Merge tag 'drm/tegra/for-5.10-rc1' of ssh://git.freedesktop.org/git/tegra/linux into drm-next

drm/tegra: Changes for v5.10-rc1

This is a handful of patches that add bridge support for Tegra devices
and fix a couple of minor issues.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200921121245.3953659-1-thierry.reding@gmail.com

drivers/gpu/drm/tegra/drm.h

@@ -12,6 +12,7 @@
 #include <linux/gpio/consumer.h>
 
 #include <drm/drm_atomic.h>
+#include <drm/drm_bridge.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_fb_helper.h>
@@ -116,6 +117,7 @@ struct tegra_output {
 	struct device_node *of_node;
 	struct device *dev;
 
+	struct drm_bridge *bridge;
 	struct drm_panel *panel;
 	struct i2c_adapter *ddc;
 	const struct edid *edid;

drivers/gpu/drm/tegra/output.c

@@ -5,6 +5,7 @@
  */
 
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 #include <drm/drm_simple_kms_helper.h>
 
@@ -99,27 +100,38 @@ int tegra_output_probe(struct tegra_output *output)
 	if (!output->of_node)
 		output->of_node = output->dev->of_node;
 
+	err = drm_of_find_panel_or_bridge(output->of_node, -1, -1,
+					  &output->panel, &output->bridge);
+	if (err && err != -ENODEV)
+		return err;
+
 	panel = of_parse_phandle(output->of_node, "nvidia,panel", 0);
 	if (panel) {
+		/*
+		 * Don't mix nvidia,panel phandle with the graph in a
+		 * device-tree.
+		 */
+		WARN_ON(output->panel || output->bridge);
+
 		output->panel = of_drm_find_panel(panel);
+		of_node_put(panel);
+
 		if (IS_ERR(output->panel))
 			return PTR_ERR(output->panel);
-
-		of_node_put(panel);
 	}
 
 	output->edid = of_get_property(output->of_node, "nvidia,edid", &size);
 
 	ddc = of_parse_phandle(output->of_node, "nvidia,ddc-i2c-bus", 0);
 	if (ddc) {
-		output->ddc = of_find_i2c_adapter_by_node(ddc);
+		output->ddc = of_get_i2c_adapter_by_node(ddc);
+		of_node_put(ddc);
+
 		if (!output->ddc) {
 			err = -EPROBE_DEFER;
 			of_node_put(ddc);
 			return err;
 		}
-
-		of_node_put(ddc);
 	}
 
 	output->hpd_gpio = devm_gpiod_get_from_of_node(output->dev,
@@ -173,7 +185,7 @@ void tegra_output_remove(struct tegra_output *output)
 		free_irq(output->hpd_irq, output);
 
 	if (output->ddc)
-		put_device(&output->ddc->dev);
+		i2c_put_adapter(output->ddc);
 }
 
 int tegra_output_init(struct drm_device *drm, struct tegra_output *output)

drivers/gpu/drm/tegra/rgb.c

@@ -7,7 +7,7 @@
 #include <linux/clk.h>
 
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_panel.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/drm_simple_kms_helper.h>
 
 #include "drm.h"
@@ -85,45 +85,13 @@ static void tegra_dc_write_regs(struct tegra_dc *dc,
 		tegra_dc_writel(dc, table[i].value, table[i].offset);
 }
 
-static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
-	.reset = drm_atomic_helper_connector_reset,
-	.detect = tegra_output_connector_detect,
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = tegra_output_connector_destroy,
-	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static enum drm_mode_status
-tegra_rgb_connector_mode_valid(struct drm_connector *connector,
-			       struct drm_display_mode *mode)
-{
-	/*
-	 * FIXME: For now, always assume that the mode is okay. There are
-	 * unresolved issues with clk_round_rate(), which doesn't always
-	 * reliably report whether a frequency can be set or not.
-	 */
-	return MODE_OK;
-}
-
-static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
-	.get_modes = tegra_output_connector_get_modes,
-	.mode_valid = tegra_rgb_connector_mode_valid,
-};
-
 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
 {
 	struct tegra_output *output = encoder_to_output(encoder);
 	struct tegra_rgb *rgb = to_rgb(output);
 
-	if (output->panel)
-		drm_panel_disable(output->panel);
-
 	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
 	tegra_dc_commit(rgb->dc);
-
-	if (output->panel)
-		drm_panel_unprepare(output->panel);
 }
 
 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
@@ -132,9 +100,6 @@ static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 	struct tegra_rgb *rgb = to_rgb(output);
 	u32 value;
 
-	if (output->panel)
-		drm_panel_prepare(output->panel);
-
 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
 
 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
@@ -156,9 +121,6 @@ static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 	tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
 
 	tegra_dc_commit(rgb->dc);
-
-	if (output->panel)
-		drm_panel_enable(output->panel);
 }
 
 static int
@@ -267,24 +229,68 @@ int tegra_dc_rgb_remove(struct tegra_dc *dc)
 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
 {
 	struct tegra_output *output = dc->rgb;
+	struct drm_connector *connector;
 	int err;
 
 	if (!dc->rgb)
 		return -ENODEV;
 
-	drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
-			   DRM_MODE_CONNECTOR_LVDS);
-	drm_connector_helper_add(&output->connector,
-				 &tegra_rgb_connector_helper_funcs);
-	output->connector.dpms = DRM_MODE_DPMS_OFF;
-
 	drm_simple_encoder_init(drm, &output->encoder, DRM_MODE_ENCODER_LVDS);
 	drm_encoder_helper_add(&output->encoder,
 			       &tegra_rgb_encoder_helper_funcs);
 
-	drm_connector_attach_encoder(&output->connector,
-					  &output->encoder);
-	drm_connector_register(&output->connector);
+	/*
+	 * Wrap directly-connected panel into DRM bridge in order to let
+	 * DRM core to handle panel for us.
+	 */
+	if (output->panel) {
+		output->bridge = devm_drm_panel_bridge_add(output->dev,
+							   output->panel);
+		if (IS_ERR(output->bridge)) {
+			dev_err(output->dev,
+				"failed to wrap panel into bridge: %pe\n",
+				output->bridge);
+			return PTR_ERR(output->bridge);
+		}
+
+		output->panel = NULL;
+	}
+
+	/*
+	 * Tegra devices that have LVDS panel utilize LVDS encoder bridge
+	 * for converting up to 28 LCD LVTTL lanes into 5/4 LVDS lanes that
+	 * go to display panel's receiver.
+	 *
+	 * Encoder usually have a power-down control which needs to be enabled
+	 * in order to transmit data to the panel.  Historically devices that
+	 * use an older device-tree version didn't model the bridge, assuming
+	 * that encoder is turned ON by default, while today's DRM allows us
+	 * to model LVDS encoder properly.
+	 *
+	 * Newer device-trees utilize LVDS encoder bridge, which provides
+	 * us with a connector and handles the display panel.
+	 *
+	 * For older device-trees we wrapped panel into the panel-bridge.
+	 */
+	if (output->bridge) {
+		err = drm_bridge_attach(&output->encoder, output->bridge,
+					NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+		if (err) {
+			dev_err(output->dev, "failed to attach bridge: %d\n",
+				err);
+			return err;
+		}
+
+		connector = drm_bridge_connector_init(drm, &output->encoder);
+		if (IS_ERR(connector)) {
+			dev_err(output->dev,
+				"failed to initialize bridge connector: %pe\n",
+				connector);
+			return PTR_ERR(connector);
+		}
+
+		drm_connector_attach_encoder(connector, &output->encoder);
+	}
 
 	err = tegra_output_init(drm, output);
 	if (err < 0) {

drivers/gpu/drm/tegra/sor.c

@@ -3728,7 +3728,12 @@ static int tegra_sor_probe(struct platform_device *pdev)
 		if (!sor->aux)
 			return -EPROBE_DEFER;
 
-		sor->output.ddc = &sor->aux->ddc;
+		if (get_device(&sor->aux->ddc.dev)) {
+			if (try_module_get(sor->aux->ddc.owner))
+				sor->output.ddc = &sor->aux->ddc;
+			else
+				put_device(&sor->aux->ddc.dev);
+		}
 	}
 
 	if (!sor->aux) {