exynos: Add support for the DisplayPort hotplug detect

Allow this function to be selected using the pinmux API.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/arm/cpu/armv7/exynos/pinmux.c

@@ -496,6 +496,16 @@ static int exynos5_pinmux_config(int peripheral, int flags)
 	case PERIPH_ID_SPI4:
 		exynos5_spi_config(peripheral);
 		break;
+	case PERIPH_ID_DPHPD:
+		/* Set Hotplug detect for DP */
+		gpio_cfg_pin(EXYNOS5_GPIO_X07, S5P_GPIO_FUNC(0x3));
+
+		/*
+		 * Hotplug detect should have an external pullup; disable the
+		 * internal pulldown so they don't fight.
+		 */
+		gpio_set_pull(EXYNOS5_GPIO_X07, S5P_GPIO_PULL_NONE);
+		break;
 	default:
 		debug("%s: invalid peripheral %d", __func__, peripheral);
 		return -1;

arch/arm/include/asm/arch-exynos/periph.h

@@ -53,6 +53,7 @@ enum periph_id {
 	PERIPH_ID_PWM2,
 	PERIPH_ID_PWM3,
 	PERIPH_ID_PWM4,
+	PERIPH_ID_DPHPD,
 	PERIPH_ID_I2C10 = 203,
 
 	PERIPH_ID_NONE = -1,