[Intel-gfx] [PATCH 06/11] drm: create hdmi output property

Shashank Sharma shashank.sharma at intel.com
Fri Apr 7 16:39:23 UTC 2017


HDMI displays can support various output types, based on
the color space and subsampling type. The possible
outputs from a HDMI 2.0 monitor could be:
 - RGB
 - YCBCR 444
 - YCBCR 422
 - YCBCR 420

This patch adds a drm property, using which, a userspace
can specify its preference, for the HDMI output type.
The output type enums are similar to the mentioned outputs
above. To handle various subsampling of YCBCR output types,
this property allows two special cases:
 - DRM_HDMI_OUTPUT_YCBCR_HQ
This indicates preferred output should be YCBCR output, with highest
subsampling rate by the source/sink, which can be typically:
 - ycbcr444
 - ycbcr422
 - ycbcr420
 - DRM_HDMI_OUTPUT_YCBCR_LQ
This indicates preferred output should be YCBCR output, with lowest
subsampling rate supported by source/sink, which can be:
 - ycbcr420
 - ycbcr422
 - ycbcr444

Default value of the property is set to 0 = RGB, so no changes if you
dont set the property.

Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Cc: Jose Abreu <joabreu at synopsys.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/drm_atomic.c        |  2 ++
 drivers/gpu/drm/drm_atomic_helper.c |  4 ++++
 drivers/gpu/drm/drm_connector.c     | 31 +++++++++++++++++++++++++++++++
 include/drm/drm_connector.h         | 14 ++++++++++++++
 include/drm/drm_mode_config.h       |  5 +++++
 5 files changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index f32506a..6ef34dc 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1123,6 +1123,8 @@ int drm_atomic_connector_set_property(struct drm_connector *connector,
 		 */
 		if (state->link_status != DRM_LINK_STATUS_GOOD)
 			state->link_status = val;
+	} else if (property == config->hdmi_output_property) {
+		state->hdmi_output = val;
 	} else if (connector->funcs->atomic_set_property) {
 		return connector->funcs->atomic_set_property(connector,
 				state, property, val);
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 8be9719..fcba3c0 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -567,6 +567,10 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 			if (old_connector_state->link_status !=
 			    new_connector_state->link_status)
 				new_crtc_state->connectors_changed = true;
+
+			if (old_connector_state->hdmi_output !=
+			    new_connector_state->hdmi_output)
+				new_crtc_state->connectors_changed = true;
 		}
 
 		if (funcs->atomic_check)
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 9f84761..10201b1 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -227,6 +227,11 @@ int drm_connector_init(struct drm_device *dev,
 					      config->edid_property,
 					      0);
 
+	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)
+		drm_object_attach_property(&connector->base,
+					   config->hdmi_output_property,
+					   0);
+
 	drm_object_attach_property(&connector->base,
 				      config->dpms_property, 0);
 
@@ -617,6 +622,25 @@ static const struct drm_prop_enum_list drm_link_status_enum_list[] = {
 };
 DRM_ENUM_NAME_FN(drm_get_link_status_name, drm_link_status_enum_list)
 
+static const struct drm_prop_enum_list drm_hdmi_output_enum_list[] = {
+	{ DRM_HDMI_OUTPUT_DEFAULT_RGB, "output_rgb" },
+	{ DRM_HDMI_OUTPUT_YCBCR422, "output_ycbcr422" },
+	{ DRM_HDMI_OUTPUT_YCBCR444, "output_ycbcr444" },
+	{ DRM_HDMI_OUTPUT_YCBCR420, "output_ycbcr420" },
+	{ DRM_HDMI_OUTPUT_YCBCR_HQ, "output_ycbcr_high_subsampling" },
+	{ DRM_HDMI_OUTPUT_YCBCR_LQ, "output_ycbcr_low_subsampling" },
+};
+
+/**
+ * drm_get_hdmi_output_name - return a string for a given hdmi output enum
+ * @type: enum of output type
+ */
+const char *drm_get_hdmi_output_name(enum drm_hdmi_output_type type)
+{
+	return drm_hdmi_output_enum_list[type].name;
+}
+EXPORT_SYMBOL(drm_get_hdmi_output_name);
+
 /**
  * drm_display_info_set_bus_formats - set the supported bus formats
  * @info: display info to store bus formats in
@@ -789,6 +813,13 @@ int drm_connector_create_standard_properties(struct drm_device *dev)
 		return -ENOMEM;
 	dev->mode_config.link_status_property = prop;
 
+	prop = drm_property_create_enum(dev, 0, "hdmi_output_format",
+					drm_hdmi_output_enum_list,
+					ARRAY_SIZE(drm_hdmi_output_enum_list));
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.hdmi_output_property = prop;
+
 	return 0;
 }
 
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 4545c6e..e872a88 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -300,6 +300,17 @@ struct drm_tv_connector_state {
 	unsigned int hue;
 };
 
+/* HDMI output pixel format */
+enum drm_hdmi_output_type {
+	DRM_HDMI_OUTPUT_DEFAULT_RGB, /* default RGB */
+	DRM_HDMI_OUTPUT_YCBCR422, /* YCBCR 422 */
+	DRM_HDMI_OUTPUT_YCBCR444, /* YCBCR 444 */
+	DRM_HDMI_OUTPUT_YCBCR420, /* YCBCR 420 */
+	DRM_HDMI_OUTPUT_YCBCR_HQ, /* Highest subsampled YUV */
+	DRM_HDMI_OUTPUT_YCBCR_LQ, /* Lowest subsampled YUV */
+	DRM_HDMI_OUTPUT_INVALID, /* Guess what ? */
+};
+
 /**
  * struct drm_connector_state - mutable connector state
  * @connector: backpointer to the connector
@@ -329,6 +340,8 @@ struct drm_connector_state {
 	struct drm_atomic_state *state;
 
 	struct drm_tv_connector_state tv;
+
+	enum drm_hdmi_output_type hdmi_output;
 };
 
 /**
@@ -945,6 +958,7 @@ static inline void drm_connector_unreference(struct drm_connector *connector)
 
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
+const char *drm_get_hdmi_output_name(enum drm_hdmi_output_type type);
 const char *drm_get_dpms_name(int val);
 const char *drm_get_dvi_i_subconnector_name(int val);
 const char *drm_get_dvi_i_select_name(int val);
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 4298171..1887261 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -740,6 +740,11 @@ struct drm_mode_config {
 	 * the position of the output on the host's screen.
 	 */
 	struct drm_property *suggested_y_property;
+	/**
+	 * @hdmi_output_property: output pixel format from HDMI display
+	 * Default is set for RGB
+	 */
+	struct drm_property *hdmi_output_property;
 
 	/* dumb ioctl parameters */
 	uint32_t preferred_depth, prefer_shadow;
-- 
2.7.4



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