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, delay: msecs_to_jiffies(m: 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(dev: host->parent);
44 struct mmc_gpio *ctx;
45
46 ctx = devm_kzalloc(dev: host->parent, size: sizeof(*ctx), GFP_KERNEL);
47 if (!ctx)
48 return -ENOMEM;
49
50 ctx->cd_debounce_delay_ms = 200;
51 ctx->cd_label = devm_kasprintf(dev: host->parent, GFP_KERNEL, fmt: "%s cd", devname);
52 if (!ctx->cd_label)
53 return -ENOMEM;
54 ctx->ro_label = devm_kasprintf(dev: host->parent, GFP_KERNEL, fmt: "%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(desc: ctx->ro_gpio);
84 return cansleep ?
85 gpiod_get_value_cansleep(desc: ctx->ro_gpio) :
86 gpiod_get_value(desc: 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(desc: ctx->cd_gpio);
99 return cansleep ?
100 gpiod_get_value_cansleep(desc: ctx->cd_gpio) :
101 gpiod_get_value(desc: 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(desc: 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(dev: host->parent, irq,
127 NULL, thread_fn: ctx->cd_gpio_isr,
128 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
129 devname: ctx->cd_label, dev_id: 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(irq: host->slot.cd_irq);
152 host->slot.cd_wake_enabled = !ret;
153 } else {
154 disable_irq_wake(irq: 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/**
163 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
164 * @host: mmc host
165 * @con_id: function within the GPIO consumer
166 * @idx: index of the GPIO to obtain in the consumer
167 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
168 * @debounce: debounce time in microseconds
169 *
170 * Note that this must be called prior to mmc_add_host()
171 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
172 *
173 * Returns zero on success, else an error.
174 */
175int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
176 unsigned int idx, bool override_active_level,
177 unsigned int debounce)
178{
179 struct mmc_gpio *ctx = host->slot.handler_priv;
180 struct gpio_desc *desc;
181 int ret;
182
183 desc = devm_gpiod_get_index(dev: host->parent, con_id, idx, flags: GPIOD_IN);
184 if (IS_ERR(ptr: desc))
185 return PTR_ERR(ptr: desc);
186
187 /* Update default label if no con_id provided */
188 if (!con_id)
189 gpiod_set_consumer_name(desc, name: ctx->cd_label);
190
191 if (debounce) {
192 ret = gpiod_set_debounce(desc, debounce);
193 if (ret < 0)
194 ctx->cd_debounce_delay_ms = debounce / 1000;
195 }
196
197 /* override forces default (active-low) polarity ... */
198 if (override_active_level && !gpiod_is_active_low(desc))
199 gpiod_toggle_active_low(desc);
200
201 /* ... or active-high */
202 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
203 gpiod_toggle_active_low(desc);
204
205 ctx->cd_gpio = desc;
206
207 return 0;
208}
209EXPORT_SYMBOL(mmc_gpiod_request_cd);
210
211/**
212 * mmc_gpiod_set_cd_config - set config for card-detection GPIO
213 * @host: mmc host
214 * @config: Generic pinconf config (from pinconf_to_config_packed())
215 *
216 * This can be used by mmc host drivers to fixup a card-detection GPIO's config
217 * (e.g. set PIN_CONFIG_BIAS_PULL_UP) after acquiring the GPIO descriptor
218 * through mmc_gpiod_request_cd().
219 *
220 * Returns:
221 * 0 on success, or a negative errno value on error.
222 */
223int mmc_gpiod_set_cd_config(struct mmc_host *host, unsigned long config)
224{
225 struct mmc_gpio *ctx = host->slot.handler_priv;
226
227 return gpiod_set_config(desc: ctx->cd_gpio, config);
228}
229EXPORT_SYMBOL(mmc_gpiod_set_cd_config);
230
231bool mmc_host_can_gpio_cd(struct mmc_host *host)
232{
233 struct mmc_gpio *ctx = host->slot.handler_priv;
234
235 return ctx->cd_gpio ? true : false;
236}
237EXPORT_SYMBOL(mmc_host_can_gpio_cd);
238
239/**
240 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
241 * @host: mmc host
242 * @con_id: function within the GPIO consumer
243 * @idx: index of the GPIO to obtain in the consumer
244 * @debounce: debounce time in microseconds
245 *
246 * Returns zero on success, else an error.
247 */
248int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
249 unsigned int idx, unsigned int debounce)
250{
251 struct mmc_gpio *ctx = host->slot.handler_priv;
252 struct gpio_desc *desc;
253 int ret;
254
255 desc = devm_gpiod_get_index(dev: host->parent, con_id, idx, flags: GPIOD_IN);
256 if (IS_ERR(ptr: desc))
257 return PTR_ERR(ptr: desc);
258
259 /* Update default label if no con_id provided */
260 if (!con_id)
261 gpiod_set_consumer_name(desc, name: ctx->ro_label);
262
263 if (debounce) {
264 ret = gpiod_set_debounce(desc, debounce);
265 if (ret < 0)
266 return ret;
267 }
268
269 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
270 gpiod_toggle_active_low(desc);
271
272 ctx->ro_gpio = desc;
273
274 return 0;
275}
276EXPORT_SYMBOL(mmc_gpiod_request_ro);
277
278bool mmc_host_can_gpio_ro(struct mmc_host *host)
279{
280 struct mmc_gpio *ctx = host->slot.handler_priv;
281
282 return ctx->ro_gpio ? true : false;
283}
284EXPORT_SYMBOL(mmc_host_can_gpio_ro);
285

source code of linux/drivers/mmc/core/slot-gpio.c