drm/bridge: display-connector: handle hdmi-pwr supply

On some devices the +5V Power pin of the HDMI connector and/or the ESD
protection logic is powered on by a separate regulator. Instead of
declaring this regulator as always-on, make hdmi-connector support the
additional hdmi-pwr supply.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230531000259.3758235-4-dmitry.baryshkov@linaro.org

drivers/gpu/drm/bridge/display-connector.c

@@ -191,6 +191,18 @@ static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static int display_connector_get_supply(struct platform_device *pdev,
+					struct display_connector *conn,
+					const char *name)
+{
+	conn->supply = devm_regulator_get_optional(&pdev->dev, name);
+
+	if (conn->supply == ERR_PTR(-ENODEV))
+		conn->supply = NULL;
+
+	return PTR_ERR_OR_ZERO(conn->supply);
+}
+
 static int display_connector_probe(struct platform_device *pdev)
 {
 	struct display_connector *conn;
@@ -316,36 +328,15 @@ static int display_connector_probe(struct platform_device *pdev)
 	if (type == DRM_MODE_CONNECTOR_DisplayPort) {
 		int ret;
 
-		conn->supply = devm_regulator_get_optional(&pdev->dev, "dp-pwr");
-
-		if (IS_ERR(conn->supply)) {
-			ret = PTR_ERR(conn->supply);
-
-			switch (ret) {
-			case -ENODEV:
-				conn->supply = NULL;
-				break;
-
-			case -EPROBE_DEFER:
-				return -EPROBE_DEFER;
-
-			default:
-				dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
-				return ret;
-			}
-		}
-
-		if (conn->supply) {
-			ret = regulator_enable(conn->supply);
-			if (ret) {
-				dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
-				return ret;
-			}
-		}
+		ret = display_connector_get_supply(pdev, conn, "dp-pwr");
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret, "failed to get DP PWR regulator\n");
 	}
 
 	/* enable DDC */
 	if (type == DRM_MODE_CONNECTOR_HDMIA) {
+		int ret;
+
 		conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
 						       GPIOD_OUT_HIGH);
 
@@ -353,6 +344,18 @@ static int display_connector_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
 			return PTR_ERR(conn->ddc_en);
 		}
+
+		ret = display_connector_get_supply(pdev, conn, "hdmi-pwr");
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret, "failed to get HDMI +5V Power regulator\n");
+	}
+
+	if (conn->supply) {
+		ret = regulator_enable(conn->supply);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to enable PWR regulator: %d\n", ret);
+			return ret;
+		}
 	}
 
 	conn->bridge.funcs = &display_connector_bridge_funcs;