1 /*
2 * Copyright 2022 Advanced Micro Devices, Inc.
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 shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: AMD
23 *
24 */
25
26 /* FILE POLICY AND INTENDED USAGE:
27 * This file implements basic dp phy functionality such as enable/disable phy
28 * output and set lane/drive settings. This file is responsible for maintaining
29 * and update software state representing current phy status such as current
30 * link settings.
31 */
32
33 #include "link_dp_phy.h"
34 #include "link_dpcd.h"
35 #include "link_dp_training.h"
36 #include "link_dp_capability.h"
37 #include "clk_mgr.h"
38 #include "resource.h"
39 #include "link_enc_cfg.h"
40 #define DC_LOGGER \
41 link->ctx->logger
42
dpcd_write_rx_power_ctrl(struct dc_link * link,bool on)43 void dpcd_write_rx_power_ctrl(struct dc_link *link, bool on)
44 {
45 uint8_t state;
46
47 state = on ? DP_POWER_STATE_D0 : DP_POWER_STATE_D3;
48
49 if (link->sync_lt_in_progress)
50 return;
51
52 core_link_write_dpcd(link, DP_SET_POWER, &state,
53 sizeof(state));
54
55 }
56
dp_enable_link_phy(struct dc_link * link,const struct link_resource * link_res,enum signal_type signal,enum clock_source_id clock_source,const struct dc_link_settings * link_settings)57 void dp_enable_link_phy(
58 struct dc_link *link,
59 const struct link_resource *link_res,
60 enum signal_type signal,
61 enum clock_source_id clock_source,
62 const struct dc_link_settings *link_settings)
63 {
64 link->cur_link_settings = *link_settings;
65 link->dc->hwss.enable_dp_link_output(link, link_res, signal,
66 clock_source, link_settings);
67 dpcd_write_rx_power_ctrl(link, true);
68 }
69
dp_disable_link_phy(struct dc_link * link,const struct link_resource * link_res,enum signal_type signal)70 void dp_disable_link_phy(struct dc_link *link,
71 const struct link_resource *link_res,
72 enum signal_type signal)
73 {
74 struct dc *dc = link->ctx->dc;
75
76 if (!link->wa_flags.dp_keep_receiver_powered &&
77 !link->skip_implict_edp_power_control &&
78 link->type != dc_connection_none)
79 dpcd_write_rx_power_ctrl(link, false);
80
81 dc->hwss.disable_link_output(link, link_res, signal);
82 /* Clear current link setting.*/
83 memset(&link->cur_link_settings, 0,
84 sizeof(link->cur_link_settings));
85
86 if (dc->clk_mgr->funcs->notify_link_rate_change)
87 dc->clk_mgr->funcs->notify_link_rate_change(dc->clk_mgr, link);
88 }
89
is_immediate_downstream(struct dc_link * link,uint32_t offset)90 static inline bool is_immediate_downstream(struct dc_link *link, uint32_t offset)
91 {
92 return (dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt) ==
93 offset);
94 }
95
dp_set_hw_lane_settings(struct dc_link * link,const struct link_resource * link_res,const struct link_training_settings * link_settings,uint32_t offset)96 void dp_set_hw_lane_settings(
97 struct dc_link *link,
98 const struct link_resource *link_res,
99 const struct link_training_settings *link_settings,
100 uint32_t offset)
101 {
102 const struct link_hwss *link_hwss = get_link_hwss(link, link_res);
103
104 if ((link_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) &&
105 !is_immediate_downstream(link, offset))
106 return;
107
108 if (link_hwss->ext.set_dp_lane_settings)
109 link_hwss->ext.set_dp_lane_settings(link, link_res,
110 &link_settings->link_settings,
111 link_settings->hw_lane_settings);
112
113 memmove(link->cur_lane_setting,
114 link_settings->hw_lane_settings,
115 sizeof(link->cur_lane_setting));
116 }
117
dp_set_drive_settings(struct dc_link * link,const struct link_resource * link_res,struct link_training_settings * lt_settings)118 void dp_set_drive_settings(
119 struct dc_link *link,
120 const struct link_resource *link_res,
121 struct link_training_settings *lt_settings)
122 {
123 /* program ASIC PHY settings*/
124 dp_set_hw_lane_settings(link, link_res, lt_settings, DPRX);
125
126 dp_hw_to_dpcd_lane_settings(lt_settings,
127 lt_settings->hw_lane_settings,
128 lt_settings->dpcd_lane_settings);
129
130 /* Notify DP sink the PHY settings from source */
131 dpcd_set_lane_settings(link, lt_settings, DPRX);
132 }
133
dp_set_fec_ready(struct dc_link * link,const struct link_resource * link_res,bool ready)134 enum dc_status dp_set_fec_ready(struct dc_link *link, const struct link_resource *link_res, bool ready)
135 {
136 /* FEC has to be "set ready" before the link training.
137 * The policy is to always train with FEC
138 * if the sink supports it and leave it enabled on link.
139 * If FEC is not supported, disable it.
140 */
141 struct link_encoder *link_enc = NULL;
142 enum dc_status status = DC_OK;
143 uint8_t fec_config = 0;
144
145 link_enc = link_enc_cfg_get_link_enc(link);
146 ASSERT(link_enc);
147 if (link_enc->funcs->fec_set_ready == NULL)
148 return DC_NOT_SUPPORTED;
149
150 if (ready && dp_should_enable_fec(link)) {
151 fec_config = 1;
152
153 status = core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
154 &fec_config, sizeof(fec_config));
155
156 if (status == DC_OK) {
157 link_enc->funcs->fec_set_ready(link_enc, true);
158 link->fec_state = dc_link_fec_ready;
159 }
160 } else {
161 if (link->fec_state == dc_link_fec_ready) {
162 fec_config = 0;
163 if (link->type != dc_connection_none)
164 core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
165 &fec_config, sizeof(fec_config));
166
167 link_enc->funcs->fec_set_ready(link_enc, false);
168 link->fec_state = dc_link_fec_not_ready;
169 }
170 }
171
172 return status;
173 }
174
dp_set_fec_enable(struct dc_link * link,bool enable)175 void dp_set_fec_enable(struct dc_link *link, bool enable)
176 {
177 struct link_encoder *link_enc = NULL;
178
179 link_enc = link_enc_cfg_get_link_enc(link);
180 ASSERT(link_enc);
181 if (link_enc->funcs->fec_set_enable == NULL)
182 return;
183
184 if (enable && dp_should_enable_fec(link)) {
185 if (link->fec_state == dc_link_fec_ready) {
186 /* According to DP spec, FEC enable sequence can first
187 * be transmitted anytime after 1000 LL codes have
188 * been transmitted on the link after link training
189 * completion. Using 1 lane RBR should have the maximum
190 * time for transmitting 1000 LL codes which is 6.173 us.
191 * So use 7 microseconds delay instead.
192 */
193 udelay(7);
194 link_enc->funcs->fec_set_enable(link_enc, true);
195 link->fec_state = dc_link_fec_enabled;
196 }
197 } else {
198 if (link->fec_state == dc_link_fec_enabled) {
199 link_enc->funcs->fec_set_enable(link_enc, false);
200 link->fec_state = dc_link_fec_ready;
201 }
202 }
203 }
204
205