rockchip: pinctrl: rk3399: add support for the HDMI I2C pins

To add HDMI support for the RK3399, this commit provides the needed
pinctrl functionality to configure the HDMI I2C pins (used for reading
the screen's EDID).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/include/asm/arch-rockchip/grf_rk3399.h

@@ -440,9 +440,11 @@ enum {
 	GRF_GPIO4C0_SEL_SHIFT   = 0,
 	GRF_GPIO4C0_SEL_MASK    = 3 << GRF_GPIO4C0_SEL_SHIFT,
 	GRF_UART2DGBB_SIN       = 2,
+	GRF_HDMII2C_SCL         = 3,
 	GRF_GPIO4C1_SEL_SHIFT   = 2,
 	GRF_GPIO4C1_SEL_MASK    = 3 << GRF_GPIO4C1_SEL_SHIFT,
 	GRF_UART2DGBB_SOUT      = 2,
+	GRF_HDMII2C_SDA         = 3,
 	GRF_GPIO4C2_SEL_SHIFT   = 4,
 	GRF_GPIO4C2_SEL_MASK    = 3 << GRF_GPIO4C2_SEL_SHIFT,
 	GRF_PWM_0               = 1,

drivers/pinctrl/rockchip/pinctrl_rk3399.c

@@ -265,6 +265,23 @@ static void pinctrl_rk3399_gmac_config(struct rk3399_grf_regs *grf, int mmc_id)
 }
 #endif
 
+#if !defined(CONFIG_SPL_BUILD)
+static void pinctrl_rk3399_hdmi_config(struct rk3399_grf_regs *grf, int hdmi_id)
+{
+	switch (hdmi_id) {
+	case PERIPH_ID_HDMI:
+		rk_clrsetreg(&grf->gpio4c_iomux,
+			     GRF_GPIO4C0_SEL_MASK | GRF_GPIO4C1_SEL_MASK,
+			     (GRF_HDMII2C_SCL << GRF_GPIO4C0_SEL_SHIFT) |
+			     (GRF_HDMII2C_SDA << GRF_GPIO4C1_SEL_SHIFT));
+		break;
+	default:
+		debug("%s: hdmi_id = %d unsupported\n", __func__, hdmi_id);
+		break;
+	}
+}
+#endif
+
 static int rk3399_pinctrl_request(struct udevice *dev, int func, int flags)
 {
 	struct rk3399_pinctrl_priv *priv = dev_get_priv(dev);
@@ -314,6 +331,11 @@ static int rk3399_pinctrl_request(struct udevice *dev, int func, int flags)
 		pinctrl_rk3399_gmac_config(priv->grf, func);
 		break;
 #endif
+#if !defined(CONFIG_SPL_BUILD)
+	case PERIPH_ID_HDMI:
+		pinctrl_rk3399_hdmi_config(priv->grf, func);
+		break;
+#endif
 	default:
 		return -EINVAL;
 	}
@@ -360,6 +382,10 @@ static int rk3399_pinctrl_get_periph_id(struct udevice *dev,
 	case 12:
 		return PERIPH_ID_GMAC;
 #endif
+#if !defined(CONFIG_SPL_BUILD)
+	case 23:
+		return PERIPH_ID_HDMI;
+#endif
 	}
 #endif
 	return -ENOENT;