mmc: slot-gpio: Allow host driver to provide isr for card-detect interrupts

One of the reasons omap_hsmmc doesn't use the slot-gpio library
is that it has some non-standard functionality in the card-detect
interrupt service routine.

To make it possible for omap_hsmmc (and maybe others) to be converted
to use slot-gpio, add 'mmc_gpio_request_cd_isr' which provide an
alternate isr to be register by the slot-gpio code.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/slot-gpio.c

@@ -25,6 +25,7 @@ struct mmc_gpio {
 	struct gpio_desc *cd_gpio;
 	bool override_ro_active_level;
 	bool override_cd_active_level;
+	irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
 	char *ro_label;
 	char cd_label[0];
 };
@@ -136,8 +137,10 @@ void mmc_gpiod_request_cd_irq(struct mmc_host *host)
 		irq = -EINVAL;
 
 	if (irq >= 0) {
+		if (!ctx->cd_gpio_isr)
+			ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
 		ret = devm_request_threaded_irq(host->parent, irq,
-			NULL, mmc_gpio_cd_irqt,
+			NULL, ctx->cd_gpio_isr,
 			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 			ctx->cd_label, host);
 		if (ret < 0)
@@ -151,6 +154,19 @@ void mmc_gpiod_request_cd_irq(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
 
+/* Register an alternate interrupt service routine for
+ * the card-detect GPIO.
+ */
+void mmc_gpio_set_cd_isr(struct mmc_host *host,
+			 irqreturn_t (*isr)(int irq, void *dev_id))
+{
+	struct mmc_gpio *ctx = host->slot.handler_priv;
+
+	WARN_ON(ctx->cd_gpio_isr);
+	ctx->cd_gpio_isr = isr;
+}
+EXPORT_SYMBOL(mmc_gpio_set_cd_isr);
+
 /**
  * mmc_gpio_request_cd - request a gpio for card-detection
  * @host: mmc host

include/linux/mmc/slot-gpio.h

@@ -26,6 +26,8 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
 int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
 			 unsigned int idx, bool override_active_level,
 			 unsigned int debounce, bool *gpio_invert);
+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);
 
 #endif