On Fri, Jul 26, 2024 at 02:50:12PM GMT, Liu Ying wrote:
> MCIMX-LVDS1[1] display module integrates a HannStar HSD100PXN1 LVDS
> display panel and a touch IC. Add an overlay to support the LVDS
> panel on i.MX53 QSB / QSRB platforms.
>
> [1] https://www.nxp.com/part/MCIMX-LVDS1
>
> Signed-off-by: Liu Ying <victor....@nxp.com>
> ---
> I mark RFC in patch subject prefix because if the DT overlay is used, both ldb
> and panel devices end up as devices deferred. However, if the DT overlay is
> not used and the devices are defined in imx53-qsb-common.dtsi, then they can
> be
> probed ok.
>
> With a dev_err_probe() added to imx_ldb_probe() in imx-ldb.c, devices_deferred
> indicates 53fa8008.ldb and panel-lvds kind of depend on each other.
>
> root@imx53qsb:~# cat /sys/kernel/debug/devices_deferred
> 53fa8008.ldb imx-ldb: failed to find panel or bridge for channel0
> panel-lvds platform: wait for supplier
> /soc/bus@50000000/ldb@53fa8008/lvds-channel@0
>
> It looks like the issue is related to fw_devlink, because if "fw_devlink=off"
> is added to kernel bootup command line, then the issue doesn't happen.
Could you please fdtdump /sys/firmware/fdt (or just generated DTB files)
in both cases and compare the dumps for sensible differences?
>
> Saravana, DT folks, any ideas?
>
> Thanks.
>
> arch/arm/boot/dts/nxp/imx/Makefile | 4 ++
> .../boot/dts/nxp/imx/imx53-qsb-common.dtsi | 4 +-
> .../dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso | 43 +++++++++++++++++++
> 3 files changed, 49 insertions(+), 2 deletions(-)
> create mode 100644 arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso
>
> diff --git a/arch/arm/boot/dts/nxp/imx/Makefile
> b/arch/arm/boot/dts/nxp/imx/Makefile
> index 92e291603ea1..7116889e1515 100644
> --- a/arch/arm/boot/dts/nxp/imx/Makefile
> +++ b/arch/arm/boot/dts/nxp/imx/Makefile
> @@ -46,8 +46,10 @@ dtb-$(CONFIG_SOC_IMX53) += \
> imx53-ppd.dtb \
> imx53-qsb.dtb \
> imx53-qsb-hdmi.dtb \
> + imx53-qsb-mcimx-lvds1.dtb \
> imx53-qsrb.dtb \
> imx53-qsrb-hdmi.dtb \
> + imx53-qsrb-mcimx-lvds1.dtb \
> imx53-sk-imx53.dtb \
> imx53-sk-imx53-atm0700d4-lvds.dtb \
> imx53-sk-imx53-atm0700d4-rgb.dtb \
> @@ -57,7 +59,9 @@ dtb-$(CONFIG_SOC_IMX53) += \
> imx53-usbarmory.dtb \
> imx53-voipac-bsb.dtb
> imx53-qsb-hdmi-dtbs := imx53-qsb.dtb imx53-qsb-hdmi.dtbo
> +imx53-qsb-mcimx-lvds1-dtbs := imx53-qsb.dtb imx53-qsb-mcimx-lvds1.dtbo
> imx53-qsrb-hdmi-dtbs := imx53-qsrb.dtb imx53-qsb-hdmi.dtbo
> +imx53-qsrb-mcimx-lvds1-dtbs := imx53-qsrb.dtb imx53-qsb-mcimx-lvds1.dtbo
> dtb-$(CONFIG_SOC_IMX6Q) += \
> imx6dl-alti6p.dtb \
> imx6dl-apf6dev.dtb \
> diff --git a/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi
> b/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi
> index 05d7a462ea25..430792a91ccf 100644
> --- a/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi
> +++ b/arch/arm/boot/dts/nxp/imx/imx53-qsb-common.dtsi
> @@ -16,7 +16,7 @@ memory@70000000 {
> <0xb0000000 0x20000000>;
> };
>
> - backlight_parallel: backlight-parallel {
> + backlight: backlight {
Nit: this seems unrelated to the LVDS support
> compatible = "pwm-backlight";
> pwms = <&pwm2 0 5000000 0>;
> brightness-levels = <0 4 8 16 32 64 128 255>;
> @@ -89,7 +89,7 @@ panel_dpi: panel {
> compatible = "sii,43wvf1g";
> pinctrl-names = "default";
> pinctrl-0 = <&pinctrl_display_power>;
> - backlight = <&backlight_parallel>;
> + backlight = <&backlight>;
> enable-gpios = <&gpio3 24 GPIO_ACTIVE_HIGH>;
>
> port {
> diff --git a/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso
> b/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso
> new file mode 100644
> index 000000000000..27f6bedf3d39
> --- /dev/null
> +++ b/arch/arm/boot/dts/nxp/imx/imx53-qsb-mcimx-lvds1.dtso
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +/dts-v1/;
> +/plugin/;
> +
> +&{/} {
> + panel-lvds {
Nit: Just 'panel' should be enough.
> + compatible = "hannstar,hsd100pxn1";
> + backlight = <&backlight>;
> + power-supply = <®_3p2v>;
> +
> + port {
> + panel_lvds_in: endpoint {
> + remote-endpoint = <&lvds0_out>;
> + };
> + };
> + };
> +};
> +
> +&ldb {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + status = "okay";
> +
> + lvds-channel@0 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + fsl,data-mapping = "spwg";
> + fsl,data-width = <18>;
> + status = "okay";
> +
> + port@2 {
> + reg = <2>;
> +
> + lvds0_out: endpoint {
> + remote-endpoint = <&panel_lvds_in>;
> + };
> + };
> + };
> +};
> --
> 2.34.1
>
--
With best wishes
Dmitry
