1 /*
2  * Copyright 2019 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Author: AMD
23  */
24 
25 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
26 #include "dc_hw_types.h"
27 #include "dsc.h"
28 #include <drm/drm_dp_helper.h>
29 
30 struct dc_dsc_policy {
31 	bool use_min_slices_h;
32 	int max_slices_h; // Maximum available if 0
33 	int min_sice_height; // Must not be less than 8
34 	int max_target_bpp;
35 	int min_target_bpp; // Minimum target bits per pixel
36 };
37 
38 const struct dc_dsc_policy dsc_policy = {
39 	.use_min_slices_h = true, // DSC Policy: Use minimum number of slices that fits the pixel clock
40 	.max_slices_h = 0, // DSC Policy: Use max available slices (in our case 4 for or 8, depending on the mode)
41 	.min_sice_height = 108, // DSC Policy: Use slice height recommended by VESA DSC Spreadsheet user guide
42 	.max_target_bpp = 16,
43 	.min_target_bpp = 8,
44 };
45 
46 
47 /* This module's internal functions */
48 
49 static uint32_t dc_dsc_bandwidth_in_kbps_from_timing(
50 	const struct dc_crtc_timing *timing)
51 {
52 	uint32_t bits_per_channel = 0;
53 	uint32_t kbps;
54 
55 	if (timing->flags.DSC) {
56 		kbps = (timing->pix_clk_100hz * timing->dsc_cfg.bits_per_pixel);
57 		kbps = kbps / 160 + ((kbps % 160) ? 1 : 0);
58 		return kbps;
59 	}
60 
61 	switch (timing->display_color_depth) {
62 	case COLOR_DEPTH_666:
63 		bits_per_channel = 6;
64 		break;
65 	case COLOR_DEPTH_888:
66 		bits_per_channel = 8;
67 		break;
68 	case COLOR_DEPTH_101010:
69 		bits_per_channel = 10;
70 		break;
71 	case COLOR_DEPTH_121212:
72 		bits_per_channel = 12;
73 		break;
74 	case COLOR_DEPTH_141414:
75 		bits_per_channel = 14;
76 		break;
77 	case COLOR_DEPTH_161616:
78 		bits_per_channel = 16;
79 		break;
80 	default:
81 		break;
82 	}
83 
84 	ASSERT(bits_per_channel != 0);
85 
86 	kbps = timing->pix_clk_100hz / 10;
87 	kbps *= bits_per_channel;
88 
89 	if (timing->flags.Y_ONLY != 1) {
90 		/*Only YOnly make reduce bandwidth by 1/3 compares to RGB*/
91 		kbps *= 3;
92 		if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420)
93 			kbps /= 2;
94 		else if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR422)
95 			kbps = kbps * 2 / 3;
96 	}
97 
98 	return kbps;
99 
100 }
101 
102 static bool dsc_buff_block_size_from_dpcd(int dpcd_buff_block_size, int *buff_block_size)
103 {
104 
105 	switch (dpcd_buff_block_size) {
106 	case DP_DSC_RC_BUF_BLK_SIZE_1:
107 		*buff_block_size = 1024;
108 		break;
109 	case DP_DSC_RC_BUF_BLK_SIZE_4:
110 		*buff_block_size = 4 * 1024;
111 		break;
112 	case DP_DSC_RC_BUF_BLK_SIZE_16:
113 		*buff_block_size = 16 * 1024;
114 		break;
115 	case DP_DSC_RC_BUF_BLK_SIZE_64:
116 		*buff_block_size = 64 * 1024;
117 		break;
118 	default: {
119 			dm_error("%s: DPCD DSC buffer size not recognized.\n", __func__);
120 			return false;
121 		}
122 	}
123 
124 	return true;
125 }
126 
127 
128 static bool dsc_line_buff_depth_from_dpcd(int dpcd_line_buff_bit_depth, int *line_buff_bit_depth)
129 {
130 	if (0 <= dpcd_line_buff_bit_depth && dpcd_line_buff_bit_depth <= 7)
131 		*line_buff_bit_depth = dpcd_line_buff_bit_depth + 9;
132 	else if (dpcd_line_buff_bit_depth == 8)
133 		*line_buff_bit_depth = 8;
134 	else {
135 		dm_error("%s: DPCD DSC buffer depth not recognized.\n", __func__);
136 		return false;
137 	}
138 
139 	return true;
140 }
141 
142 
143 static bool dsc_throughput_from_dpcd(int dpcd_throughput, int *throughput)
144 {
145 	switch (dpcd_throughput) {
146 	case DP_DSC_THROUGHPUT_MODE_0_UPSUPPORTED:
147 		*throughput = 0;
148 		break;
149 	case DP_DSC_THROUGHPUT_MODE_0_170:
150 		*throughput = 170;
151 		break;
152 	case DP_DSC_THROUGHPUT_MODE_0_340:
153 		*throughput = 340;
154 		break;
155 	case DP_DSC_THROUGHPUT_MODE_0_400:
156 		*throughput = 400;
157 		break;
158 	case DP_DSC_THROUGHPUT_MODE_0_450:
159 		*throughput = 450;
160 		break;
161 	case DP_DSC_THROUGHPUT_MODE_0_500:
162 		*throughput = 500;
163 		break;
164 	case DP_DSC_THROUGHPUT_MODE_0_550:
165 		*throughput = 550;
166 		break;
167 	case DP_DSC_THROUGHPUT_MODE_0_600:
168 		*throughput = 600;
169 		break;
170 	case DP_DSC_THROUGHPUT_MODE_0_650:
171 		*throughput = 650;
172 		break;
173 	case DP_DSC_THROUGHPUT_MODE_0_700:
174 		*throughput = 700;
175 		break;
176 	case DP_DSC_THROUGHPUT_MODE_0_750:
177 		*throughput = 750;
178 		break;
179 	case DP_DSC_THROUGHPUT_MODE_0_800:
180 		*throughput = 800;
181 		break;
182 	case DP_DSC_THROUGHPUT_MODE_0_850:
183 		*throughput = 850;
184 		break;
185 	case DP_DSC_THROUGHPUT_MODE_0_900:
186 		*throughput = 900;
187 		break;
188 	case DP_DSC_THROUGHPUT_MODE_0_950:
189 		*throughput = 950;
190 		break;
191 	case DP_DSC_THROUGHPUT_MODE_0_1000:
192 		*throughput = 1000;
193 		break;
194 	default: {
195 			dm_error("%s: DPCD DSC throughput mode not recognized.\n", __func__);
196 			return false;
197 		}
198 	}
199 
200 	return true;
201 }
202 
203 
204 static bool dsc_bpp_increment_div_from_dpcd(int bpp_increment_dpcd, uint32_t *bpp_increment_div)
205 {
206 
207 	switch (bpp_increment_dpcd) {
208 	case 0:
209 		*bpp_increment_div = 16;
210 		break;
211 	case 1:
212 		*bpp_increment_div = 8;
213 		break;
214 	case 2:
215 		*bpp_increment_div = 4;
216 		break;
217 	case 3:
218 		*bpp_increment_div = 2;
219 		break;
220 	case 4:
221 		*bpp_increment_div = 1;
222 		break;
223 	default: {
224 		dm_error("%s: DPCD DSC bits-per-pixel increment not recognized.\n", __func__);
225 		return false;
226 	}
227 	}
228 
229 	return true;
230 }
231 
232 static void get_dsc_enc_caps(
233 	const struct display_stream_compressor *dsc,
234 	struct dsc_enc_caps *dsc_enc_caps,
235 	int pixel_clock_100Hz)
236 {
237 	// This is a static HW query, so we can use any DSC
238 
239 	memset(dsc_enc_caps, 0, sizeof(struct dsc_enc_caps));
240 	if (dsc)
241 		dsc->funcs->dsc_get_enc_caps(dsc_enc_caps, pixel_clock_100Hz);
242 }
243 
244 /* Returns 'false' if no intersection was found for at least one capablity.
245  * It also implicitly validates some sink caps against invalid value of zero.
246  */
247 static bool intersect_dsc_caps(
248 	const struct dsc_dec_dpcd_caps *dsc_sink_caps,
249 	const struct dsc_enc_caps *dsc_enc_caps,
250 	enum dc_pixel_encoding pixel_encoding,
251 	struct dsc_enc_caps *dsc_common_caps)
252 {
253 	int32_t max_slices;
254 	int32_t total_sink_throughput;
255 
256 	memset(dsc_common_caps, 0, sizeof(struct dsc_enc_caps));
257 
258 	dsc_common_caps->dsc_version = min(dsc_sink_caps->dsc_version, dsc_enc_caps->dsc_version);
259 	if (!dsc_common_caps->dsc_version)
260 		return false;
261 
262 	dsc_common_caps->slice_caps.bits.NUM_SLICES_1 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_1 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_1;
263 	dsc_common_caps->slice_caps.bits.NUM_SLICES_2 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_2 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_2;
264 	dsc_common_caps->slice_caps.bits.NUM_SLICES_4 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_4 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_4;
265 	dsc_common_caps->slice_caps.bits.NUM_SLICES_8 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_8 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_8;
266 	if (!dsc_common_caps->slice_caps.raw)
267 		return false;
268 
269 	dsc_common_caps->lb_bit_depth = min(dsc_sink_caps->lb_bit_depth, dsc_enc_caps->lb_bit_depth);
270 	if (!dsc_common_caps->lb_bit_depth)
271 		return false;
272 
273 	dsc_common_caps->is_block_pred_supported = dsc_sink_caps->is_block_pred_supported && dsc_enc_caps->is_block_pred_supported;
274 
275 	dsc_common_caps->color_formats.raw = dsc_sink_caps->color_formats.raw & dsc_enc_caps->color_formats.raw;
276 	if (!dsc_common_caps->color_formats.raw)
277 		return false;
278 
279 	dsc_common_caps->color_depth.raw = dsc_sink_caps->color_depth.raw & dsc_enc_caps->color_depth.raw;
280 	if (!dsc_common_caps->color_depth.raw)
281 		return false;
282 
283 	max_slices = 0;
284 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_1)
285 		max_slices = 1;
286 
287 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_2)
288 		max_slices = 2;
289 
290 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_4)
291 		max_slices = 4;
292 
293 	total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_0_mps;
294 	if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
295 		total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_1_mps;
296 
297 	dsc_common_caps->max_total_throughput_mps = min(total_sink_throughput, dsc_enc_caps->max_total_throughput_mps);
298 
299 	dsc_common_caps->max_slice_width = min(dsc_sink_caps->max_slice_width, dsc_enc_caps->max_slice_width);
300 	if (!dsc_common_caps->max_slice_width)
301 		return false;
302 
303 	dsc_common_caps->bpp_increment_div = min(dsc_sink_caps->bpp_increment_div, dsc_enc_caps->bpp_increment_div);
304 
305 	// TODO DSC: Remove this workaround for N422 and 420 once it's fixed, or move it to get_dsc_encoder_caps()
306 	if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
307 		dsc_common_caps->bpp_increment_div = min(dsc_common_caps->bpp_increment_div, (uint32_t)8);
308 
309 	return true;
310 }
311 
312 static inline uint32_t dsc_div_by_10_round_up(uint32_t value)
313 {
314 	return (value + 9) / 10;
315 }
316 
317 static inline uint32_t calc_dsc_bpp_x16(uint32_t stream_bandwidth_kbps, uint32_t pix_clk_100hz, uint32_t bpp_increment_div)
318 {
319 	uint32_t dsc_target_bpp_x16;
320 	float f_dsc_target_bpp;
321 	float f_stream_bandwidth_100bps = stream_bandwidth_kbps * 10.0f;
322 	uint32_t precision = bpp_increment_div; // bpp_increment_div is actually precision
323 
324 	f_dsc_target_bpp = f_stream_bandwidth_100bps / pix_clk_100hz;
325 
326 	// Round down to the nearest precision stop to bring it into DSC spec range
327 	dsc_target_bpp_x16 = (uint32_t)(f_dsc_target_bpp * precision);
328 	dsc_target_bpp_x16 = (dsc_target_bpp_x16 * 16) / precision;
329 
330 	return dsc_target_bpp_x16;
331 }
332 
333 /* Get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range, and timing's pixel clock
334  * and uncompressed bandwidth.
335  */
336 static void get_dsc_bandwidth_range(
337 		const uint32_t min_bpp,
338 		const uint32_t max_bpp,
339 		const struct dsc_enc_caps *dsc_caps,
340 		const struct dc_crtc_timing *timing,
341 		struct dc_dsc_bw_range *range)
342 {
343 	/* native stream bandwidth */
344 	range->stream_kbps = dc_dsc_bandwidth_in_kbps_from_timing(timing);
345 
346 	/* max dsc target bpp */
347 	range->max_kbps = dsc_div_by_10_round_up(max_bpp * timing->pix_clk_100hz);
348 	range->max_target_bpp_x16 = max_bpp * 16;
349 	if (range->max_kbps > range->stream_kbps) {
350 		/* max dsc target bpp is capped to native bandwidth */
351 		range->max_kbps = range->stream_kbps;
352 		range->max_target_bpp_x16 = calc_dsc_bpp_x16(range->stream_kbps, timing->pix_clk_100hz, dsc_caps->bpp_increment_div);
353 	}
354 
355 	/* min dsc target bpp */
356 	range->min_kbps = dsc_div_by_10_round_up(min_bpp * timing->pix_clk_100hz);
357 	range->min_target_bpp_x16 = min_bpp * 16;
358 	if (range->min_kbps > range->max_kbps) {
359 		/* min dsc target bpp is capped to max dsc bandwidth*/
360 		range->min_kbps = range->max_kbps;
361 		range->min_target_bpp_x16 = range->max_target_bpp_x16;
362 	}
363 }
364 
365 
366 /* Decides if DSC should be used and calculates target bpp if it should, applying DSC policy.
367  *
368  * Returns:
369  *     - 'true' if DSC was required by policy and was successfully applied
370  *     - 'false' if DSC was not necessary (e.g. if uncompressed stream fits 'target_bandwidth_kbps'),
371  *        or if it couldn't be applied based on DSC policy.
372  */
373 static bool decide_dsc_target_bpp_x16(
374 		const struct dc_dsc_policy *policy,
375 		const struct dsc_enc_caps *dsc_common_caps,
376 		const int target_bandwidth_kbps,
377 		const struct dc_crtc_timing *timing,
378 		int *target_bpp_x16)
379 {
380 	bool should_use_dsc = false;
381 	struct dc_dsc_bw_range range;
382 
383 	memset(&range, 0, sizeof(range));
384 
385 	get_dsc_bandwidth_range(policy->min_target_bpp, policy->max_target_bpp,
386 			dsc_common_caps, timing, &range);
387 	if (target_bandwidth_kbps >= range.stream_kbps) {
388 		/* enough bandwidth without dsc */
389 		*target_bpp_x16 = 0;
390 		should_use_dsc = false;
391 	} else if (target_bandwidth_kbps >= range.max_kbps) {
392 		/* use max target bpp allowed */
393 		*target_bpp_x16 = range.max_target_bpp_x16;
394 		should_use_dsc = true;
395 	} else if (target_bandwidth_kbps >= range.min_kbps) {
396 		/* use target bpp that can take entire target bandwidth */
397 		*target_bpp_x16 = calc_dsc_bpp_x16(target_bandwidth_kbps, timing->pix_clk_100hz, dsc_common_caps->bpp_increment_div);
398 		should_use_dsc = true;
399 	} else {
400 		/* not enough bandwidth to fulfill minimum requirement */
401 		*target_bpp_x16 = 0;
402 		should_use_dsc = false;
403 	}
404 
405 	return should_use_dsc;
406 }
407 
408 #define MIN_AVAILABLE_SLICES_SIZE  4
409 
410 static int get_available_dsc_slices(union dsc_enc_slice_caps slice_caps, int *available_slices)
411 {
412 	int idx = 0;
413 
414 	memset(available_slices, -1, MIN_AVAILABLE_SLICES_SIZE);
415 
416 	if (slice_caps.bits.NUM_SLICES_1)
417 		available_slices[idx++] = 1;
418 
419 	if (slice_caps.bits.NUM_SLICES_2)
420 		available_slices[idx++] = 2;
421 
422 	if (slice_caps.bits.NUM_SLICES_4)
423 		available_slices[idx++] = 4;
424 
425 	if (slice_caps.bits.NUM_SLICES_8)
426 		available_slices[idx++] = 8;
427 
428 	return idx;
429 }
430 
431 
432 static int get_max_dsc_slices(union dsc_enc_slice_caps slice_caps)
433 {
434 	int max_slices = 0;
435 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
436 	int end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
437 
438 	if (end_idx > 0)
439 		max_slices = available_slices[end_idx - 1];
440 
441 	return max_slices;
442 }
443 
444 
445 // Increment sice number in available sice numbers stops if possible, or just increment if not
446 static int inc_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
447 {
448 	// Get next bigger num slices available in common caps
449 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
450 	int end_idx;
451 	int i;
452 	int new_num_slices = num_slices;
453 
454 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
455 	if (end_idx == 0) {
456 		// No available slices found
457 		new_num_slices++;
458 		return new_num_slices;
459 	}
460 
461 	// Numbers of slices found - get the next bigger number
462 	for (i = 0; i < end_idx; i++) {
463 		if (new_num_slices < available_slices[i]) {
464 			new_num_slices = available_slices[i];
465 			break;
466 		}
467 	}
468 
469 	if (new_num_slices == num_slices) // No biger number of slices found
470 		new_num_slices++;
471 
472 	return new_num_slices;
473 }
474 
475 
476 // Decrement sice number in available sice numbers stops if possible, or just decrement if not. Stop at zero.
477 static int dec_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
478 {
479 	// Get next bigger num slices available in common caps
480 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
481 	int end_idx;
482 	int i;
483 	int new_num_slices = num_slices;
484 
485 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
486 	if (end_idx == 0 && new_num_slices > 0) {
487 		// No numbers of slices found
488 		new_num_slices++;
489 		return new_num_slices;
490 	}
491 
492 	// Numbers of slices found - get the next smaller number
493 	for (i = end_idx - 1; i >= 0; i--) {
494 		if (new_num_slices > available_slices[i]) {
495 			new_num_slices = available_slices[i];
496 			break;
497 		}
498 	}
499 
500 	if (new_num_slices == num_slices) {
501 		// No smaller number of slices found
502 		new_num_slices--;
503 		if (new_num_slices < 0)
504 			new_num_slices = 0;
505 	}
506 
507 	return new_num_slices;
508 }
509 
510 
511 // Choose next bigger number of slices if the requested number of slices is not available
512 static int fit_num_slices_up(union dsc_enc_slice_caps slice_caps, int num_slices)
513 {
514 	// Get next bigger num slices available in common caps
515 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
516 	int end_idx;
517 	int i;
518 	int new_num_slices = num_slices;
519 
520 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
521 	if (end_idx == 0) {
522 		// No available slices found
523 		new_num_slices++;
524 		return new_num_slices;
525 	}
526 
527 	// Numbers of slices found - get the equal or next bigger number
528 	for (i = 0; i < end_idx; i++) {
529 		if (new_num_slices <= available_slices[i]) {
530 			new_num_slices = available_slices[i];
531 			break;
532 		}
533 	}
534 
535 	return new_num_slices;
536 }
537 
538 
539 /* Attempts to set DSC configuration for the stream, applying DSC policy.
540  * Returns 'true' if successful or 'false' if not.
541  *
542  * Parameters:
543  *
544  * dsc_sink_caps       - DSC sink decoder capabilities (from DPCD)
545  *
546  * dsc_enc_caps        - DSC encoder capabilities
547  *
548  * target_bandwidth_kbps  - Target bandwidth to fit the stream into.
549  *                          If 0, do not calculate target bpp.
550  *
551  * timing              - The stream timing to fit into 'target_bandwidth_kbps' or apply
552  *                       maximum compression to, if 'target_badwidth == 0'
553  *
554  * dsc_cfg             - DSC configuration to use if it was possible to come up with
555  *                       one for the given inputs.
556  *                       The target bitrate after DSC can be calculated by multiplying
557  *                       dsc_cfg.bits_per_pixel (in U6.4 format) by pixel rate, e.g.
558  *
559  *                       dsc_stream_bitrate_kbps = (int)ceil(timing->pix_clk_khz * dsc_cfg.bits_per_pixel / 16.0);
560  */
561 static bool setup_dsc_config(
562 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
563 		const struct dsc_enc_caps *dsc_enc_caps,
564 		int target_bandwidth_kbps,
565 		const struct dc_crtc_timing *timing,
566 		int min_slice_height_override,
567 		struct dc_dsc_config *dsc_cfg)
568 {
569 	struct dsc_enc_caps dsc_common_caps;
570 	int max_slices_h;
571 	int min_slices_h;
572 	int num_slices_h;
573 	int pic_width;
574 	int slice_width;
575 	int target_bpp;
576 	int sink_per_slice_throughput_mps;
577 	int branch_max_throughput_mps = 0;
578 	bool is_dsc_possible = false;
579 	int pic_height;
580 	int slice_height;
581 
582 	memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
583 
584 	pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
585 	pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
586 
587 	if (!dsc_sink_caps->is_dsc_supported)
588 		goto done;
589 
590 	if (dsc_sink_caps->branch_max_line_width && dsc_sink_caps->branch_max_line_width < pic_width)
591 		goto done;
592 
593 	// Intersect decoder with encoder DSC caps and validate DSC settings
594 	is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, dsc_enc_caps, timing->pixel_encoding, &dsc_common_caps);
595 	if (!is_dsc_possible)
596 		goto done;
597 
598 	if (target_bandwidth_kbps > 0) {
599 		is_dsc_possible = decide_dsc_target_bpp_x16(&dsc_policy, &dsc_common_caps, target_bandwidth_kbps, timing, &target_bpp);
600 		dsc_cfg->bits_per_pixel = target_bpp;
601 	}
602 	if (!is_dsc_possible)
603 		goto done;
604 
605 	sink_per_slice_throughput_mps = 0;
606 
607 	// Validate available DSC settings against the mode timing
608 
609 	// Validate color format (and pick up the throughput values)
610 	dsc_cfg->ycbcr422_simple = false;
611 	switch (timing->pixel_encoding)	{
612 	case PIXEL_ENCODING_RGB:
613 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.RGB;
614 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
615 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
616 		break;
617 	case PIXEL_ENCODING_YCBCR444:
618 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_444;
619 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
620 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
621 		break;
622 	case PIXEL_ENCODING_YCBCR422:
623 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_422;
624 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
625 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
626 		if (!is_dsc_possible) {
627 			is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_SIMPLE_422;
628 			dsc_cfg->ycbcr422_simple = is_dsc_possible;
629 			sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
630 		}
631 		break;
632 	case PIXEL_ENCODING_YCBCR420:
633 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_420;
634 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
635 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
636 		break;
637 	default:
638 		is_dsc_possible = false;
639 	}
640 
641 	// Validate branch's maximum throughput
642 	if (branch_max_throughput_mps && dsc_div_by_10_round_up(timing->pix_clk_100hz) > branch_max_throughput_mps * 1000)
643 		is_dsc_possible = false;
644 
645 	if (!is_dsc_possible)
646 		goto done;
647 
648 	// Color depth
649 	switch (timing->display_color_depth) {
650 	case COLOR_DEPTH_888:
651 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_8_BPC;
652 		break;
653 	case COLOR_DEPTH_101010:
654 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_10_BPC;
655 		break;
656 	case COLOR_DEPTH_121212:
657 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_12_BPC;
658 		break;
659 	default:
660 		is_dsc_possible = false;
661 	}
662 
663 	if (!is_dsc_possible)
664 		goto done;
665 
666 	// Slice width (i.e. number of slices per line)
667 	max_slices_h = get_max_dsc_slices(dsc_common_caps.slice_caps);
668 
669 	while (max_slices_h > 0) {
670 		if (pic_width % max_slices_h == 0)
671 			break;
672 
673 		max_slices_h = dec_num_slices(dsc_common_caps.slice_caps, max_slices_h);
674 	}
675 
676 	is_dsc_possible = (dsc_common_caps.max_slice_width > 0);
677 	if (!is_dsc_possible)
678 		goto done;
679 
680 	min_slices_h = pic_width / dsc_common_caps.max_slice_width;
681 	if (pic_width % dsc_common_caps.max_slice_width)
682 		min_slices_h++;
683 
684 	min_slices_h = fit_num_slices_up(dsc_common_caps.slice_caps, min_slices_h);
685 
686 	while (min_slices_h <= max_slices_h) {
687 		int pix_clk_per_slice_khz = dsc_div_by_10_round_up(timing->pix_clk_100hz) / min_slices_h;
688 		if (pix_clk_per_slice_khz <= sink_per_slice_throughput_mps * 1000)
689 			break;
690 
691 		min_slices_h = inc_num_slices(dsc_common_caps.slice_caps, min_slices_h);
692 	}
693 
694 	if (pic_width % min_slices_h != 0)
695 		min_slices_h = 0; // DSC TODO: Maybe try increasing the number of slices first?
696 
697 	is_dsc_possible = (min_slices_h <= max_slices_h);
698 	if (!is_dsc_possible)
699 		goto done;
700 
701 	if (dsc_policy.use_min_slices_h) {
702 		if (min_slices_h > 0)
703 			num_slices_h = min_slices_h;
704 		else if (max_slices_h > 0) { // Fall back to max slices if min slices is not working out
705 			if (dsc_policy.max_slices_h)
706 				num_slices_h = min(dsc_policy.max_slices_h, max_slices_h);
707 			else
708 				num_slices_h = max_slices_h;
709 		} else
710 			is_dsc_possible = false;
711 	} else {
712 		if (max_slices_h > 0) {
713 			if (dsc_policy.max_slices_h)
714 				num_slices_h = min(dsc_policy.max_slices_h, max_slices_h);
715 			else
716 				num_slices_h = max_slices_h;
717 		} else if (min_slices_h > 0) // Fall back to min slices if max slices is not possible
718 			num_slices_h = min_slices_h;
719 		else
720 			is_dsc_possible = false;
721 	}
722 
723 	if (!is_dsc_possible)
724 		goto done;
725 
726 	dsc_cfg->num_slices_h = num_slices_h;
727 	slice_width = pic_width / num_slices_h;
728 
729 	is_dsc_possible = slice_width <= dsc_common_caps.max_slice_width;
730 	if (!is_dsc_possible)
731 		goto done;
732 
733 	// Slice height (i.e. number of slices per column): start with policy and pick the first one that height is divisible by.
734 	// For 4:2:0 make sure the slice height is divisible by 2 as well.
735 	if (min_slice_height_override == 0)
736 		slice_height = min(dsc_policy.min_sice_height, pic_height);
737 	else
738 		slice_height = min(min_slice_height_override, pic_height);
739 
740 	while (slice_height < pic_height && (pic_height % slice_height != 0 ||
741 		(timing->pixel_encoding == PIXEL_ENCODING_YCBCR420 && slice_height % 2 != 0)))
742 		slice_height++;
743 
744 	if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420) // For the case when pic_height < dsc_policy.min_sice_height
745 		is_dsc_possible = (slice_height % 2 == 0);
746 
747 	if (!is_dsc_possible)
748 		goto done;
749 
750 	dsc_cfg->num_slices_v = pic_height/slice_height;
751 
752 	// Final decission: can we do DSC or not?
753 	if (is_dsc_possible) {
754 		// Fill out the rest of DSC settings
755 		dsc_cfg->block_pred_enable = dsc_common_caps.is_block_pred_supported;
756 		dsc_cfg->linebuf_depth = dsc_common_caps.lb_bit_depth;
757 		dsc_cfg->version_minor = (dsc_common_caps.dsc_version & 0xf0) >> 4;
758 	}
759 
760 done:
761 	if (!is_dsc_possible)
762 		memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
763 
764 	return is_dsc_possible;
765 }
766 
767 bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_basic_data, const uint8_t *dpcd_dsc_ext_data, struct dsc_dec_dpcd_caps *dsc_sink_caps)
768 {
769 	if (!dpcd_dsc_basic_data)
770 		return false;
771 
772 	dsc_sink_caps->is_dsc_supported = (dpcd_dsc_basic_data[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) != 0;
773 	if (!dsc_sink_caps->is_dsc_supported)
774 		return false;
775 
776 	dsc_sink_caps->dsc_version = dpcd_dsc_basic_data[DP_DSC_REV - DP_DSC_SUPPORT];
777 
778 	{
779 		int buff_block_size;
780 		int buff_size;
781 
782 		if (!dsc_buff_block_size_from_dpcd(dpcd_dsc_basic_data[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT], &buff_block_size))
783 			return false;
784 
785 		buff_size = dpcd_dsc_basic_data[DP_DSC_RC_BUF_SIZE - DP_DSC_SUPPORT] + 1;
786 		dsc_sink_caps->rc_buffer_size = buff_size * buff_block_size;
787 	}
788 
789 	dsc_sink_caps->slice_caps1.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
790 	if (!dsc_line_buff_depth_from_dpcd(dpcd_dsc_basic_data[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT], &dsc_sink_caps->lb_bit_depth))
791 		return false;
792 
793 	dsc_sink_caps->is_block_pred_supported =
794 		(dpcd_dsc_basic_data[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_BLK_PREDICTION_IS_SUPPORTED) != 0;
795 
796 	dsc_sink_caps->edp_max_bits_per_pixel =
797 		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
798 		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] << 8;
799 
800 	dsc_sink_caps->color_formats.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT];
801 	dsc_sink_caps->color_depth.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
802 
803 	{
804 		int dpcd_throughput = dpcd_dsc_basic_data[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT];
805 
806 		if (!dsc_throughput_from_dpcd(dpcd_throughput & DP_DSC_THROUGHPUT_MODE_0_MASK, &dsc_sink_caps->throughput_mode_0_mps))
807 			return false;
808 
809 		dpcd_throughput = (dpcd_throughput & DP_DSC_THROUGHPUT_MODE_1_MASK) >> DP_DSC_THROUGHPUT_MODE_1_SHIFT;
810 		if (!dsc_throughput_from_dpcd(dpcd_throughput, &dsc_sink_caps->throughput_mode_1_mps))
811 			return false;
812 	}
813 
814 	dsc_sink_caps->max_slice_width = dpcd_dsc_basic_data[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 320;
815 	dsc_sink_caps->slice_caps2.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
816 
817 	if (!dsc_bpp_increment_div_from_dpcd(dpcd_dsc_basic_data[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT], &dsc_sink_caps->bpp_increment_div))
818 		return false;
819 
820 	/* Extended caps */
821 	if (dpcd_dsc_ext_data == NULL) { // Extended DPCD DSC data can be null, e.g. because it doesn't apply to SST
822 		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
823 		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
824 		dsc_sink_caps->branch_max_line_width = 0;
825 		return true;
826 	}
827 
828 	dsc_sink_caps->branch_overall_throughput_0_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_0 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
829 	if (dsc_sink_caps->branch_overall_throughput_0_mps == 0)
830 		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
831 	else if (dsc_sink_caps->branch_overall_throughput_0_mps == 1)
832 		dsc_sink_caps->branch_overall_throughput_0_mps = 680;
833 	else {
834 		dsc_sink_caps->branch_overall_throughput_0_mps *= 50;
835 		dsc_sink_caps->branch_overall_throughput_0_mps += 600;
836 	}
837 
838 	dsc_sink_caps->branch_overall_throughput_1_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_1 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
839 	if (dsc_sink_caps->branch_overall_throughput_1_mps == 0)
840 		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
841 	else if (dsc_sink_caps->branch_overall_throughput_1_mps == 1)
842 		dsc_sink_caps->branch_overall_throughput_1_mps = 680;
843 	else {
844 		dsc_sink_caps->branch_overall_throughput_1_mps *= 50;
845 		dsc_sink_caps->branch_overall_throughput_1_mps += 600;
846 	}
847 
848 	dsc_sink_caps->branch_max_line_width = dpcd_dsc_ext_data[DP_DSC_BRANCH_MAX_LINE_WIDTH - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0] * 320;
849 	ASSERT(dsc_sink_caps->branch_max_line_width == 0 || dsc_sink_caps->branch_max_line_width >= 5120);
850 
851 	return true;
852 }
853 
854 
855 /* If DSC is possbile, get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range and
856  * timing's pixel clock and uncompressed bandwidth.
857  * If DSC is not possible, leave '*range' untouched.
858  */
859 bool dc_dsc_compute_bandwidth_range(
860 		const struct display_stream_compressor *dsc,
861 		const uint32_t dsc_min_slice_height_override,
862 		const uint32_t min_bpp,
863 		const uint32_t max_bpp,
864 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
865 		const struct dc_crtc_timing *timing,
866 		struct dc_dsc_bw_range *range)
867 {
868 	bool is_dsc_possible = false;
869 	struct dsc_enc_caps dsc_enc_caps;
870 	struct dsc_enc_caps dsc_common_caps;
871 	struct dc_dsc_config config;
872 
873 	get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
874 
875 	is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, &dsc_enc_caps,
876 			timing->pixel_encoding, &dsc_common_caps);
877 
878 	if (is_dsc_possible)
879 		is_dsc_possible = setup_dsc_config(dsc_sink_caps, &dsc_enc_caps, 0, timing,
880 				dsc_min_slice_height_override, &config);
881 
882 	if (is_dsc_possible)
883 		get_dsc_bandwidth_range(min_bpp, max_bpp, &dsc_common_caps, timing, range);
884 
885 	return is_dsc_possible;
886 }
887 
888 bool dc_dsc_compute_config(
889 		const struct display_stream_compressor *dsc,
890 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
891 		const uint32_t dsc_min_slice_height_override,
892 		uint32_t target_bandwidth_kbps,
893 		const struct dc_crtc_timing *timing,
894 		struct dc_dsc_config *dsc_cfg)
895 {
896 	bool is_dsc_possible = false;
897 	struct dsc_enc_caps dsc_enc_caps;
898 
899 	get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
900 	is_dsc_possible = setup_dsc_config(dsc_sink_caps,
901 			&dsc_enc_caps,
902 			target_bandwidth_kbps,
903 			timing, dsc_min_slice_height_override, dsc_cfg);
904 	return is_dsc_possible;
905 }
906 #endif /* CONFIG_DRM_AMD_DC_DSC_SUPPORT */
907