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* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: linux-imx, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, Kishon Vijay Abraham I, Vinod Koul, Kevin Hilman,
	Jerome Brunet, Martin Blumenstingl, Heiko Stuebner,
	Maxime Ripard, Guido Günther, Wyon Bi, Laurent Pinchart

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: linux-imx, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, Kishon Vijay Abraham I, Vinod Koul, Kevin Hilman,
	Jerome Brunet, Martin Blumenstingl, Heiko Stuebner,
	Maxime Ripard, Guido Günther, Wyon Bi, Laurent Pinchart

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: Wyon Bi, Jernej Skrabec, Jonas Karlman, David Airlie,
	Kevin Hilman, Guido Günther, Neil Armstrong, Robert Foss,
	Kishon Vijay Abraham I, Martin Blumenstingl, Vinod Koul,
	Laurent Pinchart, Andrzej Hajda, Jerome Brunet, linux-imx

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: linux-imx, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, Kishon Vijay Abraham I, Vinod Koul, Kevin Hilman,
	Jerome Brunet, Martin Blumenstingl, Heiko Stuebner,
	Maxime Ripard, Guido Günther, Wyon Bi, Laurent Pinchart

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: linux-imx, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, Kishon Vijay Abraham I, Vinod Koul, Kevin Hilman,
	Jerome Brunet, Martin Blumenstingl, Heiko Stuebner,
	Maxime Ripard, Guido Günther, Wyon Bi, Laurent Pinchart

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-01-24  2:40 ` Liu Ying
  0 siblings, 0 replies; 12+ messages in thread
From: Liu Ying @ 2022-01-24  2:40 UTC (permalink / raw)
  To: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip
  Cc: linux-imx, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, Kishon Vijay Abraham I, Vinod Koul, Kevin Hilman,
	Jerome Brunet, Martin Blumenstingl, Heiko Stuebner,
	Maxime Ripard, Guido Günther, Wyon Bi, Laurent Pinchart

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")
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Wyon Bi <bivvy.bi@rock-chips.com>
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>
---
v3->v4:
* Fix commit message as the patch doesn't fix D-PHY documentation.

v2->v3:
* Drop D-PHY documentation change. (Laurent)
* Collect R-b tags and T-b tags.
* Cc Wyon.

v1->v2:
* Use BITS_PER_BYTE macro. (Andrzej)
* Drop dsi argument from ui2bc() in nwl-dsi.c.

 drivers/gpu/drm/bridge/nwl-dsi.c                 | 12 +++++-------
 drivers/phy/amlogic/phy-meson-axg-mipi-dphy.c    |  3 ++-
 drivers/phy/phy-core-mipi-dphy.c                 |  4 ++--
 drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c |  3 ++-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index a7389a0facfb..af07eeb47ca0 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/math64.h>
@@ -196,12 +197,9 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
 /*
  * ui2bc - UI time periods to byte clock cycles
  */
-static u32 ui2bc(struct nwl_dsi *dsi, unsigned long long ui)
+static u32 ui2bc(unsigned int ui)
 {
-	u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-
-	return DIV64_U64_ROUND_UP(ui * dsi->lanes,
-				  dsi->mode.clock * 1000 * bpp);
+	return DIV_ROUND_UP(ui, BITS_PER_BYTE);
 }
 
 /*
@@ -232,12 +230,12 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	}
 
 	/* values in byte clock cycles */
-	cycles = ui2bc(dsi, cfg->clk_pre);
+	cycles = ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_pre: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_PRE, cycles);
 	cycles = ps2bc(dsi, cfg->lpx + cfg->clk_prepare + cfg->clk_zero);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap (pre): 0x%x\n", cycles);
-	cycles += ui2bc(dsi, cfg->clk_pre);
+	cycles += ui2bc(cfg->clk_pre);
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_t_post: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_T_POST, cycles);
 	cycles = ps2bc(dsi, cfg->hs_exit);
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
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
  2022-01-24  2:40 ` Liu Ying
                     ` (3 preceding siblings ...)
  (?)
@ 2022-02-02 15:22   ` Vinod Koul
  -1 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip, linux-imx, Andrzej Hajda,
	Neil Armstrong, Robert Foss, Laurent Pinchart, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter,
	Kishon Vijay Abraham I, Kevin Hilman, Jerome Brunet,
	Martin Blumenstingl, Heiko Stuebner, Maxime Ripard,
	Guido Günther, Wyon Bi

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-02-02 15:22   ` Vinod Koul
  0 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: Neil Armstrong, David Airlie, Guido Günther, dri-devel,
	Laurent Pinchart, Andrzej Hajda, linux-phy, Jerome Brunet,
	Wyon Bi, Kevin Hilman, Jernej Skrabec, Kishon Vijay Abraham I,
	linux-rockchip, linux-imx, Jonas Karlman, Martin Blumenstingl,
	linux-amlogic, linux-arm-kernel, linux-kernel, Robert Foss

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-02-02 15:22   ` Vinod Koul
  0 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip, linux-imx, Andrzej Hajda,
	Neil Armstrong, Robert Foss, Laurent Pinchart, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter,
	Kishon Vijay Abraham I, Kevin Hilman, Jerome Brunet,
	Martin Blumenstingl, Heiko Stuebner, Maxime Ripard,
	Guido Günther, Wyon Bi

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-02-02 15:22   ` Vinod Koul
  0 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip, linux-imx, Andrzej Hajda,
	Neil Armstrong, Robert Foss, Laurent Pinchart, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter,
	Kishon Vijay Abraham I, Kevin Hilman, Jerome Brunet,
	Martin Blumenstingl, Heiko Stuebner, Maxime Ripard,
	Guido Günther, Wyon Bi

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-02-02 15:22   ` Vinod Koul
  0 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip, linux-imx, Andrzej Hajda,
	Neil Armstrong, Robert Foss, Laurent Pinchart, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter,
	Kishon Vijay Abraham I, Kevin Hilman, Jerome Brunet,
	Martin Blumenstingl, Heiko Stuebner, Maxime Ripard,
	Guido Günther, Wyon Bi

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4] phy: dphy: Correct clk_pre parameter
@ 2022-02-02 15:22   ` Vinod Koul
  0 siblings, 0 replies; 12+ messages in thread
From: Vinod Koul @ 2022-02-02 15:22 UTC (permalink / raw)
  To: Liu Ying
  Cc: dri-devel, linux-kernel, linux-phy, linux-arm-kernel,
	linux-amlogic, linux-rockchip, linux-imx, Andrzej Hajda,
	Neil Armstrong, Robert Foss, Laurent Pinchart, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter,
	Kishon Vijay Abraham I, Kevin Hilman, Jerome Brunet,
	Martin Blumenstingl, Heiko Stuebner, Maxime Ripard,
	Guido Günther, Wyon Bi

On 24-01-22, 10:40, Liu Ying wrote:
> 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.

Applied, thanks

-- 
~Vinod

-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2022-02-02 15:42 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-24  2:40 [PATCH v4] phy: dphy: Correct clk_pre parameter Liu Ying
2022-01-24  2:40 ` Liu Ying
2022-01-24  2:40 ` Liu Ying
2022-01-24  2:40 ` Liu Ying
2022-01-24  2:40 ` Liu Ying
2022-01-24  2:40 ` Liu Ying
2022-02-02 15:22 ` Vinod Koul
2022-02-02 15:22   ` Vinod Koul
2022-02-02 15:22   ` Vinod Koul
2022-02-02 15:22   ` Vinod Koul
2022-02-02 15:22   ` Vinod Koul
2022-02-02 15:22   ` Vinod Koul

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