--- /dev/null
+/*
+ * 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>
+
+#include "slot-gpio.h"
+
+struct mmc_gpio {
+ struct gpio_desc *ro_gpio;
+ struct gpio_desc *cd_gpio;
+ bool override_ro_active_level;
+ bool override_cd_active_level;
+ irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
+ 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;
+}
+
+int mmc_gpio_alloc(struct mmc_host *host)
+{
+ size_t len = strlen(dev_name(host->parent)) + 4;
+ struct mmc_gpio *ctx = devm_kzalloc(host->parent,
+ 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;
+ host->slot.cd_irq = -EINVAL;
+ }
+
+ 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 worry about freeing up memory.
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
+{
+ struct mmc_gpio *ctx = host->slot.handler_priv;
+ int ret;
+
+ if (!gpio_is_valid(gpio))
+ return -EINVAL;
+
+ ret = devm_gpio_request_one(host->parent, 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) {
+ if (!ctx->cd_gpio_isr)
+ ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
+ ret = devm_request_threaded_irq(host->parent, irq,
+ NULL, ctx->cd_gpio_isr,
+ 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);
+
+/* Register an alternate interrupt service routine for
+ * the card-detect GPIO.
+ */
+void mmc_gpio_set_cd_isr(struct mmc_host *host,
+ irqreturn_t (*isr)(int irq, void *dev_id))
+{
+ struct mmc_gpio *ctx = host->slot.handler_priv;
+
+ WARN_ON(ctx->cd_gpio_isr);
+ ctx->cd_gpio_isr = isr;
+}
+EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
+
+/**
+ * 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 worry about freeing up memory.
+ *
+ * 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 = host->slot.handler_priv;
+ int ret;
+
+ ret = devm_gpio_request_one(host->parent, 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);
+
+ return 0;
+}
+EXPORT_SYMBOL(mmc_gpio_request_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
+ * @gpio_invert: will return whether the GPIO line is inverted or not, set
+ * to NULL to ignore
+ *
+ * Use this function in place of mmc_gpio_request_cd() to use the GPIO
+ * descriptor API. Note 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, bool *gpio_invert)
+{
+ struct mmc_gpio *ctx = host->slot.handler_priv;
+ struct gpio_desc *desc;
+ int ret;
+
+ if (!con_id)
+ con_id = ctx->cd_label;
+
+ desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ if (debounce) {
+ ret = gpiod_set_debounce(desc, debounce);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (gpio_invert)
+ *gpio_invert = !gpiod_is_active_low(desc);
+
+ ctx->override_cd_active_level = override_active_level;
+ ctx->cd_gpio = desc;
+
+ return 0;
+}
+EXPORT_SYMBOL(mmc_gpiod_request_cd);
+
+/**
+ * mmc_gpiod_request_ro - request a gpio descriptor for write protection
+ * @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
+ * @gpio_invert: will return whether the GPIO line is inverted or not,
+ * set to NULL to ignore
+ *
+ * Use this function in place of mmc_gpio_request_ro() to use the GPIO
+ * descriptor API.
+ *
+ * Returns zero on success, else an error.
+ */
+int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
+ unsigned int idx, bool override_active_level,
+ unsigned int debounce, bool *gpio_invert)
+{
+ struct mmc_gpio *ctx = host->slot.handler_priv;
+ struct gpio_desc *desc;
+ int ret;
+
+ if (!con_id)
+ con_id = ctx->ro_label;
+
+ desc = devm_gpiod_get_index(host->parent, con_id, idx, GPIOD_IN);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ if (debounce) {
+ ret = gpiod_set_debounce(desc, debounce);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (gpio_invert)
+ *gpio_invert = !gpiod_is_active_low(desc);
+
+ ctx->override_ro_active_level = override_active_level;
+ ctx->ro_gpio = desc;
+
+ return 0;
+}
+EXPORT_SYMBOL(mmc_gpiod_request_ro);
Code Review / kvmfornfv.git / blobdiff