1 // SPDX-License-Identifier: GPL-2.0-only
3 * Generic GPIO card-detect helper
5 * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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>
17 #include "slot-gpio.h"
20 struct gpio_desc *ro_gpio;
21 struct gpio_desc *cd_gpio;
22 irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
25 u32 cd_debounce_delay_ms;
29 static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
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;
35 host->trigger_card_event = true;
36 mmc_detect_change(host, msecs_to_jiffies(ctx->cd_debounce_delay_ms));
41 int mmc_gpio_alloc(struct mmc_host *host)
43 const char *devname = dev_name(host->parent);
46 ctx = devm_kzalloc(host->parent, sizeof(*ctx), GFP_KERNEL);
50 ctx->cd_debounce_delay_ms = 200;
51 ctx->cd_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s cd", devname);
54 ctx->ro_label = devm_kasprintf(host->parent, GFP_KERNEL, "%s ro", devname);
57 ctx->cd_irq = -EINVAL;
58 host->slot.handler_priv = ctx;
59 host->slot.cd_irq = -EINVAL;
64 void mmc_gpio_set_cd_irq(struct mmc_host *host, int irq)
66 struct mmc_gpio *ctx = host->slot.handler_priv;
73 EXPORT_SYMBOL(mmc_gpio_set_cd_irq);
75 int mmc_gpio_get_ro(struct mmc_host *host)
77 struct mmc_gpio *ctx = host->slot.handler_priv;
79 if (!ctx || !ctx->ro_gpio)
82 return gpiod_get_value_cansleep(ctx->ro_gpio);
84 EXPORT_SYMBOL(mmc_gpio_get_ro);
86 int mmc_gpio_get_cd(struct mmc_host *host)
88 struct mmc_gpio *ctx = host->slot.handler_priv;
91 if (!ctx || !ctx->cd_gpio)
94 cansleep = gpiod_cansleep(ctx->cd_gpio);
96 gpiod_get_value_cansleep(ctx->cd_gpio) :
97 gpiod_get_value(ctx->cd_gpio);
99 EXPORT_SYMBOL(mmc_gpio_get_cd);
101 void mmc_gpiod_request_cd_irq(struct mmc_host *host)
103 struct mmc_gpio *ctx = host->slot.handler_priv;
107 if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
111 * Do not use IRQ if the platform prefers to poll, e.g., because that
112 * IRQ number is already used by another unit and cannot be shared.
114 if (ctx->cd_irq >= 0)
116 else if (!(host->caps & MMC_CAP_NEEDS_POLL))
117 irq = gpiod_to_irq(ctx->cd_gpio);
120 if (!ctx->cd_gpio_isr)
121 ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
122 ret = devm_request_threaded_irq(host->parent, irq,
123 NULL, ctx->cd_gpio_isr,
124 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
125 ctx->cd_label, host);
130 host->slot.cd_irq = irq;
133 host->caps |= MMC_CAP_NEEDS_POLL;
135 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
137 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
141 if (!(host->caps & MMC_CAP_CD_WAKE) ||
142 host->slot.cd_irq < 0 ||
143 on == host->slot.cd_wake_enabled)
147 ret = enable_irq_wake(host->slot.cd_irq);
148 host->slot.cd_wake_enabled = !ret;
150 disable_irq_wake(host->slot.cd_irq);
151 host->slot.cd_wake_enabled = false;
156 EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
158 /* Register an alternate interrupt service routine for
159 * the card-detect GPIO.
161 void mmc_gpio_set_cd_isr(struct mmc_host *host,
162 irqreturn_t (*isr)(int irq, void *dev_id))
164 struct mmc_gpio *ctx = host->slot.handler_priv;
166 WARN_ON(ctx->cd_gpio_isr);
167 ctx->cd_gpio_isr = isr;
169 EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
172 * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
174 * @con_id: function within the GPIO consumer
175 * @idx: index of the GPIO to obtain in the consumer
176 * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
177 * @debounce: debounce time in microseconds
179 * Note that this must be called prior to mmc_add_host()
180 * otherwise the caller must also call mmc_gpiod_request_cd_irq().
182 * Returns zero on success, else an error.
184 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
185 unsigned int idx, bool override_active_level,
186 unsigned int debounce)
188 struct mmc_gpio *ctx = host->slot.handler_priv;
189 struct gpio_desc *desc;
192 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
194 return PTR_ERR(desc);
196 /* Update default label if no con_id provided */
198 gpiod_set_consumer_name(desc, ctx->cd_label);
201 ret = gpiod_set_debounce(desc, debounce);
203 ctx->cd_debounce_delay_ms = debounce / 1000;
206 /* override forces default (active-low) polarity ... */
207 if (override_active_level && !gpiod_is_active_low(desc))
208 gpiod_toggle_active_low(desc);
210 /* ... or active-high */
211 if (host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
212 gpiod_toggle_active_low(desc);
218 EXPORT_SYMBOL(mmc_gpiod_request_cd);
220 bool mmc_can_gpio_cd(struct mmc_host *host)
222 struct mmc_gpio *ctx = host->slot.handler_priv;
224 return ctx->cd_gpio ? true : false;
226 EXPORT_SYMBOL(mmc_can_gpio_cd);
229 * mmc_gpiod_request_ro - request a gpio descriptor for write protection
231 * @con_id: function within the GPIO consumer
232 * @idx: index of the GPIO to obtain in the consumer
233 * @debounce: debounce time in microseconds
235 * Returns zero on success, else an error.
237 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
238 unsigned int idx, unsigned int debounce)
240 struct mmc_gpio *ctx = host->slot.handler_priv;
241 struct gpio_desc *desc;
244 desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
246 return PTR_ERR(desc);
248 /* Update default label if no con_id provided */
250 gpiod_set_consumer_name(desc, ctx->ro_label);
253 ret = gpiod_set_debounce(desc, debounce);
258 if (host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
259 gpiod_toggle_active_low(desc);
265 EXPORT_SYMBOL(mmc_gpiod_request_ro);
267 bool mmc_can_gpio_ro(struct mmc_host *host)
269 struct mmc_gpio *ctx = host->slot.handler_priv;
271 return ctx->ro_gpio ? true : false;
273 EXPORT_SYMBOL(mmc_can_gpio_ro);