mmc: slot-gpio: add gpiod variant to get wp GPIO

This makes it possible to get the write protect (read only)
GPIO line from a GPIO descriptor. Written to exactly mirror
the card detect function.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

2 files changed, 51 insertions, 0 deletions

diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 908c2b29e79f..e3fce4493fab 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -326,6 +326,54 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 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
+ *
+ * Use this function in place of mmc_gpio_request_ro() to use the GPIO
+ * descriptor API.  Note that it is paired with mmc_gpiod_free_ro() not
+ * mmc_gpio_free_ro().
+ *
+ * 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)
+{
+        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->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;
+        }
+
+        ctx->override_ro_active_level = override_active_level;
+        ctx->ro_gpio = desc;
+
+        return 0;
+}
+EXPORT_SYMBOL(mmc_gpiod_request_ro);
+
+/**
  * mmc_gpiod_free_cd - free the card-detection gpio descriptor
  * @host: mmc host
  *
diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
index d2433381e828..a0d0442c15bf 100644
--- a/include/linux/mmc/slot-gpio.h
+++ b/include/linux/mmc/slot-gpio.h
@@ -25,6 +25,9 @@ void mmc_gpio_free_cd(struct mmc_host *host);
 int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
                          unsigned int idx, bool override_active_level,
                          unsigned int debounce);
+int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
+                         unsigned int idx, bool override_active_level,
+                         unsigned int debounce);
 void mmc_gpiod_free_cd(struct mmc_host *host);
 void mmc_gpiod_request_cd_irq(struct mmc_host *host);