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94223d04 ACO |
1 | /* |
2 | * Copyright © 2008-2015 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 | ||
24 | #include "intel_drv.h" | |
25 | ||
8ab5de2e PD |
26 | static void |
27 | intel_dp_dump_link_status(const uint8_t link_status[DP_LINK_STATUS_SIZE]) | |
28 | { | |
29 | ||
30 | DRM_DEBUG_KMS("ln0_1:0x%x ln2_3:0x%x align:0x%x sink:0x%x adj_req0_1:0x%x adj_req2_3:0x%x", | |
31 | link_status[0], link_status[1], link_status[2], | |
32 | link_status[3], link_status[4], link_status[5]); | |
33 | } | |
34 | ||
94223d04 ACO |
35 | static void |
36 | intel_get_adjust_train(struct intel_dp *intel_dp, | |
37 | const uint8_t link_status[DP_LINK_STATUS_SIZE]) | |
38 | { | |
39 | uint8_t v = 0; | |
40 | uint8_t p = 0; | |
41 | int lane; | |
42 | uint8_t voltage_max; | |
43 | uint8_t preemph_max; | |
44 | ||
45 | for (lane = 0; lane < intel_dp->lane_count; lane++) { | |
46 | uint8_t this_v = drm_dp_get_adjust_request_voltage(link_status, lane); | |
47 | uint8_t this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane); | |
48 | ||
49 | if (this_v > v) | |
50 | v = this_v; | |
51 | if (this_p > p) | |
52 | p = this_p; | |
53 | } | |
54 | ||
55 | voltage_max = intel_dp_voltage_max(intel_dp); | |
56 | if (v >= voltage_max) | |
57 | v = voltage_max | DP_TRAIN_MAX_SWING_REACHED; | |
58 | ||
59 | preemph_max = intel_dp_pre_emphasis_max(intel_dp, v); | |
60 | if (p >= preemph_max) | |
61 | p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; | |
62 | ||
63 | for (lane = 0; lane < 4; lane++) | |
64 | intel_dp->train_set[lane] = v | p; | |
65 | } | |
66 | ||
67 | static bool | |
68 | intel_dp_set_link_train(struct intel_dp *intel_dp, | |
69 | uint8_t dp_train_pat) | |
70 | { | |
71 | uint8_t buf[sizeof(intel_dp->train_set) + 1]; | |
72 | int ret, len; | |
73 | ||
74 | intel_dp_program_link_training_pattern(intel_dp, dp_train_pat); | |
75 | ||
76 | buf[0] = dp_train_pat; | |
77 | if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) == | |
78 | DP_TRAINING_PATTERN_DISABLE) { | |
79 | /* don't write DP_TRAINING_LANEx_SET on disable */ | |
80 | len = 1; | |
81 | } else { | |
82 | /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */ | |
83 | memcpy(buf + 1, intel_dp->train_set, intel_dp->lane_count); | |
84 | len = intel_dp->lane_count + 1; | |
85 | } | |
86 | ||
87 | ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_PATTERN_SET, | |
88 | buf, len); | |
89 | ||
90 | return ret == len; | |
91 | } | |
92 | ||
93 | static bool | |
94 | intel_dp_reset_link_train(struct intel_dp *intel_dp, | |
95 | uint8_t dp_train_pat) | |
96 | { | |
91df09d9 | 97 | memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); |
94223d04 ACO |
98 | intel_dp_set_signal_levels(intel_dp); |
99 | return intel_dp_set_link_train(intel_dp, dp_train_pat); | |
100 | } | |
101 | ||
102 | static bool | |
103 | intel_dp_update_link_train(struct intel_dp *intel_dp) | |
104 | { | |
105 | int ret; | |
106 | ||
107 | intel_dp_set_signal_levels(intel_dp); | |
108 | ||
109 | ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_LANE0_SET, | |
110 | intel_dp->train_set, intel_dp->lane_count); | |
111 | ||
112 | return ret == intel_dp->lane_count; | |
113 | } | |
114 | ||
7bfaddf0 DP |
115 | static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp) |
116 | { | |
117 | int lane; | |
118 | ||
119 | for (lane = 0; lane < intel_dp->lane_count; lane++) | |
120 | if ((intel_dp->train_set[lane] & | |
121 | DP_TRAIN_MAX_SWING_REACHED) == 0) | |
122 | return false; | |
123 | ||
124 | return true; | |
125 | } | |
126 | ||
94223d04 | 127 | /* Enable corresponding port and start training pattern 1 */ |
13b1996e | 128 | static bool |
94223d04 ACO |
129 | intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) |
130 | { | |
94223d04 | 131 | uint8_t voltage; |
13b1996e | 132 | int voltage_tries, max_vswing_tries; |
94223d04 ACO |
133 | uint8_t link_config[2]; |
134 | uint8_t link_bw, rate_select; | |
135 | ||
ad64217b ACO |
136 | if (intel_dp->prepare_link_retrain) |
137 | intel_dp->prepare_link_retrain(intel_dp); | |
94223d04 ACO |
138 | |
139 | intel_dp_compute_rate(intel_dp, intel_dp->link_rate, | |
140 | &link_bw, &rate_select); | |
141 | ||
142 | /* Write the link configuration data */ | |
143 | link_config[0] = link_bw; | |
144 | link_config[1] = intel_dp->lane_count; | |
145 | if (drm_dp_enhanced_frame_cap(intel_dp->dpcd)) | |
146 | link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; | |
147 | drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2); | |
13b1996e | 148 | |
94223d04 ACO |
149 | if (intel_dp->num_sink_rates) |
150 | drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET, | |
151 | &rate_select, 1); | |
152 | ||
153 | link_config[0] = 0; | |
154 | link_config[1] = DP_SET_ANSI_8B10B; | |
155 | drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2); | |
156 | ||
157 | intel_dp->DP |= DP_PORT_EN; | |
158 | ||
159 | /* clock recovery */ | |
160 | if (!intel_dp_reset_link_train(intel_dp, | |
161 | DP_TRAINING_PATTERN_1 | | |
162 | DP_LINK_SCRAMBLING_DISABLE)) { | |
163 | DRM_ERROR("failed to enable link training\n"); | |
13b1996e | 164 | return false; |
94223d04 ACO |
165 | } |
166 | ||
13b1996e DP |
167 | voltage_tries = 1; |
168 | max_vswing_tries = 0; | |
94223d04 ACO |
169 | for (;;) { |
170 | uint8_t link_status[DP_LINK_STATUS_SIZE]; | |
171 | ||
172 | drm_dp_link_train_clock_recovery_delay(intel_dp->dpcd); | |
13b1996e | 173 | |
94223d04 ACO |
174 | if (!intel_dp_get_link_status(intel_dp, link_status)) { |
175 | DRM_ERROR("failed to get link status\n"); | |
13b1996e | 176 | return false; |
94223d04 ACO |
177 | } |
178 | ||
179 | if (drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) { | |
180 | DRM_DEBUG_KMS("clock recovery OK\n"); | |
13b1996e | 181 | return true; |
94223d04 ACO |
182 | } |
183 | ||
13b1996e DP |
184 | if (voltage_tries == 5) { |
185 | DRM_DEBUG_KMS("Same voltage tried 5 times\n"); | |
186 | return false; | |
187 | } | |
188 | ||
189 | if (max_vswing_tries == 1) { | |
190 | DRM_DEBUG_KMS("Max Voltage Swing reached\n"); | |
191 | return false; | |
94223d04 ACO |
192 | } |
193 | ||
94223d04 ACO |
194 | voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK; |
195 | ||
196 | /* Update training set as requested by target */ | |
197 | intel_get_adjust_train(intel_dp, link_status); | |
198 | if (!intel_dp_update_link_train(intel_dp)) { | |
199 | DRM_ERROR("failed to update link training\n"); | |
13b1996e | 200 | return false; |
94223d04 | 201 | } |
13b1996e DP |
202 | |
203 | if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == | |
204 | voltage) | |
205 | ++voltage_tries; | |
206 | else | |
207 | voltage_tries = 1; | |
208 | ||
209 | if (intel_dp_link_max_vswing_reached(intel_dp)) | |
210 | ++max_vswing_tries; | |
211 | ||
94223d04 ACO |
212 | } |
213 | } | |
214 | ||
23a5110d JN |
215 | /* |
216 | * Pick training pattern for channel equalization. Training Pattern 3 for HBR2 | |
217 | * or 1.2 devices that support it, Training Pattern 2 otherwise. | |
218 | */ | |
219 | static u32 intel_dp_training_pattern(struct intel_dp *intel_dp) | |
94223d04 | 220 | { |
23a5110d | 221 | u32 training_pattern = DP_TRAINING_PATTERN_2; |
bfcef5d2 | 222 | bool source_tps3, sink_tps3; |
94223d04 ACO |
223 | |
224 | /* | |
94223d04 | 225 | * Intel platforms that support HBR2 also support TPS3. TPS3 support is |
bfcef5d2 JN |
226 | * also mandatory for downstream devices that support HBR2. However, not |
227 | * all sinks follow the spec. | |
94223d04 ACO |
228 | * |
229 | * Due to WaDisableHBR2 SKL < B0 is the only exception where TPS3 is | |
bfcef5d2 | 230 | * supported in source but still not enabled. |
94223d04 | 231 | */ |
bfcef5d2 JN |
232 | source_tps3 = intel_dp_source_supports_hbr2(intel_dp); |
233 | sink_tps3 = drm_dp_tps3_supported(intel_dp->dpcd); | |
234 | ||
235 | if (source_tps3 && sink_tps3) { | |
94223d04 | 236 | training_pattern = DP_TRAINING_PATTERN_3; |
bfcef5d2 JN |
237 | } else if (intel_dp->link_rate == 540000) { |
238 | if (!source_tps3) | |
239 | DRM_DEBUG_KMS("5.4 Gbps link rate without source HBR2/TPS3 support\n"); | |
240 | if (!sink_tps3) | |
241 | DRM_DEBUG_KMS("5.4 Gbps link rate without sink TPS3 support\n"); | |
242 | } | |
94223d04 | 243 | |
23a5110d JN |
244 | return training_pattern; |
245 | } | |
246 | ||
c92bd2fa | 247 | static bool |
23a5110d JN |
248 | intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp) |
249 | { | |
c92bd2fa | 250 | int tries; |
23a5110d | 251 | u32 training_pattern; |
c92bd2fa | 252 | uint8_t link_status[DP_LINK_STATUS_SIZE]; |
23a5110d JN |
253 | |
254 | training_pattern = intel_dp_training_pattern(intel_dp); | |
255 | ||
94223d04 ACO |
256 | /* channel equalization */ |
257 | if (!intel_dp_set_link_train(intel_dp, | |
258 | training_pattern | | |
259 | DP_LINK_SCRAMBLING_DISABLE)) { | |
260 | DRM_ERROR("failed to start channel equalization\n"); | |
c92bd2fa | 261 | return false; |
94223d04 ACO |
262 | } |
263 | ||
c92bd2fa NM |
264 | intel_dp->channel_eq_status = false; |
265 | for (tries = 0; tries < 5; tries++) { | |
94223d04 ACO |
266 | |
267 | drm_dp_link_train_channel_eq_delay(intel_dp->dpcd); | |
268 | if (!intel_dp_get_link_status(intel_dp, link_status)) { | |
269 | DRM_ERROR("failed to get link status\n"); | |
270 | break; | |
271 | } | |
272 | ||
273 | /* Make sure clock is still ok */ | |
274 | if (!drm_dp_clock_recovery_ok(link_status, | |
275 | intel_dp->lane_count)) { | |
c92bd2fa NM |
276 | intel_dp_dump_link_status(link_status); |
277 | DRM_DEBUG_KMS("Clock recovery check failed, cannot " | |
278 | "continue channel equalization\n"); | |
279 | break; | |
94223d04 ACO |
280 | } |
281 | ||
282 | if (drm_dp_channel_eq_ok(link_status, | |
283 | intel_dp->lane_count)) { | |
c92bd2fa NM |
284 | intel_dp->channel_eq_status = true; |
285 | DRM_DEBUG_KMS("Channel EQ done. DP Training " | |
286 | "successful\n"); | |
94223d04 ACO |
287 | break; |
288 | } | |
289 | ||
94223d04 ACO |
290 | /* Update training set as requested by target */ |
291 | intel_get_adjust_train(intel_dp, link_status); | |
292 | if (!intel_dp_update_link_train(intel_dp)) { | |
293 | DRM_ERROR("failed to update link training\n"); | |
294 | break; | |
295 | } | |
c92bd2fa NM |
296 | } |
297 | ||
298 | /* Try 5 times, else fail and try at lower BW */ | |
299 | if (tries == 5) { | |
300 | intel_dp_dump_link_status(link_status); | |
301 | DRM_DEBUG_KMS("Channel equalization failed 5 times\n"); | |
94223d04 ACO |
302 | } |
303 | ||
304 | intel_dp_set_idle_link_train(intel_dp); | |
305 | ||
c92bd2fa NM |
306 | return intel_dp->channel_eq_status; |
307 | ||
94223d04 ACO |
308 | } |
309 | ||
310 | void intel_dp_stop_link_train(struct intel_dp *intel_dp) | |
311 | { | |
312 | intel_dp_set_link_train(intel_dp, | |
313 | DP_TRAINING_PATTERN_DISABLE); | |
314 | } | |
315 | ||
316 | void | |
317 | intel_dp_start_link_train(struct intel_dp *intel_dp) | |
318 | { | |
319 | intel_dp_link_training_clock_recovery(intel_dp); | |
320 | intel_dp_link_training_channel_equalization(intel_dp); | |
321 | } |