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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 NVIDIA Corporation
4 */
5
6#include <linux/errno.h>
7#include <linux/kernel.h>
8
9#include "mipi-phy.h"
10
11/*
12 * Default D-PHY timings based on MIPI D-PHY specification. Derived from the
13 * valid ranges specified in Section 6.9, Table 14, Page 40 of the D-PHY
14 * specification (v1.2) with minor adjustments.
15 */
16int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing,
17 unsigned long period)
18{
19 timing->clkmiss = 0;
20 timing->clkpost = 70 + 52 * period;
21 timing->clkpre = 8;
22 timing->clkprepare = 65;
23 timing->clksettle = 95;
24 timing->clktermen = 0;
25 timing->clktrail = 80;
26 timing->clkzero = 260;
27 timing->dtermen = 0;
28 timing->eot = 0;
29 timing->hsexit = 120;
30 timing->hsprepare = 65 + 5 * period;
31 timing->hszero = 145 + 5 * period;
32 timing->hssettle = 85 + 6 * period;
33 timing->hsskip = 40;
34
35 /*
36 * The MIPI D-PHY specification (Section 6.9, v1.2, Table 14, Page 40)
37 * contains this formula as:
38 *
39 * T_HS-TRAIL = max(n * 8 * period, 60 + n * 4 * period)
40 *
41 * where n = 1 for forward-direction HS mode and n = 4 for reverse-
42 * direction HS mode. There's only one setting and this function does
43 * not parameterize on anything other that period, so this code will
44 * assumes that reverse-direction HS mode is supported and uses n = 4.
45 */
46 timing->hstrail = max(4 * 8 * period, 60 + 4 * 4 * period);
47
48 timing->init = 100000;
49 timing->lpx = 60;
50 timing->taget = 5 * timing->lpx;
51 timing->tago = 4 * timing->lpx;
52 timing->tasure = 2 * timing->lpx;
53 timing->wakeup = 1000000;
54
55 return 0;
56}
57
58/*
59 * Validate D-PHY timing according to MIPI D-PHY specification (v1.2, Section
60 * Section 6.9 "Global Operation Timing Parameters").
61 */
62int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing,
63 unsigned long period)
64{
65 if (timing->clkmiss > 60)
66 return -EINVAL;
67
68 if (timing->clkpost < (60 + 52 * period))
69 return -EINVAL;
70
71 if (timing->clkpre < 8)
72 return -EINVAL;
73
74 if (timing->clkprepare < 38 || timing->clkprepare > 95)
75 return -EINVAL;
76
77 if (timing->clksettle < 95 || timing->clksettle > 300)
78 return -EINVAL;
79
80 if (timing->clktermen > 38)
81 return -EINVAL;
82
83 if (timing->clktrail < 60)
84 return -EINVAL;
85
86 if (timing->clkprepare + timing->clkzero < 300)
87 return -EINVAL;
88
89 if (timing->dtermen > 35 + 4 * period)
90 return -EINVAL;
91
92 if (timing->eot > 105 + 12 * period)
93 return -EINVAL;
94
95 if (timing->hsexit < 100)
96 return -EINVAL;
97
98 if (timing->hsprepare < 40 + 4 * period ||
99 timing->hsprepare > 85 + 6 * period)
100 return -EINVAL;
101
102 if (timing->hsprepare + timing->hszero < 145 + 10 * period)
103 return -EINVAL;
104
105 if ((timing->hssettle < 85 + 6 * period) ||
106 (timing->hssettle > 145 + 10 * period))
107 return -EINVAL;
108
109 if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period)
110 return -EINVAL;
111
112 if (timing->hstrail < max(8 * period, 60 + 4 * period))
113 return -EINVAL;
114
115 if (timing->init < 100000)
116 return -EINVAL;
117
118 if (timing->lpx < 50)
119 return -EINVAL;
120
121 if (timing->taget != 5 * timing->lpx)
122 return -EINVAL;
123
124 if (timing->tago != 4 * timing->lpx)
125 return -EINVAL;
126
127 if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx)
128 return -EINVAL;
129
130 if (timing->wakeup < 1000000)
131 return -EINVAL;
132
133 return 0;
134}
1/*
2 * Copyright (C) 2013 NVIDIA Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/errno.h>
10#include <linux/kernel.h>
11
12#include "mipi-phy.h"
13
14/*
15 * Default D-PHY timings based on MIPI D-PHY specification. Derived from
16 * the valid ranges specified in Section 5.9 of the D-PHY specification
17 * with minor adjustments.
18 */
19int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing,
20 unsigned long period)
21{
22 timing->clkmiss = 0;
23 timing->clkpost = 70 + 52 * period;
24 timing->clkpre = 8;
25 timing->clkprepare = 65;
26 timing->clksettle = 95;
27 timing->clktermen = 0;
28 timing->clktrail = 80;
29 timing->clkzero = 260;
30 timing->dtermen = 0;
31 timing->eot = 0;
32 timing->hsexit = 120;
33 timing->hsprepare = 65 + 5 * period;
34 timing->hszero = 145 + 5 * period;
35 timing->hssettle = 85 + 6 * period;
36 timing->hsskip = 40;
37 timing->hstrail = max(8 * period, 60 + 4 * period);
38 timing->init = 100000;
39 timing->lpx = 60;
40 timing->taget = 5 * timing->lpx;
41 timing->tago = 4 * timing->lpx;
42 timing->tasure = 2 * timing->lpx;
43 timing->wakeup = 1000000;
44
45 return 0;
46}
47
48/*
49 * Validate D-PHY timing according to MIPI Alliance Specification for D-PHY,
50 * Section 5.9 "Global Operation Timing Parameters".
51 */
52int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing,
53 unsigned long period)
54{
55 if (timing->clkmiss > 60)
56 return -EINVAL;
57
58 if (timing->clkpost < (60 + 52 * period))
59 return -EINVAL;
60
61 if (timing->clkpre < 8)
62 return -EINVAL;
63
64 if (timing->clkprepare < 38 || timing->clkprepare > 95)
65 return -EINVAL;
66
67 if (timing->clksettle < 95 || timing->clksettle > 300)
68 return -EINVAL;
69
70 if (timing->clktermen > 38)
71 return -EINVAL;
72
73 if (timing->clktrail < 60)
74 return -EINVAL;
75
76 if (timing->clkprepare + timing->clkzero < 300)
77 return -EINVAL;
78
79 if (timing->dtermen > 35 + 4 * period)
80 return -EINVAL;
81
82 if (timing->eot > 105 + 12 * period)
83 return -EINVAL;
84
85 if (timing->hsexit < 100)
86 return -EINVAL;
87
88 if (timing->hsprepare < 40 + 4 * period ||
89 timing->hsprepare > 85 + 6 * period)
90 return -EINVAL;
91
92 if (timing->hsprepare + timing->hszero < 145 + 10 * period)
93 return -EINVAL;
94
95 if ((timing->hssettle < 85 + 6 * period) ||
96 (timing->hssettle > 145 + 10 * period))
97 return -EINVAL;
98
99 if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period)
100 return -EINVAL;
101
102 if (timing->hstrail < max(8 * period, 60 + 4 * period))
103 return -EINVAL;
104
105 if (timing->init < 100000)
106 return -EINVAL;
107
108 if (timing->lpx < 50)
109 return -EINVAL;
110
111 if (timing->taget != 5 * timing->lpx)
112 return -EINVAL;
113
114 if (timing->tago != 4 * timing->lpx)
115 return -EINVAL;
116
117 if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx)
118 return -EINVAL;
119
120 if (timing->wakeup < 1000000)
121 return -EINVAL;
122
123 return 0;
124}