Re: [PATCH v8 5/5] arm64: dts: qcom: sdm845-google: Add STM FTS touchscreen support

[Bjorn Andersson <andersson@kernel.org>]

On Fri, Sep 25, 2026 at 11:22:23PM +0200, David Heidelberg via B4 Relay wrote:
> From: Petr Hodina <petr.hodina@protonmail.com>
> 
> Basic touchscreen connected to second i2c bus.
> 
> Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
> Co-developed-by: David Heidelberg <david@ixit.cz>
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>  arch/arm64/boot/dts/qcom/sdm845-google-blueline.dts | 19 ++++++++++++++++++-
>  arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi  |  2 +-
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-google-blueline.dts b/arch/arm64/boot/dts/qcom/sdm845-google-blueline.dts
> index fa89be500fb85..51c835dca43f1 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-google-blueline.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-google-blueline.dts
> @@ -21,17 +21,34 @@ &framebuffer0 {
>  	stride = <(1080 * 4)>;
>  };
>  
>  &i2c2 {
>  	clock-frequency = <1000000>;
>  
>  	status = "okay";
>  
> -	/* ST,FTS @ 49 */
> +	touchscreen@49 {
> +		compatible = "st,stmfts5";
> +		reg = <0x49>;
> +
> +		pinctrl-0 = <&touchscreen_irq_n>, <&touchscreen_reset>;
> +		pinctrl-names = "default";
> +
> +		interrupts-extended = <&tlmm 125 IRQ_TYPE_LEVEL_LOW>;
> +
> +		mode-switch-gpios = <&tlmm 136 GPIO_ACTIVE_HIGH>;

It's not clear to me how this worked or when it started failing, but due
to a conflict with the reboot-mode binding dt-validate crashes when we
reach this property.

I opened a PR to handle it here:
https://github.com/devicetree-org/dt-schema/pull/212

Regards,
Bjorn

> +		reset-gpios = <&tlmm 99 GPIO_ACTIVE_LOW>;
> +
> +		avdd-supply = <&vreg_l19a_3p3>;
> +		vdd-supply = <&vreg_l14a_1p8>;
> +
> +		touchscreen-size-x = <1080>;
> +		touchscreen-size-y = <2160>;
> +	};
>  };
>  
>  &mdss_dsi0 {
>  	vdda-supply = <&vdda_mipi_dsi0_1p2>;
>  
>  	status = "okay";
>  
>  	panel@0 {
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
> index f1379857e2742..6ae1973aa8ac7 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
> @@ -504,17 +504,17 @@ firmware-pins {
>  
>  	touchscreen_reset: ts-reset-state {
>  		pins = "gpio99";
>  		function = "gpio";
>  		drive-strength = <8>;
>  		bias-pull-up;
>  	};
>  
> -	touchscreen_pins: ts-pins-gpio-state {
> +	touchscreen_irq_n: ts-irq-n-gpio-state {
>  		pins = "gpio125";
>  		function = "gpio";
>  		drive-strength = <2>;
>  		bias-disable;
>  	};
>  
>  	touchscreen_i2c_pins: qup-i2c2-gpio-state {
>  		pins = "gpio27", "gpio28";
> 
> -- 
> 2.55.0
> 
>