1 /*
2  * Copyright © 2013 Intel Corporation
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 (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Author: Damien Lespiau <damien.lespiau@intel.com>
24  *
25  */
26 
27 #include <linux/circ_buf.h>
28 #include <linux/ctype.h>
29 #include <linux/debugfs.h>
30 #include <linux/seq_file.h>
31 
32 #include "intel_atomic.h"
33 #include "intel_de.h"
34 #include "intel_display_types.h"
35 #include "intel_pipe_crc.h"
36 
37 static const char * const pipe_crc_sources[] = {
38 	[INTEL_PIPE_CRC_SOURCE_NONE] = "none",
39 	[INTEL_PIPE_CRC_SOURCE_PLANE1] = "plane1",
40 	[INTEL_PIPE_CRC_SOURCE_PLANE2] = "plane2",
41 	[INTEL_PIPE_CRC_SOURCE_PLANE3] = "plane3",
42 	[INTEL_PIPE_CRC_SOURCE_PLANE4] = "plane4",
43 	[INTEL_PIPE_CRC_SOURCE_PLANE5] = "plane5",
44 	[INTEL_PIPE_CRC_SOURCE_PLANE6] = "plane6",
45 	[INTEL_PIPE_CRC_SOURCE_PLANE7] = "plane7",
46 	[INTEL_PIPE_CRC_SOURCE_PIPE] = "pipe",
47 	[INTEL_PIPE_CRC_SOURCE_TV] = "TV",
48 	[INTEL_PIPE_CRC_SOURCE_DP_B] = "DP-B",
49 	[INTEL_PIPE_CRC_SOURCE_DP_C] = "DP-C",
50 	[INTEL_PIPE_CRC_SOURCE_DP_D] = "DP-D",
51 	[INTEL_PIPE_CRC_SOURCE_AUTO] = "auto",
52 };
53 
54 static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
55 				 u32 *val)
56 {
57 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
58 		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
59 
60 	switch (*source) {
61 	case INTEL_PIPE_CRC_SOURCE_PIPE:
62 		*val = PIPE_CRC_ENABLE | PIPE_CRC_INCLUDE_BORDER_I8XX;
63 		break;
64 	case INTEL_PIPE_CRC_SOURCE_NONE:
65 		*val = 0;
66 		break;
67 	default:
68 		return -EINVAL;
69 	}
70 
71 	return 0;
72 }
73 
74 static int i9xx_pipe_crc_auto_source(struct drm_i915_private *dev_priv,
75 				     enum pipe pipe,
76 				     enum intel_pipe_crc_source *source)
77 {
78 	struct drm_device *dev = &dev_priv->drm;
79 	struct intel_encoder *encoder;
80 	struct intel_crtc *crtc;
81 	struct intel_digital_port *dig_port;
82 	int ret = 0;
83 
84 	*source = INTEL_PIPE_CRC_SOURCE_PIPE;
85 
86 	drm_modeset_lock_all(dev);
87 	for_each_intel_encoder(dev, encoder) {
88 		if (!encoder->base.crtc)
89 			continue;
90 
91 		crtc = to_intel_crtc(encoder->base.crtc);
92 
93 		if (crtc->pipe != pipe)
94 			continue;
95 
96 		switch (encoder->type) {
97 		case INTEL_OUTPUT_TVOUT:
98 			*source = INTEL_PIPE_CRC_SOURCE_TV;
99 			break;
100 		case INTEL_OUTPUT_DP:
101 		case INTEL_OUTPUT_EDP:
102 			dig_port = enc_to_dig_port(encoder);
103 			switch (dig_port->base.port) {
104 			case PORT_B:
105 				*source = INTEL_PIPE_CRC_SOURCE_DP_B;
106 				break;
107 			case PORT_C:
108 				*source = INTEL_PIPE_CRC_SOURCE_DP_C;
109 				break;
110 			case PORT_D:
111 				*source = INTEL_PIPE_CRC_SOURCE_DP_D;
112 				break;
113 			default:
114 				drm_WARN(dev, 1, "nonexisting DP port %c\n",
115 					 port_name(dig_port->base.port));
116 				break;
117 			}
118 			break;
119 		default:
120 			break;
121 		}
122 	}
123 	drm_modeset_unlock_all(dev);
124 
125 	return ret;
126 }
127 
128 static int vlv_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
129 				enum pipe pipe,
130 				enum intel_pipe_crc_source *source,
131 				u32 *val)
132 {
133 	bool need_stable_symbols = false;
134 
135 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
136 		int ret = i9xx_pipe_crc_auto_source(dev_priv, pipe, source);
137 		if (ret)
138 			return ret;
139 	}
140 
141 	switch (*source) {
142 	case INTEL_PIPE_CRC_SOURCE_PIPE:
143 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_VLV;
144 		break;
145 	case INTEL_PIPE_CRC_SOURCE_DP_B:
146 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_B_VLV;
147 		need_stable_symbols = true;
148 		break;
149 	case INTEL_PIPE_CRC_SOURCE_DP_C:
150 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_C_VLV;
151 		need_stable_symbols = true;
152 		break;
153 	case INTEL_PIPE_CRC_SOURCE_DP_D:
154 		if (!IS_CHERRYVIEW(dev_priv))
155 			return -EINVAL;
156 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_D_VLV;
157 		need_stable_symbols = true;
158 		break;
159 	case INTEL_PIPE_CRC_SOURCE_NONE:
160 		*val = 0;
161 		break;
162 	default:
163 		return -EINVAL;
164 	}
165 
166 	/*
167 	 * When the pipe CRC tap point is after the transcoders we need
168 	 * to tweak symbol-level features to produce a deterministic series of
169 	 * symbols for a given frame. We need to reset those features only once
170 	 * a frame (instead of every nth symbol):
171 	 *   - DC-balance: used to ensure a better clock recovery from the data
172 	 *     link (SDVO)
173 	 *   - DisplayPort scrambling: used for EMI reduction
174 	 */
175 	if (need_stable_symbols) {
176 		u32 tmp = intel_de_read(dev_priv, PORT_DFT2_G4X);
177 
178 		tmp |= DC_BALANCE_RESET_VLV;
179 		switch (pipe) {
180 		case PIPE_A:
181 			tmp |= PIPE_A_SCRAMBLE_RESET;
182 			break;
183 		case PIPE_B:
184 			tmp |= PIPE_B_SCRAMBLE_RESET;
185 			break;
186 		case PIPE_C:
187 			tmp |= PIPE_C_SCRAMBLE_RESET;
188 			break;
189 		default:
190 			return -EINVAL;
191 		}
192 		intel_de_write(dev_priv, PORT_DFT2_G4X, tmp);
193 	}
194 
195 	return 0;
196 }
197 
198 static int i9xx_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
199 				 enum pipe pipe,
200 				 enum intel_pipe_crc_source *source,
201 				 u32 *val)
202 {
203 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
204 		int ret = i9xx_pipe_crc_auto_source(dev_priv, pipe, source);
205 		if (ret)
206 			return ret;
207 	}
208 
209 	switch (*source) {
210 	case INTEL_PIPE_CRC_SOURCE_PIPE:
211 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_I9XX;
212 		break;
213 	case INTEL_PIPE_CRC_SOURCE_TV:
214 		if (!SUPPORTS_TV(dev_priv))
215 			return -EINVAL;
216 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_TV_PRE;
217 		break;
218 	case INTEL_PIPE_CRC_SOURCE_NONE:
219 		*val = 0;
220 		break;
221 	default:
222 		/*
223 		 * The DP CRC source doesn't work on g4x.
224 		 * It can be made to work to some degree by selecting
225 		 * the correct CRC source before the port is enabled,
226 		 * and not touching the CRC source bits again until
227 		 * the port is disabled. But even then the bits
228 		 * eventually get stuck and a reboot is needed to get
229 		 * working CRCs on the pipe again. Let's simply
230 		 * refuse to use DP CRCs on g4x.
231 		 */
232 		return -EINVAL;
233 	}
234 
235 	return 0;
236 }
237 
238 static void vlv_undo_pipe_scramble_reset(struct drm_i915_private *dev_priv,
239 					 enum pipe pipe)
240 {
241 	u32 tmp = intel_de_read(dev_priv, PORT_DFT2_G4X);
242 
243 	switch (pipe) {
244 	case PIPE_A:
245 		tmp &= ~PIPE_A_SCRAMBLE_RESET;
246 		break;
247 	case PIPE_B:
248 		tmp &= ~PIPE_B_SCRAMBLE_RESET;
249 		break;
250 	case PIPE_C:
251 		tmp &= ~PIPE_C_SCRAMBLE_RESET;
252 		break;
253 	default:
254 		return;
255 	}
256 	if (!(tmp & PIPE_SCRAMBLE_RESET_MASK))
257 		tmp &= ~DC_BALANCE_RESET_VLV;
258 	intel_de_write(dev_priv, PORT_DFT2_G4X, tmp);
259 }
260 
261 static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
262 				u32 *val)
263 {
264 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
265 		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
266 
267 	switch (*source) {
268 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
269 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_ILK;
270 		break;
271 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
272 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_ILK;
273 		break;
274 	case INTEL_PIPE_CRC_SOURCE_PIPE:
275 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_ILK;
276 		break;
277 	case INTEL_PIPE_CRC_SOURCE_NONE:
278 		*val = 0;
279 		break;
280 	default:
281 		return -EINVAL;
282 	}
283 
284 	return 0;
285 }
286 
287 static void
288 intel_crtc_crc_setup_workarounds(struct intel_crtc *crtc, bool enable)
289 {
290 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
291 	struct intel_crtc_state *pipe_config;
292 	struct drm_atomic_state *state;
293 	struct drm_modeset_acquire_ctx ctx;
294 	int ret;
295 
296 	drm_modeset_acquire_init(&ctx, 0);
297 
298 	state = drm_atomic_state_alloc(&dev_priv->drm);
299 	if (!state) {
300 		ret = -ENOMEM;
301 		goto unlock;
302 	}
303 
304 	state->acquire_ctx = &ctx;
305 
306 retry:
307 	pipe_config = intel_atomic_get_crtc_state(state, crtc);
308 	if (IS_ERR(pipe_config)) {
309 		ret = PTR_ERR(pipe_config);
310 		goto put_state;
311 	}
312 
313 	pipe_config->uapi.mode_changed = pipe_config->has_psr;
314 	pipe_config->crc_enabled = enable;
315 
316 	if (IS_HASWELL(dev_priv) &&
317 	    pipe_config->hw.active && crtc->pipe == PIPE_A &&
318 	    pipe_config->cpu_transcoder == TRANSCODER_EDP)
319 		pipe_config->uapi.mode_changed = true;
320 
321 	ret = drm_atomic_commit(state);
322 
323 put_state:
324 	if (ret == -EDEADLK) {
325 		drm_atomic_state_clear(state);
326 		drm_modeset_backoff(&ctx);
327 		goto retry;
328 	}
329 
330 	drm_atomic_state_put(state);
331 unlock:
332 	drm_WARN(&dev_priv->drm, ret,
333 		 "Toggling workaround to %i returns %i\n", enable, ret);
334 	drm_modeset_drop_locks(&ctx);
335 	drm_modeset_acquire_fini(&ctx);
336 }
337 
338 static int ivb_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
339 				enum pipe pipe,
340 				enum intel_pipe_crc_source *source,
341 				u32 *val)
342 {
343 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
344 		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
345 
346 	switch (*source) {
347 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
348 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_IVB;
349 		break;
350 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
351 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
352 		break;
353 	case INTEL_PIPE_CRC_SOURCE_PIPE:
354 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
355 		break;
356 	case INTEL_PIPE_CRC_SOURCE_NONE:
357 		*val = 0;
358 		break;
359 	default:
360 		return -EINVAL;
361 	}
362 
363 	return 0;
364 }
365 
366 static int skl_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
367 				enum pipe pipe,
368 				enum intel_pipe_crc_source *source,
369 				u32 *val)
370 {
371 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
372 		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
373 
374 	switch (*source) {
375 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
376 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_1_SKL;
377 		break;
378 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
379 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_2_SKL;
380 		break;
381 	case INTEL_PIPE_CRC_SOURCE_PLANE3:
382 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_3_SKL;
383 		break;
384 	case INTEL_PIPE_CRC_SOURCE_PLANE4:
385 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_4_SKL;
386 		break;
387 	case INTEL_PIPE_CRC_SOURCE_PLANE5:
388 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_5_SKL;
389 		break;
390 	case INTEL_PIPE_CRC_SOURCE_PLANE6:
391 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_6_SKL;
392 		break;
393 	case INTEL_PIPE_CRC_SOURCE_PLANE7:
394 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PLANE_7_SKL;
395 		break;
396 	case INTEL_PIPE_CRC_SOURCE_PIPE:
397 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DMUX_SKL;
398 		break;
399 	case INTEL_PIPE_CRC_SOURCE_NONE:
400 		*val = 0;
401 		break;
402 	default:
403 		return -EINVAL;
404 	}
405 
406 	return 0;
407 }
408 
409 static int get_new_crc_ctl_reg(struct drm_i915_private *dev_priv,
410 			       enum pipe pipe,
411 			       enum intel_pipe_crc_source *source, u32 *val)
412 {
413 	if (DISPLAY_VER(dev_priv) == 2)
414 		return i8xx_pipe_crc_ctl_reg(source, val);
415 	else if (DISPLAY_VER(dev_priv) < 5)
416 		return i9xx_pipe_crc_ctl_reg(dev_priv, pipe, source, val);
417 	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
418 		return vlv_pipe_crc_ctl_reg(dev_priv, pipe, source, val);
419 	else if (IS_IRONLAKE(dev_priv) || IS_SANDYBRIDGE(dev_priv))
420 		return ilk_pipe_crc_ctl_reg(source, val);
421 	else if (DISPLAY_VER(dev_priv) < 9)
422 		return ivb_pipe_crc_ctl_reg(dev_priv, pipe, source, val);
423 	else
424 		return skl_pipe_crc_ctl_reg(dev_priv, pipe, source, val);
425 }
426 
427 static int
428 display_crc_ctl_parse_source(const char *buf, enum intel_pipe_crc_source *s)
429 {
430 	int i;
431 
432 	if (!buf) {
433 		*s = INTEL_PIPE_CRC_SOURCE_NONE;
434 		return 0;
435 	}
436 
437 	i = match_string(pipe_crc_sources, ARRAY_SIZE(pipe_crc_sources), buf);
438 	if (i < 0)
439 		return i;
440 
441 	*s = i;
442 	return 0;
443 }
444 
445 void intel_crtc_crc_init(struct intel_crtc *crtc)
446 {
447 	struct intel_pipe_crc *pipe_crc = &crtc->pipe_crc;
448 
449 	spin_lock_init(&pipe_crc->lock);
450 }
451 
452 static int i8xx_crc_source_valid(struct drm_i915_private *dev_priv,
453 				 const enum intel_pipe_crc_source source)
454 {
455 	switch (source) {
456 	case INTEL_PIPE_CRC_SOURCE_PIPE:
457 	case INTEL_PIPE_CRC_SOURCE_NONE:
458 		return 0;
459 	default:
460 		return -EINVAL;
461 	}
462 }
463 
464 static int i9xx_crc_source_valid(struct drm_i915_private *dev_priv,
465 				 const enum intel_pipe_crc_source source)
466 {
467 	switch (source) {
468 	case INTEL_PIPE_CRC_SOURCE_PIPE:
469 	case INTEL_PIPE_CRC_SOURCE_TV:
470 	case INTEL_PIPE_CRC_SOURCE_NONE:
471 		return 0;
472 	default:
473 		return -EINVAL;
474 	}
475 }
476 
477 static int vlv_crc_source_valid(struct drm_i915_private *dev_priv,
478 				const enum intel_pipe_crc_source source)
479 {
480 	switch (source) {
481 	case INTEL_PIPE_CRC_SOURCE_PIPE:
482 	case INTEL_PIPE_CRC_SOURCE_DP_B:
483 	case INTEL_PIPE_CRC_SOURCE_DP_C:
484 	case INTEL_PIPE_CRC_SOURCE_DP_D:
485 	case INTEL_PIPE_CRC_SOURCE_NONE:
486 		return 0;
487 	default:
488 		return -EINVAL;
489 	}
490 }
491 
492 static int ilk_crc_source_valid(struct drm_i915_private *dev_priv,
493 				const enum intel_pipe_crc_source source)
494 {
495 	switch (source) {
496 	case INTEL_PIPE_CRC_SOURCE_PIPE:
497 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
498 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
499 	case INTEL_PIPE_CRC_SOURCE_NONE:
500 		return 0;
501 	default:
502 		return -EINVAL;
503 	}
504 }
505 
506 static int ivb_crc_source_valid(struct drm_i915_private *dev_priv,
507 				const enum intel_pipe_crc_source source)
508 {
509 	switch (source) {
510 	case INTEL_PIPE_CRC_SOURCE_PIPE:
511 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
512 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
513 	case INTEL_PIPE_CRC_SOURCE_NONE:
514 		return 0;
515 	default:
516 		return -EINVAL;
517 	}
518 }
519 
520 static int skl_crc_source_valid(struct drm_i915_private *dev_priv,
521 				const enum intel_pipe_crc_source source)
522 {
523 	switch (source) {
524 	case INTEL_PIPE_CRC_SOURCE_PIPE:
525 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
526 	case INTEL_PIPE_CRC_SOURCE_PLANE2:
527 	case INTEL_PIPE_CRC_SOURCE_PLANE3:
528 	case INTEL_PIPE_CRC_SOURCE_PLANE4:
529 	case INTEL_PIPE_CRC_SOURCE_PLANE5:
530 	case INTEL_PIPE_CRC_SOURCE_PLANE6:
531 	case INTEL_PIPE_CRC_SOURCE_PLANE7:
532 	case INTEL_PIPE_CRC_SOURCE_NONE:
533 		return 0;
534 	default:
535 		return -EINVAL;
536 	}
537 }
538 
539 static int
540 intel_is_valid_crc_source(struct drm_i915_private *dev_priv,
541 			  const enum intel_pipe_crc_source source)
542 {
543 	if (DISPLAY_VER(dev_priv) == 2)
544 		return i8xx_crc_source_valid(dev_priv, source);
545 	else if (DISPLAY_VER(dev_priv) < 5)
546 		return i9xx_crc_source_valid(dev_priv, source);
547 	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
548 		return vlv_crc_source_valid(dev_priv, source);
549 	else if (IS_IRONLAKE(dev_priv) || IS_SANDYBRIDGE(dev_priv))
550 		return ilk_crc_source_valid(dev_priv, source);
551 	else if (DISPLAY_VER(dev_priv) < 9)
552 		return ivb_crc_source_valid(dev_priv, source);
553 	else
554 		return skl_crc_source_valid(dev_priv, source);
555 }
556 
557 const char *const *intel_crtc_get_crc_sources(struct drm_crtc *crtc,
558 					      size_t *count)
559 {
560 	*count = ARRAY_SIZE(pipe_crc_sources);
561 	return pipe_crc_sources;
562 }
563 
564 int intel_crtc_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
565 				 size_t *values_cnt)
566 {
567 	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
568 	enum intel_pipe_crc_source source;
569 
570 	if (display_crc_ctl_parse_source(source_name, &source) < 0) {
571 		drm_dbg(&dev_priv->drm, "unknown source %s\n", source_name);
572 		return -EINVAL;
573 	}
574 
575 	if (source == INTEL_PIPE_CRC_SOURCE_AUTO ||
576 	    intel_is_valid_crc_source(dev_priv, source) == 0) {
577 		*values_cnt = 5;
578 		return 0;
579 	}
580 
581 	return -EINVAL;
582 }
583 
584 int intel_crtc_set_crc_source(struct drm_crtc *_crtc, const char *source_name)
585 {
586 	struct intel_crtc *crtc = to_intel_crtc(_crtc);
587 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
588 	struct intel_pipe_crc *pipe_crc = &crtc->pipe_crc;
589 	enum intel_display_power_domain power_domain;
590 	enum intel_pipe_crc_source source;
591 	enum pipe pipe = crtc->pipe;
592 	intel_wakeref_t wakeref;
593 	u32 val = 0; /* shut up gcc */
594 	int ret = 0;
595 	bool enable;
596 
597 	if (display_crc_ctl_parse_source(source_name, &source) < 0) {
598 		drm_dbg(&dev_priv->drm, "unknown source %s\n", source_name);
599 		return -EINVAL;
600 	}
601 
602 	power_domain = POWER_DOMAIN_PIPE(pipe);
603 	wakeref = intel_display_power_get_if_enabled(dev_priv, power_domain);
604 	if (!wakeref) {
605 		drm_dbg_kms(&dev_priv->drm,
606 			    "Trying to capture CRC while pipe is off\n");
607 		return -EIO;
608 	}
609 
610 	enable = source != INTEL_PIPE_CRC_SOURCE_NONE;
611 	if (enable)
612 		intel_crtc_crc_setup_workarounds(crtc, true);
613 
614 	ret = get_new_crc_ctl_reg(dev_priv, pipe, &source, &val);
615 	if (ret != 0)
616 		goto out;
617 
618 	pipe_crc->source = source;
619 	intel_de_write(dev_priv, PIPE_CRC_CTL(pipe), val);
620 	intel_de_posting_read(dev_priv, PIPE_CRC_CTL(pipe));
621 
622 	if (!source) {
623 		if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
624 			vlv_undo_pipe_scramble_reset(dev_priv, pipe);
625 	}
626 
627 	pipe_crc->skipped = 0;
628 
629 out:
630 	if (!enable)
631 		intel_crtc_crc_setup_workarounds(crtc, false);
632 
633 	intel_display_power_put(dev_priv, power_domain, wakeref);
634 
635 	return ret;
636 }
637 
638 void intel_crtc_enable_pipe_crc(struct intel_crtc *crtc)
639 {
640 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
641 	struct intel_pipe_crc *pipe_crc = &crtc->pipe_crc;
642 	enum pipe pipe = crtc->pipe;
643 	u32 val = 0;
644 
645 	if (!crtc->base.crc.opened)
646 		return;
647 
648 	if (get_new_crc_ctl_reg(dev_priv, pipe, &pipe_crc->source, &val) < 0)
649 		return;
650 
651 	/* Don't need pipe_crc->lock here, IRQs are not generated. */
652 	pipe_crc->skipped = 0;
653 
654 	intel_de_write(dev_priv, PIPE_CRC_CTL(pipe), val);
655 	intel_de_posting_read(dev_priv, PIPE_CRC_CTL(pipe));
656 }
657 
658 void intel_crtc_disable_pipe_crc(struct intel_crtc *crtc)
659 {
660 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
661 	struct intel_pipe_crc *pipe_crc = &crtc->pipe_crc;
662 	enum pipe pipe = crtc->pipe;
663 
664 	/* Swallow crc's until we stop generating them. */
665 	spin_lock_irq(&pipe_crc->lock);
666 	pipe_crc->skipped = INT_MIN;
667 	spin_unlock_irq(&pipe_crc->lock);
668 
669 	intel_de_write(dev_priv, PIPE_CRC_CTL(pipe), 0);
670 	intel_de_posting_read(dev_priv, PIPE_CRC_CTL(pipe));
671 	intel_synchronize_irq(dev_priv);
672 }
673