1 files changed, 355 insertions, 0 deletions
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
new file mode 100644
index 00000000000..5f89cb83d5f
--- /dev/null
+++ b/drivers/mmc/core/slot-gpio.c
@@ -0,0 +1,355 @@
+/*
+ * Generic GPIO card-detect helper
+ *
+ * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+struct mmc_gpio {
+	struct gpio_desc *ro_gpio;
+	struct gpio_desc *cd_gpio;
+	bool override_ro_active_level;
+	bool override_cd_active_level;
+	char *ro_label;
+	char cd_label[0];
+};
+
+static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
+{
+	/* Schedule a card detection after a debounce timeout */
+	struct mmc_host *host = dev_id;
+
+	host->trigger_card_event = true;
+	mmc_detect_change(host, msecs_to_jiffies(200));
+
+	return IRQ_HANDLED;
+}
+
+static int mmc_gpio_alloc(struct mmc_host *host)
+{
+	size_t len = strlen(dev_name(host->parent)) + 4;
+	struct mmc_gpio *ctx;
+
+	mutex_lock(&host->slot.lock);
+
+	ctx = host->slot.handler_priv;
+	if (!ctx) {
+		/*
+		 * devm_kzalloc() can be called after device_initialize(), even
+		 * before device_add(), i.e., between mmc_alloc_host() and
+		 * mmc_add_host()
+		 */
+		ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
+				   GFP_KERNEL);
+		if (ctx) {
+			ctx->ro_label = ctx->cd_label + len;
+			snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
+			snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
+			host->slot.handler_priv = ctx;
+		}
+	}
+
+	mutex_unlock(&host->slot.lock);
+
+	return ctx ? 0 : -ENOMEM;
+}
+
+int mmc_gpio_get_ro(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	if (!ctx || !ctx->ro_gpio)
+		return -ENOSYS;
+
+	if (ctx->override_ro_active_level)
+		return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
+			!!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
+
+	return gpiod_get_value_cansleep(ctx->ro_gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_get_ro);
+
+int mmc_gpio_get_cd(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	if (!ctx || !ctx->cd_gpio)
+		return -ENOSYS;
+
+	if (ctx->override_cd_active_level)
+		return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
+			!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
+
+	return gpiod_get_value_cansleep(ctx->cd_gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_get_cd);
+
+/**
+ * mmc_gpio_request_ro - request a gpio for write-protection
+ * @host: mmc host
+ * @gpio: gpio number requested
+ *
+ * As devm_* managed functions are used in mmc_gpio_request_ro(), client
+ * drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up,
+ * if the requesting and freeing are only needed at probing and unbinding time
+ * for once.  However, if client drivers do something special like runtime
+ * switching for write-protection, they are responsible for calling
+ * mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own.
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
+{
+	struct mmc_gpio *ctx;
+	int ret;
+
+	if (!gpio_is_valid(gpio))
+		return -EINVAL;
+
+	ret = mmc_gpio_alloc(host);
+	if (ret < 0)
+		return ret;
+
+	ctx = host->slot.handler_priv;
+
+	ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
+				    ctx->ro_label);
+	if (ret < 0)
+		return ret;
+
+	ctx->override_ro_active_level = true;
+	ctx->ro_gpio = gpio_to_desc(gpio);
+
+	return 0;
+}
+EXPORT_SYMBOL(mmc_gpio_request_ro);
+
+void mmc_gpiod_request_cd_irq(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+	int ret, irq;
+
+	if (host->slot.cd_irq >= 0 || !ctx || !ctx->cd_gpio)
+		return;
+
+	irq = gpiod_to_irq(ctx->cd_gpio);
+
+	/*
+	 * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
+	 * still prefer to poll, e.g., because that IRQ number is already used
+	 * by another unit and cannot be shared.
+	 */
+	if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
+		irq = -EINVAL;
+
+	if (irq >= 0) {
+		ret = devm_request_threaded_irq(&host->class_dev, irq,
+			NULL, mmc_gpio_cd_irqt,
+			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+			ctx->cd_label, host);
+		if (ret < 0)
+			irq = ret;
+	}
+
+	host->slot.cd_irq = irq;
+
+	if (irq < 0)
+		host->caps |= MMC_CAP_NEEDS_POLL;
+}
+EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
+
+/**
+ * mmc_gpio_request_cd - request a gpio for card-detection
+ * @host: mmc host
+ * @gpio: gpio number requested
+ * @debounce: debounce time in microseconds
+ *
+ * As devm_* managed functions are used in mmc_gpio_request_cd(), client
+ * drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up,
+ * if the requesting and freeing are only needed at probing and unbinding time
+ * for once.  However, if client drivers do something special like runtime
+ * switching for card-detection, they are responsible for calling
+ * mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own.
+ *
+ * If GPIO debouncing is desired, set the debounce parameter to a non-zero
+ * value. The caller is responsible for ensuring that the GPIO driver associated
+ * with the GPIO supports debouncing, otherwise an error will be returned.
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
+			unsigned int debounce)
+{
+	struct mmc_gpio *ctx;
+	int ret;
+
+	ret = mmc_gpio_alloc(host);
+	if (ret < 0)
+		return ret;
+
+	ctx = host->slot.handler_priv;
+
+	ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
+				    ctx->cd_label);
+	if (ret < 0)
+		/*
+		 * don't bother freeing memory. It might still get used by other
+		 * slot functions, in any case it will be freed, when the device
+		 * is destroyed.
+		 */
+		return ret;
+
+	if (debounce) {
+		ret = gpio_set_debounce(gpio, debounce);
+		if (ret < 0)
+			return ret;
+	}
+
+	ctx->override_cd_active_level = true;
+	ctx->cd_gpio = gpio_to_desc(gpio);
+
+	mmc_gpiod_request_cd_irq(host);
+
+	return 0;
+}
+EXPORT_SYMBOL(mmc_gpio_request_cd);
+
+/**
+ * mmc_gpio_free_ro - free the write-protection gpio
+ * @host: mmc host
+ *
+ * It's provided only for cases that client drivers need to manually free
+ * up the write-protection gpio requested by mmc_gpio_request_ro().
+ */
+void mmc_gpio_free_ro(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+	int gpio;
+
+	if (!ctx || !ctx->ro_gpio)
+		return;
+
+	gpio = desc_to_gpio(ctx->ro_gpio);
+	ctx->ro_gpio = NULL;
+
+	devm_gpio_free(&host->class_dev, gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_free_ro);
+
+/**
+ * mmc_gpio_free_cd - free the card-detection gpio
+ * @host: mmc host
+ *
+ * It's provided only for cases that client drivers need to manually free
+ * up the card-detection gpio requested by mmc_gpio_request_cd().
+ */
+void mmc_gpio_free_cd(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+	int gpio;
+
+	if (!ctx || !ctx->cd_gpio)
+		return;
+
+	if (host->slot.cd_irq >= 0) {
+		devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
+		host->slot.cd_irq = -EINVAL;
+	}
+
+	gpio = desc_to_gpio(ctx->cd_gpio);
+	ctx->cd_gpio = NULL;
+
+	devm_gpio_free(&host->class_dev, gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_free_cd);
+
+/**
+ * mmc_gpiod_request_cd - request a gpio descriptor for card-detection
+ * @host: mmc host
+ * @con_id: function within the GPIO consumer
+ * @idx: index of the GPIO to obtain in the consumer
+ * @override_active_level: ignore %GPIO_ACTIVE_LOW flag
+ * @debounce: debounce time in microseconds
+ *
+ * Use this function in place of mmc_gpio_request_cd() to use the GPIO
+ * descriptor API.  Note that it is paired with mmc_gpiod_free_cd() not
+ * mmc_gpio_free_cd().  Note also that it must be called prior to mmc_add_host()
+ * otherwise the caller must also call mmc_gpiod_request_cd_irq().
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
+			 unsigned int idx, bool override_active_level,
+			 unsigned int debounce)
+{
+	struct mmc_gpio *ctx;
+	struct gpio_desc *desc;
+	int ret;
+
+	ret = mmc_gpio_alloc(host);
+	if (ret < 0)
+		return ret;
+
+	ctx = host->slot.handler_priv;
+
+	if (!con_id)
+		con_id = ctx->cd_label;
+
+	desc = devm_gpiod_get_index(host->parent, con_id, idx);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	ret = gpiod_direction_input(desc);
+	if (ret < 0)
+		return ret;
+
+	if (debounce) {
+		ret = gpiod_set_debounce(desc, debounce);
+		if (ret < 0)
+			return ret;
+	}
+
+	ctx->override_cd_active_level = override_active_level;
+	ctx->cd_gpio = desc;
+
+	return 0;
+}
+EXPORT_SYMBOL(mmc_gpiod_request_cd);
+
+/**
+ * mmc_gpiod_free_cd - free the card-detection gpio descriptor
+ * @host: mmc host
+ *
+ * It's provided only for cases that client drivers need to manually free
+ * up the card-detection gpio requested by mmc_gpiod_request_cd().
+ */
+void mmc_gpiod_free_cd(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	if (!ctx || !ctx->cd_gpio)
+		return;
+
+	if (host->slot.cd_irq >= 0) {
+		devm_free_irq(&host->class_dev, host->slot.cd_irq, host);
+		host->slot.cd_irq = -EINVAL;
+	}
+
+	devm_gpiod_put(&host->class_dev, ctx->cd_gpio);
+
+	ctx->cd_gpio = NULL;
+}
+EXPORT_SYMBOL(mmc_gpiod_free_cd);