1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
// SPDX-License-Identifier: GPL-2.0-or-later
#include <asm/unaligned.h>
#include <drm/bridge/cdns-mhdp.h>
#include <drm/drm_print.h>
#include <linux/io.h>
#define LINK_TRAINING_TIMEOUT_MS 500
#define LINK_TRAINING_RETRY_MS 20
static inline u32 get_unaligned_be24(const void *p)
{
const u8 *_p = p;
return _p[0] << 16 | _p[1] << 8 | _p[2];
}
static inline void put_unaligned_be24(u32 val, void *p)
{
u8 *_p = p;
_p[0] = val >> 16;
_p[1] = val >> 8;
_p[2] = val;
}
int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp,
u32 addr, u8 *data, u16 len)
{
u8 msg[5], reg[5];
int ret;
put_unaligned_be16(len, msg);
put_unaligned_be24(addr, msg + 2);
ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
DPTX_READ_DPCD, sizeof(msg), msg);
if (ret)
goto err_dpcd_read;
ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX,
DPTX_READ_DPCD,
sizeof(reg) + len);
if (ret)
goto err_dpcd_read;
ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg));
if (ret)
goto err_dpcd_read;
ret = cdns_mhdp_mailbox_read_receive(mhdp, data, len);
err_dpcd_read:
return ret;
}
EXPORT_SYMBOL(cdns_mhdp_dpcd_read);
int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8 value)
{
u8 msg[6], reg[5];
int ret;
put_unaligned_be16(1, msg);
put_unaligned_be24(addr, msg + 2);
msg[5] = value;
ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
DPTX_WRITE_DPCD, sizeof(msg), msg);
if (ret)
goto err_dpcd_write;
ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX,
DPTX_WRITE_DPCD, sizeof(reg));
if (ret)
goto err_dpcd_write;
ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg));
if (ret)
goto err_dpcd_write;
if (addr != get_unaligned_be24(reg + 2))
ret = -EINVAL;
err_dpcd_write:
if (ret)
DRM_DEV_ERROR(mhdp->dev, "dpcd write failed: %d\n", ret);
return ret;
}
EXPORT_SYMBOL(cdns_mhdp_dpcd_write);
static int cdns_mhdp_training_start(struct cdns_mhdp_device *mhdp)
{
unsigned long timeout;
u8 msg, event[2];
int ret;
msg = LINK_TRAINING_RUN;
/* start training */
ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
DPTX_TRAINING_CONTROL, sizeof(msg), &msg);
if (ret)
goto err_training_start;
timeout = jiffies + msecs_to_jiffies(LINK_TRAINING_TIMEOUT_MS);
while (time_before(jiffies, timeout)) {
msleep(LINK_TRAINING_RETRY_MS);
ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
DPTX_READ_EVENT, 0, NULL);
if (ret)
goto err_training_start;
ret = cdns_mhdp_mailbox_validate_receive(mhdp,
MB_MODULE_ID_DP_TX,
DPTX_READ_EVENT,
sizeof(event));
if (ret)
goto err_training_start;
ret = cdns_mhdp_mailbox_read_receive(mhdp, event,
sizeof(event));
if (ret)
goto err_training_start;
if (event[1] & CLK_RECOVERY_FAILED)
DRM_DEV_ERROR(mhdp->dev, "clock recovery failed\n");
else if (event[1] & EQ_PHASE_FINISHED)
return 0;
}
ret = -ETIMEDOUT;
err_training_start:
DRM_DEV_ERROR(mhdp->dev, "training failed: %d\n", ret);
return ret;
}
static int cdns_mhdp_get_training_status(struct cdns_mhdp_device *mhdp)
{
u8 status[10];
int ret;
ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
DPTX_READ_LINK_STAT, 0, NULL);
if (ret)
goto err_get_training_status;
ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX,
DPTX_READ_LINK_STAT,
sizeof(status));
if (ret)
goto err_get_training_status;
ret = cdns_mhdp_mailbox_read_receive(mhdp, status, sizeof(status));
if (ret)
goto err_get_training_status;
mhdp->dp.rate = drm_dp_bw_code_to_link_rate(status[0]);
mhdp->dp.num_lanes = status[1];
err_get_training_status:
if (ret)
DRM_DEV_ERROR(mhdp->dev, "get training status failed: %d\n",
ret);
return ret;
}
int cdns_mhdp_train_link(struct cdns_mhdp_device *mhdp)
{
int ret;
ret = cdns_mhdp_training_start(mhdp);
if (ret) {
DRM_DEV_ERROR(mhdp->dev, "Failed to start training %d\n",
ret);
return ret;
}
ret = cdns_mhdp_get_training_status(mhdp);
if (ret) {
DRM_DEV_ERROR(mhdp->dev, "Failed to get training stat %d\n",
ret);
return ret;
}
DRM_DEV_DEBUG_KMS(mhdp->dev, "rate:0x%x, lanes:%d\n", mhdp->dp.rate,
mhdp->dp.num_lanes);
return ret;
}
EXPORT_SYMBOL(cdns_mhdp_train_link);
|
