mmc: slot-gpio: Add a function to enable/disable card detect IRQ wakeup

Commit 03dbaa04a2 ("mmc: slot-gpio: Add support to enable irq wake on
cd_irq") enabled wakeup at initialization. However drivers may wish to
enable and disable based on different criteria. Add a helper function
mmc_gpio_set_cd_wake() to make it easy for drivers to do that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/core.c

@@ -2655,8 +2655,7 @@ void mmc_start_host(struct mmc_host *host)
 void mmc_stop_host(struct mmc_host *host)
 {
 	if (host->slot.cd_irq >= 0) {
-		if (host->slot.cd_wake_enabled)
-			disable_irq_wake(host->slot.cd_irq);
+		mmc_gpio_set_cd_wake(host, false);
 		disable_irq(host->slot.cd_irq);
 	}
 

drivers/mmc/core/slot-gpio.c

@@ -154,6 +154,27 @@ void mmc_gpiod_request_cd_irq(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
 
+int mmc_gpio_set_cd_wake(struct mmc_host *host, bool on)
+{
+	int ret = 0;
+
+	if (!(host->caps & MMC_CAP_CD_WAKE) ||
+	    host->slot.cd_irq < 0 ||
+	    on == host->slot.cd_wake_enabled)
+		return 0;
+
+	if (on) {
+		ret = enable_irq_wake(host->slot.cd_irq);
+		host->slot.cd_wake_enabled = !ret;
+	} else {
+		disable_irq_wake(host->slot.cd_irq);
+		host->slot.cd_wake_enabled = false;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(mmc_gpio_set_cd_wake);
+
 /* Register an alternate interrupt service routine for
  * the card-detect GPIO.
  */