drm: Add DP1.4 VSC SDP Payload related Data Structures

It adds new enumeration definitions for VSC SDP Payload for Pixel
Encoding/Colorimetry Format.
And it adds a new drm data structure for DP VSC SDP.

enum dp_colorspace and enum dp_colorimetry correspond "Pixel Encoding and
Colorimetry Formats". enum dp_dynamic_range corresponds "Dynamic Range".
And enum dp_content_type corresponds "Content Type"
All of them are based on DP 1.4 spec [Table 2-117: VSC SDP Payload for
DB16 through DB18].

v3: Add a new drm data structure for DP VSC SDP
v5: Addressed review comments from Uma
    - Add kernel docs for added data structures
    - Rename enum dp_colorspace to dp_pixelformat
    - Polish commit message
    - Fix typos
    - Drop self-explanatory comments

Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200211074657.231405-2-gwan-gyeong.mun@intel.com

include/drm/drm_dp_helper.h

@@ -1209,6 +1209,136 @@ struct dp_sdp {
 #define EDP_VSC_PSR_UPDATE_RFB		(1<<1)
 #define EDP_VSC_PSR_CRC_VALUES_VALID	(1<<2)
 
+/**
+ * enum dp_pixelformat - drm DP Pixel encoding formats
+ *
+ * This enum is used to indicate DP VSC SDP Pixel encoding formats.
+ * It is based on DP 1.4 spec [Table 2-117: VSC SDP Payload for DB16 through
+ * DB18]
+ *
+ * @DP_PIXELFORMAT_RGB: RGB pixel encoding format
+ * @DP_PIXELFORMAT_YUV444: YCbCr 4:4:4 pixel encoding format
+ * @DP_PIXELFORMAT_YUV422: YCbCr 4:2:2 pixel encoding format
+ * @DP_PIXELFORMAT_YUV420: YCbCr 4:2:0 pixel encoding format
+ * @DP_PIXELFORMAT_Y_ONLY: Y Only pixel encoding format
+ * @DP_PIXELFORMAT_RAW: RAW pixel encoding format
+ * @DP_PIXELFORMAT_RESERVED: Reserved pixel encoding format
+ */
+enum dp_pixelformat {
+	DP_PIXELFORMAT_RGB = 0,
+	DP_PIXELFORMAT_YUV444 = 0x1,
+	DP_PIXELFORMAT_YUV422 = 0x2,
+	DP_PIXELFORMAT_YUV420 = 0x3,
+	DP_PIXELFORMAT_Y_ONLY = 0x4,
+	DP_PIXELFORMAT_RAW = 0x5,
+	DP_PIXELFORMAT_RESERVED = 0x6,
+};
+
+/**
+ * enum dp_colorimetry - drm DP Colorimetry formats
+ *
+ * This enum is used to indicate DP VSC SDP Colorimetry formats.
+ * It is based on DP 1.4 spec [Table 2-117: VSC SDP Payload for DB16 through
+ * DB18] and a name of enum member follows DRM_MODE_COLORIMETRY definition.
+ *
+ * @DP_COLORIMETRY_DEFAULT: sRGB (IEC 61966-2-1) or
+ *                          ITU-R BT.601 colorimetry format
+ * @DP_COLORIMETRY_RGB_WIDE_FIXED: RGB wide gamut fixed point colorimetry format
+ * @DP_COLORIMETRY_BT709_YCC: ITU-R BT.709 colorimetry format
+ * @DP_COLORIMETRY_RGB_WIDE_FLOAT: RGB wide gamut floating point
+ *                                 (scRGB (IEC 61966-2-2)) colorimetry format
+ * @DP_COLORIMETRY_XVYCC_601: xvYCC601 colorimetry format
+ * @DP_COLORIMETRY_OPRGB: OpRGB colorimetry format
+ * @DP_COLORIMETRY_XVYCC_709: xvYCC709 colorimetry format
+ * @DP_COLORIMETRY_DCI_P3_RGB: DCI-P3 (SMPTE RP 431-2) colorimetry format
+ * @DP_COLORIMETRY_SYCC_601: sYCC601 colorimetry format
+ * @DP_COLORIMETRY_RGB_CUSTOM: RGB Custom Color Profile colorimetry format
+ * @DP_COLORIMETRY_OPYCC_601: opYCC601 colorimetry format
+ * @DP_COLORIMETRY_BT2020_RGB: ITU-R BT.2020 R' G' B' colorimetry format
+ * @DP_COLORIMETRY_BT2020_CYCC: ITU-R BT.2020 Y'c C'bc C'rc colorimetry format
+ * @DP_COLORIMETRY_BT2020_YCC: ITU-R BT.2020 Y' C'b C'r colorimetry format
+ */
+enum dp_colorimetry {
+	DP_COLORIMETRY_DEFAULT = 0,
+	DP_COLORIMETRY_RGB_WIDE_FIXED = 0x1,
+	DP_COLORIMETRY_BT709_YCC = 0x1,
+	DP_COLORIMETRY_RGB_WIDE_FLOAT = 0x2,
+	DP_COLORIMETRY_XVYCC_601 = 0x2,
+	DP_COLORIMETRY_OPRGB = 0x3,
+	DP_COLORIMETRY_XVYCC_709 = 0x3,
+	DP_COLORIMETRY_DCI_P3_RGB = 0x4,
+	DP_COLORIMETRY_SYCC_601 = 0x4,
+	DP_COLORIMETRY_RGB_CUSTOM = 0x5,
+	DP_COLORIMETRY_OPYCC_601 = 0x5,
+	DP_COLORIMETRY_BT2020_RGB = 0x6,
+	DP_COLORIMETRY_BT2020_CYCC = 0x6,
+	DP_COLORIMETRY_BT2020_YCC = 0x7,
+};
+
+/**
+ * enum dp_dynamic_range - drm DP Dynamic Range
+ *
+ * This enum is used to indicate DP VSC SDP Dynamic Range.
+ * It is based on DP 1.4 spec [Table 2-117: VSC SDP Payload for DB16 through
+ * DB18]
+ *
+ * @DP_DYNAMIC_RANGE_VESA: VESA range
+ * @DP_DYNAMIC_RANGE_CTA: CTA range
+ */
+enum dp_dynamic_range {
+	DP_DYNAMIC_RANGE_VESA = 0,
+	DP_DYNAMIC_RANGE_CTA = 1,
+};
+
+/**
+ * enum dp_content_type - drm DP Content Type
+ *
+ * This enum is used to indicate DP VSC SDP Content Types.
+ * It is based on DP 1.4 spec [Table 2-117: VSC SDP Payload for DB16 through
+ * DB18]
+ * CTA-861-G defines content types and expected processing by a sink device
+ *
+ * @DP_CONTENT_TYPE_NOT_DEFINED: Not defined type
+ * @DP_CONTENT_TYPE_GRAPHICS: Graphics type
+ * @DP_CONTENT_TYPE_PHOTO: Photo type
+ * @DP_CONTENT_TYPE_VIDEO: Video type
+ * @DP_CONTENT_TYPE_GAME: Game type
+ */
+enum dp_content_type {
+	DP_CONTENT_TYPE_NOT_DEFINED = 0x00,
+	DP_CONTENT_TYPE_GRAPHICS = 0x01,
+	DP_CONTENT_TYPE_PHOTO = 0x02,
+	DP_CONTENT_TYPE_VIDEO = 0x03,
+	DP_CONTENT_TYPE_GAME = 0x04,
+};
+
+/**
+ * struct drm_dp_vsc_sdp - drm DP VSC SDP
+ *
+ * This structure represents a DP VSC SDP of drm
+ * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and
+ * [Table 2-117: VSC SDP Payload for DB16 through DB18]
+ *
+ * @sdp_type: secondary-data packet type
+ * @revision: revision number
+ * @length: number of valid data bytes
+ * @pixelformat: pixel encoding format
+ * @colorimetry: colorimetry format
+ * @bpc: bit per color
+ * @dynamic_range: dynamic range information
+ * @content_type: CTA-861-G defines content types and expected processing by a sink device
+ */
+struct drm_dp_vsc_sdp {
+	unsigned char sdp_type;
+	unsigned char revision;
+	unsigned char length;
+	enum dp_pixelformat pixelformat;
+	enum dp_colorimetry colorimetry;
+	int bpc;
+	enum dp_dynamic_range dynamic_range;
+	enum dp_content_type content_type;
+};
+
 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
 
 static inline int