| /* |
| * Copyright (C) 2013 NVIDIA Corporation |
| * |
| * Permission to use, copy, modify, distribute, and sell this software and its |
| * documentation for any purpose is hereby granted without fee, provided that |
| * the above copyright notice appear in all copies and that both that copyright |
| * notice and this permission notice appear in supporting documentation, and |
| * that the name of the copyright holders not be used in advertising or |
| * publicity pertaining to distribution of the software without specific, |
| * written prior permission. The copyright holders make no representations |
| * about the suitability of this software for any purpose. It is provided "as |
| * is" without express or implied warranty. |
| * |
| * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO |
| * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR |
| * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, |
| * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER |
| * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE |
| * OF THIS SOFTWARE. |
| */ |
| |
| #include <linux/kernel.h> |
| |
| #include "mipi-phy.h" |
| |
| /* |
| * Default D-PHY timings based on MIPI D-PHY specification. Derived from |
| * the valid ranges specified in Section 5.9 of the D-PHY specification |
| * with minor adjustments. |
| */ |
| int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing, |
| unsigned long period) |
| { |
| timing->clkmiss = 0; |
| timing->clkpost = 70 + 52 * period; |
| timing->clkpre = 8; |
| timing->clkprepare = 65; |
| timing->clksettle = 95; |
| timing->clktermen = 0; |
| timing->clktrail = 80; |
| timing->clkzero = 260; |
| timing->dtermen = 0; |
| timing->eot = 0; |
| timing->hsexit = 120; |
| timing->hsprepare = 65 + 5 * period; |
| timing->hszero = 145 + 5 * period; |
| timing->hssettle = 85 + 6 * period; |
| timing->hsskip = 40; |
| timing->hstrail = max(8 * period, 60 + 4 * period); |
| timing->init = 100000; |
| timing->lpx = 60; |
| timing->taget = 5 * timing->lpx; |
| timing->tago = 4 * timing->lpx; |
| timing->tasure = 2 * timing->lpx; |
| timing->wakeup = 1000000; |
| |
| return 0; |
| } |
| |
| /* |
| * Validate D-PHY timing according to MIPI Alliance Specification for D-PHY, |
| * Section 5.9 "Global Operation Timing Parameters". |
| */ |
| int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing, |
| unsigned long period) |
| { |
| if (timing->clkmiss > 60) |
| return -EINVAL; |
| |
| if (timing->clkpost < (60 + 52 * period)) |
| return -EINVAL; |
| |
| if (timing->clkpre < 8) |
| return -EINVAL; |
| |
| if (timing->clkprepare < 38 || timing->clkprepare > 95) |
| return -EINVAL; |
| |
| if (timing->clksettle < 95 || timing->clksettle > 300) |
| return -EINVAL; |
| |
| if (timing->clktermen > 38) |
| return -EINVAL; |
| |
| if (timing->clktrail < 60) |
| return -EINVAL; |
| |
| if (timing->clkprepare + timing->clkzero < 300) |
| return -EINVAL; |
| |
| if (timing->dtermen > 35 + 4 * period) |
| return -EINVAL; |
| |
| if (timing->eot > 105 + 12 * period) |
| return -EINVAL; |
| |
| if (timing->hsexit < 100) |
| return -EINVAL; |
| |
| if (timing->hsprepare < 40 + 4 * period || |
| timing->hsprepare > 85 + 6 * period) |
| return -EINVAL; |
| |
| if (timing->hsprepare + timing->hszero < 145 + 10 * period) |
| return -EINVAL; |
| |
| if ((timing->hssettle < 85 + 6 * period) || |
| (timing->hssettle > 145 + 10 * period)) |
| return -EINVAL; |
| |
| if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period) |
| return -EINVAL; |
| |
| if (timing->hstrail < max(8 * period, 60 + 4 * period)) |
| return -EINVAL; |
| |
| if (timing->init < 100000) |
| return -EINVAL; |
| |
| if (timing->lpx < 50) |
| return -EINVAL; |
| |
| if (timing->taget != 5 * timing->lpx) |
| return -EINVAL; |
| |
| if (timing->tago != 4 * timing->lpx) |
| return -EINVAL; |
| |
| if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx) |
| return -EINVAL; |
| |
| if (timing->wakeup < 1000000) |
| return -EINVAL; |
| |
| return 0; |
| } |