mmc: core: expose the capability of gpio card detect

Add new helper API mmc_can_gpio_cd for slot-gpio to make
host drivers know whether it supports gpio card detect.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/slot-gpio.c

@@ -258,6 +258,14 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 }
 EXPORT_SYMBOL(mmc_gpiod_request_cd);
 
+bool mmc_can_gpio_cd(struct mmc_host *host)
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	return ctx->cd_gpio ? true : false;
+}
+EXPORT_SYMBOL(mmc_can_gpio_cd);
+
 /**
  * mmc_gpiod_request_ro - request a gpio descriptor for write protection
  * @host: mmc host

include/linux/mmc/slot-gpio.h

@@ -29,5 +29,6 @@ int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 void mmc_gpio_set_cd_isr(struct mmc_host *host,
 			 irqreturn_t (*isr)(int irq, void *dev_id));
 void mmc_gpiod_request_cd_irq(struct mmc_host *host);
+bool mmc_can_gpio_cd(struct mmc_host *host);
 
 #endif