serial: mctrl_gpio: implement interrupt handling

This allows to reduce the per-driver boiler plate considerably.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
index 6d046fc..3c4ac9a 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.h
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -22,6 +22,8 @@
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
 
+struct uart_port;
+
 enum mctrl_gpio_idx {
 	UART_GPIO_CTS,
 	UART_GPIO_DSR,
@@ -60,6 +62,15 @@
 				      enum mctrl_gpio_idx gidx);
 
 /*
+ * Request and set direction of modem control lines GPIOs and sets up irq
+ * handling.
+ * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
+ * allocation error.
+ */
+struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
+
+/*
  * Request and set direction of modem control lines GPIOs.
  * devm_* functions are used, so there's no need to call mctrl_gpio_free().
  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
@@ -75,6 +86,16 @@
  */
 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
 
+/*
+ * Enable gpio interrupts to report status line changes.
+ */
+void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
+
+/*
+ * Disable gpio interrupts to report status line changes.
+ */
+void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
+
 #else /* GPIOLIB */
 
 static inline
@@ -96,6 +117,12 @@
 }
 
 static inline
+struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline
 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 {
 	return ERR_PTR(-ENOSYS);
@@ -106,6 +133,14 @@
 {
 }
 
+void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
+{
+}
+
+void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+{
+}
+
 #endif /* GPIOLIB */
 
 #endif