delete unused GPIO_SET_ALT_3

src/drivers/drv_gpio.h

@@ -71,9 +71,6 @@
 /** configure the board GPIOs in (arg) as inputs */
 #define GPIO_SET_INPUT	GPIOC(2)
 
-/** configure the board GPIO (arg) for the third alternate function (if supported) */
-#define GPIO_SET_ALT_3	GPIOC(5)
-
 /** configure the board GPIO (arg) for the fourth alternate function (if supported) */
 #define GPIO_SET_ALT_4	GPIOC(6)
 

src/drivers/px4fmu/fmu.cpp

@@ -2910,7 +2910,6 @@ PX4FMU::gpio_ioctl(struct file *filp, int cmd, unsigned long arg)
 		ret = gpio_set_function(arg, cmd);
 		break;
 
-	case GPIO_SET_ALT_3:
 	case GPIO_SET_ALT_4:
 		ret = -EINVAL;
 		break;