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