2 * Copyright (C) 2013 NVIDIA Corporation
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.
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
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.
19 int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing,
23 timing->clkpost = 70 + 52 * period;
25 timing->clkprepare = 65;
26 timing->clksettle = 95;
27 timing->clktermen = 0;
28 timing->clktrail = 80;
29 timing->clkzero = 260;
33 timing->hsprepare = 65 + 5 * period;
34 timing->hszero = 145 + 5 * period;
35 timing->hssettle = 85 + 6 * period;
37 timing->hstrail = max(8 * period, 60 + 4 * period);
38 timing->init = 100000;
40 timing->taget = 5 * timing->lpx;
41 timing->tago = 4 * timing->lpx;
42 timing->tasure = 2 * timing->lpx;
43 timing->wakeup = 1000000;
49 * Validate D-PHY timing according to MIPI Alliance Specification for D-PHY,
50 * Section 5.9 "Global Operation Timing Parameters".
52 int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing,
55 if (timing->clkmiss > 60)
58 if (timing->clkpost < (60 + 52 * period))
61 if (timing->clkpre < 8)
64 if (timing->clkprepare < 38 || timing->clkprepare > 95)
67 if (timing->clksettle < 95 || timing->clksettle > 300)
70 if (timing->clktermen > 38)
73 if (timing->clktrail < 60)
76 if (timing->clkprepare + timing->clkzero < 300)
79 if (timing->dtermen > 35 + 4 * period)
82 if (timing->eot > 105 + 12 * period)
85 if (timing->hsexit < 100)
88 if (timing->hsprepare < 40 + 4 * period ||
89 timing->hsprepare > 85 + 6 * period)
92 if (timing->hsprepare + timing->hszero < 145 + 10 * period)
95 if ((timing->hssettle < 85 + 6 * period) ||
96 (timing->hssettle > 145 + 10 * period))
99 if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period)
102 if (timing->hstrail < max(8 * period, 60 + 4 * period))
105 if (timing->init < 100000)
108 if (timing->lpx < 50)
111 if (timing->taget != 5 * timing->lpx)
114 if (timing->tago != 4 * timing->lpx)
117 if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx)
120 if (timing->wakeup < 1000000)