2 * Copyright © 2009 Keith Packard
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <sys/cdefs.h>
24 __FBSDID("$FreeBSD$");
26 #include <dev/drm2/drmP.h>
27 #include <dev/drm2/drm_dp_helper.h>
32 * These functions contain some common logic and helpers at various abstraction
33 * levels to deal with Display Port sink devices and related things like DP aux
34 * channel transfers, EDID reading over DP aux channels, decoding certain DPCD
38 /* Helpers for DP link training */
39 static u8 dp_link_status(u8 link_status[DP_LINK_STATUS_SIZE], int r)
41 return link_status[r - DP_LANE0_1_STATUS];
44 static u8 dp_get_lane_status(u8 link_status[DP_LINK_STATUS_SIZE],
47 int i = DP_LANE0_1_STATUS + (lane >> 1);
48 int s = (lane & 1) * 4;
49 u8 l = dp_link_status(link_status, i);
50 return (l >> s) & 0xf;
53 bool drm_dp_channel_eq_ok(u8 link_status[DP_LINK_STATUS_SIZE],
60 lane_align = dp_link_status(link_status,
61 DP_LANE_ALIGN_STATUS_UPDATED);
62 if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
64 for (lane = 0; lane < lane_count; lane++) {
65 lane_status = dp_get_lane_status(link_status, lane);
66 if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
71 EXPORT_SYMBOL(drm_dp_channel_eq_ok);
73 bool drm_dp_clock_recovery_ok(u8 link_status[DP_LINK_STATUS_SIZE],
79 for (lane = 0; lane < lane_count; lane++) {
80 lane_status = dp_get_lane_status(link_status, lane);
81 if ((lane_status & DP_LANE_CR_DONE) == 0)
86 EXPORT_SYMBOL(drm_dp_clock_recovery_ok);
88 u8 drm_dp_get_adjust_request_voltage(u8 link_status[DP_LINK_STATUS_SIZE],
91 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
93 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
94 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
95 u8 l = dp_link_status(link_status, i);
97 return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
99 EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage);
101 u8 drm_dp_get_adjust_request_pre_emphasis(u8 link_status[DP_LINK_STATUS_SIZE],
104 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
105 int s = ((lane & 1) ?
106 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
107 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
108 u8 l = dp_link_status(link_status, i);
110 return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
112 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
114 void drm_dp_link_train_clock_recovery_delay(u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
115 if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0)
118 mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4);
120 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
122 void drm_dp_link_train_channel_eq_delay(u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
123 if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0)
126 mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4);
128 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
130 u8 drm_dp_link_rate_to_bw_code(int link_rate)
135 return DP_LINK_BW_1_62;
137 return DP_LINK_BW_2_7;
139 return DP_LINK_BW_5_4;
142 EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
144 int drm_dp_bw_code_to_link_rate(u8 link_bw)
147 case DP_LINK_BW_1_62:
156 EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);