Commit 29efdc29 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Thierry Reding
Browse files

drm/tegra: output: rgb: Support LVDS encoder bridge 



Newer Tegra device-trees will specify a video output graph, which involves
LVDS encoder bridge. This patch adds support for the LVDS encoder bridge
to the RGB output, allowing us to model the display hardware properly.

Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent f00b9dd5

drivers/gpu/drm/tegra/rgb.c

+49 −9
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/clk.h>



#include <drm/drm_atomic_helper.h>

#include <drm/drm_bridge_connector.h>

#include <drm/drm_panel.h>

#include <drm/drm_simple_kms_helper.h>
@@ -267,24 +268,63 @@ 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_simple_encoder_init(drm, &output->encoder, DRM_MODE_ENCODER_LVDS);

	drm_encoder_helper_add(&output->encoder,

			       &tegra_rgb_encoder_helper_funcs);



	/*

	 * 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 fall back to our own connector and use

	 * nvidia,panel phandle.

	 */

	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);

	} else {

		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);

	}



	err = tegra_output_init(drm, output);

	if (err < 0) {