Re: [PATCH v2 1/9] arm64: dts: imx8mp-skov-revb-mi1010ait-1cp1: Add panel-timing node to panel node

From: Marek Vasut
Date: Sat Oct 12 2024 - 17:26:06 EST


On 10/12/24 9:35 AM, Liu Ying wrote:
Add a panel-timing node to panel node to override any fixed display
modes written in a panel driver. This way, 68.9MHz clock frequency
specified in panel-timing node may accommodate 7-fold 482.3MHz
"media_ldb" clock which is derived from 964.6MHz "video_pll1" clock.
The above clock frequencies align to the clock rates assigned in the
lvds_bridge node and media_blk_ctrl node in this DT file.

This should be able to suppress this LDB driver warning:
[ 17.206644] fsl-ldb 32ec0000.blk-ctrl:bridge@5c: Configured LDB clock (70000000 Hz) does not match requested LVDS clock: 490000000 Hz

This also makes the display mode used by the panel pass mode validation
against pixel clock rate and "media_ldb" clock rate in a certain display
driver.

Fixes: 6d382d51d979 ("arm64: dts: freescale: Add SKOV IMX8MP CPU revB board")
Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
---
v2:
* No change.

.../freescale/imx8mp-skov-revb-mi1010ait-1cp1.dts | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-mi1010ait-1cp1.dts b/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-mi1010ait-1cp1.dts
index 3c2efdc59bfa..4e9f76de7462 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-mi1010ait-1cp1.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-mi1010ait-1cp1.dts
@@ -13,6 +13,21 @@ panel {
backlight = <&backlight>;
power-supply = <&reg_tft_vcom>;
+ panel-timing {
+ clock-frequency = <68900000>;
+ hactive = <1280>;
+ vactive = <800>;
+ hfront-porch = <30>;
+ hback-porch = <30>;
+ hsync-len = <10>;
+ vfront-porch = <5>;
+ vback-porch = <5>;
+ vsync-len = <5>;
+ hsync-active = <0>;
+ vsync-active = <0>;
+ de-active = <1>;
+ };
There is an existing entry for this panel in panel-simple.c , please do not duplicate timings in the DT:

drivers/gpu/drm/panel/panel-simple.c: .timings = &multi_inno_mi1010ait_1cp_timing,
drivers/gpu/drm/panel/panel-simple.c: .compatible = "multi-inno,mi1010ait-1cp",
drivers/gpu/drm/panel/panel-simple.c: .data = &multi_inno_mi1010ait_1cp,