drm/msm/hdmi: Make HDMI core get its PHY

Make HDMI core get its PHY by parsing the "phys" phandle. The core will use
this PHY reference to enable/disable PHY. The driver defers probe until PHY
isn't available.

The DT bindings used here is the same as the one used for PHYs using the
common PHY framework bindings.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/hdmi/hdmi.c

@@ -81,12 +81,46 @@ static void hdmi_destroy(struct hdmi *hdmi)
 	if (phy)
 		phy->funcs->destroy(phy);
 
+	if (hdmi->phy_dev) {
+		put_device(hdmi->phy_dev);
+		hdmi->phy = NULL;
+		hdmi->phy_dev = NULL;
+	}
+
 	if (hdmi->i2c)
 		hdmi_i2c_destroy(hdmi->i2c);
 
 	platform_set_drvdata(hdmi->pdev, NULL);
 }
 
+static int hdmi_get_phy(struct hdmi *hdmi)
+{
+	struct platform_device *pdev = hdmi->pdev;
+	struct platform_device *phy_pdev;
+	struct device_node *phy_node;
+
+	phy_node = of_parse_phandle(pdev->dev.of_node, "phys", 0);
+	if (!phy_node) {
+		dev_err(&pdev->dev, "cannot find phy device\n");
+		return -ENXIO;
+	}
+
+	phy_pdev = of_find_device_by_node(phy_node);
+	if (phy_pdev)
+		hdmi->phy = platform_get_drvdata(phy_pdev);
+
+	of_node_put(phy_node);
+
+	if (!phy_pdev || !hdmi->phy) {
+		dev_err(&pdev->dev, "phy driver is not ready\n");
+		return -EPROBE_DEFER;
+	}
+
+	hdmi->phy_dev = get_device(&phy_pdev->dev);
+
+	return 0;
+}
+
 /* construct hdmi at bind/probe time, grab all the resources.  If
  * we are to EPROBE_DEFER we want to do it here, rather than later
  * at modeset_init() time
@@ -230,6 +264,12 @@ static struct hdmi *hdmi_init(struct platform_device *pdev)
 		goto fail;
 	}
 
+	ret = hdmi_get_phy(hdmi);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get phy\n");
+		goto fail;
+	}
+
 	hdmi->hdcp_ctrl = hdmi_hdcp_init(hdmi);
 	if (IS_ERR(hdmi->hdcp_ctrl)) {
 		dev_warn(&pdev->dev, "failed to init hdcp: disabled\n");

drivers/gpu/drm/msm/hdmi/hdmi.h

@@ -70,6 +70,8 @@ struct hdmi {
 	struct clk **pwr_clks;
 
 	struct hdmi_phy *phy;
+	struct device *phy_dev;
+
 	struct i2c_adapter *i2c;
 	struct drm_connector *connector;
 	struct drm_bridge *bridge;