mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
3153fa38e3
According to the comment of the function phy_mipi_dphy_get_default_config(),
it uses minimum D-PHY timings based on MIPI D-PHY specification. They are
derived from the valid ranges specified in Section 6.9, Table 14, Page 41
of the D-PHY specification (v1.2). The table 14 explicitly mentions that
the minimum T-LPX parameter is 50 nanoseconds and the minimum TA-SURE
parameter is T-LPX nanoseconds. Likewise, the kernel doc of the 'lpx' and
'ta_sure' members of struct phy_configure_opts_mipi_dphy mentions that
the minimum values are 50000 picoseconds and @lpx picoseconds respectively.
Also, the function phy_mipi_dphy_config_validate() checks if cfg->lpx is
less than 50000 picoseconds and if cfg->ta_sure is less than cfg->lpx,
which hints the same minimum values.
Without this patch, the function phy_mipi_dphy_get_default_config()
wrongly sets cfg->lpx to 60000 picoseconds and cfg->ta_sure to 2 * cfg->lpx.
So, let's correct them to 50000 picoseconds and cfg->lpx respectively.
Note that I've only tested the patch with RM67191 DSI panel on i.MX8mq EVK.
Help is needed to test with other i.MX8mq, Meson and Rockchip platforms,
as I don't have the hardwares.
Fixes: dddc97e823
("phy: dphy: Add configuration helpers")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Link: https://lore.kernel.org/r/20220216071257.1647703-1-victor.liu@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
165 lines
3.7 KiB
C
165 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Copyright (C) 2013 NVIDIA Corporation
|
|
* Copyright (C) 2018 Cadence Design Systems Inc.
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/time64.h>
|
|
|
|
#include <linux/phy/phy.h>
|
|
#include <linux/phy/phy-mipi-dphy.h>
|
|
|
|
/*
|
|
* Minimum D-PHY timings based on MIPI D-PHY specification. Derived
|
|
* from the valid ranges specified in Section 6.9, Table 14, Page 41
|
|
* of the D-PHY specification (v1.2).
|
|
*/
|
|
int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
|
|
unsigned int bpp,
|
|
unsigned int lanes,
|
|
struct phy_configure_opts_mipi_dphy *cfg)
|
|
{
|
|
unsigned long long hs_clk_rate;
|
|
unsigned long long ui;
|
|
|
|
if (!cfg)
|
|
return -EINVAL;
|
|
|
|
hs_clk_rate = pixel_clock * bpp;
|
|
do_div(hs_clk_rate, lanes);
|
|
|
|
ui = ALIGN(PSEC_PER_SEC, hs_clk_rate);
|
|
do_div(ui, hs_clk_rate);
|
|
|
|
cfg->clk_miss = 0;
|
|
cfg->clk_post = 60000 + 52 * ui;
|
|
cfg->clk_pre = 8;
|
|
cfg->clk_prepare = 38000;
|
|
cfg->clk_settle = 95000;
|
|
cfg->clk_term_en = 0;
|
|
cfg->clk_trail = 60000;
|
|
cfg->clk_zero = 262000;
|
|
cfg->d_term_en = 0;
|
|
cfg->eot = 0;
|
|
cfg->hs_exit = 100000;
|
|
cfg->hs_prepare = 40000 + 4 * ui;
|
|
cfg->hs_zero = 105000 + 6 * ui;
|
|
cfg->hs_settle = 85000 + 6 * ui;
|
|
cfg->hs_skip = 40000;
|
|
|
|
/*
|
|
* The MIPI D-PHY specification (Section 6.9, v1.2, Table 14, Page 40)
|
|
* contains this formula as:
|
|
*
|
|
* T_HS-TRAIL = max(n * 8 * ui, 60 + n * 4 * ui)
|
|
*
|
|
* where n = 1 for forward-direction HS mode and n = 4 for reverse-
|
|
* direction HS mode. There's only one setting and this function does
|
|
* not parameterize on anything other that ui, so this code will
|
|
* assumes that reverse-direction HS mode is supported and uses n = 4.
|
|
*/
|
|
cfg->hs_trail = max(4 * 8 * ui, 60000 + 4 * 4 * ui);
|
|
|
|
cfg->init = 100;
|
|
cfg->lpx = 50000;
|
|
cfg->ta_get = 5 * cfg->lpx;
|
|
cfg->ta_go = 4 * cfg->lpx;
|
|
cfg->ta_sure = cfg->lpx;
|
|
cfg->wakeup = 1000;
|
|
|
|
cfg->hs_clk_rate = hs_clk_rate;
|
|
cfg->lanes = lanes;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
|
|
|
|
/*
|
|
* Validate D-PHY configuration according to MIPI D-PHY specification
|
|
* (v1.2, Section Section 6.9 "Global Operation Timing Parameters").
|
|
*/
|
|
int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg)
|
|
{
|
|
unsigned long long ui;
|
|
|
|
if (!cfg)
|
|
return -EINVAL;
|
|
|
|
ui = ALIGN(PSEC_PER_SEC, cfg->hs_clk_rate);
|
|
do_div(ui, cfg->hs_clk_rate);
|
|
|
|
if (cfg->clk_miss > 60000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_post < (60000 + 52 * ui))
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_pre < 8)
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_prepare < 38000 || cfg->clk_prepare > 95000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_settle < 95000 || cfg->clk_settle > 300000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_term_en > 38000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->clk_trail < 60000)
|
|
return -EINVAL;
|
|
|
|
if ((cfg->clk_prepare + cfg->clk_zero) < 300000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->d_term_en > (35000 + 4 * ui))
|
|
return -EINVAL;
|
|
|
|
if (cfg->eot > (105000 + 12 * ui))
|
|
return -EINVAL;
|
|
|
|
if (cfg->hs_exit < 100000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->hs_prepare < (40000 + 4 * ui) ||
|
|
cfg->hs_prepare > (85000 + 6 * ui))
|
|
return -EINVAL;
|
|
|
|
if ((cfg->hs_prepare + cfg->hs_zero) < (145000 + 10 * ui))
|
|
return -EINVAL;
|
|
|
|
if ((cfg->hs_settle < (85000 + 6 * ui)) ||
|
|
(cfg->hs_settle > (145000 + 10 * ui)))
|
|
return -EINVAL;
|
|
|
|
if (cfg->hs_skip < 40000 || cfg->hs_skip > (55000 + 4 * ui))
|
|
return -EINVAL;
|
|
|
|
if (cfg->hs_trail < max(8 * ui, 60000 + 4 * ui))
|
|
return -EINVAL;
|
|
|
|
if (cfg->init < 100)
|
|
return -EINVAL;
|
|
|
|
if (cfg->lpx < 50000)
|
|
return -EINVAL;
|
|
|
|
if (cfg->ta_get != (5 * cfg->lpx))
|
|
return -EINVAL;
|
|
|
|
if (cfg->ta_go != (4 * cfg->lpx))
|
|
return -EINVAL;
|
|
|
|
if (cfg->ta_sure < cfg->lpx || cfg->ta_sure > (2 * cfg->lpx))
|
|
return -EINVAL;
|
|
|
|
if (cfg->wakeup < 1000)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(phy_mipi_dphy_config_validate);
|