 * Returns:
233 * 0 on success, or a negative errno value on error.
234 */
235int mmc_gpiod_set_cd_config(struct mmc_host *host, unsigned long config)
236{
237 struct mmc_gpio *ctx = host->slot.handler_priv;
238
239 return gpiod_set_config(ctx->cd_gpio, config);
240}
241EXPORT_SYMBOL(mmc_gpiod_set_cd_config);
242
243bool mmc_can_gpio_cd(struct mmc_host *host)
244{
245 struct mmc_gpio *ctx = host->slot.handler_priv;
246
247 return ctx->cd_gpio ? true : false;
248}
249EXPORT_SYMBOL(mmc_can_gpio_cd);
250
251/**
252 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
253 * @host: mmc host
254 * @con_id: function within the GPIO consumer
255 * @idx: index of the GPIO to obtain in the consumer
256 * @debounce: debounce time in microseconds
257 *
258 * Returns zero on success, else an error.
259 */
260int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
261 unsigned int idx, unsigned int debounce)
262{
263 struct mmc_gpio *ctx = host->slot.handler_priv;
264 struct gpio_desc *desc;
265 int ret;
266
267 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
268 if (IS_ERR(desc))
269 return PTR_ERR(desc);
270
271 /* Update default label if no con_id provided */
272 if (!con_id)
273 gpiod_set_consumer_name(desc, ctx->ro_label);
274
275 if (debounce) {
276 ret = gpiod_set_debounce(desc, debounce);
277 if (ret < 0)
278 return ret;
279 }
280
281 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
282 gpiod_toggle_active_low(desc);
283
284 ctx->ro_gpio = desc;
285
286 return 0;
287}
288EXPORT_SYMBOL(mmc_gpiod_request_ro);
289
290bool mmc_can_gpio_ro(struct mmc_host *host)
291{
292 struct mmc_gpio *ctx = host->slot.handler_priv;
293
294 return ctx->ro_gpio ? true : false;
295}
296EXPORT_SYMBOL(mmc_can_gpio_ro);