Newer Tegra device-trees will specify a video output graph that involves LVDS encoder bridge, This patch adds support for the LVDS encoder bridge to the RGB output, allowing us to model display hardware properly.
Signed-off-by: Dmitry Osipenko <[email protected]> --- drivers/gpu/drm/tegra/drm.h | 2 ++ drivers/gpu/drm/tegra/output.c | 10 ++++++++++ drivers/gpu/drm/tegra/rgb.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+) diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h index 804869799305..cccd368b6752 100644 --- a/drivers/gpu/drm/tegra/drm.h +++ b/drivers/gpu/drm/tegra/drm.h @@ -12,6 +12,7 @@ #include <linux/of_gpio.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; diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c index a6a711d54e88..37fc6b8c173f 100644 --- a/drivers/gpu/drm/tegra/output.c +++ b/drivers/gpu/drm/tegra/output.c @@ -180,6 +180,16 @@ int tegra_output_init(struct drm_device *drm, struct tegra_output *output) int connector_type; int err; + if (output->bridge) { + err = drm_bridge_attach(&output->encoder, output->bridge, + NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); + if (err) { + dev_err(output->dev, "cannot connect bridge: %d\n", + err); + return err; + } + } + if (output->panel) { err = drm_panel_attach(output->panel, &output->connector); if (err < 0) diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c index 0562a7eb793f..0df213e92664 100644 --- a/drivers/gpu/drm/tegra/rgb.c +++ b/drivers/gpu/drm/tegra/rgb.c @@ -5,6 +5,7 @@ */ #include <linux/clk.h> +#include <linux/of_graph.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_panel.h> @@ -210,6 +211,7 @@ static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = { int tegra_dc_rgb_probe(struct tegra_dc *dc) { + const unsigned int encoder_port = 0, panel_port = 1; struct device_node *np; struct tegra_rgb *rgb; int err; @@ -226,6 +228,38 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc) rgb->output.of_node = np; rgb->dc = dc; + /* + * Tegra devices that have LVDS panel utilize LVDS-encoder bridge + * for converting 24/18 RGB data-lanes into 8 lanes. Encoder usually + * have a powerdown control which needs to be enabled in order to + * transfer 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 may utilize output->encoder->panel graph. + * + * For older device-trees we fall back to use nvidia,panel phandle. + */ + np = of_graph_get_remote_node(rgb->output.of_node, encoder_port, -1); + if (np) { + rgb->output.bridge = of_drm_find_bridge(np); + of_node_put(np); + + if (!rgb->output.bridge) + return -EPROBE_DEFER; + + np = of_graph_get_remote_node(rgb->output.bridge->of_node, + panel_port, -1); + if (np) { + rgb->output.panel = of_drm_find_panel(np); + of_node_put(np); + + if (IS_ERR(rgb->output.panel)) + return PTR_ERR(rgb->output.panel); + } + } + err = tegra_output_probe(&rgb->output); if (err < 0) return err; -- 2.26.0 _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
