drm/amd/display: Add support for extended DSC DPCD caps

[why]
A few of the new DSC DPCD caps were introduced by a DP 1.4a SCR in order
to give DSC branch decoders a chance to expose their maximum throughput
and maximum line width limitations.

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/include/dpcd_structs.h

@@ -0,0 +1,168 @@
+/*
+ * dpcd_structs.h
+ *
+ *  Created on: Oct 31, 2018
+ *      Author: jlei
+ */
+
+#ifndef DAL_INCLUDE_DPCD_STRUCTS_H_
+#define DAL_INCLUDE_DPCD_STRUCTS_H_
+
+struct dpcd_receive_port0_cap01 {
+	union {
+		struct {
+			// Byte 0
+			unsigned char reserved0				:1; // Bit0
+			unsigned char local_edid_present		:1;
+			unsigned char associated_to_preceding_port	:1;
+			unsigned char hblank_expansion_capable		:1;
+			unsigned char buffer_size_unit			:1; // Bit4
+			unsigned char buffer_size_per_port		:1;
+			unsigned char reserved1				:2;
+
+			// Byte 1
+			unsigned char buffer_size			:8;
+		} fields;
+		unsigned char raw[2];
+	};
+};
+
+#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
+
+struct dpcd_dsc_basic_capabilities {
+	union {
+		struct {
+			// Byte 0
+			struct {
+
+				unsigned char dsc_support				:1; // Bit0
+				unsigned char reserved					:7;
+			} dsc_support;
+
+			// Byte 1
+			struct {
+				unsigned char dsc_version_major	:4;
+				unsigned char dsc_version_minor	:4;
+			} dsc_algorithm_revision;
+
+			// Byte 2
+			struct {
+				unsigned char rc_block_buffer_size	:2;
+				unsigned char reserved	:6;
+			} dsc_rc_buffer_block_size;
+
+			// Byte 3
+			unsigned char dsc_rc_buffer_size;
+
+			// Byte 4
+			struct {
+				unsigned char one_slice_per_dp_dsc_sink_device		:1; // Bit0
+				unsigned char two_slices_per_dp_dsc_sink_device		:1;
+				unsigned char reserved					:1;
+				unsigned char four_slices_per_dp_dsc_sink_device	:1;
+				unsigned char six_slices_per_dp_dsc_sink_device		:1; // Bit 4
+				unsigned char eight_slices_per_dp_dsc_sink_device	:1;
+				unsigned char ten_slices_per_dp_dsc_sink_device		:1;
+				unsigned char twelve_slices_per_dp_dsc_sink_device	:1;
+			} dsc_slice_capabilities_1;
+
+			// Byte 5
+			struct {
+				unsigned char line_buffer_bit_depth	:4;
+				unsigned char reserved			:4;
+			} dsc_line_buffer_bit_depth;
+
+			// Byte 6
+			struct {
+				unsigned char block_prediction_support	:1;
+				unsigned char reserved			:7;
+			} dsc_block_prediction_support;
+
+			// Byte 7,8
+			struct {
+				unsigned char maximum_bits_per_pixel_supported_by_the_decompressor_low	:7;
+				unsigned char maximum_bits_per_pixel_supported_by_the_decompressor_high	:7;
+			} maximum_bits_per_pixel_supported_by_the_decompressor;
+
+			// Byte 9
+			struct {
+				unsigned char rgb_support			:1; // Bit0
+				unsigned char y_cb_cr_444_support		:1;
+				unsigned char y_cb_cr_simple_422_support	:1;
+				unsigned char y_cb_cr_native_422_support	:1;
+				unsigned char y_cb_cr_native_420_support	:1; // Bit 4
+				unsigned char reserved				:3;
+			} dsc_decoder_color_format_capabilities;
+
+			// Byte 10
+			struct {
+				unsigned char reserved0				:1; // Bit0
+				unsigned char eight_bits_per_color_support	:1;
+				unsigned char ten_bits_per_color_support	:1;
+				unsigned char twelve_bits_per_color_support	:1;
+				unsigned char reserved1				:4; // Bit 4
+			} dsc_decoder_color_depth_capabilities;
+
+			// Byte 11
+			struct {
+				unsigned char throughput_mode_0			:4;
+				unsigned char throughput_mode_1			:4;
+			} peak_dsc_throughput_dsc_sink;
+
+			// Byte 12
+			unsigned char dsc_maximum_slice_width;
+
+			// Byte 13
+			struct {
+				unsigned char sixteen_slices_per_dsc_sink_device	:1;
+				unsigned char twenty_slices_per_dsc_sink_device		:1;
+				unsigned char twentyfour_slices_per_dsc_sink_device	:1;
+				unsigned char reserved					:5;
+			} dsc_slice_capabilities_2;
+
+			// Byte 14
+			unsigned char reserved;
+
+			// Byte 15
+			struct {
+				unsigned char increment_of_bits_per_pixel_supported	:3;
+				unsigned char reserved					:5;
+			} bits_per_pixel_increment;
+		} fields;
+		unsigned char raw[16];
+	};
+};
+
+struct dpcd_dsc_ext_capabilities {
+	union {
+		struct {
+			unsigned char branch_overall_throughput_0; // Byte 0
+			unsigned char branch_overall_throughput_1; // Byte 1
+			unsigned char branch_max_line_width; // Byte 2
+		} fields;
+		unsigned char raw[3];
+	};
+};
+
+struct dpcd_dsc_capabilities {
+	struct dpcd_dsc_basic_capabilities dsc_basic_caps;
+	struct dpcd_dsc_ext_capabilities dsc_ext_caps;
+};
+
+struct dpcd_fec_capability {
+	union {
+		struct {
+			// Byte 0
+			unsigned char fec_capable				:1; // Bit0
+			unsigned char uncorrected_block_error_count_capable	:1;
+			unsigned char corrected_block_error_count_capable	:1;
+			unsigned char bit_error_count_capable			:1;
+			unsigned char reserved					:4; // Bit4
+		} fields;
+		unsigned char raw[1];
+	};
+};
+
+#endif
+
+#endif /* DAL_INCLUDE_DPCD_STRUCTS_H_ */