[PATCH 3/3] drm/bridge: display-connector: handle hdmi-pwr supply

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On some devices the 5V 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>
---
 drivers/gpu/drm/bridge/display-connector.c | 37 +++++++++++++++++-----
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
index 0d94e6edea50..037ba2eb5a2f 100644
--- a/drivers/gpu/drm/bridge/display-connector.c
+++ b/drivers/gpu/drm/bridge/display-connector.c
@@ -337,18 +337,12 @@ static int display_connector_probe(struct platform_device *pdev)
 				return ret;
 			}
 		}
-
-		if (conn->connector_pwr) {
-			ret = regulator_enable(conn->connector_pwr);
-			if (ret) {
-				dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
-				return ret;
-			}
-		}
 	}
 
 	/* enable DDC */
 	if (type == DRM_MODE_CONNECTOR_HDMIA) {
+		int ret;
+
 		conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
 						       GPIOD_OUT_HIGH);
 
@@ -356,6 +350,33 @@ 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);
 		}
+
+		conn->connector_pwr = devm_regulator_get_optional(&pdev->dev, "hdmi-pwr");
+
+		if (IS_ERR(conn->connector_pwr)) {
+			ret = PTR_ERR(conn->connector_pwr);
+
+			switch (ret) {
+			case -ENODEV:
+				conn->connector_pwr = NULL;
+				break;
+
+			case -EPROBE_DEFER:
+				return -EPROBE_DEFER;
+
+			default:
+				dev_err(&pdev->dev, "failed to get HDMI PWR regulator: %d\n", ret);
+				return ret;
+			}
+		}
+	}
+
+	if (conn->connector_pwr) {
+		ret = regulator_enable(conn->connector_pwr);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
+			return ret;
+		}
 	}
 
 	conn->bridge.funcs = &display_connector_bridge_funcs;
-- 
2.39.2