Commit 00686ac5 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Sam Ravnborg
Browse files

drm: bridge: simple-bridge: Delegate operations to next bridge 



Instead of poking into the DT node of the next bridge for its DDC bus
and implementing the .get_modes() and .detect() connector operations
manually, retrieve the next bridge in the chain and delegate these
operations to it.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200526011505.31884-7-laurent.pinchart+renesas@ideasonboard.com
parent 11d3cf80

drivers/gpu/drm/bridge/simple-bridge.c

+39 −65
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ struct simple_bridge { 


	const struct simple_bridge_info *info;



	struct i2c_adapter	*ddc;

	struct drm_bridge	*next_bridge;

	struct regulator	*vdd;

	struct gpio_desc	*enable;

};
@@ -52,29 +52,28 @@ static int simple_bridge_get_modes(struct drm_connector *connector) 
	struct edid *edid;

	int ret;



	if (!sbridge->ddc)

		goto fallback;

	if (sbridge->next_bridge->ops & DRM_BRIDGE_OP_EDID) {

		edid = drm_bridge_get_edid(sbridge->next_bridge, connector);

		if (!edid)

			DRM_INFO("EDID read failed. Fallback to standard modes\n");

	} else {

		edid = NULL;

	}



	edid = drm_get_edid(connector, sbridge->ddc);

	if (!edid) {

		DRM_INFO("EDID readout failed, falling back to standard modes\n");

		goto fallback;

		/*

		 * In case we cannot retrieve the EDIDs (missing or broken DDC

		 * bus from the next bridge), fallback on the XGA standards and

		 * prefer a mode pretty much anyone can handle.

		 */

		ret = drm_add_modes_noedid(connector, 1920, 1200);

		drm_set_preferred_mode(connector, 1024, 768);

		return ret;

	}



	drm_connector_update_edid_property(connector, edid);

	ret = drm_add_edid_modes(connector, edid);

	kfree(edid);

	return ret;



fallback:

	/*

	 * In case we cannot retrieve the EDIDs (broken or missing i2c

	 * bus), fallback on the XGA standards

	 */

	ret = drm_add_modes_noedid(connector, 1920, 1200);



	/* And prefer a mode pretty much anyone can handle */

	drm_set_preferred_mode(connector, 1024, 768);



	return ret;

}
@@ -88,16 +87,7 @@ simple_bridge_connector_detect(struct drm_connector *connector, bool force) 
{

	struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);



	/*

	 * Even if we have an I2C bus, we can't assume that the cable

	 * is disconnected if drm_probe_ddc fails. Some cables don't

	 * wire the DDC pins, or the I2C bus might not be working at

	 * all.

	 */

	if (sbridge->ddc && drm_probe_ddc(sbridge->ddc))

		return connector_status_connected;



	return connector_status_unknown;

	return drm_bridge_detect(sbridge->next_bridge);

}



static const struct drm_connector_funcs simple_bridge_con_funcs = {
@@ -120,6 +110,11 @@ static int simple_bridge_attach(struct drm_bridge *bridge, 
		return -EINVAL;

	}



	ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,

				DRM_BRIDGE_ATTACH_NO_CONNECTOR);

	if (ret < 0)

		return ret;



	if (!bridge->encoder) {

		DRM_ERROR("Missing encoder\n");

		return -ENODEV;
@@ -130,7 +125,7 @@ static int simple_bridge_attach(struct drm_bridge *bridge, 
	ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector,

					  &simple_bridge_con_funcs,

					  sbridge->info->connector_type,

					  sbridge->ddc);

					  sbridge->next_bridge->ddc);

	if (ret) {

		DRM_ERROR("Failed to initialize connector\n");

		return ret;
@@ -172,31 +167,10 @@ static const struct drm_bridge_funcs simple_bridge_bridge_funcs = { 
	.disable	= simple_bridge_disable,

};



static struct i2c_adapter *simple_bridge_retrieve_ddc(struct device *dev)

{

	struct device_node *phandle, *remote;

	struct i2c_adapter *ddc;



	remote = of_graph_get_remote_node(dev->of_node, 1, -1);

	if (!remote)

		return ERR_PTR(-EINVAL);



	phandle = of_parse_phandle(remote, "ddc-i2c-bus", 0);

	of_node_put(remote);

	if (!phandle)

		return ERR_PTR(-ENODEV);



	ddc = of_get_i2c_adapter_by_node(phandle);

	of_node_put(phandle);

	if (!ddc)

		return ERR_PTR(-EPROBE_DEFER);



	return ddc;

}



static int simple_bridge_probe(struct platform_device *pdev)

{

	struct simple_bridge *sbridge;

	struct device_node *remote;



	sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);

	if (!sbridge)
@@ -205,6 +179,20 @@ static int simple_bridge_probe(struct platform_device *pdev) 


	sbridge->info = of_device_get_match_data(&pdev->dev);



	/* Get the next bridge in the pipeline. */

	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);

	if (!remote)

		return -EINVAL;



	sbridge->next_bridge = of_drm_find_bridge(remote);

	of_node_put(remote);



	if (!sbridge->next_bridge) {

		dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");

		return -EPROBE_DEFER;

	}



	/* Get the regulator and GPIO resources. */

	sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");

	if (IS_ERR(sbridge->vdd)) {

		int ret = PTR_ERR(sbridge->vdd);
@@ -222,18 +210,7 @@ static int simple_bridge_probe(struct platform_device *pdev) 
		return PTR_ERR(sbridge->enable);

	}



	sbridge->ddc = simple_bridge_retrieve_ddc(&pdev->dev);

	if (IS_ERR(sbridge->ddc)) {

		if (PTR_ERR(sbridge->ddc) == -ENODEV) {

			dev_dbg(&pdev->dev,

				"No i2c bus specified. Disabling EDID readout\n");

			sbridge->ddc = NULL;

		} else {

			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");

			return PTR_ERR(sbridge->ddc);

		}

	}



	/* Register the bridge. */

	sbridge->bridge.funcs = &simple_bridge_bridge_funcs;

	sbridge->bridge.of_node = pdev->dev.of_node;

	sbridge->bridge.timings = sbridge->info->timings;
@@ -249,9 +226,6 @@ static int simple_bridge_remove(struct platform_device *pdev) 


	drm_bridge_remove(&sbridge->bridge);



	if (sbridge->ddc)

		i2c_put_adapter(sbridge->ddc);



	return 0;

}