[v2, 1/8] drm: Add optional COLOR_ENCODING and COLOR_RANGE properties to drm_plane

Ville Syrjälä ville.syrjala at linux.intel.com
Fri Nov 30 14:29:16 UTC 2018


On Fri, Nov 30, 2018 at 03:20:59PM +0100, Andrzej Hajda wrote:
> Hi Ville,
> 
> As Christoph cannot respond till middle next week I can try to respond
> in his absence, as I am familiar with the subject.
> 
> On 30.11.2018 14:25, Ville Syrjälä wrote:
> > On Fri, Nov 30, 2018 at 02:08:11PM +0100, Christoph Manszewski wrote:
> >> Hi,
> >>
> >> I am looking for a way to export the color encoding and range selection
> >> to user space. I came across those properties and am wondering, why
> >> they are meant only for non RGB color encodings. Would it be okay, to
> >> modify them and use with RGB formats as well?
> > What you trying to do? Input limited range RGB data and expand to full
> > range?
> 
> 
> For example. But there are two more general questions, which
> surprisingly we have not found answer for.
> 
> 1. What color encoding and range drm should expect on its input RGB
> buffers by default?

RGB is just RGB. There is no encoding. It's assumed to be full range
because no one really uses anything else.

> 
> 2. How userspace should inform drm that given buffer has specified
> non-default color encoding and range?
> 
> 
> Hopefully this patch introduces such properties but only for YCbCr
> formats, the question is what should be the best way to expand it to RGB
> formats:
> 
> A. Add another enums: DRM_COLOR_RGB_BT601 and friends.

BT.601 specifies how to encoder RGB data as YCbCr. So without
YCbCr BT.601 does not mean anything. Well, the standard does
contain other things as well I suppose, but for the purposes
of the color encoding prop only that one part is relevant.

> 
> B. Reuse current enums, but remove format information from them:
> DRM_COLOR_YCBCR_BT601 => DRM_COLOR_BT601.
> 
> 
> Regards
> 
> Andrzej
> 
> >
> >> Regards,
> >> Chris
> >>
> >>
> >> On 02/19/2018 09:28 PM, Ville Syrjala wrote:
> >>> From: Jyri Sarha <jsarha at ti.com>
> >>>
> >>> Add a standard optional properties to support different non RGB color
> >>> encodings in DRM planes. COLOR_ENCODING select the supported non RGB
> >>> color encoding, for instance ITU-R BT.709 YCbCr. COLOR_RANGE selects
> >>> the value ranges within the selected color encoding. The properties
> >>> are stored to drm_plane object to allow different set of supported
> >>> encoding for different planes on the device.
> >>>
> >>> v2: Add/fix kerneldocs, verify bitmasks (danvet)
> >>>
> >>> Cc: Harry Wentland <harry.wentland at amd.com>
> >>> Cc: Daniel Vetter <daniel at ffwll.ch>
> >>> Cc: Daniel Stone <daniel at fooishbar.org>
> >>> Cc: Russell King - ARM Linux <linux at armlinux.org.uk>
> >>> Cc: Ilia Mirkin <imirkin at alum.mit.edu>
> >>> Cc: Hans Verkuil <hverkuil at xs4all.nl>
> >>> Cc: Uma Shankar <uma.shankar at intel.com>
> >>> Cc: Shashank Sharma <shashank.sharma at intel.com>
> >>> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> >>> [vsyrjala v2: Add/fix kerneldocs, verify bitmasks]
> >>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> >>> ---
> >>>   drivers/gpu/drm/drm_atomic.c     |   8 +++
> >>>   drivers/gpu/drm/drm_color_mgmt.c | 103 +++++++++++++++++++++++++++++++++++++++
> >>>   include/drm/drm_color_mgmt.h     |  19 ++++++++
> >>>   include/drm/drm_plane.h          |  32 ++++++++++++
> >>>   4 files changed, 162 insertions(+)
> >>>
> >>> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> >>> index 46733d534587..452a0b0bafbc 100644
> >>> --- a/drivers/gpu/drm/drm_atomic.c
> >>> +++ b/drivers/gpu/drm/drm_atomic.c
> >>> @@ -759,6 +759,10 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
> >>>   		state->rotation = val;
> >>>   	} else if (property == plane->zpos_property) {
> >>>   		state->zpos = val;
> >>> +	} else if (property == plane->color_encoding_property) {
> >>> +		state->color_encoding = val;
> >>> +	} else if (property == plane->color_range_property) {
> >>> +		state->color_range = val;
> >>>   	} else if (plane->funcs->atomic_set_property) {
> >>>   		return plane->funcs->atomic_set_property(plane, state,
> >>>   				property, val);
> >>> @@ -818,6 +822,10 @@ drm_atomic_plane_get_property(struct drm_plane *plane,
> >>>   		*val = state->rotation;
> >>>   	} else if (property == plane->zpos_property) {
> >>>   		*val = state->zpos;
> >>> +	} else if (property == plane->color_encoding_property) {
> >>> +		*val = state->color_encoding;
> >>> +	} else if (property == plane->color_range_property) {
> >>> +		*val = state->color_range;
> >>>   	} else if (plane->funcs->atomic_get_property) {
> >>>   		return plane->funcs->atomic_get_property(plane, state, property, val);
> >>>   	} else {
> >>> diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
> >>> index 0d002b045bd2..4b83e078d3e9 100644
> >>> --- a/drivers/gpu/drm/drm_color_mgmt.c
> >>> +++ b/drivers/gpu/drm/drm_color_mgmt.c
> >>> @@ -88,6 +88,20 @@
> >>>    * drm_mode_crtc_set_gamma_size(). Drivers which support both should use
> >>>    * drm_atomic_helper_legacy_gamma_set() to alias the legacy gamma ramp with the
> >>>    * "GAMMA_LUT" property above.
> >>> + *
> >>> + * Support for different non RGB color encodings is controlled through
> >>> + * &drm_plane specific COLOR_ENCODING and COLOR_RANGE properties. They
> >>> + * are set up by calling drm_plane_create_color_properties().
> >>> + *
> >>> + * "COLOR_ENCODING"
> >>> + * 	Optional plane enum property to support different non RGB
> >>> + * 	color encodings. The driver can provide a subset of standard
> >>> + * 	enum values supported by the DRM plane.
> >>> + *
> >>> + * "COLOR_RANGE"
> >>> + * 	Optional plane enum property to support different non RGB
> >>> + * 	color parameter ranges. The driver can provide a subset of
> >>> + * 	standard enum values supported by the DRM plane.
> >>>    */
> >>>   
> >>>   /**
> >>> @@ -339,3 +353,92 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev,
> >>>   	drm_modeset_unlock(&crtc->mutex);
> >>>   	return ret;
> >>>   }
> >>> +
> >>> +static const char * const color_encoding_name[] = {
> >>> +	[DRM_COLOR_YCBCR_BT601] = "ITU-R BT.601 YCbCr",
> >>> +	[DRM_COLOR_YCBCR_BT709] = "ITU-R BT.709 YCbCr",
> >>> +	[DRM_COLOR_YCBCR_BT2020] = "ITU-R BT.2020 YCbCr",
> >>> +};
> >>> +
> >>> +static const char * const color_range_name[] = {
> >>> +	[DRM_COLOR_YCBCR_FULL_RANGE] = "YCbCr full range",
> >>> +	[DRM_COLOR_YCBCR_LIMITED_RANGE] = "YCbCr limited range",
> >>> +};
> >>> +
> >>> +/**
> >>> + * drm_plane_create_color_properties - color encoding related plane properties
> >>> + * @plane: plane object
> >>> + * @supported_encodings: bitfield indicating supported color encodings
> >>> + * @supported_ranges: bitfileld indicating supported color ranges
> >>> + * @default_encoding: default color encoding
> >>> + * @default_range: default color range
> >>> + *
> >>> + * Create and attach plane specific COLOR_ENCODING and COLOR_RANGE
> >>> + * properties to @plane. The supported encodings and ranges should
> >>> + * be provided in supported_encodings and supported_ranges bitmasks.
> >>> + * Each bit set in the bitmask indicates that its number as enum
> >>> + * value is supported.
> >>> + */
> >>> +int drm_plane_create_color_properties(struct drm_plane *plane,
> >>> +				      u32 supported_encodings,
> >>> +				      u32 supported_ranges,
> >>> +				      enum drm_color_encoding default_encoding,
> >>> +				      enum drm_color_range default_range)
> >>> +{
> >>> +	struct drm_device *dev = plane->dev;
> >>> +	struct drm_property *prop;
> >>> +	struct drm_prop_enum_list enum_list[max(DRM_COLOR_ENCODING_MAX,
> >>> +						DRM_COLOR_RANGE_MAX)];
> >>> +	int i, len;
> >>> +
> >>> +	if (WARN_ON(supported_encodings == 0 ||
> >>> +		    (supported_encodings & -BIT(DRM_COLOR_ENCODING_MAX)) != 0 ||
> >>> +		    (supported_encodings & BIT(default_encoding)) == 0))
> >>> +		return -EINVAL;
> >>> +
> >>> +	if (WARN_ON(supported_ranges == 0 ||
> >>> +		    (supported_ranges & -BIT(DRM_COLOR_RANGE_MAX)) != 0 ||
> >>> +		    (supported_ranges & BIT(default_range)) == 0))
> >>> +		return -EINVAL;
> >>> +
> >>> +	len = 0;
> >>> +	for (i = 0; i < DRM_COLOR_ENCODING_MAX; i++) {
> >>> +		if ((supported_encodings & BIT(i)) == 0)
> >>> +			continue;
> >>> +
> >>> +		enum_list[len].type = i;
> >>> +		enum_list[len].name = color_encoding_name[i];
> >>> +		len++;
> >>> +	}
> >>> +
> >>> +	prop = drm_property_create_enum(dev, 0, "COLOR_ENCODING",
> >>> +					enum_list, len);
> >>> +	if (!prop)
> >>> +		return -ENOMEM;
> >>> +	plane->color_encoding_property = prop;
> >>> +	drm_object_attach_property(&plane->base, prop, default_encoding);
> >>> +	if (plane->state)
> >>> +		plane->state->color_encoding = default_encoding;
> >>> +
> >>> +	len = 0;
> >>> +	for (i = 0; i < DRM_COLOR_RANGE_MAX; i++) {
> >>> +		if ((supported_ranges & BIT(i)) == 0)
> >>> +			continue;
> >>> +
> >>> +		enum_list[len].type = i;
> >>> +		enum_list[len].name = color_range_name[i];
> >>> +		len++;
> >>> +	}
> >>> +
> >>> +	prop = drm_property_create_enum(dev, 0,	"COLOR_RANGE",
> >>> +					enum_list, len);
> >>> +	if (!prop)
> >>> +		return -ENOMEM;
> >>> +	plane->color_range_property = prop;
> >>> +	drm_object_attach_property(&plane->base, prop, default_range);
> >>> +	if (plane->state)
> >>> +		plane->state->color_range = default_range;
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +EXPORT_SYMBOL(drm_plane_create_color_properties);
> >>> diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
> >>> index 03a59cbce621..b3b6d302ca8c 100644
> >>> --- a/include/drm/drm_color_mgmt.h
> >>> +++ b/include/drm/drm_color_mgmt.h
> >>> @@ -26,6 +26,7 @@
> >>>   #include <linux/ctype.h>
> >>>   
> >>>   struct drm_crtc;
> >>> +struct drm_plane;
> >>>   
> >>>   uint32_t drm_color_lut_extract(uint32_t user_input, uint32_t bit_precision);
> >>>   
> >>> @@ -37,4 +38,22 @@ void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,
> >>>   int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
> >>>   				 int gamma_size);
> >>>   
> >>> +enum drm_color_encoding {
> >>> +	DRM_COLOR_YCBCR_BT601,
> >>> +	DRM_COLOR_YCBCR_BT709,
> >>> +	DRM_COLOR_YCBCR_BT2020,
> >>> +	DRM_COLOR_ENCODING_MAX,
> >>> +};
> >>> +
> >>> +enum drm_color_range {
> >>> +	DRM_COLOR_YCBCR_LIMITED_RANGE,
> >>> +	DRM_COLOR_YCBCR_FULL_RANGE,
> >>> +	DRM_COLOR_RANGE_MAX,
> >>> +};
> >>> +
> >>> +int drm_plane_create_color_properties(struct drm_plane *plane,
> >>> +				      u32 supported_encodings,
> >>> +				      u32 supported_ranges,
> >>> +				      enum drm_color_encoding default_encoding,
> >>> +				      enum drm_color_range default_range);
> >>>   #endif
> >>> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> >>> index 8185e3468a23..f7bf4a48b1c3 100644
> >>> --- a/include/drm/drm_plane.h
> >>> +++ b/include/drm/drm_plane.h
> >>> @@ -26,6 +26,7 @@
> >>>   #include <linux/list.h>
> >>>   #include <linux/ctype.h>
> >>>   #include <drm/drm_mode_object.h>
> >>> +#include <drm/drm_color_mgmt.h>
> >>>   
> >>>   struct drm_crtc;
> >>>   struct drm_printer;
> >>> @@ -112,6 +113,20 @@ struct drm_plane_state {
> >>>   	unsigned int zpos;
> >>>   	unsigned int normalized_zpos;
> >>>   
> >>> +	/**
> >>> +	 * @color_encoding:
> >>> +	 *
> >>> +	 * Color encoding for non RGB formats
> >>> +	 */
> >>> +	enum drm_color_encoding color_encoding;
> >>> +
> >>> +	/**
> >>> +	 * @color_range:
> >>> +	 *
> >>> +	 * Color range for non RGB formats
> >>> +	 */
> >>> +	enum drm_color_range color_range;
> >>> +
> >>>   	/* Clipped coordinates */
> >>>   	struct drm_rect src, dst;
> >>>   
> >>> @@ -558,6 +573,23 @@ struct drm_plane {
> >>>   
> >>>   	struct drm_property *zpos_property;
> >>>   	struct drm_property *rotation_property;
> >>> +
> >>> +	/**
> >>> +	 * @color_encoding_property:
> >>> +	 *
> >>> +	 * Optional "COLOR_ENCODING" enum property for specifying
> >>> +	 * color encoding for non RGB formats.
> >>> +	 * See drm_plane_create_color_properties().
> >>> +	 */
> >>> +	struct drm_property *color_encoding_property;
> >>> +	/**
> >>> +	 * @color_range_property:
> >>> +	 *
> >>> +	 * Optional "COLOR_RANGE" enum property for specifying
> >>> +	 * color range for non RGB formats.
> >>> +	 * See drm_plane_create_color_properties().
> >>> +	 */
> >>> +	struct drm_property *color_range_property;
> >>>   };
> >>>   
> >>>   #define obj_to_plane(x) container_of(x, struct drm_plane, base)
> 

-- 
Ville Syrjälä
Intel


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