mmc: core: Add mmc_gpiod_set_cd_config() function

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>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240410191639.526324-2-hdegoede@redhat.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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;

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);