drm/tegra: hdmi - Add connector supply support

Revert commit 18ebc0f404d5 "drm/tegra: hdmi: Enable VDD earlier for
hotplug/DDC" and instead add a new supply for the +5V pin on the HDMI
connector.

The vdd-supply property refers to the regulator that supplies the
AVDD_HDMI input on Tegra, rather than the +5V HDMI connector pin. This
was never a problem before, because all boards had that pin hooked up to
a regulator that was always on. Starting with Dalmore and continuing
with Venice2, the +5V pin is controllable via a GPIO. For reasons
unknown, the GPIO ended up as the controlling GPIO of the AVDD_HDMI
supply in the Dalmore and Venice2 DTS files. But that's not correct.
Instead, a separate supply must be introduced so that the +5V pin can be
controlled separately from the supplies that feed the HDMI block within
Tegra.

A new hdmi-supply property is introduced that takes the place of the
vdd-supply and vdd-supply is only enabled when HDMI is enabled rather
than all the time.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/hdmi.c b/drivers/gpu/drm/tegra/hdmi.c
index 6928015..8b797913 100644
--- a/drivers/gpu/drm/tegra/hdmi.c
+++ b/drivers/gpu/drm/tegra/hdmi.c
@@ -42,6 +42,7 @@
 	struct device *dev;
 	bool enabled;
 
+	struct regulator *hdmi;
 	struct regulator *vdd;
 	struct regulator *pll;
 
@@ -710,6 +711,12 @@
 	h_back_porch = mode->htotal - mode->hsync_end;
 	h_front_porch = mode->hsync_start - mode->hdisplay;
 
+	err = regulator_enable(hdmi->vdd);
+	if (err < 0) {
+		dev_err(hdmi->dev, "failed to enable VDD regulator: %d\n", err);
+		return err;
+	}
+
 	err = regulator_enable(hdmi->pll);
 	if (err < 0) {
 		dev_err(hdmi->dev, "failed to enable PLL regulator: %d\n", err);
@@ -950,6 +957,7 @@
 	reset_control_assert(hdmi->rst);
 	clk_disable(hdmi->clk);
 	regulator_disable(hdmi->pll);
+	regulator_disable(hdmi->vdd);
 
 	hdmi->enabled = false;
 
@@ -1256,13 +1264,6 @@
 	struct tegra_hdmi *hdmi = host1x_client_to_hdmi(client);
 	int err;
 
-	err = regulator_enable(hdmi->vdd);
-	if (err < 0) {
-		dev_err(client->dev, "failed to enable VDD regulator: %d\n",
-			err);
-		return err;
-	}
-
 	hdmi->output.type = TEGRA_OUTPUT_HDMI;
 	hdmi->output.dev = client->dev;
 	hdmi->output.ops = &hdmi_ops;
@@ -1279,6 +1280,13 @@
 			dev_err(client->dev, "debugfs setup failed: %d\n", err);
 	}
 
+	err = regulator_enable(hdmi->hdmi);
+	if (err < 0) {
+		dev_err(client->dev, "failed to enable HDMI regulator: %d\n",
+			err);
+		return err;
+	}
+
 	return 0;
 }
 
@@ -1287,6 +1295,8 @@
 	struct tegra_hdmi *hdmi = host1x_client_to_hdmi(client);
 	int err;
 
+	regulator_disable(hdmi->hdmi);
+
 	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
 		err = tegra_hdmi_debugfs_exit(hdmi);
 		if (err < 0)
@@ -1306,8 +1316,6 @@
 		return err;
 	}
 
-	regulator_disable(hdmi->vdd);
-
 	return 0;
 }
 
@@ -1399,6 +1407,12 @@
 		return err;
 	}
 
+	hdmi->hdmi = devm_regulator_get(&pdev->dev, "hdmi");
+	if (IS_ERR(hdmi->hdmi)) {
+		dev_err(&pdev->dev, "failed to get HDMI regulator\n");
+		return PTR_ERR(hdmi->hdmi);
+	}
+
 	hdmi->vdd = devm_regulator_get(&pdev->dev, "vdd");
 	if (IS_ERR(hdmi->vdd)) {
 		dev_err(&pdev->dev, "failed to get VDD regulator\n");