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: Laurent Pinchart laurent.pinchart@ideasonboard.com Acked-by: Sam Ravnborg sam@ravnborg.org Signed-off-by: Dmitry Osipenko digetx@gmail.com --- drivers/gpu/drm/tegra/rgb.c | 58 +++++++++++++++++++++++++++++++------ 1 file changed, 49 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c index 0562a7eb793f..9a7024ec96bc 100644 --- a/drivers/gpu/drm/tegra/rgb.c +++ b/drivers/gpu/drm/tegra/rgb.c @@ -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_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); + /* + * 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_connector_attach_encoder(&output->connector, + &output->encoder); + drm_connector_register(&output->connector); + }
err = tegra_output_init(drm, output); if (err < 0) {