xref: /linux/drivers/gpu/drm/i915/display/intel_vrr.c (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  *
5  */
6 
7 #include "i915_reg.h"
8 #include "intel_de.h"
9 #include "intel_display_types.h"
10 #include "intel_vrr.h"
11 #include "intel_vrr_regs.h"
12 #include "intel_dp.h"
13 
14 #define FIXED_POINT_PRECISION		100
15 #define CMRR_PRECISION_TOLERANCE	10
16 
intel_vrr_is_capable(struct intel_connector * connector)17 bool intel_vrr_is_capable(struct intel_connector *connector)
18 {
19 	struct intel_display *display = to_intel_display(connector);
20 	const struct drm_display_info *info = &connector->base.display_info;
21 	struct intel_dp *intel_dp;
22 
23 	/*
24 	 * DP Sink is capable of VRR video timings if
25 	 * Ignore MSA bit is set in DPCD.
26 	 * EDID monitor range also should be atleast 10 for reasonable
27 	 * Adaptive Sync or Variable Refresh Rate end user experience.
28 	 */
29 	switch (connector->base.connector_type) {
30 	case DRM_MODE_CONNECTOR_eDP:
31 		if (!connector->panel.vbt.vrr)
32 			return false;
33 		fallthrough;
34 	case DRM_MODE_CONNECTOR_DisplayPort:
35 		intel_dp = intel_attached_dp(connector);
36 
37 		if (!drm_dp_sink_can_do_video_without_timing_msa(intel_dp->dpcd))
38 			return false;
39 
40 		break;
41 	default:
42 		return false;
43 	}
44 
45 	return HAS_VRR(display) &&
46 		info->monitor_range.max_vfreq - info->monitor_range.min_vfreq > 10;
47 }
48 
intel_vrr_is_in_range(struct intel_connector * connector,int vrefresh)49 bool intel_vrr_is_in_range(struct intel_connector *connector, int vrefresh)
50 {
51 	const struct drm_display_info *info = &connector->base.display_info;
52 
53 	return intel_vrr_is_capable(connector) &&
54 		vrefresh >= info->monitor_range.min_vfreq &&
55 		vrefresh <= info->monitor_range.max_vfreq;
56 }
57 
intel_vrr_possible(const struct intel_crtc_state * crtc_state)58 bool intel_vrr_possible(const struct intel_crtc_state *crtc_state)
59 {
60 	return crtc_state->vrr.flipline;
61 }
62 
63 void
intel_vrr_check_modeset(struct intel_atomic_state * state)64 intel_vrr_check_modeset(struct intel_atomic_state *state)
65 {
66 	int i;
67 	struct intel_crtc_state *old_crtc_state, *new_crtc_state;
68 	struct intel_crtc *crtc;
69 
70 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
71 					    new_crtc_state, i) {
72 		if (new_crtc_state->uapi.vrr_enabled !=
73 		    old_crtc_state->uapi.vrr_enabled)
74 			new_crtc_state->uapi.mode_changed = true;
75 	}
76 }
77 
78 /*
79  * Without VRR registers get latched at:
80  *  vblank_start
81  *
82  * With VRR the earliest registers can get latched is:
83  *  intel_vrr_vmin_vblank_start(), which if we want to maintain
84  *  the correct min vtotal is >=vblank_start+1
85  *
86  * The latest point registers can get latched is the vmax decision boundary:
87  *  intel_vrr_vmax_vblank_start()
88  *
89  * Between those two points the vblank exit starts (and hence registers get
90  * latched) ASAP after a push is sent.
91  *
92  * framestart_delay is programmable 1-4.
93  */
intel_vrr_vblank_exit_length(const struct intel_crtc_state * crtc_state)94 static int intel_vrr_vblank_exit_length(const struct intel_crtc_state *crtc_state)
95 {
96 	struct intel_display *display = to_intel_display(crtc_state);
97 
98 	if (DISPLAY_VER(display) >= 13)
99 		return crtc_state->vrr.guardband;
100 	else
101 		/* The hw imposes the extra scanline before frame start */
102 		return crtc_state->vrr.pipeline_full + crtc_state->framestart_delay + 1;
103 }
104 
intel_vrr_vmin_vblank_start(const struct intel_crtc_state * crtc_state)105 int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state)
106 {
107 	/* Min vblank actually determined by flipline that is always >=vmin+1 */
108 	return crtc_state->vrr.vmin + 1 - intel_vrr_vblank_exit_length(crtc_state);
109 }
110 
intel_vrr_vmax_vblank_start(const struct intel_crtc_state * crtc_state)111 int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state)
112 {
113 	return crtc_state->vrr.vmax - intel_vrr_vblank_exit_length(crtc_state);
114 }
115 
116 static bool
is_cmrr_frac_required(struct intel_crtc_state * crtc_state)117 is_cmrr_frac_required(struct intel_crtc_state *crtc_state)
118 {
119 	struct intel_display *display = to_intel_display(crtc_state);
120 	int calculated_refresh_k, actual_refresh_k, pixel_clock_per_line;
121 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
122 
123 	if (!HAS_CMRR(display))
124 		return false;
125 
126 	actual_refresh_k =
127 		drm_mode_vrefresh(adjusted_mode) * FIXED_POINT_PRECISION;
128 	pixel_clock_per_line =
129 		adjusted_mode->crtc_clock * 1000 / adjusted_mode->crtc_htotal;
130 	calculated_refresh_k =
131 		pixel_clock_per_line * FIXED_POINT_PRECISION / adjusted_mode->crtc_vtotal;
132 
133 	if ((actual_refresh_k - calculated_refresh_k) < CMRR_PRECISION_TOLERANCE)
134 		return false;
135 
136 	return true;
137 }
138 
139 static unsigned int
cmrr_get_vtotal(struct intel_crtc_state * crtc_state,bool video_mode_required)140 cmrr_get_vtotal(struct intel_crtc_state *crtc_state, bool video_mode_required)
141 {
142 	int multiplier_m = 1, multiplier_n = 1, vtotal, desired_refresh_rate;
143 	u64 adjusted_pixel_rate;
144 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
145 
146 	desired_refresh_rate = drm_mode_vrefresh(adjusted_mode);
147 
148 	if (video_mode_required) {
149 		multiplier_m = 1001;
150 		multiplier_n = 1000;
151 	}
152 
153 	crtc_state->cmrr.cmrr_n = mul_u32_u32(desired_refresh_rate * adjusted_mode->crtc_htotal,
154 					      multiplier_n);
155 	vtotal = DIV_ROUND_UP_ULL(mul_u32_u32(adjusted_mode->crtc_clock * 1000, multiplier_n),
156 				  crtc_state->cmrr.cmrr_n);
157 	adjusted_pixel_rate = mul_u32_u32(adjusted_mode->crtc_clock * 1000, multiplier_m);
158 	crtc_state->cmrr.cmrr_m = do_div(adjusted_pixel_rate, crtc_state->cmrr.cmrr_n);
159 
160 	return vtotal;
161 }
162 
163 void
intel_vrr_compute_config(struct intel_crtc_state * crtc_state,struct drm_connector_state * conn_state)164 intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
165 			 struct drm_connector_state *conn_state)
166 {
167 	struct intel_display *display = to_intel_display(crtc_state);
168 	struct intel_connector *connector =
169 		to_intel_connector(conn_state->connector);
170 	struct intel_dp *intel_dp = intel_attached_dp(connector);
171 	bool is_edp = intel_dp_is_edp(intel_dp);
172 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
173 	const struct drm_display_info *info = &connector->base.display_info;
174 	int vmin, vmax;
175 
176 	/*
177 	 * FIXME all joined pipes share the same transcoder.
178 	 * Need to account for that during VRR toggle/push/etc.
179 	 */
180 	if (crtc_state->joiner_pipes)
181 		return;
182 
183 	if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
184 		return;
185 
186 	crtc_state->vrr.in_range =
187 		intel_vrr_is_in_range(connector, drm_mode_vrefresh(adjusted_mode));
188 	if (!crtc_state->vrr.in_range)
189 		return;
190 
191 	if (HAS_LRR(display))
192 		crtc_state->update_lrr = true;
193 
194 	vmin = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
195 			    adjusted_mode->crtc_htotal * info->monitor_range.max_vfreq);
196 	vmax = adjusted_mode->crtc_clock * 1000 /
197 		(adjusted_mode->crtc_htotal * info->monitor_range.min_vfreq);
198 
199 	vmin = max_t(int, vmin, adjusted_mode->crtc_vtotal);
200 	vmax = max_t(int, vmax, adjusted_mode->crtc_vtotal);
201 
202 	if (vmin >= vmax)
203 		return;
204 
205 	/*
206 	 * flipline determines the min vblank length the hardware will
207 	 * generate, and flipline>=vmin+1, hence we reduce vmin by one
208 	 * to make sure we can get the actual min vblank length.
209 	 */
210 	crtc_state->vrr.vmin = vmin - 1;
211 	crtc_state->vrr.vmax = vmax;
212 
213 	crtc_state->vrr.flipline = crtc_state->vrr.vmin + 1;
214 
215 	/*
216 	 * When panel is VRR capable and userspace has
217 	 * not enabled adaptive sync mode then Fixed Average
218 	 * Vtotal mode should be enabled.
219 	 */
220 	if (crtc_state->uapi.vrr_enabled) {
221 		crtc_state->vrr.enable = true;
222 		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
223 	} else if (is_cmrr_frac_required(crtc_state) && is_edp) {
224 		crtc_state->vrr.enable = true;
225 		crtc_state->cmrr.enable = true;
226 		/*
227 		 * TODO: Compute precise target refresh rate to determine
228 		 * if video_mode_required should be true. Currently set to
229 		 * false due to uncertainty about the precise target
230 		 * refresh Rate.
231 		 */
232 		crtc_state->vrr.vmax = cmrr_get_vtotal(crtc_state, false);
233 		crtc_state->vrr.vmin = crtc_state->vrr.vmax;
234 		crtc_state->vrr.flipline = crtc_state->vrr.vmin;
235 		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
236 	}
237 
238 	if (intel_dp->as_sdp_supported && crtc_state->vrr.enable) {
239 		crtc_state->vrr.vsync_start =
240 			(crtc_state->hw.adjusted_mode.crtc_vtotal -
241 			 crtc_state->hw.adjusted_mode.vsync_start);
242 		crtc_state->vrr.vsync_end =
243 			(crtc_state->hw.adjusted_mode.crtc_vtotal -
244 			 crtc_state->hw.adjusted_mode.vsync_end);
245 	}
246 }
247 
intel_vrr_compute_config_late(struct intel_crtc_state * crtc_state)248 void intel_vrr_compute_config_late(struct intel_crtc_state *crtc_state)
249 {
250 	struct intel_display *display = to_intel_display(crtc_state);
251 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
252 
253 	if (!intel_vrr_possible(crtc_state))
254 		return;
255 
256 	if (DISPLAY_VER(display) >= 13) {
257 		crtc_state->vrr.guardband =
258 			crtc_state->vrr.vmin + 1 - adjusted_mode->crtc_vblank_start;
259 	} else {
260 		crtc_state->vrr.pipeline_full =
261 			min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vblank_start -
262 			    crtc_state->framestart_delay - 1);
263 	}
264 }
265 
trans_vrr_ctl(const struct intel_crtc_state * crtc_state)266 static u32 trans_vrr_ctl(const struct intel_crtc_state *crtc_state)
267 {
268 	struct intel_display *display = to_intel_display(crtc_state);
269 
270 	if (DISPLAY_VER(display) >= 13)
271 		return VRR_CTL_IGN_MAX_SHIFT | VRR_CTL_FLIP_LINE_EN |
272 			XELPD_VRR_CTL_VRR_GUARDBAND(crtc_state->vrr.guardband);
273 	else
274 		return VRR_CTL_IGN_MAX_SHIFT | VRR_CTL_FLIP_LINE_EN |
275 			VRR_CTL_PIPELINE_FULL(crtc_state->vrr.pipeline_full) |
276 			VRR_CTL_PIPELINE_FULL_OVERRIDE;
277 }
278 
intel_vrr_set_transcoder_timings(const struct intel_crtc_state * crtc_state)279 void intel_vrr_set_transcoder_timings(const struct intel_crtc_state *crtc_state)
280 {
281 	struct intel_display *display = to_intel_display(crtc_state);
282 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
283 
284 	/*
285 	 * This bit seems to have two meanings depending on the platform:
286 	 * TGL: generate VRR "safe window" for DSB vblank waits
287 	 * ADL/DG2: make TRANS_SET_CONTEXT_LATENCY effective with VRR
288 	 */
289 	if (IS_DISPLAY_VER(display, 12, 13))
290 		intel_de_rmw(display, CHICKEN_TRANS(display, cpu_transcoder),
291 			     0, PIPE_VBLANK_WITH_DELAY);
292 
293 	if (!intel_vrr_possible(crtc_state)) {
294 		intel_de_write(display,
295 			       TRANS_VRR_CTL(display, cpu_transcoder), 0);
296 		return;
297 	}
298 
299 	if (crtc_state->cmrr.enable) {
300 		intel_de_write(display, TRANS_CMRR_M_HI(display, cpu_transcoder),
301 			       upper_32_bits(crtc_state->cmrr.cmrr_m));
302 		intel_de_write(display, TRANS_CMRR_M_LO(display, cpu_transcoder),
303 			       lower_32_bits(crtc_state->cmrr.cmrr_m));
304 		intel_de_write(display, TRANS_CMRR_N_HI(display, cpu_transcoder),
305 			       upper_32_bits(crtc_state->cmrr.cmrr_n));
306 		intel_de_write(display, TRANS_CMRR_N_LO(display, cpu_transcoder),
307 			       lower_32_bits(crtc_state->cmrr.cmrr_n));
308 	}
309 
310 	intel_de_write(display, TRANS_VRR_VMIN(display, cpu_transcoder),
311 		       crtc_state->vrr.vmin - 1);
312 	intel_de_write(display, TRANS_VRR_VMAX(display, cpu_transcoder),
313 		       crtc_state->vrr.vmax - 1);
314 	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
315 		       trans_vrr_ctl(crtc_state));
316 	intel_de_write(display, TRANS_VRR_FLIPLINE(display, cpu_transcoder),
317 		       crtc_state->vrr.flipline - 1);
318 }
319 
intel_vrr_send_push(const struct intel_crtc_state * crtc_state)320 void intel_vrr_send_push(const struct intel_crtc_state *crtc_state)
321 {
322 	struct intel_display *display = to_intel_display(crtc_state);
323 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
324 
325 	if (!crtc_state->vrr.enable)
326 		return;
327 
328 	intel_de_write(display, TRANS_PUSH(display, cpu_transcoder),
329 		       TRANS_PUSH_EN | TRANS_PUSH_SEND);
330 }
331 
intel_vrr_is_push_sent(const struct intel_crtc_state * crtc_state)332 bool intel_vrr_is_push_sent(const struct intel_crtc_state *crtc_state)
333 {
334 	struct intel_display *display = to_intel_display(crtc_state);
335 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
336 
337 	if (!crtc_state->vrr.enable)
338 		return false;
339 
340 	return intel_de_read(display, TRANS_PUSH(display, cpu_transcoder)) & TRANS_PUSH_SEND;
341 }
342 
intel_vrr_enable(const struct intel_crtc_state * crtc_state)343 void intel_vrr_enable(const struct intel_crtc_state *crtc_state)
344 {
345 	struct intel_display *display = to_intel_display(crtc_state);
346 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
347 
348 	if (!crtc_state->vrr.enable)
349 		return;
350 
351 	intel_de_write(display, TRANS_PUSH(display, cpu_transcoder),
352 		       TRANS_PUSH_EN);
353 
354 	if (HAS_AS_SDP(display))
355 		intel_de_write(display,
356 			       TRANS_VRR_VSYNC(display, cpu_transcoder),
357 			       VRR_VSYNC_END(crtc_state->vrr.vsync_end) |
358 			       VRR_VSYNC_START(crtc_state->vrr.vsync_start));
359 
360 	if (crtc_state->cmrr.enable) {
361 		intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
362 			       VRR_CTL_VRR_ENABLE | VRR_CTL_CMRR_ENABLE |
363 			       trans_vrr_ctl(crtc_state));
364 	} else {
365 		intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
366 			       VRR_CTL_VRR_ENABLE | trans_vrr_ctl(crtc_state));
367 	}
368 }
369 
intel_vrr_disable(const struct intel_crtc_state * old_crtc_state)370 void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state)
371 {
372 	struct intel_display *display = to_intel_display(old_crtc_state);
373 	enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
374 
375 	if (!old_crtc_state->vrr.enable)
376 		return;
377 
378 	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
379 		       trans_vrr_ctl(old_crtc_state));
380 	intel_de_wait_for_clear(display,
381 				TRANS_VRR_STATUS(display, cpu_transcoder),
382 				VRR_STATUS_VRR_EN_LIVE, 1000);
383 	intel_de_write(display, TRANS_PUSH(display, cpu_transcoder), 0);
384 
385 	if (HAS_AS_SDP(display))
386 		intel_de_write(display,
387 			       TRANS_VRR_VSYNC(display, cpu_transcoder), 0);
388 }
389 
intel_vrr_get_config(struct intel_crtc_state * crtc_state)390 void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
391 {
392 	struct intel_display *display = to_intel_display(crtc_state);
393 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
394 	u32 trans_vrr_ctl, trans_vrr_vsync;
395 
396 	trans_vrr_ctl = intel_de_read(display,
397 				      TRANS_VRR_CTL(display, cpu_transcoder));
398 
399 	crtc_state->vrr.enable = trans_vrr_ctl & VRR_CTL_VRR_ENABLE;
400 	if (HAS_CMRR(display))
401 		crtc_state->cmrr.enable = (trans_vrr_ctl & VRR_CTL_CMRR_ENABLE);
402 
403 	if (crtc_state->cmrr.enable) {
404 		crtc_state->cmrr.cmrr_n =
405 			intel_de_read64_2x32(display, TRANS_CMRR_N_LO(display, cpu_transcoder),
406 					     TRANS_CMRR_N_HI(display, cpu_transcoder));
407 		crtc_state->cmrr.cmrr_m =
408 			intel_de_read64_2x32(display, TRANS_CMRR_M_LO(display, cpu_transcoder),
409 					     TRANS_CMRR_M_HI(display, cpu_transcoder));
410 	}
411 
412 	if (DISPLAY_VER(display) >= 13)
413 		crtc_state->vrr.guardband =
414 			REG_FIELD_GET(XELPD_VRR_CTL_VRR_GUARDBAND_MASK, trans_vrr_ctl);
415 	else
416 		if (trans_vrr_ctl & VRR_CTL_PIPELINE_FULL_OVERRIDE)
417 			crtc_state->vrr.pipeline_full =
418 				REG_FIELD_GET(VRR_CTL_PIPELINE_FULL_MASK, trans_vrr_ctl);
419 
420 	if (trans_vrr_ctl & VRR_CTL_FLIP_LINE_EN) {
421 		crtc_state->vrr.flipline = intel_de_read(display,
422 							 TRANS_VRR_FLIPLINE(display, cpu_transcoder)) + 1;
423 		crtc_state->vrr.vmax = intel_de_read(display,
424 						     TRANS_VRR_VMAX(display, cpu_transcoder)) + 1;
425 		crtc_state->vrr.vmin = intel_de_read(display,
426 						     TRANS_VRR_VMIN(display, cpu_transcoder)) + 1;
427 	}
428 
429 	if (crtc_state->vrr.enable) {
430 		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
431 
432 		if (HAS_AS_SDP(display)) {
433 			trans_vrr_vsync =
434 				intel_de_read(display,
435 					      TRANS_VRR_VSYNC(display, cpu_transcoder));
436 			crtc_state->vrr.vsync_start =
437 				REG_FIELD_GET(VRR_VSYNC_START_MASK, trans_vrr_vsync);
438 			crtc_state->vrr.vsync_end =
439 				REG_FIELD_GET(VRR_VSYNC_END_MASK, trans_vrr_vsync);
440 		}
441 	}
442 }
443