[PATCH v4 4/7] drm/sun4i: tcon: Refactor the LVDS and panel probing

[Maxime Ripard]

The current code to parse the DT, deal with the older device trees, and
register either the RGB or LVDS output has so far grown organically into
the bind function and has become quite hard to extend properly.

Let's move it into a single function that grabs all the resources it needs
and registers the proper panel output.

Reviewed-by: Chen-Yu Tsai <wens at csie.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Maxime Ripard <maxime at cerno.tech>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 127 +++++++++++++----------------
 1 file changed, 58 insertions(+), 69 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 1e643bc7e786..32757175f86b 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -885,6 +885,63 @@ static int sun4i_tcon_init_regmap(struct device *dev,
 	return 0;
 }
 
+static int sun4i_tcon_register_panel(struct drm_device *drm,
+				     struct sun4i_tcon *tcon)
+{
+	struct device_node *companion;
+	struct device_node *remote;
+	struct device *dev = tcon->dev;
+	int ret;
+
+	/*
+	 * If we have an LVDS panel connected to the TCON, we should
+	 * just probe the LVDS connector. Otherwise, let's just register
+	 * an RGB panel.
+	 */
+	remote = of_graph_get_remote_node(dev->of_node, 1, 0);
+	if (!tcon->quirks->supports_lvds ||
+	    !of_device_is_compatible(remote, "panel-lvds"))
+		return sun4i_rgb_init(drm, tcon);
+
+	/*
+	 * This can only be made optional since we've had DT
+	 * nodes without the LVDS reset properties.
+	 *
+	 * If the property is missing, just disable LVDS, and
+	 * print a warning.
+	 */
+	tcon->lvds_rst = devm_reset_control_get_optional(dev, "lvds");
+	if (IS_ERR(tcon->lvds_rst)) {
+		dev_err(dev, "Couldn't get our reset line\n");
+		return PTR_ERR(tcon->lvds_rst);
+	} else if (!tcon->lvds_rst) {
+		dev_warn(dev, "Missing LVDS reset property, please upgrade your DT\n");
+		return -ENODEV;
+	}
+
+	reset_control_reset(tcon->lvds_rst);
+
+	/*
+	 * This can only be made optional since we've had DT
+	 * nodes without the LVDS clocks properties.
+	 *
+	 * If the property is missing, just disable LVDS, and
+	 * print a warning.
+	 */
+	if (tcon->quirks->has_lvds_alt) {
+		tcon->lvds_pll = devm_clk_get_optional(dev, "lvds-alt");
+		if (IS_ERR(tcon->lvds_pll)) {
+			dev_err(dev, "Couldn't get the LVDS PLL\n");
+			return PTR_ERR(tcon->lvds_pll);
+		} else if (!tcon->lvds_pll) {
+			dev_warn(dev, "Missing LVDS PLL clock, please upgrade your DT\n");
+			return -ENODEV;
+		}
+	}
+
+	return sun4i_lvds_init(drm, tcon);
+}
+
 /*
  * On SoCs with the old display pipeline design (Display Engine 1.0),
  * the TCON is always tied to just one backend. Hence we can traverse
@@ -1132,10 +1189,8 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	struct drm_device *drm = data;
 	struct sun4i_drv *drv = drm->dev_private;
 	struct sunxi_engine *engine;
-	struct device_node *remote;
 	struct sun4i_tcon *tcon;
 	struct reset_control *edp_rstc;
-	bool has_lvds_rst, has_lvds_alt, can_lvds;
 	int ret;
 
 	engine = sun4i_tcon_find_engine(drv, dev->of_node);
@@ -1180,58 +1235,6 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 		return ret;
 	}
 
-	if (tcon->quirks->supports_lvds) {
-		/*
-		 * This can only be made optional since we've had DT
-		 * nodes without the LVDS reset properties.
-		 *
-		 * If the property is missing, just disable LVDS, and
-		 * print a warning.
-		 */
-		tcon->lvds_rst = devm_reset_control_get_optional(dev, "lvds");
-		if (IS_ERR(tcon->lvds_rst)) {
-			dev_err(dev, "Couldn't get our reset line\n");
-			return PTR_ERR(tcon->lvds_rst);
-		} else if (tcon->lvds_rst) {
-			has_lvds_rst = true;
-			reset_control_reset(tcon->lvds_rst);
-		} else {
-			has_lvds_rst = false;
-		}
-
-		/*
-		 * This can only be made optional since we've had DT
-		 * nodes without the LVDS reset properties.
-		 *
-		 * If the property is missing, just disable LVDS, and
-		 * print a warning.
-		 */
-		if (tcon->quirks->has_lvds_alt) {
-			tcon->lvds_pll = devm_clk_get(dev, "lvds-alt");
-			if (IS_ERR(tcon->lvds_pll)) {
-				if (PTR_ERR(tcon->lvds_pll) == -ENOENT) {
-					has_lvds_alt = false;
-				} else {
-					dev_err(dev, "Couldn't get the LVDS PLL\n");
-					return PTR_ERR(tcon->lvds_pll);
-				}
-			} else {
-				has_lvds_alt = true;
-			}
-		}
-
-		if (!has_lvds_rst ||
-		    (tcon->quirks->has_lvds_alt && !has_lvds_alt)) {
-			dev_warn(dev, "Missing LVDS properties, Please upgrade your DT\n");
-			dev_warn(dev, "LVDS output disabled\n");
-			can_lvds = false;
-		} else {
-			can_lvds = true;
-		}
-	} else {
-		can_lvds = false;
-	}
-
 	ret = sun4i_tcon_init_clocks(dev, tcon);
 	if (ret) {
 		dev_err(dev, "Couldn't init our TCON clocks\n");
@@ -1266,21 +1269,7 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	}
 
 	if (tcon->quirks->has_channel_0) {
-		/*
-		 * If we have an LVDS panel connected to the TCON, we should
-		 * just probe the LVDS connector. Otherwise, just probe RGB as
-		 * we used to.
-		 */
-		remote = of_graph_get_remote_node(dev->of_node, 1, 0);
-		if (of_device_is_compatible(remote, "panel-lvds"))
-			if (can_lvds)
-				ret = sun4i_lvds_init(drm, tcon);
-			else
-				ret = -EINVAL;
-		else
-			ret = sun4i_rgb_init(drm, tcon);
-		of_node_put(remote);
-
+		ret = sun4i_tcon_register_panel(drm, tcon);
 		if (ret < 0)
 			goto err_free_dotclock;
 	}
-- 
2.29.2