drm/bridge: ti-sn65dsi83: Do not cache dsi_lanes and host twice

The DSI lane count can be accessed via the dsi device pointer, make use
of that. The DSI host pointer is only used in sn65dsi83_host_attach(),
move the code around so that the host does not have to be cached in the
driver private data. This simplifies the code further. No functional
change.

This has the added bonus that lt9211, tc358767, sn65dsi83 now use very
similar *_mipi_dsi_host_attach() which is ripe for deduplication.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220612102918.13874-1-marex@denx.de

drivers/gpu/drm/bridge/ti-sn65dsi83.c

@@ -140,12 +140,10 @@ struct sn65dsi83 {
 	struct drm_bridge		bridge;
 	struct device			*dev;
 	struct regmap			*regmap;
-	struct device_node		*host_node;
 	struct mipi_dsi_device		*dsi;
 	struct drm_bridge		*panel_bridge;
 	struct gpio_desc		*enable_gpio;
 	struct regulator		*vcc;
-	int				dsi_lanes;
 	bool				lvds_dual_link;
 	bool				lvds_dual_link_even_odd_swap;
 };
@@ -306,7 +304,7 @@ static u8 sn65dsi83_get_dsi_range(struct sn65dsi83 *ctx,
 	 */
 	return DIV_ROUND_UP(clamp((unsigned int)mode->clock *
 			    mipi_dsi_pixel_format_to_bpp(ctx->dsi->format) /
-			    ctx->dsi_lanes / 2, 40000U, 500000U), 5000U);
+			    ctx->dsi->lanes / 2, 40000U, 500000U), 5000U);
 }
 
 static u8 sn65dsi83_get_dsi_div(struct sn65dsi83 *ctx)
@@ -314,7 +312,7 @@ static u8 sn65dsi83_get_dsi_div(struct sn65dsi83 *ctx)
 	/* The divider is (DSI_CLK / LVDS_CLK) - 1, which really is: */
 	unsigned int dsi_div = mipi_dsi_pixel_format_to_bpp(ctx->dsi->format);
 
-	dsi_div /= ctx->dsi_lanes;
+	dsi_div /= ctx->dsi->lanes;
 
 	if (!ctx->lvds_dual_link)
 		dsi_div /= 2;
@@ -405,7 +403,7 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
 	/* Set number of DSI lanes and LVDS link config. */
 	regmap_write(ctx->regmap, REG_DSI_LANE,
 		     REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE |
-		     REG_DSI_LANE_CHA_DSI_LANES(~(ctx->dsi_lanes - 1)) |
+		     REG_DSI_LANE_CHA_DSI_LANES(~(ctx->dsi->lanes - 1)) |
 		     /* CHB is DSI85-only, set to default on DSI83/DSI84 */
 		     REG_DSI_LANE_CHB_DSI_LANES(3));
 	/* No equalization. */
@@ -569,22 +567,6 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
 {
 	struct drm_bridge *panel_bridge;
 	struct device *dev = ctx->dev;
-	struct device_node *endpoint;
-	int ret;
-
-	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
-	ctx->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
-	ctx->host_node = of_graph_get_remote_port_parent(endpoint);
-	of_node_put(endpoint);
-
-	if (ctx->dsi_lanes <= 0 || ctx->dsi_lanes > 4) {
-		ret = -EINVAL;
-		goto err_put_node;
-	}
-	if (!ctx->host_node) {
-		ret = -ENODEV;
-		goto err_put_node;
-	}
 
 	ctx->lvds_dual_link = false;
 	ctx->lvds_dual_link_even_odd_swap = false;
@@ -610,10 +592,8 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
 	}
 
 	panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 2, 0);
-	if (IS_ERR(panel_bridge)) {
-		ret = PTR_ERR(panel_bridge);
-		goto err_put_node;
-	}
+	if (IS_ERR(panel_bridge))
+		return PTR_ERR(panel_bridge);
 
 	ctx->panel_bridge = panel_bridge;
 
@@ -623,15 +603,13 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
 				     "Failed to get supply 'vcc'\n");
 
 	return 0;
-
-err_put_node:
-	of_node_put(ctx->host_node);
-	return ret;
 }
 
 static int sn65dsi83_host_attach(struct sn65dsi83 *ctx)
 {
 	struct device *dev = ctx->dev;
+	struct device_node *host_node;
+	struct device_node *endpoint;
 	struct mipi_dsi_device *dsi;
 	struct mipi_dsi_host *host;
 	const struct mipi_dsi_device_info info = {
@@ -639,13 +617,20 @@ static int sn65dsi83_host_attach(struct sn65dsi83 *ctx)
 		.channel = 0,
 		.node = NULL,
 	};
-	int ret;
+	int dsi_lanes, ret;
 
-	host = of_find_mipi_dsi_host_by_node(ctx->host_node);
-	if (!host) {
-		dev_err(dev, "failed to find dsi host\n");
+	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
+	dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
+	host_node = of_graph_get_remote_port_parent(endpoint);
+	host = of_find_mipi_dsi_host_by_node(host_node);
+	of_node_put(host_node);
+	of_node_put(endpoint);
+
+	if (!host)
 		return -EPROBE_DEFER;
-	}
+
+	if (dsi_lanes < 0)
+		return dsi_lanes;
 
 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
 	if (IS_ERR(dsi))
@@ -654,7 +639,7 @@ static int sn65dsi83_host_attach(struct sn65dsi83 *ctx)
 
 	ctx->dsi = dsi;
 
-	dsi->lanes = ctx->dsi_lanes;
+	dsi->lanes = dsi_lanes;
 	dsi->format = MIPI_DSI_FMT_RGB888;
 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST;
 
@@ -701,10 +686,8 @@ static int sn65dsi83_probe(struct i2c_client *client,
 		return ret;
 
 	ctx->regmap = devm_regmap_init_i2c(client, &sn65dsi83_regmap_config);
-	if (IS_ERR(ctx->regmap)) {
-		ret = PTR_ERR(ctx->regmap);
-		goto err_put_node;
-	}
+	if (IS_ERR(ctx->regmap))
+		return PTR_ERR(ctx->regmap);
 
 	dev_set_drvdata(dev, ctx);
 	i2c_set_clientdata(client, ctx);
@@ -721,8 +704,6 @@ static int sn65dsi83_probe(struct i2c_client *client,
 
 err_remove_bridge:
 	drm_bridge_remove(&ctx->bridge);
-err_put_node:
-	of_node_put(ctx->host_node);
 	return ret;
 }
 
@@ -731,7 +712,6 @@ static int sn65dsi83_remove(struct i2c_client *client)
 	struct sn65dsi83 *ctx = i2c_get_clientdata(client);
 
 	drm_bridge_remove(&ctx->bridge);
-	of_node_put(ctx->host_node);
 
 	return 0;
 }