1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  *
5  */
6 
7 #include "i915_drv.h"
8 #include "intel_de.h"
9 #include "intel_display_types.h"
10 #include "intel_vrr.h"
11 
12 bool intel_vrr_is_capable(struct drm_connector *connector)
13 {
14 	struct intel_dp *intel_dp;
15 	const struct drm_display_info *info = &connector->display_info;
16 	struct drm_i915_private *i915 = to_i915(connector->dev);
17 
18 	if (connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
19 	    connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort)
20 		return false;
21 
22 	intel_dp = intel_attached_dp(to_intel_connector(connector));
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 	return HAS_VRR(i915) &&
30 		drm_dp_sink_can_do_video_without_timing_msa(intel_dp->dpcd) &&
31 		info->monitor_range.max_vfreq - info->monitor_range.min_vfreq > 10;
32 }
33 
34 void
35 intel_vrr_check_modeset(struct intel_atomic_state *state)
36 {
37 	int i;
38 	struct intel_crtc_state *old_crtc_state, *new_crtc_state;
39 	struct intel_crtc *crtc;
40 
41 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
42 					    new_crtc_state, i) {
43 		if (new_crtc_state->uapi.vrr_enabled !=
44 		    old_crtc_state->uapi.vrr_enabled)
45 			new_crtc_state->uapi.mode_changed = true;
46 	}
47 }
48 
49 /*
50  * Without VRR registers get latched at:
51  *  vblank_start
52  *
53  * With VRR the earliest registers can get latched is:
54  *  intel_vrr_vmin_vblank_start(), which if we want to maintain
55  *  the correct min vtotal is >=vblank_start+1
56  *
57  * The latest point registers can get latched is the vmax decision boundary:
58  *  intel_vrr_vmax_vblank_start()
59  *
60  * Between those two points the vblank exit starts (and hence registers get
61  * latched) ASAP after a push is sent.
62  *
63  * framestart_delay is programmable 0-3.
64  */
65 static int intel_vrr_vblank_exit_length(const struct intel_crtc_state *crtc_state)
66 {
67 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
68 	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
69 
70 	/* The hw imposes the extra scanline before frame start */
71 	if (DISPLAY_VER(i915) >= 13)
72 		return crtc_state->vrr.guardband + i915->framestart_delay + 1;
73 	else
74 		return crtc_state->vrr.pipeline_full + i915->framestart_delay + 1;
75 }
76 
77 int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state)
78 {
79 	/* Min vblank actually determined by flipline that is always >=vmin+1 */
80 	return crtc_state->vrr.vmin + 1 - intel_vrr_vblank_exit_length(crtc_state);
81 }
82 
83 int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state)
84 {
85 	return crtc_state->vrr.vmax - intel_vrr_vblank_exit_length(crtc_state);
86 }
87 
88 void
89 intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
90 			 struct drm_connector_state *conn_state)
91 {
92 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
93 	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
94 	struct intel_connector *connector =
95 		to_intel_connector(conn_state->connector);
96 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
97 	const struct drm_display_info *info = &connector->base.display_info;
98 	int vmin, vmax;
99 
100 	if (!intel_vrr_is_capable(&connector->base))
101 		return;
102 
103 	if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
104 		return;
105 
106 	if (!crtc_state->uapi.vrr_enabled)
107 		return;
108 
109 	vmin = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
110 			    adjusted_mode->crtc_htotal * info->monitor_range.max_vfreq);
111 	vmax = adjusted_mode->crtc_clock * 1000 /
112 		(adjusted_mode->crtc_htotal * info->monitor_range.min_vfreq);
113 
114 	vmin = max_t(int, vmin, adjusted_mode->crtc_vtotal);
115 	vmax = max_t(int, vmax, adjusted_mode->crtc_vtotal);
116 
117 	if (vmin >= vmax)
118 		return;
119 
120 	/*
121 	 * flipline determines the min vblank length the hardware will
122 	 * generate, and flipline>=vmin+1, hence we reduce vmin by one
123 	 * to make sure we can get the actual min vblank length.
124 	 */
125 	crtc_state->vrr.vmin = vmin - 1;
126 	crtc_state->vrr.vmax = vmax;
127 	crtc_state->vrr.enable = true;
128 
129 	crtc_state->vrr.flipline = crtc_state->vrr.vmin + 1;
130 
131 	/*
132 	 * For XE_LPD+, we use guardband and pipeline override
133 	 * is deprecated.
134 	 */
135 	if (DISPLAY_VER(i915) >= 13)
136 		crtc_state->vrr.guardband =
137 			crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay -
138 			i915->window2_delay;
139 	else
140 		/*
141 		 * FIXME: s/4/framestart_delay+1/ to get consistent
142 		 * earliest/latest points for register latching regardless
143 		 * of the framestart_delay used?
144 		 *
145 		 * FIXME: this really needs the extra scanline to provide consistent
146 		 * behaviour for all framestart_delay values. Otherwise with
147 		 * framestart_delay==3 we will end up extending the min vblank by
148 		 * one extra line.
149 		 */
150 		crtc_state->vrr.pipeline_full =
151 			min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay - 4 - 1);
152 
153 	crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
154 }
155 
156 void intel_vrr_enable(struct intel_encoder *encoder,
157 		      const struct intel_crtc_state *crtc_state)
158 {
159 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
160 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
161 	u32 trans_vrr_ctl;
162 
163 	if (!crtc_state->vrr.enable)
164 		return;
165 
166 	if (DISPLAY_VER(dev_priv) >= 13)
167 		trans_vrr_ctl = VRR_CTL_VRR_ENABLE |
168 			VRR_CTL_IGN_MAX_SHIFT | VRR_CTL_FLIP_LINE_EN |
169 			XELPD_VRR_CTL_VRR_GUARDBAND(crtc_state->vrr.guardband);
170 	else
171 		trans_vrr_ctl = VRR_CTL_VRR_ENABLE |
172 			VRR_CTL_IGN_MAX_SHIFT | VRR_CTL_FLIP_LINE_EN |
173 			VRR_CTL_PIPELINE_FULL(crtc_state->vrr.pipeline_full) |
174 			VRR_CTL_PIPELINE_FULL_OVERRIDE;
175 
176 	intel_de_write(dev_priv, TRANS_VRR_VMIN(cpu_transcoder), crtc_state->vrr.vmin - 1);
177 	intel_de_write(dev_priv, TRANS_VRR_VMAX(cpu_transcoder), crtc_state->vrr.vmax - 1);
178 	intel_de_write(dev_priv, TRANS_VRR_CTL(cpu_transcoder), trans_vrr_ctl);
179 	intel_de_write(dev_priv, TRANS_VRR_FLIPLINE(cpu_transcoder), crtc_state->vrr.flipline - 1);
180 	intel_de_write(dev_priv, TRANS_PUSH(cpu_transcoder), TRANS_PUSH_EN);
181 }
182 
183 void intel_vrr_send_push(const struct intel_crtc_state *crtc_state)
184 {
185 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
186 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
187 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
188 
189 	if (!crtc_state->vrr.enable)
190 		return;
191 
192 	intel_de_write(dev_priv, TRANS_PUSH(cpu_transcoder),
193 		       TRANS_PUSH_EN | TRANS_PUSH_SEND);
194 }
195 
196 void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state)
197 {
198 	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
199 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
200 	enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
201 
202 	if (!old_crtc_state->vrr.enable)
203 		return;
204 
205 	intel_de_write(dev_priv, TRANS_VRR_CTL(cpu_transcoder), 0);
206 	intel_de_write(dev_priv, TRANS_PUSH(cpu_transcoder), 0);
207 }
208 
209 void intel_vrr_get_config(struct intel_crtc *crtc,
210 			  struct intel_crtc_state *crtc_state)
211 {
212 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
213 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
214 	u32 trans_vrr_ctl;
215 
216 	trans_vrr_ctl = intel_de_read(dev_priv, TRANS_VRR_CTL(cpu_transcoder));
217 	crtc_state->vrr.enable = trans_vrr_ctl & VRR_CTL_VRR_ENABLE;
218 	if (!crtc_state->vrr.enable)
219 		return;
220 
221 	if (DISPLAY_VER(dev_priv) >= 13)
222 		crtc_state->vrr.guardband =
223 			REG_FIELD_GET(XELPD_VRR_CTL_VRR_GUARDBAND_MASK, trans_vrr_ctl);
224 	else
225 		if (trans_vrr_ctl & VRR_CTL_PIPELINE_FULL_OVERRIDE)
226 			crtc_state->vrr.pipeline_full =
227 				REG_FIELD_GET(VRR_CTL_PIPELINE_FULL_MASK, trans_vrr_ctl);
228 	if (trans_vrr_ctl & VRR_CTL_FLIP_LINE_EN)
229 		crtc_state->vrr.flipline = intel_de_read(dev_priv, TRANS_VRR_FLIPLINE(cpu_transcoder)) + 1;
230 	crtc_state->vrr.vmax = intel_de_read(dev_priv, TRANS_VRR_VMAX(cpu_transcoder)) + 1;
231 	crtc_state->vrr.vmin = intel_de_read(dev_priv, TRANS_VRR_VMIN(cpu_transcoder)) + 1;
232 
233 	crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
234 }
235