1 /* SPDX-License-Identifier: MIT
2 * Copyright (C) 2018 Intel Corp.
5 * Manasi Navare <manasi.d.navare@intel.com>
11 #include <drm/drm_dp_helper.h>
13 /* VESA Display Stream Compression DSC 1.2 constants */
14 #define DSC_NUM_BUF_RANGES 15
15 #define DSC_MUX_WORD_SIZE_8_10_BPC 48
16 #define DSC_MUX_WORD_SIZE_12_BPC 64
17 #define DSC_RC_PIXELS_PER_GROUP 3
18 #define DSC_SCALE_DECREMENT_INTERVAL_MAX 4095
19 #define DSC_RANGE_BPG_OFFSET_MASK 0x3f
21 /* DSC Rate Control Constants */
22 #define DSC_RC_MODEL_SIZE_CONST 8192
23 #define DSC_RC_EDGE_FACTOR_CONST 6
24 #define DSC_RC_TGT_OFFSET_HI_CONST 3
25 #define DSC_RC_TGT_OFFSET_LO_CONST 3
27 /* DSC PPS constants and macros */
28 #define DSC_PPS_VERSION_MAJOR_SHIFT 4
29 #define DSC_PPS_BPC_SHIFT 4
30 #define DSC_PPS_MSB_SHIFT 8
31 #define DSC_PPS_LSB_MASK (0xFF << 0)
32 #define DSC_PPS_BPP_HIGH_MASK (0x3 << 8)
33 #define DSC_PPS_VBR_EN_SHIFT 2
34 #define DSC_PPS_SIMPLE422_SHIFT 3
35 #define DSC_PPS_CONVERT_RGB_SHIFT 4
36 #define DSC_PPS_BLOCK_PRED_EN_SHIFT 5
37 #define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK (0x3 << 8)
38 #define DSC_PPS_SCALE_DEC_INT_HIGH_MASK (0xF << 8)
39 #define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT 4
40 #define DSC_PPS_RC_RANGE_MINQP_SHIFT 11
41 #define DSC_PPS_RC_RANGE_MAXQP_SHIFT 6
42 #define DSC_PPS_NATIVE_420_SHIFT 1
43 #define DSC_1_2_MAX_LINEBUF_DEPTH_BITS 16
44 #define DSC_1_2_MAX_LINEBUF_DEPTH_VAL 0
45 #define DSC_1_1_MAX_LINEBUF_DEPTH_BITS 13
48 * struct drm_dsc_rc_range_parameters - DSC Rate Control range parameters
50 * This defines different rate control parameters used by the DSC engine
51 * to compress the frame.
53 struct drm_dsc_rc_range_parameters {
55 * @range_min_qp: Min Quantization Parameters allowed for this range
59 * @range_max_qp: Max Quantization Parameters allowed for this range
64 * Bits/group offset to apply to target for this group
70 * struct drm_dsc_config - Parameters required to configure DSC
72 * Driver populates this structure with all the parameters required
73 * to configure the display stream compression on the source.
75 struct drm_dsc_config {
78 * Bits per component for previous reconstructed line buffer
82 * @bits_per_component: Bits per component to code (8/10/12)
84 u8 bits_per_component;
87 * Flag to indicate if RGB - YCoCg conversion is needed
88 * True if RGB input, False if YCoCg input
92 * @slice_count: Number fo slices per line used by the DSC encoder
96 * @slice_width: Width of each slice in pixels
100 * @slice_height: Slice height in pixels
104 * @simple_422: True if simple 4_2_2 mode is enabled else False
108 * @pic_width: Width of the input display frame in pixels
112 * @pic_height: Vertical height of the input display frame
116 * @rc_tgt_offset_high:
117 * Offset to bits/group used by RC to determine QP adjustment
119 u8 rc_tgt_offset_high;
121 * @rc_tgt_offset_low:
122 * Offset to bits/group used by RC to determine QP adjustment
124 u8 rc_tgt_offset_low;
127 * Target bits per pixel with 4 fractional bits, bits_per_pixel << 4
132 * Factor to determine if an edge is present based on the bits produced
136 * @rc_quant_incr_limit1:
137 * Slow down incrementing once the range reaches this value
139 u8 rc_quant_incr_limit1;
141 * @rc_quant_incr_limit0:
142 * Slow down incrementing once the range reaches this value
144 u8 rc_quant_incr_limit0;
146 * @initial_xmit_delay:
147 * Number of pixels to delay the initial transmission
149 u16 initial_xmit_delay;
151 * @initial_dec_delay:
152 * Initial decoder delay, number of pixel times that the decoder
153 * accumulates data in its rate buffer before starting to decode
156 u16 initial_dec_delay;
158 * @block_pred_enable:
159 * True if block prediction is used to code any groups within the
160 * picture. False if BP not used
162 bool block_pred_enable;
164 * @first_line_bpg_offset:
165 * Number of additional bits allocated for each group on the first
168 u8 first_line_bpg_offset;
170 * @initial_offset: Value to use for RC model offset at slice start
174 * @rc_buf_thresh: Thresholds defining each of the buffer ranges
176 u16 rc_buf_thresh[DSC_NUM_BUF_RANGES - 1];
179 * Parameters for each of the RC ranges defined in
180 * &struct drm_dsc_rc_range_parameters
182 struct drm_dsc_rc_range_parameters rc_range_params[DSC_NUM_BUF_RANGES];
184 * @rc_model_size: Total size of RC model
188 * @flatness_min_qp: Minimum QP where flatness information is sent
192 * @flatness_max_qp: Maximum QP where flatness information is sent
196 * @initial_scale_value: Initial value for the scale factor
198 u8 initial_scale_value;
200 * @scale_decrement_interval:
201 * Specifies number of group times between decrementing the scale factor
202 * at beginning of a slice.
204 u16 scale_decrement_interval;
206 * @scale_increment_interval:
207 * Number of group times between incrementing the scale factor value
208 * used at the beginning of a slice.
210 u16 scale_increment_interval;
212 * @nfl_bpg_offset: Non first line BPG offset to be used
216 * @slice_bpg_offset: BPG offset used to enforce slice bit
218 u16 slice_bpg_offset;
220 * @final_offset: Final RC linear transformation offset value
224 * @vbr_enable: True if VBR mode is enabled, false if disabled
228 * @mux_word_size: Mux word size (in bits) for SSM mode
233 * The (max) size in bytes of the "chunks" that are used in slice
236 u16 slice_chunk_size;
238 * @rc_bits: Rate control buffer size in bits
242 * @dsc_version_minor: DSC minor version
244 u8 dsc_version_minor;
246 * @dsc_version_major: DSC major version
248 u8 dsc_version_major;
250 * @native_422: True if Native 4:2:2 supported, else false
254 * @native_420: True if Native 4:2:0 supported else false.
258 * @second_line_bpg_offset:
259 * Additional bits/grp for seconnd line of slice for native 4:2:0
261 u8 second_line_bpg_offset;
264 * Num of bits deallocated for each grp that is not in second line of
269 * @second_line_offset_adj:
270 * Offset adjustment for second line in Native 4:2:0 mode
272 u16 second_line_offset_adj;
276 * struct picture_parameter_set - Represents 128 bytes of Picture Parameter Set
278 * The VESA DSC standard defines picture parameter set (PPS) which display
279 * stream compression encoders must communicate to decoders.
280 * The PPS is encapsulated in 128 bytes (PPS 0 through PPS 127). The fields in
281 * this structure are as per Table 4.1 in Vesa DSC specification v1.1/v1.2.
282 * The PPS fields that span over more than a byte should be stored in Big Endian
285 struct drm_dsc_picture_parameter_set {
288 * PPS0[3:0] - dsc_version_minor: Contains Minor version of DSC
289 * PPS0[7:4] - dsc_version_major: Contains major version of DSC
294 * PPS1[7:0] - Application specific identifier that can be
295 * used to differentiate between different PPS tables.
300 * PPS2[7:0]- RESERVED Byte
305 * PPS3[3:0] - linebuf_depth: Contains linebuffer bit depth used to
306 * generate the bitstream. (0x0 - 16 bits for DSC 1.2, 0x8 - 8 bits,
307 * 0xA - 10 bits, 0xB - 11 bits, 0xC - 12 bits, 0xD - 13 bits,
308 * 0xE - 14 bits for DSC1.2, 0xF - 14 bits for DSC 1.2.
309 * PPS3[7:4] - bits_per_component: Bits per component for the original
310 * pixels of the encoded picture.
311 * 0x0 = 16bpc (allowed only when dsc_version_minor = 0x2)
312 * 0x8 = 8bpc, 0xA = 10bpc, 0xC = 12bpc, 0xE = 14bpc (also
313 * allowed only when dsc_minor_version = 0x2)
318 * PPS4[1:0] -These are the most significant 2 bits of
319 * compressed BPP bits_per_pixel[9:0] syntax element.
320 * PPS4[2] - vbr_enable: 0 = VBR disabled, 1 = VBR enabled
321 * PPS4[3] - simple_422: Indicates if decoder drops samples to
322 * reconstruct the 4:2:2 picture.
323 * PPS4[4] - Convert_rgb: Indicates if DSC color space conversion is
325 * PPS4[5] - blobk_pred_enable: Indicates if BP is used to code any
327 * PPS4[7:6] - Reseved bits
331 * @bits_per_pixel_low:
332 * PPS5[7:0] - This indicates the lower significant 8 bits of
333 * the compressed BPP bits_per_pixel[9:0] element.
335 u8 bits_per_pixel_low;
338 * PPS6[7:0], PPS7[7:0] -pic_height: Specifies the number of pixel rows
344 * PPS8[7:0], PPS9[7:0] - pic_width: Number of pixel columns within
350 * PPS10[7:0], PPS11[7:0] - Slice height in units of pixels.
355 * PPS12[7:0], PPS13[7:0] - Slice width in terms of pixels.
360 * PPS14[7:0], PPS15[7:0] - Size in units of bytes of the chunks
361 * that are used for slice multiplexing.
365 * @initial_xmit_delay_high:
366 * PPS16[1:0] - Most Significant two bits of initial transmission delay.
367 * It specifies the number of pixel times that the encoder waits before
368 * transmitting data from its rate buffer.
369 * PPS16[7:2] - Reserved
371 u8 initial_xmit_delay_high;
373 * @initial_xmit_delay_low:
374 * PPS17[7:0] - Least significant 8 bits of initial transmission delay.
376 u8 initial_xmit_delay_low;
378 * @initial_dec_delay:
380 * PPS18[7:0], PPS19[7:0] - Initial decoding delay which is the number
381 * of pixel times that the decoder accumulates data in its rate buffer
382 * before starting to decode and output pixels.
384 __be16 initial_dec_delay;
388 * PPS20[7:0] - Reserved
392 * @initial_scale_value:
393 * PPS21[5:0] - Initial rcXformScale factor used at beginning
395 * PPS21[7:6] - Reserved
397 u8 initial_scale_value;
399 * @scale_increment_interval:
400 * PPS22[7:0], PPS23[7:0] - Number of group times between incrementing
401 * the rcXformScale factor at end of a slice.
403 __be16 scale_increment_interval;
405 * @scale_decrement_interval_high:
406 * PPS24[3:0] - Higher 4 bits indicating number of group times between
407 * decrementing the rcXformScale factor at beginning of a slice.
408 * PPS24[7:4] - Reserved
410 u8 scale_decrement_interval_high;
412 * @scale_decrement_interval_low:
413 * PPS25[7:0] - Lower 8 bits of scale decrement interval
415 u8 scale_decrement_interval_low;
422 * @first_line_bpg_offset:
423 * PPS27[4:0] - Number of additional bits that are allocated
424 * for each group on first line of a slice.
425 * PPS27[7:5] - Reserved
427 u8 first_line_bpg_offset;
430 * PPS28[7:0], PPS29[7:0] - Number of bits including frac bits
431 * deallocated for each group for groups after the first line of slice.
433 __be16 nfl_bpg_offset;
436 * PPS30, PPS31[7:0] - Number of bits that are deallocated for each
437 * group to enforce the slice constraint.
439 __be16 slice_bpg_offset;
442 * PPS32,33[7:0] - Initial value for rcXformOffset
444 __be16 initial_offset;
447 * PPS34,35[7:0] - Maximum end-of-slice value for rcXformOffset
452 * PPS36[4:0] - Minimum QP at which flatness is signaled and
453 * flatness QP adjustment is made.
454 * PPS36[7:5] - Reserved
459 * PPS37[4:0] - Max QP at which flatness is signalled and
460 * the flatness adjustment is made.
461 * PPS37[7:5] - Reserved
466 * PPS38,39[7:0] - Number of bits within RC Model.
468 __be16 rc_model_size;
471 * PPS40[3:0] - Ratio of current activity vs, previous
472 * activity to determine presence of edge.
473 * PPS40[7:4] - Reserved
477 * @rc_quant_incr_limit0:
478 * PPS41[4:0] - QP threshold used in short term RC
479 * PPS41[7:5] - Reserved
481 u8 rc_quant_incr_limit0;
483 * @rc_quant_incr_limit1:
484 * PPS42[4:0] - QP threshold used in short term RC
485 * PPS42[7:5] - Reserved
487 u8 rc_quant_incr_limit1;
490 * PPS43[3:0] - Lower end of the variability range around the target
491 * bits per group that is allowed by short term RC.
492 * PPS43[7:4]- Upper end of the variability range around the target
493 * bits per group that i allowed by short term rc.
498 * PPS44[7:0] - PPS57[7:0] - Specifies the thresholds in RC model for
499 * the 15 ranges defined by 14 thresholds.
501 u8 rc_buf_thresh[DSC_NUM_BUF_RANGES - 1];
503 * @rc_range_parameters:
504 * PPS58[7:0] - PPS87[7:0]
505 * Parameters that correspond to each of the 15 ranges.
507 __be16 rc_range_parameters[DSC_NUM_BUF_RANGES];
510 * PPS88[0] - 0 = Native 4:2:2 not used
511 * 1 = Native 4:2:2 used
512 * PPS88[1] - 0 = Native 4:2:0 not use
513 * 1 = Native 4:2:0 used
514 * PPS88[7:2] - Reserved 6 bits
518 * @second_line_bpg_offset:
519 * PPS89[4:0] - Additional bits/group budget for the
520 * second line of a slice in Native 4:2:0 mode.
521 * Set to 0 if DSC minor version is 1 or native420 is 0.
522 * PPS89[7:5] - Reserved
524 u8 second_line_bpg_offset;
527 * PPS90[7:0], PPS91[7:0] - Number of bits that are deallocated
528 * for each group that is not in the second line of a slice.
530 __be16 nsl_bpg_offset;
532 * @second_line_offset_adj:
533 * PPS92[7:0], PPS93[7:0] - Used as offset adjustment for the second
534 * line in Native 4:2:0 mode.
536 __be16 second_line_offset_adj;
538 * @pps_long_94_reserved:
539 * PPS 94, 95, 96, 97 - Reserved
541 u32 pps_long_94_reserved;
543 * @pps_long_98_reserved:
544 * PPS 98, 99, 100, 101 - Reserved
546 u32 pps_long_98_reserved;
548 * @pps_long_102_reserved:
549 * PPS 102, 103, 104, 105 - Reserved
551 u32 pps_long_102_reserved;
553 * @pps_long_106_reserved:
554 * PPS 106, 107, 108, 109 - reserved
556 u32 pps_long_106_reserved;
558 * @pps_long_110_reserved:
559 * PPS 110, 111, 112, 113 - reserved
561 u32 pps_long_110_reserved;
563 * @pps_long_114_reserved:
564 * PPS 114 - 117 - reserved
566 u32 pps_long_114_reserved;
568 * @pps_long_118_reserved:
569 * PPS 118 - 121 - reserved
571 u32 pps_long_118_reserved;
573 * @pps_long_122_reserved:
574 * PPS 122- 125 - reserved
576 u32 pps_long_122_reserved;
578 * @pps_short_126_reserved:
579 * PPS 126, 127 - reserved
581 __be16 pps_short_126_reserved;
585 * struct drm_dsc_pps_infoframe - DSC infoframe carrying the Picture Parameter
588 * This structure represents the DSC PPS infoframe required to send the Picture
589 * Parameter Set metadata required before enabling VESA Display Stream
590 * Compression. This is based on the DP Secondary Data Packet structure and
591 * comprises of SDP Header as defined &struct struct dp_sdp_header in drm_dp_helper.h
592 * and PPS payload defined in &struct drm_dsc_picture_parameter_set.
594 * @pps_header: Header for PPS as per DP SDP header format of type
595 * &struct dp_sdp_header
596 * @pps_payload: PPS payload fields as per DSC specification Table 4-1
597 * as represented in &struct drm_dsc_picture_parameter_set
599 struct drm_dsc_pps_infoframe {
600 struct dp_sdp_header pps_header;
601 struct drm_dsc_picture_parameter_set pps_payload;
604 void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header);
605 void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_sdp,
606 const struct drm_dsc_config *dsc_cfg);
607 int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg);
609 #endif /* _DRM_DSC_H_ */