drm/omap: hdmi: Allocate EDID in the .read_edid() operation

Bring the omapdss-specific .read_edid() operation in sync with the
drm_bridge .get_edid() operation to ease code reuse.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-29-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/omapdrm/dss/hdmi4.c

@@ -405,31 +405,45 @@ static void hdmi_disconnect(struct omap_dss_device *src,
 	omapdss_device_disconnect(dst, dst->next);
 }
 
-static int hdmi_read_edid(struct omap_dss_device *dssdev,
-		u8 *edid, int len)
+#define MAX_EDID	512
+
+static struct edid *hdmi_read_edid(struct omap_dss_device *dssdev)
 {
 	struct omap_hdmi *hdmi = dssdev_to_hdmi(dssdev);
 	bool need_enable;
+	u8 *edid;
 	int r;
 
+	edid = kzalloc(MAX_EDID, GFP_KERNEL);
+	if (!edid)
+		return NULL;
+
 	need_enable = hdmi->core_enabled == false;
 
 	if (need_enable) {
 		r = hdmi4_core_enable(&hdmi->core);
-		if (r)
-			return r;
+		if (r) {
+			kfree(edid);
+			return NULL;
+		}
+	}
+
+	r = read_edid(hdmi, edid, MAX_EDID);
+	if (r < 0) {
+		kfree(edid);
+		edid = NULL;
+	} else {
+		unsigned int cec_addr;
+
+		cec_addr = r >= 256 ? cec_get_edid_phys_addr(edid, r, NULL)
+			 : CEC_PHYS_ADDR_INVALID;
+		hdmi4_cec_set_phys_addr(&hdmi->core, cec_addr);
 	}
 
-	r = read_edid(hdmi, edid, len);
-	if (r >= 256)
-		hdmi4_cec_set_phys_addr(&hdmi->core,
-					cec_get_edid_phys_addr(edid, r, NULL));
-	else
-		hdmi4_cec_set_phys_addr(&hdmi->core, CEC_PHYS_ADDR_INVALID);
 	if (need_enable)
 		hdmi4_core_disable(&hdmi->core);
 
-	return r;
+	return (struct edid *)edid;
 }
 
 static void hdmi_lost_hotplug(struct omap_dss_device *dssdev)