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1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright (C) 2013-2019 NVIDIA Corporation.
4 * Copyright (C) 2015 Rob Clark
5 */
6
7#ifndef DRM_TEGRA_DP_H
8#define DRM_TEGRA_DP_H 1
9
10#include <linux/types.h>
11
12struct drm_display_info;
13struct drm_display_mode;
14struct drm_dp_aux;
15struct drm_dp_link;
16
17/**
18 * struct drm_dp_link_caps - DP link capabilities
19 */
20struct drm_dp_link_caps {
21 /**
22 * @enhanced_framing:
23 *
24 * enhanced framing capability (mandatory as of DP 1.2)
25 */
26 bool enhanced_framing;
27
28 /**
29 * @tps3_supported:
30 *
31 * training pattern sequence 3 supported for equalization
32 */
33 bool tps3_supported;
34
35 /**
36 * @fast_training:
37 *
38 * AUX CH handshake not required for link training
39 */
40 bool fast_training;
41
42 /**
43 * @channel_coding:
44 *
45 * ANSI 8B/10B channel coding capability
46 */
47 bool channel_coding;
48
49 /**
50 * @alternate_scrambler_reset:
51 *
52 * eDP alternate scrambler reset capability
53 */
54 bool alternate_scrambler_reset;
55};
56
57void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
58 const struct drm_dp_link_caps *src);
59
60/**
61 * struct drm_dp_link_ops - DP link operations
62 */
63struct drm_dp_link_ops {
64 /**
65 * @apply_training: apply the link training
66 */
67 int (*apply_training)(struct drm_dp_link *link);
68
69 /**
70 * @configure: configure the DP link
71 */
72 int (*configure)(struct drm_dp_link *link);
73};
74
75#define DP_TRAIN_VOLTAGE_SWING_LEVEL(x) ((x) << 0)
76#define DP_TRAIN_PRE_EMPHASIS_LEVEL(x) ((x) << 3)
77#define DP_LANE_POST_CURSOR(i, x) (((x) & 0x3) << (((i) & 1) << 2))
78
79/**
80 * struct drm_dp_link_train_set - link training settings
81 * @voltage_swing: per-lane voltage swing
82 * @pre_emphasis: per-lane pre-emphasis
83 * @post_cursor: per-lane post-cursor
84 */
85struct drm_dp_link_train_set {
86 unsigned int voltage_swing[4];
87 unsigned int pre_emphasis[4];
88 unsigned int post_cursor[4];
89};
90
91/**
92 * struct drm_dp_link_train - link training state information
93 * @request: currently requested settings
94 * @adjust: adjustments requested by sink
95 * @pattern: currently requested training pattern
96 * @clock_recovered: flag to track if clock recovery has completed
97 * @channel_equalized: flag to track if channel equalization has completed
98 */
99struct drm_dp_link_train {
100 struct drm_dp_link_train_set request;
101 struct drm_dp_link_train_set adjust;
102
103 unsigned int pattern;
104
105 bool clock_recovered;
106 bool channel_equalized;
107};
108
109/**
110 * struct drm_dp_link - DP link capabilities and configuration
111 * @revision: DP specification revision supported on the link
112 * @max_rate: maximum clock rate supported on the link
113 * @max_lanes: maximum number of lanes supported on the link
114 * @caps: capabilities supported on the link (see &drm_dp_link_caps)
115 * @aux_rd_interval: AUX read interval to use for training (in microseconds)
116 * @aux_rd_interval.cr: clock recovery read interval
117 * @aux_rd_interval.ce: channel equalization read interval
118 * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)
119 * @rate: currently configured link rate
120 * @lanes: currently configured number of lanes
121 * @rates: additional supported link rates in kHz (eDP 1.4)
122 * @num_rates: number of additional supported link rates (eDP 1.4)
123 */
124struct drm_dp_link {
125 unsigned char revision;
126 unsigned int max_rate;
127 unsigned int max_lanes;
128
129 struct drm_dp_link_caps caps;
130
131 struct {
132 unsigned int cr;
133 unsigned int ce;
134 } aux_rd_interval;
135
136 unsigned char edp;
137
138 unsigned int rate;
139 unsigned int lanes;
140
141 unsigned long rates[DP_MAX_SUPPORTED_RATES];
142 unsigned int num_rates;
143
144 /**
145 * @ops: DP link operations
146 */
147 const struct drm_dp_link_ops *ops;
148
149 /**
150 * @aux: DP AUX channel
151 */
152 struct drm_dp_aux *aux;
153
154 /**
155 * @train: DP link training state
156 */
157 struct drm_dp_link_train train;
158};
159
160int drm_dp_link_add_rate(struct drm_dp_link *link, unsigned long rate);
161int drm_dp_link_remove_rate(struct drm_dp_link *link, unsigned long rate);
162void drm_dp_link_update_rates(struct drm_dp_link *link);
163
164int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
165int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
166int drm_dp_link_choose(struct drm_dp_link *link,
167 const struct drm_display_mode *mode,
168 const struct drm_display_info *info);
169
170void drm_dp_link_train_init(struct drm_dp_link_train *train);
171int drm_dp_link_train(struct drm_dp_link *link);
172
173#endif