[PATCH v3 1/6] mmc: core: Add mmc_gpiod_set_cd_config() function

[Hans de Goede <hdegoede@redhat.com>]

Some mmc host drivers may need to fixup a card-detection GPIO's config
to e.g. enable the GPIO controllers builtin pull-up resistor on devices
where the firmware description of the GPIO is broken (e.g. GpioInt with
PullNone instead of PullUp in ACPI DSDT).

Since this is the exception rather then the rule adding a config
parameter to mmc_gpiod_request_cd() seems undesirable, so instead
add a new mmc_gpiod_set_cd_config() function. This is simply a wrapper
to call gpiod_set_config() on the card-detect GPIO acquired through
mmc_gpiod_request_cd().

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Group mmc_gpiod_set_cd_config() prototype in slot-gpio.h together
  with mmc_gpiod_set_cd_config()
---
 drivers/mmc/core/slot-gpio.c  | 20 ++++++++++++++++++++
 include/linux/mmc/slot-gpio.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 39f45c2b6de8..8791656e9e20 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -221,6 +221,26 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 }
 EXPORT_SYMBOL(mmc_gpiod_request_cd);
 
+/**
+ * mmc_gpiod_set_cd_config - set config for card-detection GPIO
+ * @host: mmc host
+ * @config: Generic pinconf config (from pinconf_to_config_packed())
+ *
+ * This can be used by mmc host drivers to fixup a card-detection GPIO's config
+ * (e.g. set PIN_CONFIG_BIAS_PULL_UP) after acquiring the GPIO descriptor
+ * through mmc_gpiod_request_cd().
+ *
+ * Returns:
+ * 0 on success, or a negative errno value on error.
+ */
+int mmc_gpiod_set_cd_config(struct mmc_host *host, unsigned long config)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	return gpiod_set_config(ctx->cd_gpio, config);
+}
+EXPORT_SYMBOL(mmc_gpiod_set_cd_config);
+
 bool mmc_can_gpio_cd(struct mmc_host *host)
 {
 	struct mmc_gpio *ctx = host->slot.handler_priv;
diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
index 5d3d15e97868..66272fdce43d 100644
--- a/include/linux/mmc/slot-gpio.h
+++ b/include/linux/mmc/slot-gpio.h
@@ -21,6 +21,7 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 			 unsigned int debounce);
 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 			 unsigned int idx, unsigned int debounce);
+int mmc_gpiod_set_cd_config(struct mmc_host *host, unsigned long config);
 void mmc_gpio_set_cd_isr(struct mmc_host *host,
 			 irqreturn_t (*isr)(int irq, void *dev_id));
 int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on);
-- 
2.44.0