From: Andri Yngvason <andri@yngvason.is>
Adds a new general DRM property named "color format" which can be used by
userspace to force the display driver output a particular color format.
Possible options are:
- auto (setup by default, driver internally picks the color format)
- rgb
- ycbcr444
- ycbcr422
- ycbcr420
Drivers should advertise from this list the formats which they support.
Together with this list and EDID data from the sink we should be able
to relay a list of usable color formats to users to pick from.
Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Signed-off-by: Andri Yngvason <andri@yngvason.is>
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
---
drivers/gpu/drm/drm_atomic_helper.c | 5 +
drivers/gpu/drm/drm_atomic_uapi.c | 4 +
drivers/gpu/drm/drm_connector.c | 180 ++++++++++++++++++++++++++++++++++++
include/drm/drm_connector.h | 54 ++++++++++-
4 files changed, 238 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index e641fcf8c568..25f354b2cc0d 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -736,6 +736,11 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
if (old_connector_state->max_requested_bpc !=
new_connector_state->max_requested_bpc)
new_crtc_state->connectors_changed = true;
+
+ if (old_connector_state->color_format !=
+ new_connector_state->color_format)
+ new_crtc_state->connectors_changed = true;
+
}
if (funcs->atomic_check)
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index b2cb5ae5a139..2f093b0d1628 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -784,6 +784,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
state->privacy_screen_sw_state = val;
} else if (property == connector->broadcast_rgb_property) {
state->hdmi.broadcast_rgb = val;
+ } else if (property == connector->color_format_property) {
+ state->color_format = drm_color_format_enum_to_color_format(val);
} else if (connector->funcs->atomic_set_property) {
return connector->funcs->atomic_set_property(connector,
state, property, val);
@@ -869,6 +871,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
*val = state->privacy_screen_sw_state;
} else if (property == connector->broadcast_rgb_property) {
*val = state->hdmi.broadcast_rgb;
+ } else if (property == connector->color_format_property) {
+ *val = drm_color_format_to_color_format_enum(state->color_format);
} else if (connector->funcs->atomic_get_property) {
return connector->funcs->atomic_get_property(connector,
state, property, val);
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 272d6254ea47..0ad7be0a2d09 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1348,6 +1348,55 @@ static const char * const colorspace_names[] = {
[DRM_MODE_COLORIMETRY_BT601_YCC] = "BT601_YCC",
};
+u32
+drm_color_format_to_color_format_enum(enum drm_color_format fmt)
+{
+ switch (fmt) {
+ default:
+ case DRM_COLOR_FORMAT_AUTO:
+ return DRM_MODE_COLOR_FORMAT_AUTO;
+ case DRM_COLOR_FORMAT_RGB444:
+ return DRM_MODE_COLOR_FORMAT_RGB444;
+ case DRM_COLOR_FORMAT_YCBCR444:
+ return DRM_MODE_COLOR_FORMAT_YCBCR444;
+ case DRM_COLOR_FORMAT_YCBCR422:
+ return DRM_MODE_COLOR_FORMAT_YCBCR422;
+ case DRM_COLOR_FORMAT_YCBCR420:
+ return DRM_MODE_COLOR_FORMAT_YCBCR420;
+ }
+}
+
+u32
+drm_color_format_enum_to_color_format(enum drm_color_format_enum fmt_enum)
+{
+ switch (fmt_enum) {
+ default:
+ case DRM_MODE_COLOR_FORMAT_RGB444:
+ return DRM_COLOR_FORMAT_RGB444;
+ case DRM_MODE_COLOR_FORMAT_AUTO:
+ return DRM_COLOR_FORMAT_AUTO;
+ case DRM_MODE_COLOR_FORMAT_YCBCR444:
+ return DRM_COLOR_FORMAT_YCBCR444;
+ case DRM_MODE_COLOR_FORMAT_YCBCR422:
+ return DRM_COLOR_FORMAT_YCBCR422;
+ case DRM_MODE_COLOR_FORMAT_YCBCR420:
+ return DRM_COLOR_FORMAT_YCBCR420;
+ }
+}
+
+/**
+ * drm_get_color_format_name - return a string for color format
+ * @colorspace: color format to compute name of
+ *
+ */
+const char *drm_get_color_format_name(enum drm_color_format color_fmt)
+{
+ u32 conv_color_fmt = drm_color_format_to_color_format_enum(color_fmt);
+
+ return drm_hdmi_connector_get_output_format_name(conv_color_fmt);
+}
+EXPORT_SYMBOL(drm_get_color_format_name);
+
/**
* drm_get_colorspace_name - return a string for color encoding
* @colorspace: color space to compute name of
@@ -1377,6 +1426,22 @@ static const u32 hdmi_colorspaces =
BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65) |
BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER);
+/* already bit-shifted */
+static const u32 hdmi_colorformats =
+ DRM_COLOR_FORMAT_AUTO |
+ DRM_COLOR_FORMAT_RGB444 |
+ DRM_COLOR_FORMAT_YCBCR444 |
+ DRM_COLOR_FORMAT_YCBCR422 |
+ DRM_COLOR_FORMAT_YCBCR420;
+
+/* already bit-shifted */
+static const u32 dp_colorformats =
+ DRM_COLOR_FORMAT_AUTO |
+ DRM_COLOR_FORMAT_RGB444 |
+ DRM_COLOR_FORMAT_YCBCR444 |
+ DRM_COLOR_FORMAT_YCBCR422 |
+ DRM_COLOR_FORMAT_YCBCR420;
+
/*
* As per DP 1.4a spec, 2.2.5.7.5 VSC SDP Payload for Pixel Encoding/Colorimetry
* Format Table 2-120
@@ -2628,6 +2693,101 @@ int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector,
}
EXPORT_SYMBOL(drm_mode_create_hdmi_colorspace_property);
+static int drm_mode_create_color_format_property(struct drm_connector *connector,
+ u32 supported_color_formats)
+{
+ struct drm_device *dev = connector->dev;
+ struct drm_prop_enum_list enum_list[DRM_MODE_COLOR_FORMAT_COUNT];
+ int i, len;
+
+ if (connector->color_format_property)
+ return 0;
+
+ if (!supported_color_formats) {
+ drm_err(dev, "No supported color formats provded on [CONNECTOR:%d:%s]\n",
+ connector->base.id, connector->name);
+ return -EINVAL;
+ }
+
+ if ((supported_color_formats & -BIT(DRM_MODE_COLOR_FORMAT_COUNT)) != 0) {
+ drm_err(dev, "Unknown colorspace provded on [CONNECTOR:%d:%s]\n",
+ connector->base.id, connector->name);
+ return -EINVAL;
+ }
+
+ len = 0;
+ for (i = 0; i < DRM_MODE_COLOR_FORMAT_COUNT; i++) {
+ if (!(supported_color_formats & BIT(i)))
+ continue;
+
+ enum_list[len].type = i;
+ if (i != DRM_MODE_COLOR_FORMAT_AUTO)
+ enum_list[len].name = output_format_str[i];
+ else
+ enum_list[len].name = "AUTO";
+ len++;
+ }
+
+ connector->color_format_property =
+ drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, "color format",
+ enum_list, len);
+
+ if (!connector->color_format_property)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/**
+ * drm_mode_create_hdmi_color_format_property - create hdmi color format property
+ * @connector: connector to create the color format property on.
+ * @supported_color_formats: bitmap of supported color formats
+ *
+ * Called by a driver the first time it's needed, must be attached to desired
+ * HDMI connectors.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_mode_create_hdmi_color_format_property(struct drm_connector *connector,
+ u32 supported_color_formats)
+{
+ u32 color_formats;
+
+ if (supported_color_formats)
+ color_formats = supported_color_formats & hdmi_colorformats;
+ else
+ color_formats = hdmi_colorformats;
+
+ return drm_mode_create_color_format_property(connector, color_formats);
+}
+EXPORT_SYMBOL(drm_mode_create_hdmi_color_format_property);
+
+/**
+ * drm_mode_create_dp_color_format_property - create dp color format property
+ * @connector: connector to create the Colorspace property on.
+ * @supported_color_formats: bitmap of supported color formats
+ *
+ * Called by a driver the first time it's needed, must be attached to desired
+ * DP connectors.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_mode_create_dp_color_format_property(struct drm_connector *connector,
+ u32 supported_color_formats)
+{
+ u32 color_formats;
+
+ if (supported_color_formats)
+ color_formats = supported_color_formats & dp_colorformats;
+ else
+ color_formats = dp_colorformats;
+
+ return drm_mode_create_color_format_property(connector, color_formats);
+}
+EXPORT_SYMBOL(drm_mode_create_dp_color_format_property);
+
/**
* drm_mode_create_dp_colorspace_property - create dp colorspace property
* @connector: connector to create the Colorspace property on.
@@ -2845,6 +3005,26 @@ int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
}
EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
+/**
+ * drm_connector_attach_color_format_property - attach "force color format" property
+ * @connector: connector to attach force color format property on.
+ *
+ * This is used to add support for selecting a color format on a connector.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_color_format_property(struct drm_connector *connector)
+{
+ struct drm_property *prop = connector->color_format_property;
+
+ drm_object_attach_property(&connector->base, prop, DRM_COLOR_FORMAT_AUTO);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_color_format_property);
+
+
/**
* drm_connector_attach_hdr_output_metadata_property - attach "HDR_OUTPUT_METADA" property
* @connector: connector to attach the property on.
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 8f34f4b8183d..a071079fd3ad 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -556,6 +556,26 @@ enum drm_colorspace {
DRM_MODE_COLORIMETRY_COUNT
};
+enum drm_color_format_enum {
+ DRM_MODE_COLOR_FORMAT_RGB444 = HDMI_COLORSPACE_RGB,
+ DRM_MODE_COLOR_FORMAT_YCBCR422 = HDMI_COLORSPACE_YUV422,
+ DRM_MODE_COLOR_FORMAT_YCBCR444 = HDMI_COLORSPACE_YUV444,
+ DRM_MODE_COLOR_FORMAT_YCBCR420 = HDMI_COLORSPACE_YUV420,
+ /* auto case, driver will set the color_format */
+ DRM_MODE_COLOR_FORMAT_AUTO,
+ DRM_MODE_COLOR_FORMAT_COUNT
+};
+
+enum drm_color_format {
+ DRM_COLOR_FORMAT_NONE = 0,
+ DRM_COLOR_FORMAT_RGB444 = (1 << 0),
+ DRM_COLOR_FORMAT_YCBCR422 = (1 << 1),
+ DRM_COLOR_FORMAT_YCBCR444 = (1 << 2),
+ DRM_COLOR_FORMAT_YCBCR420 = (1 << 3),
+ /* auto case, driver will set the color_format */
+ DRM_COLOR_FORMAT_AUTO = (1 << 4),
+};
+
/**
* enum drm_bus_flags - bus_flags info for &drm_display_info
*
@@ -699,11 +719,6 @@ struct drm_display_info {
*/
enum subpixel_order subpixel_order;
-#define DRM_COLOR_FORMAT_RGB444 (1<<0)
-#define DRM_COLOR_FORMAT_YCBCR444 (1<<1)
-#define DRM_COLOR_FORMAT_YCBCR422 (1<<2)
-#define DRM_COLOR_FORMAT_YCBCR420 (1<<3)
-
/**
* @panel_orientation: Read only connector property for built-in panels,
* indicating the orientation of the panel vs the device's casing.
@@ -1107,6 +1122,13 @@ struct drm_connector_state {
*/
enum drm_colorspace colorspace;
+ /**
+ * @color_format: State variable for Connector property to request
+ * color format change on Sink. This is most commonly used to switch
+ * between RGB to YUV and vice-versa.
+ */
+ enum drm_color_format color_format;
+
/**
* @writeback_job: Writeback job for writeback connectors
*
@@ -2060,6 +2082,12 @@ struct drm_connector {
*/
struct drm_property *colorspace_property;
+ /**
+ * @color_format_property: Connector property to set the suitable
+ * color format supported by the sink.
+ */
+ struct drm_property *color_format_property;
+
/**
* @path_blob_ptr:
*
@@ -2461,6 +2489,12 @@ int drm_mode_create_dp_colorspace_property(struct drm_connector *connector,
int drm_mode_create_content_type_property(struct drm_device *dev);
int drm_mode_create_suggested_offset_properties(struct drm_device *dev);
+int drm_mode_create_hdmi_color_format_property(struct drm_connector *connector,
+ u32 supported_color_formats);
+
+int drm_mode_create_dp_color_format_property(struct drm_connector *connector,
+ u32 supported_color_formats);
+
int drm_connector_set_path_property(struct drm_connector *connector,
const char *path);
int drm_connector_set_tile_property(struct drm_connector *connector);
@@ -2542,6 +2576,16 @@ bool drm_connector_has_possible_encoder(struct drm_connector *connector,
struct drm_encoder *encoder);
const char *drm_get_colorspace_name(enum drm_colorspace colorspace);
+int drm_connector_attach_color_format_property(struct drm_connector *connector);
+
+const char *drm_get_color_format_name(enum drm_color_format color_fmt);
+
+u32
+drm_color_format_to_color_format_enum(enum drm_color_format fmt);
+
+u32
+drm_color_format_enum_to_color_format(enum drm_color_format_enum fmt_enum);
+
/**
* drm_for_each_connector_iter - connector_list iterator macro
* @connector: &struct drm_connector pointer used as cursor
--
2.51.2On Mon, Nov 17, 2025 at 08:11:46PM +0100, Nicolas Frattaroli wrote:
> From: Andri Yngvason <andri@yngvason.is>
>
> Adds a new general DRM property named "color format" which can be used by
s/Adds/Add/
> userspace to force the display driver output a particular color format.
>
> Possible options are:
> - auto (setup by default, driver internally picks the color format)
> - rgb
> - ycbcr444
> - ycbcr422
> - ycbcr420
>
> Drivers should advertise from this list the formats which they support.
> Together with this list and EDID data from the sink we should be able
> to relay a list of usable color formats to users to pick from.
>
> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
> Signed-off-by: Andri Yngvason <andri@yngvason.is>
> Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 5 +
> drivers/gpu/drm/drm_atomic_uapi.c | 4 +
> drivers/gpu/drm/drm_connector.c | 180 ++++++++++++++++++++++++++++++++++++
> include/drm/drm_connector.h | 54 ++++++++++-
> 4 files changed, 238 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index e641fcf8c568..25f354b2cc0d 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -736,6 +736,11 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
> if (old_connector_state->max_requested_bpc !=
> new_connector_state->max_requested_bpc)
> new_crtc_state->connectors_changed = true;
> +
> + if (old_connector_state->color_format !=
> + new_connector_state->color_format)
> + new_crtc_state->connectors_changed = true;
> +
> }
>
> if (funcs->atomic_check)
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index b2cb5ae5a139..2f093b0d1628 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -784,6 +784,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
> state->privacy_screen_sw_state = val;
> } else if (property == connector->broadcast_rgb_property) {
> state->hdmi.broadcast_rgb = val;
> + } else if (property == connector->color_format_property) {
> + state->color_format = drm_color_format_enum_to_color_format(val);
> } else if (connector->funcs->atomic_set_property) {
> return connector->funcs->atomic_set_property(connector,
> state, property, val);
> @@ -869,6 +871,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
> *val = state->privacy_screen_sw_state;
> } else if (property == connector->broadcast_rgb_property) {
> *val = state->hdmi.broadcast_rgb;
> + } else if (property == connector->color_format_property) {
> + *val = drm_color_format_to_color_format_enum(state->color_format);
> } else if (connector->funcs->atomic_get_property) {
> return connector->funcs->atomic_get_property(connector,
> state, property, val);
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 272d6254ea47..0ad7be0a2d09 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -1348,6 +1348,55 @@ static const char * const colorspace_names[] = {
> [DRM_MODE_COLORIMETRY_BT601_YCC] = "BT601_YCC",
> };
>
> +u32
> +drm_color_format_to_color_format_enum(enum drm_color_format fmt)
> +{
> + switch (fmt) {
> + default:
> + case DRM_COLOR_FORMAT_AUTO:
> + return DRM_MODE_COLOR_FORMAT_AUTO;
> + case DRM_COLOR_FORMAT_RGB444:
> + return DRM_MODE_COLOR_FORMAT_RGB444;
> + case DRM_COLOR_FORMAT_YCBCR444:
> + return DRM_MODE_COLOR_FORMAT_YCBCR444;
> + case DRM_COLOR_FORMAT_YCBCR422:
> + return DRM_MODE_COLOR_FORMAT_YCBCR422;
> + case DRM_COLOR_FORMAT_YCBCR420:
> + return DRM_MODE_COLOR_FORMAT_YCBCR420;
> + }
> +}
> +
> +u32
> +drm_color_format_enum_to_color_format(enum drm_color_format_enum fmt_enum)
> +{
> + switch (fmt_enum) {
> + default:
> + case DRM_MODE_COLOR_FORMAT_RGB444:
> + return DRM_COLOR_FORMAT_RGB444;
> + case DRM_MODE_COLOR_FORMAT_AUTO:
> + return DRM_COLOR_FORMAT_AUTO;
> + case DRM_MODE_COLOR_FORMAT_YCBCR444:
> + return DRM_COLOR_FORMAT_YCBCR444;
> + case DRM_MODE_COLOR_FORMAT_YCBCR422:
> + return DRM_COLOR_FORMAT_YCBCR422;
> + case DRM_MODE_COLOR_FORMAT_YCBCR420:
> + return DRM_COLOR_FORMAT_YCBCR420;
> + }
It seems this could be simplified to
return BIT(fmt_enum);
The above function could also be simplified by using ffs().
> +}
> +
> +/**
> + * drm_get_color_format_name - return a string for color format
> + * @colorspace: color format to compute name of
s/colorspace/color_fmt/
Please make sure to compile the documentation and check for warnings in
the next iteration.
> + *
> + */
> +const char *drm_get_color_format_name(enum drm_color_format color_fmt)
> +{
> + u32 conv_color_fmt = drm_color_format_to_color_format_enum(color_fmt);
> +
> + return drm_hdmi_connector_get_output_format_name(conv_color_fmt);
> +}
> +EXPORT_SYMBOL(drm_get_color_format_name);
Could we flip that and make drm_hdmi_connector_get_output_format_name()
a wrapper around drm_get_color_format_name() ?
> +
> /**
> * drm_get_colorspace_name - return a string for color encoding
> * @colorspace: color space to compute name of
> @@ -1377,6 +1426,22 @@ static const u32 hdmi_colorspaces =
> BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65) |
> BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER);
>
> +/* already bit-shifted */
> +static const u32 hdmi_colorformats =
> + DRM_COLOR_FORMAT_AUTO |
> + DRM_COLOR_FORMAT_RGB444 |
> + DRM_COLOR_FORMAT_YCBCR444 |
> + DRM_COLOR_FORMAT_YCBCR422 |
> + DRM_COLOR_FORMAT_YCBCR420;
> +
> +/* already bit-shifted */
> +static const u32 dp_colorformats =
> + DRM_COLOR_FORMAT_AUTO |
> + DRM_COLOR_FORMAT_RGB444 |
> + DRM_COLOR_FORMAT_YCBCR444 |
> + DRM_COLOR_FORMAT_YCBCR422 |
> + DRM_COLOR_FORMAT_YCBCR420;
> +
> /*
> * As per DP 1.4a spec, 2.2.5.7.5 VSC SDP Payload for Pixel Encoding/Colorimetry
> * Format Table 2-120
> @@ -2628,6 +2693,101 @@ int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector,
> }
> EXPORT_SYMBOL(drm_mode_create_hdmi_colorspace_property);
>
> +static int drm_mode_create_color_format_property(struct drm_connector *connector,
> + u32 supported_color_formats)
> +{
> + struct drm_device *dev = connector->dev;
> + struct drm_prop_enum_list enum_list[DRM_MODE_COLOR_FORMAT_COUNT];
> + int i, len;
Neither can be negative, you can use unsigned int.
> +
> + if (connector->color_format_property)
> + return 0;
> +
> + if (!supported_color_formats) {
> + drm_err(dev, "No supported color formats provded on [CONNECTOR:%d:%s]\n",
s/provded/provided/
> + connector->base.id, connector->name);
Incorrect alignment.
> + return -EINVAL;
> + }
> +
> + if ((supported_color_formats & -BIT(DRM_MODE_COLOR_FORMAT_COUNT)) != 0) {
GENMASK(DRM_MODE_COLOR_FORMAT_COUNT - 1, 0)
would be clearer than
-BIT(DRM_MODE_COLOR_FORMAT_COUNT)
> + drm_err(dev, "Unknown colorspace provded on [CONNECTOR:%d:%s]\n",
s/colorspace/color format/
s/provded/provided/
> + connector->base.id, connector->name);
> + return -EINVAL;
> + }
> +
> + len = 0;
> + for (i = 0; i < DRM_MODE_COLOR_FORMAT_COUNT; i++) {
> + if (!(supported_color_formats & BIT(i)))
> + continue;
> +
> + enum_list[len].type = i;
> + if (i != DRM_MODE_COLOR_FORMAT_AUTO)
> + enum_list[len].name = output_format_str[i];
> + else
> + enum_list[len].name = "AUTO";
> + len++;
> + }
> +
> + connector->color_format_property =
> + drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, "color format",
> + enum_list, len);
> +
> + if (!connector->color_format_property)
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +/**
> + * drm_mode_create_hdmi_color_format_property - create hdmi color format property
> + * @connector: connector to create the color format property on.
> + * @supported_color_formats: bitmap of supported color formats
You don't document that supported_color_formats can be 0. I think I'd
actually drop that possibility, it's not used by drivers in this series,
and it seems to be error-prone. If a later version of HDMI or DP adds
support for more color formats, those would get automatically advertised
while not supported by drivers.
> + *
> + * Called by a driver the first time it's needed, must be attached to desired
> + * HDMI connectors.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_mode_create_hdmi_color_format_property(struct drm_connector *connector,
> + u32 supported_color_formats)
> +{
> + u32 color_formats;
> +
> + if (supported_color_formats)
> + color_formats = supported_color_formats & hdmi_colorformats;
> + else
> + color_formats = hdmi_colorformats;
> +
> + return drm_mode_create_color_format_property(connector, color_formats);
> +}
> +EXPORT_SYMBOL(drm_mode_create_hdmi_color_format_property);
I think we could simplify the API here by picking the defaults based on
the connector type:
int drm_mode_create_color_format_property(struct drm_connector *connector,
u32 supported_color_formats)
{
struct drm_device *dev = connector->dev;
struct drm_prop_enum_list enum_list[DRM_MODE_COLOR_FORMAT_COUNT];
unsigned int i, len;
if (connector->color_format_property)
return 0;
switch (connector->type) {
case DRM_MODE_CONNECTOR_HDMIA:
case DRM_MODE_CONNECTOR_HDMIB:
supported_color_formats &= hdmi_colorformats;
break;
case DRM_MODE_CONNECTOR_DisplayPort:
case DRM_MODE_CONNECTOR_eDP:
supported_color_formats &= dp_colorformats;
break;
default:
drm_err(dev, ...);
return -EINVAL;
}
if (!supported_color_formats) {
drm_err(dev, "No supported color formats provided on [CONNECTOR:%d:%s]\n",
connector->base.id, connector->name);
return -EINVAL;
}
...
}
> +
> +/**
> + * drm_mode_create_dp_color_format_property - create dp color format property
> + * @connector: connector to create the Colorspace property on.
> + * @supported_color_formats: bitmap of supported color formats
> + *
> + * Called by a driver the first time it's needed, must be attached to desired
> + * DP connectors.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_mode_create_dp_color_format_property(struct drm_connector *connector,
> + u32 supported_color_formats)
> +{
> + u32 color_formats;
> +
> + if (supported_color_formats)
> + color_formats = supported_color_formats & dp_colorformats;
> + else
> + color_formats = dp_colorformats;
> +
> + return drm_mode_create_color_format_property(connector, color_formats);
> +}
> +EXPORT_SYMBOL(drm_mode_create_dp_color_format_property);
> +
> /**
> * drm_mode_create_dp_colorspace_property - create dp colorspace property
> * @connector: connector to create the Colorspace property on.
> @@ -2845,6 +3005,26 @@ int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
> }
> EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
>
> +/**
> + * drm_connector_attach_color_format_property - attach "force color format" property
> + * @connector: connector to attach force color format property on.
> + *
> + * This is used to add support for selecting a color format on a connector.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_connector_attach_color_format_property(struct drm_connector *connector)
> +{
> + struct drm_property *prop = connector->color_format_property;
> +
> + drm_object_attach_property(&connector->base, prop, DRM_COLOR_FORMAT_AUTO);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_connector_attach_color_format_property);
> +
> +
> /**
> * drm_connector_attach_hdr_output_metadata_property - attach "HDR_OUTPUT_METADA" property
> * @connector: connector to attach the property on.
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 8f34f4b8183d..a071079fd3ad 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -556,6 +556,26 @@ enum drm_colorspace {
> DRM_MODE_COLORIMETRY_COUNT
> };
>
> +enum drm_color_format_enum {
Please document this.
> + DRM_MODE_COLOR_FORMAT_RGB444 = HDMI_COLORSPACE_RGB,
> + DRM_MODE_COLOR_FORMAT_YCBCR422 = HDMI_COLORSPACE_YUV422,
> + DRM_MODE_COLOR_FORMAT_YCBCR444 = HDMI_COLORSPACE_YUV444,
> + DRM_MODE_COLOR_FORMAT_YCBCR420 = HDMI_COLORSPACE_YUV420,
> + /* auto case, driver will set the color_format */
> + DRM_MODE_COLOR_FORMAT_AUTO,
> + DRM_MODE_COLOR_FORMAT_COUNT
> +};
> +
> +enum drm_color_format {
> + DRM_COLOR_FORMAT_NONE = 0,
> + DRM_COLOR_FORMAT_RGB444 = (1 << 0),
> + DRM_COLOR_FORMAT_YCBCR422 = (1 << 1),
> + DRM_COLOR_FORMAT_YCBCR444 = (1 << 2),
> + DRM_COLOR_FORMAT_YCBCR420 = (1 << 3),
> + /* auto case, driver will set the color_format */
> + DRM_COLOR_FORMAT_AUTO = (1 << 4),
> +};
It would be nicer to have a single enum, and use
BIT(DRM_MODE_COLOR_FORMAT_*) wherever a mask is used.
> +
> /**
> * enum drm_bus_flags - bus_flags info for &drm_display_info
> *
> @@ -699,11 +719,6 @@ struct drm_display_info {
> */
> enum subpixel_order subpixel_order;
>
> -#define DRM_COLOR_FORMAT_RGB444 (1<<0)
> -#define DRM_COLOR_FORMAT_YCBCR444 (1<<1)
> -#define DRM_COLOR_FORMAT_YCBCR422 (1<<2)
> -#define DRM_COLOR_FORMAT_YCBCR420 (1<<3)
> -
> /**
> * @panel_orientation: Read only connector property for built-in panels,
> * indicating the orientation of the panel vs the device's casing.
> @@ -1107,6 +1122,13 @@ struct drm_connector_state {
> */
> enum drm_colorspace colorspace;
>
> + /**
> + * @color_format: State variable for Connector property to request
> + * color format change on Sink. This is most commonly used to switch
> + * between RGB to YUV and vice-versa.
> + */
> + enum drm_color_format color_format;
> +
> /**
> * @writeback_job: Writeback job for writeback connectors
> *
> @@ -2060,6 +2082,12 @@ struct drm_connector {
> */
> struct drm_property *colorspace_property;
>
> + /**
> + * @color_format_property: Connector property to set the suitable
> + * color format supported by the sink.
> + */
> + struct drm_property *color_format_property;
> +
> /**
> * @path_blob_ptr:
> *
> @@ -2461,6 +2489,12 @@ int drm_mode_create_dp_colorspace_property(struct drm_connector *connector,
> int drm_mode_create_content_type_property(struct drm_device *dev);
> int drm_mode_create_suggested_offset_properties(struct drm_device *dev);
>
> +int drm_mode_create_hdmi_color_format_property(struct drm_connector *connector,
> + u32 supported_color_formats);
> +
> +int drm_mode_create_dp_color_format_property(struct drm_connector *connector,
> + u32 supported_color_formats);
> +
> int drm_connector_set_path_property(struct drm_connector *connector,
> const char *path);
> int drm_connector_set_tile_property(struct drm_connector *connector);
> @@ -2542,6 +2576,16 @@ bool drm_connector_has_possible_encoder(struct drm_connector *connector,
> struct drm_encoder *encoder);
> const char *drm_get_colorspace_name(enum drm_colorspace colorspace);
>
> +int drm_connector_attach_color_format_property(struct drm_connector *connector);
> +
> +const char *drm_get_color_format_name(enum drm_color_format color_fmt);
> +
> +u32
> +drm_color_format_to_color_format_enum(enum drm_color_format fmt);
This holds on a single line.
> +
> +u32
> +drm_color_format_enum_to_color_format(enum drm_color_format_enum fmt_enum);
I'd avoid the line break here too.
> +
> /**
> * drm_for_each_connector_iter - connector_list iterator macro
> * @connector: &struct drm_connector pointer used as cursor
--
Regards,
Laurent Pinchart
Hi Nicolas, kernel test robot noticed the following build warnings: [auto build test WARNING on d1d18879e01e4c9efcb85a96d188a8e4326136dd] url: https://github.com/intel-lab-lkp/linux/commits/Nicolas-Frattaroli/drm-amd-display-Remove-unnecessary-SIGNAL_TYPE_HDMI_TYPE_A-check/20251118-031440 base: d1d18879e01e4c9efcb85a96d188a8e4326136dd patch link: https://lore.kernel.org/r/20251117-color-format-v4-2-0ded72bd1b00%40collabora.com patch subject: [PATCH v4 02/10] drm: Add new general DRM property "color format" config: arm-randconfig-001-20251118 (https://download.01.org/0day-ci/archive/20251118/202511181958.eS8Ctiow-lkp@intel.com/config) compiler: arm-linux-gnueabi-gcc (GCC) 8.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251118/202511181958.eS8Ctiow-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202511181958.eS8Ctiow-lkp@intel.com/ All warnings (new ones prefixed by >>): >> Warning: drivers/gpu/drm/drm_connector.c:1392 function parameter 'color_fmt' not described in 'drm_get_color_format_name' >> Warning: drivers/gpu/drm/drm_connector.c:1392 function parameter 'color_fmt' not described in 'drm_get_color_format_name' -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
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