[PATCH v2 0/2] arm64: dts: glymur-crd: Add reset GPIO to touchscreen

[PATCH v2 0/2] arm64: dts: glymur-crd: Add reset GPIO to touchscreen

[Pradyot Kumar Nayak]

The touchscreen on Glymur/Mahua CRDs has a dedicated GPIO reset line that must
be explicitly modeled in DT so the i2c-hid driver can deassert it on resume.
Without this, the device stays offline after suspend/resume and all I2C
transactions fail with -ENXIO.

Patch 1 adds reset-gpios to the hid-over-i2c binding.
Patch 2 wires the GPIO in the Glymur CRD DTSI.

prerequisite-message-id: 20260519-glymur-mahua-common-nodes-v2-1-9f1b89a3f398@oss.qualcomm.com

Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
---
Changes in v2:
- Add dt-bindings patch to document reset-gpios in hid-over-i2c schema
  (flagged by dtbs_check on v1)
- No change to the DTS patch itself
- Link to v1: https://lore.kernel.org/r/20260522-arm64-dts-glymur-crd-add-reset-gpio-to-touchscreen-v1-1-c7653924acdc@oss.qualcomm.com

---
Pradyot Kumar Nayak (2):
      dt-bindings: input: hid-over-i2c: Add reset-gpios property
      arm64: dts: glymur-crd: Add reset GPIO to touchscreen node

 Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 4 ++++
 arch/arm64/boot/dts/qcom/glymur-crd.dtsi                  | 2 ++
 2 files changed, 6 insertions(+)
---
base-commit: 1d376e58cb4a94f89de0fa9195d583ad6b86eb89
change-id: 20260522-arm64-dts-glymur-crd-add-reset-gpio-to-touchscreen-5892beded29b

Best regards,
-- 
Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>

[PATCH v2 1/2] dt-bindings: input: hid-over-i2c: Add reset-gpios property

[Pradyot Kumar Nayak]

Document reset-gpios property for devices that explicitly require
the reset line to be de-asserted during power up.

Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
index 138caad96a29..fe0ec4fce673 100644
--- a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
+++ b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
@@ -50,6 +50,10 @@ properties:
     description: Time required by the device after enabling its regulators
       or powering it on, before it is ready for communication.
 
+  reset-gpios:
+    maxItems: 1
+    description: GPIO line used to reset the device.
+
   touchscreen-inverted-x: true
 
   touchscreen-inverted-y: true

-- 
2.43.0

Re: [PATCH v2 1/2] dt-bindings: input: hid-over-i2c: Add reset-gpios property

[Conor Dooley]

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On Sat, May 23, 2026 at 01:25:37AM +0530, Pradyot Kumar Nayak wrote:
> Document reset-gpios property for devices that explicitly require
> the reset line to be de-asserted during power up.

If there are devices that require this, it seems short-sighted to not
add their compatibles to hid-over-i2c.yaml and make the property
required for them.
pw-bot: changes-requested

Cheers,
Conor.

> 
> Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
> ---
>  Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> index 138caad96a29..fe0ec4fce673 100644
> --- a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> +++ b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> @@ -50,6 +50,10 @@ properties:
>      description: Time required by the device after enabling its regulators
>        or powering it on, before it is ready for communication.
>  
> +  reset-gpios:
> +    maxItems: 1
> +    description: GPIO line used to reset the device.
> +
>    touchscreen-inverted-x: true
>  
>    touchscreen-inverted-y: true
> 
> -- 
> 2.43.0
> 

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Re: [PATCH v2 1/2] dt-bindings: input: hid-over-i2c: Add reset-gpios property

[Dmitry Baryshkov]

On Sat, May 23, 2026 at 01:25:37AM +0530, Pradyot Kumar Nayak wrote:
> Document reset-gpios property for devices that explicitly require
> the reset line to be de-asserted during power up.
> 
> Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
> ---
>  Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> index 138caad96a29..fe0ec4fce673 100644
> --- a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> +++ b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> @@ -50,6 +50,10 @@ properties:
>      description: Time required by the device after enabling its regulators
>        or powering it on, before it is ready for communication.
>  
> +  reset-gpios:
> +    maxItems: 1
> +    description: GPIO line used to reset the device.
> +

If you are extending the schema, where are the driver changes?

>    touchscreen-inverted-x: true
>  
>    touchscreen-inverted-y: true
> 
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry

Re: [PATCH v2 1/2] dt-bindings: input: hid-over-i2c: Add reset-gpios property

[Hans de Goede]

Hi,

On 22-May-26 21:55, Pradyot Kumar Nayak wrote:
> Document reset-gpios property for devices that explicitly require
> the reset line to be de-asserted during power up.
> 
> Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
> ---
>  Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> index 138caad96a29..fe0ec4fce673 100644
> --- a/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> +++ b/Documentation/devicetree/bindings/input/hid-over-i2c.yaml
> @@ -50,6 +50,10 @@ properties:
>      description: Time required by the device after enabling its regulators
>        or powering it on, before it is ready for communication.
>  
> +  reset-gpios:
> +    maxItems: 1
> +    description: GPIO line used to reset the device.
> +

For I2C HID devices which need a reset, we typically also
need reset timings, trying to do I2C transfers to the device directly
after the reset has been de-asserted typically will not work and
some touchscreen-model specific delay is necessary.

So far in the DT world this has been handled by touchscreen
vendor specific bindings:

Documentation/devicetree/bindings/input/elan,ekth6915.yaml
Documentation/devicetree/bindings/input/focaltech,ft8112.yaml
Documentation/devicetree/bindings/input/ilitek,ili9882t.yaml

Which are all 3 handled by:

drivers/hid/i2c-hid/i2c-hid-of-elan.c

Which has per compatible match-data with the reset timings.

You should probably extend drivers/hid/i2c-hid/i2c-hid-of-elan.c
with support for the CRD touchscreen and either add a new
compatible to one of the existing 3 bindings; or if the touchscreen
controller IC is from a vendor without a binding yet maybe add
a new bindings file?

There also is:

Documentation/devicetree/bindings/input/goodix,gt7375p.yaml

which is handled by:

drivers/hid/i2c-hid/i2c-hid-of-goodix.c

and is special in its own way.

Regards,

Hans

[PATCH v2 2/2] arm64: dts: glymur-crd: Add reset GPIO to touchscreen node

[Pradyot Kumar Nayak]

The touchscreen module on Glymur/Mahua CRDs is different from the one
used on Hamoa CRDs and requires the reset-gpios to be wired to the device.
Without this in place the reset line will remain permanently asserted
during resume leaving the device offline and causing all I2C transactions
to fail with -ENXIO.

Error Logs:
i2c_hid_of 3-0038: failed to change power setting.
i2c_hid_of 3-0038: PM: dpm_run_callback(): i2c_hid_core_pm_resume [i2c_hid] returns -6
i2c_hid_of 3-0038: PM: failed to resume async: error -6

Add the reset GPIO so the driver can deassert the line on resume,
restoring I2C communication with the device.

Fixes: e6bf559f7eb9 ("arm64: dts: qcom: glymur-crd: Enable keyboard, trackpad and touchscreen")
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Pradyot Kumar Nayak <pradyot.nayak@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/glymur-crd.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/glymur-crd.dtsi b/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
index 1de3a49f49e4..2259577b9ae1 100644
--- a/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
+++ b/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
@@ -623,6 +623,8 @@ touchscreen@38 {
 		vdd-supply = <&vreg_misc_3p3>;
 		vddl-supply = <&vreg_l15b_e0_1p8>;
 
+		reset-gpios = <&tlmm 48 GPIO_ACTIVE_LOW>;
+
 		pinctrl-0 = <&ts0_default>;
 		pinctrl-names = "default";
 	};

-- 
2.43.0