[v8] Input: synaptics-rmi4 - add quirks for third party touchscreen controllers

[PATCH v8 1/7] dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b

Posted by David Heidelberg via B4 Relay 1 week, 2 days ago

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
@@ -18,9 +18,14 @@ description: |
 
 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

-- 
2.53.0

Re: [PATCH v8 1/7] dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b

Posted by Dmitry Torokhov 1 week, 2 days ago

On Tue, Mar 24, 2026 at 08:40:34PM +0100, David Heidelberg via B4 Relay wrote:
> 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
> @@ -18,9 +18,14 @@ description: |
>  
>  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

I thought that all the workarounds will be keyed off this new
compatible, but I do not see that. What am I missing?

Thanks.

-- 
Dmitry

Re: [PATCH v8 1/7] dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b

Posted by David Heidelberg 1 week, 1 day ago

On 24/03/2026 20:42, Dmitry Torokhov wrote:
> On Tue, Mar 24, 2026 at 08:40:34PM +0100, David Heidelberg via B4 Relay wrote:
>> 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
>> @@ -18,9 +18,14 @@ description: |
>>   
>>   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
> 
> I thought that all the workarounds will be keyed off this new
> compatible, but I do not see that. What am I missing?

The compatible is used for sequence in the

Input: synaptics-rmi4 - support fallback values for PDT descriptor bytes

where it is used to provide values missing for OP6 (and possible others in the 
future, when added).

 From my understanding the series, only two patches (1st and last) are specific 
for the OP6, rest will likely benefit various TS not implementing full Synaptics 
set. All measures apply only when touchscreen reports something wrong.

David

> 
> Thanks.
> 

-- 
David Heidelberg