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linux/drivers/phy/phy-core-mipi-dphy.c

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phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
/* 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
phy: phy-core-mipi-dphy.c: Correct reference version The rest of the code refers to version 1.2 of the MIPI D-PHY specification. But this comment refers to 2.1, while a sub comment of the function refers to 1.2 again. Replace 2.1 with 1.2. Signed-off-by: Sebastian Fricke <sebastian.fricke@posteo.net> Link: https://lore.kernel.org/r/20210421041740.8451-1-sebastian.fricke@posteo.net Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-04-21 12:17:41 +08:00
* of the D-PHY specification (v1.2).
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
*/
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;
phy: dphy: Correct clk_pre parameter The D-PHY specification (v1.2) explicitly mentions that the T-CLK-PRE parameter's unit is Unit Interval(UI) and the minimum value is 8. Also, kernel doc of the 'clk_pre' member of struct phy_configure_opts_mipi_dphy mentions that it should be in UI. However, the dphy core driver wrongly sets 'clk_pre' to 8000, which seems to hint that it's in picoseconds. So, let's fix the dphy core driver to correctly reflect the T-CLK-PRE parameter's minimum value according to the D-PHY specification. I'm assuming that all impacted custom drivers shall program values in TxByteClkHS cycles into hardware for the T-CLK-PRE parameter. The D-PHY specification mentions that the frequency of TxByteClkHS is exactly 1/8 the High-Speed(HS) bit rate(each HS bit consumes one UI). So, relevant custom driver code is changed to program those values as DIV_ROUND_UP(cfg->clk_pre, BITS_PER_BYTE), then. 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: 2ed869990e14 ("phy: Add MIPI D-PHY configuration options") Tested-by: Liu Ying <victor.liu@nxp.com> # RM67191 DSI panel on i.MX8mq EVK Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> # for phy-meson-axg-mipi-dphy.c Tested-by: Neil Armstrong <narmstrong@baylibre.com> # for phy-meson-axg-mipi-dphy.c Tested-by: Guido Günther <agx@sigxcpu.org> # Librem 5 (imx8mq) with it's rather picky panel Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Liu Ying <victor.liu@nxp.com> Link: https://lore.kernel.org/r/20220124024007.1465018-1-victor.liu@nxp.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-01-24 10:40:07 +08:00
cfg->clk_pre = 8;
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
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);
phy: dphy: Change units of wakeup and init parameters The Init and wakeup D-PHY parameters are in the micro/milliseconds range, putting the values real close to the types limits if they were in picoseconds. Move them to microseconds which should be better fit. Suggested-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2019-01-21 23:45:47 +08:00
cfg->init = 100;
phy: dphy: Correct lpx parameter and its derivatives(ta_{get,go,sure}) 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: dddc97e82303 ("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>
2022-02-16 15:12:57 +08:00
cfg->lpx = 50000;
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
cfg->ta_get = 5 * cfg->lpx;
cfg->ta_go = 4 * cfg->lpx;
phy: dphy: Correct lpx parameter and its derivatives(ta_{get,go,sure}) 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: dddc97e82303 ("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>
2022-02-16 15:12:57 +08:00
cfg->ta_sure = cfg->lpx;
phy: dphy: Change units of wakeup and init parameters The Init and wakeup D-PHY parameters are in the micro/milliseconds range, putting the values real close to the types limits if they were in picoseconds. Move them to microseconds which should be better fit. Suggested-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2019-01-21 23:45:47 +08:00
cfg->wakeup = 1000;
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
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;
phy: dphy: Correct clk_pre parameter The D-PHY specification (v1.2) explicitly mentions that the T-CLK-PRE parameter's unit is Unit Interval(UI) and the minimum value is 8. Also, kernel doc of the 'clk_pre' member of struct phy_configure_opts_mipi_dphy mentions that it should be in UI. However, the dphy core driver wrongly sets 'clk_pre' to 8000, which seems to hint that it's in picoseconds. So, let's fix the dphy core driver to correctly reflect the T-CLK-PRE parameter's minimum value according to the D-PHY specification. I'm assuming that all impacted custom drivers shall program values in TxByteClkHS cycles into hardware for the T-CLK-PRE parameter. The D-PHY specification mentions that the frequency of TxByteClkHS is exactly 1/8 the High-Speed(HS) bit rate(each HS bit consumes one UI). So, relevant custom driver code is changed to program those values as DIV_ROUND_UP(cfg->clk_pre, BITS_PER_BYTE), then. 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: 2ed869990e14 ("phy: Add MIPI D-PHY configuration options") Tested-by: Liu Ying <victor.liu@nxp.com> # RM67191 DSI panel on i.MX8mq EVK Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> # for phy-meson-axg-mipi-dphy.c Tested-by: Neil Armstrong <narmstrong@baylibre.com> # for phy-meson-axg-mipi-dphy.c Tested-by: Guido Günther <agx@sigxcpu.org> # Librem 5 (imx8mq) with it's rather picky panel Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Liu Ying <victor.liu@nxp.com> Link: https://lore.kernel.org/r/20220124024007.1465018-1-victor.liu@nxp.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-01-24 10:40:07 +08:00
if (cfg->clk_pre < 8)
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
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;
phy: dphy: Change units of wakeup and init parameters The Init and wakeup D-PHY parameters are in the micro/milliseconds range, putting the values real close to the types limits if they were in picoseconds. Move them to microseconds which should be better fit. Suggested-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2019-01-21 23:45:47 +08:00
if (cfg->init < 100)
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
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;
phy: dphy: Change units of wakeup and init parameters The Init and wakeup D-PHY parameters are in the micro/milliseconds range, putting the values real close to the types limits if they were in picoseconds. Move them to microseconds which should be better fit. Suggested-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2019-01-21 23:45:47 +08:00
if (cfg->wakeup < 1000)
phy: dphy: Add configuration helpers The MIPI D-PHY spec defines default values and boundaries for most of the parameters it defines. Introduce helpers to help drivers get meaningful values based on their current parameters, and validate the boundaries of these parameters if needed. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-07 21:55:31 +08:00
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(phy_mipi_dphy_config_validate);
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