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 <trace/hooks/mmc_core.h>
18
19 #include "slot-gpio.h"
20
21 struct mmc_gpio {
22 struct gpio_desc *ro_gpio;
23 struct gpio_desc *cd_gpio;
24 irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
25 char *ro_label;
26 char *cd_label;
27 u32 cd_debounce_delay_ms;
28 };
29
mmc_gpio_cd_irqt(int irq,void * dev_id)30 static 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 struct mmc_gpio *ctx = host->slot.handler_priv;
35 bool allow = true;
36
37 trace_android_vh_mmc_gpio_cd_irqt(host, &allow);
38 if (!allow)
39 return IRQ_HANDLED;
40
41 host->trigger_card_event = true;
42 mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
43
44 return IRQ_HANDLED;
45 }
46
mmc_gpio_alloc(struct mmc_host * host)47 int mmc_gpio_alloc(struct mmc_host *host)
48 {
49 struct mmc_gpio *ctx = devm_kzalloc(host->parent,
50 sizeof(*ctx), GFP_KERNEL);
51
52 if (ctx) {
53 ctx->cd_debounce_delay_ms = 200;
54 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL,
55 "%s cd", dev_name(host->parent));
56 if (!ctx->cd_label)
57 return -ENOMEM;
58 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL,
59 "%s ro", dev_name(host->parent));
60 if (!ctx->ro_label)
61 return -ENOMEM;
62 host->slot.handler_priv = ctx;
63 host->slot.cd_irq = -EINVAL;
64 }
65
66 return ctx ? 0 : -ENOMEM;
67 }
68
mmc_gpio_get_ro(struct mmc_host * host)69 int mmc_gpio_get_ro(struct mmc_host *host)
70 {
71 struct mmc_gpio *ctx = host->slot.handler_priv;
72
73 if (!ctx || !ctx->ro_gpio)
74 return -ENOSYS;
75
76 return gpiod_get_value_cansleep(ctx->ro_gpio);
77 }
78 EXPORT_SYMBOL(mmc_gpio_get_ro);
79
mmc_gpio_get_cd(struct mmc_host * host)80 int mmc_gpio_get_cd(struct mmc_host *host)
81 {
82 struct mmc_gpio *ctx = host->slot.handler_priv;
83 int cansleep;
84
85 if (!ctx || !ctx->cd_gpio)
86 return -ENOSYS;
87
88 cansleep = gpiod_cansleep(ctx->cd_gpio);
89 return cansleep ?
90 gpiod_get_value_cansleep(ctx->cd_gpio) :
91 gpiod_get_value(ctx->cd_gpio);
92 }
93 EXPORT_SYMBOL(mmc_gpio_get_cd);
94
mmc_gpiod_request_cd_irq(struct mmc_host * host)95 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
96 {
97 struct mmc_gpio *ctx = host->slot.handler_priv;
98 int irq = -EINVAL;
99 int ret;
100
101 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
102 return;
103
104 /*
105 * Do not use IRQ if the platform prefers to poll, e.g., because that
106 * IRQ number is already used by another unit and cannot be shared.
107 */
108 if (!(host->caps & MMC_CAP_NEEDS_POLL))
109 irq = gpiod_to_irq(ctx->cd_gpio);
110
111 if (irq >= 0) {
112 if (!ctx->cd_gpio_isr)
113 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
114 ret = devm_request_threaded_irq(host->parent, irq,
115 NULL, ctx->cd_gpio_isr,
116 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
117 ctx->cd_label, host);
118 if (ret < 0)
119 irq = ret;
120 }
121
122 host->slot.cd_irq = irq;
123
124 if (irq < 0)
125 host->caps |= MMC_CAP_NEEDS_POLL;
126 }
127 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
128
mmc_gpio_set_cd_wake(struct mmc_host * host,bool on)129 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
130 {
131 int ret = 0;
132
133 if (!(host->caps & MMC_CAP_CD_WAKE) ||
134 host->slot.cd_irq < 0 ||
135 on == host->slot.cd_wake_enabled)
136 return 0;
137
138 if (on) {
139 ret = enable_irq_wake(host->slot.cd_irq);
140 host->slot.cd_wake_enabled = !ret;
141 } else {
142 disable_irq_wake(host->slot.cd_irq);
143 host->slot.cd_wake_enabled = false;
144 }
145
146 return ret;
147 }
148 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
149
150 /* Register an alternate interrupt service routine for
151 * the card-detect GPIO.
152 */
mmc_gpio_set_cd_isr(struct mmc_host * host,irqreturn_t (* isr)(int irq,void * dev_id))153 void mmc_gpio_set_cd_isr(struct mmc_host *host,
154 irqreturn_t (*isr)(int irq, void *dev_id))
155 {
156 struct mmc_gpio *ctx = host->slot.handler_priv;
157
158 WARN_ON(ctx->cd_gpio_isr);
159 ctx->cd_gpio_isr = isr;
160 }
161 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
162
163 /**
164 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
165 * @host: mmc host
166 * @con_id: function within the GPIO consumer
167 * @idx: index of the GPIO to obtain in the consumer
168 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
169 * @debounce: debounce time in microseconds
170 *
171 * Note that this must be called prior to mmc_add_host()
172 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
173 *
174 * Returns zero on success, else an error.
175 */
mmc_gpiod_request_cd(struct mmc_host * host,const char * con_id,unsigned int idx,bool override_active_level,unsigned int debounce)176 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
177 unsigned int idx, bool override_active_level,
178 unsigned int debounce)
179 {
180 struct mmc_gpio *ctx = host->slot.handler_priv;
181 struct gpio_desc *desc;
182 int ret;
183
184 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
185 if (IS_ERR(desc))
186 return PTR_ERR(desc);
187
188 if (debounce) {
189 ret = gpiod_set_debounce(desc, debounce);
190 if (ret < 0)
191 ctx->cd_debounce_delay_ms = debounce / 1000;
192 }
193
194 /* override forces default (active-low) polarity ... */
195 if (override_active_level && !gpiod_is_active_low(desc))
196 gpiod_toggle_active_low(desc);
197
198 /* ... or active-high */
199 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
200 gpiod_toggle_active_low(desc);
201
202 ctx->cd_gpio = desc;
203
204 return 0;
205 }
206 EXPORT_SYMBOL(mmc_gpiod_request_cd);
207
mmc_can_gpio_cd(struct mmc_host * host)208 bool mmc_can_gpio_cd(struct mmc_host *host)
209 {
210 struct mmc_gpio *ctx = host->slot.handler_priv;
211
212 return ctx->cd_gpio ? true : false;
213 }
214 EXPORT_SYMBOL(mmc_can_gpio_cd);
215
216 /**
217 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
218 * @host: mmc host
219 * @con_id: function within the GPIO consumer
220 * @idx: index of the GPIO to obtain in the consumer
221 * @debounce: debounce time in microseconds
222 *
223 * Returns zero on success, else an error.
224 */
mmc_gpiod_request_ro(struct mmc_host * host,const char * con_id,unsigned int idx,unsigned int debounce)225 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
226 unsigned int idx, unsigned int debounce)
227 {
228 struct mmc_gpio *ctx = host->slot.handler_priv;
229 struct gpio_desc *desc;
230 int ret;
231
232 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
233 if (IS_ERR(desc))
234 return PTR_ERR(desc);
235
236 if (debounce) {
237 ret = gpiod_set_debounce(desc, debounce);
238 if (ret < 0)
239 return ret;
240 }
241
242 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
243 gpiod_toggle_active_low(desc);
244
245 ctx->ro_gpio = desc;
246
247 return 0;
248 }
249 EXPORT_SYMBOL(mmc_gpiod_request_ro);
250
mmc_can_gpio_ro(struct mmc_host * host)251 bool mmc_can_gpio_ro(struct mmc_host *host)
252 {
253 struct mmc_gpio *ctx = host->slot.handler_priv;
254
255 return ctx->ro_gpio ? true : false;
256 }
257 EXPORT_SYMBOL(mmc_can_gpio_ro);
258