[PATCH v2 0/2] Introduce OnePlus 6/6T touchscreen compatible

[PATCH v2 0/2] Introduce OnePlus 6/6T touchscreen compatible

[David Heidelberg via B4 Relay]

Mostly related to the
  https://codeberg.org/sdm845/linux/commits/branch/b4/synaptics-rmi4
series, but independent on other changes which I trying to upstream for
more than one year.

Signed-off-by: David Heidelberg <david@ixit.cz>
---
Changes in v2:
- Add R-b tag.
- Link to v1: https://lore.kernel.org/r/20260408-synaptics-rmi4-dt-v1-0-2d32bacce673@ixit.cz

---
David Heidelberg (2):
      dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b
      arm64: dts: qcom: sdm845-oneplus: Update compatible to include model

 Documentation/devicetree/bindings/input/syna,rmi4.yaml | 11 ++++++++---
 arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi    |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)
---
base-commit: 5200f5f493f79f14bbdc349e402a40dfb32f23c8
change-id: 20260408-synaptics-rmi4-dt-8aebf31790dc

Best regards,
-- 
David Heidelberg <david@ixit.cz>

[PATCH v2 1/2] dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b

[David Heidelberg via B4 Relay]

From: David Heidelberg <david@ixit.cz>

Mostly irrelevant for authentic Synaptics touchscreens, but very important
for applying workarounds to cheap TS knockoffs.

These knockoffs work well with the downstream driver, and since the user
has no way to distinguish them, later in this patch set, we introduce
workarounds to ensure they function as well as possible.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David Heidelberg <david@ixit.cz>
---
 Documentation/devicetree/bindings/input/syna,rmi4.yaml | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/syna,rmi4.yaml b/Documentation/devicetree/bindings/input/syna,rmi4.yaml
index 8685ef4481f4a..fb4804ac3544d 100644
--- a/Documentation/devicetree/bindings/input/syna,rmi4.yaml
+++ b/Documentation/devicetree/bindings/input/syna,rmi4.yaml
@@ -13,19 +13,24 @@ maintainers:
 
 description: |
   The Synaptics RMI4 (Register Mapped Interface 4) core is able to support RMI4
   devices using different transports (I2C, SPI) and different functions (e.g.
   Function 1, 2D sensors using Function 11 or 12).
 
 properties:
   compatible:
-    enum:
-      - syna,rmi4-i2c
-      - syna,rmi4-spi
+    oneOf:
+      - enum:
+          - syna,rmi4-i2c
+          - syna,rmi4-spi
+      - items:
+          - enum:
+              - syna,rmi4-s3706b  # OnePlus 6/6T
+          - const: syna,rmi4-i2c
 
   reg:
     maxItems: 1
 
   '#address-cells':
     const: 1
 
   '#size-cells':

-- 
2.53.0

[PATCH v2 2/2] arm64: dts: qcom: sdm845-oneplus: Update compatible to include model

[David Heidelberg via B4 Relay]

From: David Heidelberg <david@ixit.cz>

We know the driver is reporting s3706b, introduce the compatible so we
can more easily introduce quirks for weird touchscreen replacements in
followup series.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
---
 arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
index 6b7378cf4d493..148164d456a5a 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
@@ -475,17 +475,17 @@ bq27441_fg: bq27441-battery@55 {
 	};
 };
 
 &i2c12 {
 	status = "okay";
 	clock-frequency = <400000>;
 
 	synaptics-rmi4-i2c@20 {
-		compatible = "syna,rmi4-i2c";
+		compatible = "syna,rmi4-s3706b", "syna,rmi4-i2c";
 		reg = <0x20>;
 		#address-cells = <1>;
 		#size-cells = <0>;
 		interrupts-extended = <&tlmm 125 IRQ_TYPE_EDGE_FALLING>;
 
 		pinctrl-names = "default";
 		pinctrl-0 = <&ts_default_pins>;
 

-- 
2.53.0

Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-oneplus: Update compatible to include model

[Dmitry Torokhov]

Hi David,

On Sat, May 23, 2026 at 11:45:35AM +0200, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
> 
> We know the driver is reporting s3706b, introduce the compatible so we
> can more easily introduce quirks for weird touchscreen replacements in
> followup series.
> 
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>  arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> index 6b7378cf4d493..148164d456a5a 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> @@ -475,17 +475,17 @@ bq27441_fg: bq27441-battery@55 {
>  	};
>  };
>  
>  &i2c12 {
>  	status = "okay";
>  	clock-frequency = <400000>;
>  
>  	synaptics-rmi4-i2c@20 {
> -		compatible = "syna,rmi4-i2c";
> +		compatible = "syna,rmi4-s3706b", "syna,rmi4-i2c";

So I believe we established that this device (s3706b) does not in fact
implement rmi4 protocol properly. Why do we have "syna,rmi4-i2c" as a
fallback? Shouldn't it be just "syna,rmi4-s3706b"?

Thanks.

-- 
Dmitry

Re: [PATCH v2 2/2] arm64: dts: qcom: sdm845-oneplus: Update compatible to include model

[David Heidelberg]

On 27/05/2026 23:56, Dmitry Torokhov wrote:
> Hi David,
> 
> On Sat, May 23, 2026 at 11:45:35AM +0200, David Heidelberg via B4 Relay wrote:
>> From: David Heidelberg <david@ixit.cz>
>>
>> We know the driver is reporting s3706b, introduce the compatible so we
>> can more easily introduce quirks for weird touchscreen replacements in
>> followup series.
>>
>> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
>> Signed-off-by: David Heidelberg <david@ixit.cz>
>> ---
>>   arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
>> index 6b7378cf4d493..148164d456a5a 100644
>> --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
>> @@ -475,17 +475,17 @@ bq27441_fg: bq27441-battery@55 {
>>   	};
>>   };
>>   
>>   &i2c12 {
>>   	status = "okay";
>>   	clock-frequency = <400000>;
>>   
>>   	synaptics-rmi4-i2c@20 {
>> -		compatible = "syna,rmi4-i2c";
>> +		compatible = "syna,rmi4-s3706b", "syna,rmi4-i2c";
> 
> So I believe we established that this device (s3706b) does not in fact
> implement rmi4 protocol properly. Why do we have "syna,rmi4-i2c" as a
> fallback? Shouldn't it be just "syna,rmi4-s3706b"?

The vendor supplies s3706b which does implement the RMI4 properly.

The 3rd party replacement impersonating original parts may not implement it 
properly, but I don't address this issue in this initial submission.

With this compatible we know which original part is used by the vendor and 
installed in the phones, so later we can deduct specific sequences for the 
replacement aftermarket parts to keep phone touchscreen working same as they do 
on Android without affecting other devices.

David

> 
> Thanks.
> 

-- 
David Heidelberg