1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2013 NVIDIA Corporation
4 * Copyright (C) 2018 Cadence Design Systems Inc.
5 */
6
7 #include <common.h>
8 #include <div64.h>
9
10 #include <phy-mipi-dphy.h>
11
12 #define PSEC_PER_SEC 1000000000000LL
13
14 /*
15 * Minimum D-PHY timings based on MIPI D-PHY specification. Derived
16 * from the valid ranges specified in Section 6.9, Table 14, Page 41
17 * of the D-PHY specification (v2.1).
18 */
phy_mipi_dphy_get_default_config(unsigned long pixel_clock,unsigned int bpp,unsigned int lanes,struct phy_configure_opts_mipi_dphy * cfg)19 int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
20 unsigned int bpp,
21 unsigned int lanes,
22 struct phy_configure_opts_mipi_dphy *cfg)
23 {
24 unsigned long long hs_clk_rate;
25 unsigned long long ui;
26
27 if (!cfg)
28 return -EINVAL;
29
30 hs_clk_rate = pixel_clock * bpp;
31 do_div(hs_clk_rate, lanes);
32
33 ui = ALIGN(PSEC_PER_SEC, hs_clk_rate);
34 do_div(ui, hs_clk_rate);
35
36 cfg->clk_miss = 0;
37 cfg->clk_post = 60000 + 52 * ui;
38 cfg->clk_pre = 8000;
39 cfg->clk_prepare = 38000;
40 cfg->clk_settle = 95000;
41 cfg->clk_term_en = 0;
42 cfg->clk_trail = 60000;
43 cfg->clk_zero = 262000;
44 cfg->d_term_en = 0;
45 cfg->eot = 0;
46 cfg->hs_exit = 100000;
47 cfg->hs_prepare = 40000 + 4 * ui;
48 cfg->hs_zero = 105000 + 6 * ui;
49 cfg->hs_settle = 85000 + 6 * ui;
50 cfg->hs_skip = 40000;
51
52 /*
53 * The MIPI D-PHY specification (Section 6.9, v1.2, Table 14, Page 40)
54 * contains this formula as:
55 *
56 * T_HS-TRAIL = max(n * 8 * ui, 60 + n * 4 * ui)
57 *
58 * where n = 1 for forward-direction HS mode and n = 4 for reverse-
59 * direction HS mode. There's only one setting and this function does
60 * not parameterize on anything other that ui, so this code will
61 * assumes that reverse-direction HS mode is supported and uses n = 4.
62 */
63 cfg->hs_trail = max(4 * 8 * ui, 60000 + 4 * 4 * ui);
64
65 cfg->init = 100;
66 cfg->lpx = 60000;
67 cfg->ta_get = 5 * cfg->lpx;
68 cfg->ta_go = 4 * cfg->lpx;
69 cfg->ta_sure = 2 * cfg->lpx;
70 cfg->wakeup = 1000;
71
72 cfg->hs_clk_rate = hs_clk_rate;
73 cfg->lanes = lanes;
74
75 return 0;
76 }
77
78 /*
79 * Validate D-PHY configuration according to MIPI D-PHY specification
80 * (v1.2, Section Section 6.9 "Global Operation Timing Parameters").
81 */
phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy * cfg)82 int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg)
83 {
84 unsigned long long ui;
85
86 if (!cfg)
87 return -EINVAL;
88
89 ui = ALIGN(PSEC_PER_SEC, cfg->hs_clk_rate);
90 do_div(ui, cfg->hs_clk_rate);
91
92 if (cfg->clk_miss > 60000)
93 return -EINVAL;
94
95 if (cfg->clk_post < (60000 + 52 * ui))
96 return -EINVAL;
97
98 if (cfg->clk_pre < 8000)
99 return -EINVAL;
100
101 if (cfg->clk_prepare < 38000 || cfg->clk_prepare > 95000)
102 return -EINVAL;
103
104 if (cfg->clk_settle < 95000 || cfg->clk_settle > 300000)
105 return -EINVAL;
106
107 if (cfg->clk_term_en > 38000)
108 return -EINVAL;
109
110 if (cfg->clk_trail < 60000)
111 return -EINVAL;
112
113 if ((cfg->clk_prepare + cfg->clk_zero) < 300000)
114 return -EINVAL;
115
116 if (cfg->d_term_en > (35000 + 4 * ui))
117 return -EINVAL;
118
119 if (cfg->eot > (105000 + 12 * ui))
120 return -EINVAL;
121
122 if (cfg->hs_exit < 100000)
123 return -EINVAL;
124
125 if (cfg->hs_prepare < (40000 + 4 * ui) ||
126 cfg->hs_prepare > (85000 + 6 * ui))
127 return -EINVAL;
128
129 if ((cfg->hs_prepare + cfg->hs_zero) < (145000 + 10 * ui))
130 return -EINVAL;
131
132 if ((cfg->hs_settle < (85000 + 6 * ui)) ||
133 (cfg->hs_settle > (145000 + 10 * ui)))
134 return -EINVAL;
135
136 if (cfg->hs_skip < 40000 || cfg->hs_skip > (55000 + 4 * ui))
137 return -EINVAL;
138
139 if (cfg->hs_trail < max(8 * ui, 60000 + 4 * ui))
140 return -EINVAL;
141
142 if (cfg->init < 100)
143 return -EINVAL;
144
145 if (cfg->lpx < 50000)
146 return -EINVAL;
147
148 if (cfg->ta_get != (5 * cfg->lpx))
149 return -EINVAL;
150
151 if (cfg->ta_go != (4 * cfg->lpx))
152 return -EINVAL;
153
154 if (cfg->ta_sure < cfg->lpx || cfg->ta_sure > (2 * cfg->lpx))
155 return -EINVAL;
156
157 if (cfg->wakeup < 1000)
158 return -EINVAL;
159
160 return 0;
161 }
162