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
19 struct mmc_gpio {
20 struct gpio_desc *ro_gpio;
21 struct gpio_desc *cd_gpio;
22 bool override_cd_active_level;
23 irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
24 char *ro_label;
25 char *cd_label;
26 u32 cd_debounce_delay_ms;
27 };
28
mmc_gpio_cd_irqt(int irq,void * dev_id)29 static 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
mmc_gpio_alloc(struct mmc_host * host)41 int mmc_gpio_alloc(struct mmc_host *host)
42 {
43 struct mmc_gpio *ctx = devm_kzalloc(host->parent,
44 sizeof(*ctx), GFP_KERNEL);
45
46 if (ctx) {
47 ctx->cd_debounce_delay_ms = 200;
48 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL,
49 "%s cd", dev_name(host->parent));
50 if (!ctx->cd_label)
51 return -ENOMEM;
52 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL,
53 "%s ro", dev_name(host->parent));
54 if (!ctx->ro_label)
55 return -ENOMEM;
56 host->slot.handler_priv = ctx;
57 host->slot.cd_irq = -EINVAL;
58 }
59
60 return ctx ? 0 : -ENOMEM;
61 }
62
mmc_gpio_get_ro(struct mmc_host * host)63 int mmc_gpio_get_ro(struct mmc_host *host)
64 {
65 struct mmc_gpio *ctx = host->slot.handler_priv;
66 int cansleep;
67
68 if (!ctx || !ctx->ro_gpio)
69 return -ENOSYS;
70
71 cansleep = gpiod_cansleep(ctx->ro_gpio);
72 return cansleep ?
73 gpiod_get_value_cansleep(ctx->ro_gpio) :
74 gpiod_get_value(ctx->ro_gpio);
75 }
76 EXPORT_SYMBOL(mmc_gpio_get_ro);
77
mmc_gpio_get_cd(struct mmc_host * host)78 int mmc_gpio_get_cd(struct mmc_host *host)
79 {
80 struct mmc_gpio *ctx = host->slot.handler_priv;
81 int cansleep;
82
83 if (!ctx || !ctx->cd_gpio)
84 return -ENOSYS;
85
86 cansleep = gpiod_cansleep(ctx->cd_gpio);
87 if (ctx->override_cd_active_level) {
88 int value = cansleep ?
89 gpiod_get_raw_value_cansleep(ctx->cd_gpio) :
90 gpiod_get_raw_value(ctx->cd_gpio);
91 return !value ^ !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
92 }
93
94 return cansleep ?
95 gpiod_get_value_cansleep(ctx->cd_gpio) :
96 gpiod_get_value(ctx->cd_gpio);
97 }
98 EXPORT_SYMBOL(mmc_gpio_get_cd);
99
mmc_gpiod_request_cd_irq(struct mmc_host * host)100 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
101 {
102 struct mmc_gpio *ctx = host->slot.handler_priv;
103 int irq = -EINVAL;
104 int ret;
105
106 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
107 return;
108
109 /*
110 * Do not use IRQ if the platform prefers to poll, e.g., because that
111 * IRQ number is already used by another unit and cannot be shared.
112 */
113 if (!(host->caps & MMC_CAP_NEEDS_POLL))
114 irq = gpiod_to_irq(ctx->cd_gpio);
115
116 if (irq >= 0) {
117 if (!ctx->cd_gpio_isr)
118 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
119 ret = devm_request_threaded_irq(host->parent, irq,
120 NULL, ctx->cd_gpio_isr,
121 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
122 ctx->cd_label, host);
123 if (ret < 0)
124 irq = ret;
125 }
126
127 host->slot.cd_irq = irq;
128
129 if (irq < 0)
130 host->caps |= MMC_CAP_NEEDS_POLL;
131 }
132 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
133
mmc_gpio_set_cd_wake(struct mmc_host * host,bool on)134 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
135 {
136 int ret = 0;
137
138 if (!(host->caps & MMC_CAP_CD_WAKE) ||
139 host->slot.cd_irq < 0 ||
140 on == host->slot.cd_wake_enabled)
141 return 0;
142
143 if (on) {
144 ret = enable_irq_wake(host->slot.cd_irq);
145 host->slot.cd_wake_enabled = !ret;
146 } else {
147 disable_irq_wake(host->slot.cd_irq);
148 host->slot.cd_wake_enabled = false;
149 }
150
151 return ret;
152 }
153 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
154
155 /* Register an alternate interrupt service routine for
156 * the card-detect GPIO.
157 */
mmc_gpio_set_cd_isr(struct mmc_host * host,irqreturn_t (* isr)(int irq,void * dev_id))158 void mmc_gpio_set_cd_isr(struct mmc_host *host,
159 irqreturn_t (*isr)(int irq, void *dev_id))
160 {
161 struct mmc_gpio *ctx = host->slot.handler_priv;
162
163 WARN_ON(ctx->cd_gpio_isr);
164 ctx->cd_gpio_isr = isr;
165 }
166 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
167
168 /**
169 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
170 * @host: mmc host
171 * @con_id: function within the GPIO consumer
172 * @idx: index of the GPIO to obtain in the consumer
173 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
174 * @debounce: debounce time in microseconds
175 * @gpio_invert: will return whether the GPIO line is inverted or not, set
176 * to NULL to ignore
177 *
178 * Note that this must be called prior to mmc_add_host()
179 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
180 *
181 * Returns zero on success, else an error.
182 */
mmc_gpiod_request_cd(struct mmc_host * host,const char * con_id,unsigned int idx,bool override_active_level,unsigned int debounce,bool * gpio_invert)183 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
184 unsigned int idx, bool override_active_level,
185 unsigned int debounce, bool *gpio_invert)
186 {
187 struct mmc_gpio *ctx = host->slot.handler_priv;
188 struct gpio_desc *desc;
189 int ret;
190
191 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
192 if (IS_ERR(desc))
193 return PTR_ERR(desc);
194
195 if (debounce) {
196 ret = gpiod_set_debounce(desc, debounce);
197 if (ret < 0)
198 ctx->cd_debounce_delay_ms = debounce / 1000;
199 }
200
201 if (gpio_invert)
202 *gpio_invert = !gpiod_is_active_low(desc);
203
204 ctx->override_cd_active_level = override_active_level;
205 ctx->cd_gpio = desc;
206
207 return 0;
208 }
209 EXPORT_SYMBOL(mmc_gpiod_request_cd);
210
mmc_can_gpio_cd(struct mmc_host * host)211 bool mmc_can_gpio_cd(struct mmc_host *host)
212 {
213 struct mmc_gpio *ctx = host->slot.handler_priv;
214
215 return ctx->cd_gpio ? true : false;
216 }
217 EXPORT_SYMBOL(mmc_can_gpio_cd);
218
219 /**
220 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
221 * @host: mmc host
222 * @con_id: function within the GPIO consumer
223 * @idx: index of the GPIO to obtain in the consumer
224 * @debounce: debounce time in microseconds
225 * @gpio_invert: will return whether the GPIO line is inverted or not,
226 * set to NULL to ignore
227 *
228 * Returns zero on success, else an error.
229 */
mmc_gpiod_request_ro(struct mmc_host * host,const char * con_id,unsigned int idx,unsigned int debounce,bool * gpio_invert)230 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
231 unsigned int idx,
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 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
239 if (IS_ERR(desc))
240 return PTR_ERR(desc);
241
242 if (debounce) {
243 ret = gpiod_set_debounce(desc, debounce);
244 if (ret < 0)
245 return ret;
246 }
247
248 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
249 gpiod_toggle_active_low(desc);
250
251 if (gpio_invert)
252 *gpio_invert = !gpiod_is_active_low(desc);
253
254 ctx->ro_gpio = desc;
255
256 return 0;
257 }
258 EXPORT_SYMBOL(mmc_gpiod_request_ro);
259
mmc_can_gpio_ro(struct mmc_host * host)260 bool mmc_can_gpio_ro(struct mmc_host *host)
261 {
262 struct mmc_gpio *ctx = host->slot.handler_priv;
263
264 return ctx->ro_gpio ? true : false;
265 }
266 EXPORT_SYMBOL(mmc_can_gpio_ro);
267