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authorLiu Ying <victor.liu@nxp.com>2022-01-24 10:40:07 +0800
committerVinod Koul <vkoul@kernel.org>2022-02-02 10:33:04 +0530
commit9a8406ba1a9a2965c27e0db1d7753471d12ee9ff (patch)
tree2fceeab99e34a3b57eb2f930866ff402ea2fa372 /drivers/phy
parent46e994717807f4b935c44d81dde9dd8bcd9a4f5d (diff)
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>
Diffstat (limited to 'drivers/phy')
-rw-r--r--drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c3
-rw-r--r--drivers/phy/phy-core-mipi-dphy.c4
-rw-r--r--drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c3
3 files changed, 6 insertions, 4 deletions
diff --git a/drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c b/drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c
index cd2332bf0e31..fdbd64c03e12 100644
--- a/drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c
+++ b/drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c
@@ -9,6 +9,7 @@
#include <linux/bitfield.h>
#include <linux/bitops.h>
+#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
@@ -250,7 +251,7 @@ static int phy_meson_axg_mipi_dphy_power_on(struct phy *phy)
(DIV_ROUND_UP(priv->config.clk_zero, temp) << 16) |
(DIV_ROUND_UP(priv->config.clk_prepare, temp) << 24));
regmap_write(priv->regmap, MIPI_DSI_CLK_TIM1,
- DIV_ROUND_UP(priv->config.clk_pre, temp));
+ DIV_ROUND_UP(priv->config.clk_pre, BITS_PER_BYTE));
regmap_write(priv->regmap, MIPI_DSI_HS_TIM,
DIV_ROUND_UP(priv->config.hs_exit, temp) |
diff --git a/drivers/phy/phy-core-mipi-dphy.c b/drivers/phy/phy-core-mipi-dphy.c
index 288c9c67aa74..ccb4045685cd 100644
--- a/drivers/phy/phy-core-mipi-dphy.c
+++ b/drivers/phy/phy-core-mipi-dphy.c
@@ -36,7 +36,7 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
cfg->clk_miss = 0;
cfg->clk_post = 60000 + 52 * ui;
- cfg->clk_pre = 8000;
+ cfg->clk_pre = 8;
cfg->clk_prepare = 38000;
cfg->clk_settle = 95000;
cfg->clk_term_en = 0;
@@ -97,7 +97,7 @@ int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg)
if (cfg->clk_post < (60000 + 52 * ui))
return -EINVAL;
- if (cfg->clk_pre < 8000)
+ if (cfg->clk_pre < 8)
return -EINVAL;
if (cfg->clk_prepare < 38000 || cfg->clk_prepare > 95000)
diff --git a/drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c b/drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c
index 347dc79a18c1..630e01b5c19b 100644
--- a/drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c
@@ -5,6 +5,7 @@
* Author: Wyon Bi <bivvy.bi@rock-chips.com>
*/
+#include <linux/bits.h>
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/iopoll.h>
@@ -364,7 +365,7 @@ static void inno_dsidphy_mipi_mode_enable(struct inno_dsidphy *inno)
* The value of counter for HS Tclk-pre
* Tclk-pre = Tpin_txbyteclkhs * value
*/
- clk_pre = DIV_ROUND_UP(cfg->clk_pre, t_txbyteclkhs);
+ clk_pre = DIV_ROUND_UP(cfg->clk_pre, BITS_PER_BYTE);
/*
* The value of counter for HS Tlpx Time