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[2/6] dt-bindings: pwm: samsung: add specific compatible for Tesla FSD

Message ID 20231205092229.19135-3-krzysztof.kozlowski@linaro.org
State New
Headers show
Series dt-bindings: samsung: continued - add specific compatibles for Tesla FSD Hi, | expand

Commit Message

Krzysztof Kozlowski Dec. 5, 2023, 9:22 a.m. UTC
Tesla FSD is a derivative of Samsung Exynos SoC, thus just like the
others it reuses several devices from older designs.  Historically we
kept the old (block's) compatible only.  This works fine and there is no
bug here, however guidelines expressed in
Documentation/devicetree/bindings/writing-bindings.rst state that:
1. Compatibles should be specific.
2. We should add new compatibles in case of bugs or features.

Add Tesla FSD compatible specific to be used with an existing fallback.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

---

I propose to take the patch through Samsung SoC (me). See cover letter
for explanation.
---
 Documentation/devicetree/bindings/pwm/pwm-samsung.yaml | 1 +
 1 file changed, 1 insertion(+)

Comments

Thierry Reding Dec. 6, 2023, 4:16 p.m. UTC | #1
On Tue, Dec 05, 2023 at 10:22:25AM +0100, Krzysztof Kozlowski wrote:
> Tesla FSD is a derivative of Samsung Exynos SoC, thus just like the
> others it reuses several devices from older designs.  Historically we
> kept the old (block's) compatible only.  This works fine and there is no
> bug here, however guidelines expressed in
> Documentation/devicetree/bindings/writing-bindings.rst state that:
> 1. Compatibles should be specific.
> 2. We should add new compatibles in case of bugs or features.
> 
> Add Tesla FSD compatible specific to be used with an existing fallback.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> ---
> 
> I propose to take the patch through Samsung SoC (me). See cover letter
> for explanation.
> ---
>  Documentation/devicetree/bindings/pwm/pwm-samsung.yaml | 1 +
>  1 file changed, 1 insertion(+)

You point to the guidelines that say we should have specific compatible
strings, but then the string that you add seems very generic. Now, I'm
obviously not an expert on Tesla hardware, but just FSD seems to be
quite generic according to the internet. It seems like the chip derived
from Samsung used to be known as AP3/HW3, but there's now also AP4/HW4,
so I wonder if those differ in some way and if these shouldn't include
some sort of version/generation number.

Thierry
Krzysztof Kozlowski Dec. 6, 2023, 5:35 p.m. UTC | #2
On 06/12/2023 17:16, Thierry Reding wrote:
> On Tue, Dec 05, 2023 at 10:22:25AM +0100, Krzysztof Kozlowski wrote:
>> Tesla FSD is a derivative of Samsung Exynos SoC, thus just like the
>> others it reuses several devices from older designs.  Historically we
>> kept the old (block's) compatible only.  This works fine and there is no
>> bug here, however guidelines expressed in
>> Documentation/devicetree/bindings/writing-bindings.rst state that:
>> 1. Compatibles should be specific.
>> 2. We should add new compatibles in case of bugs or features.
>>
>> Add Tesla FSD compatible specific to be used with an existing fallback.
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>
>> ---
>>
>> I propose to take the patch through Samsung SoC (me). See cover letter
>> for explanation.
>> ---
>>  Documentation/devicetree/bindings/pwm/pwm-samsung.yaml | 1 +
>>  1 file changed, 1 insertion(+)
> 
> You point to the guidelines that say we should have specific compatible> strings, but then the string that you add seems very generic. Now, I'm
> obviously not an expert on Tesla hardware, but just FSD seems to be
> quite generic according to the internet. It seems like the chip derived
> from Samsung used to be known as AP3/HW3, but there's now also AP4/HW4,
> so I wonder if those differ in some way and if these shouldn't include
> some sort of version/generation number.

That's the compatible chosen that time for entire platform, as a
consensus, for all SoC components. Thus the PWM compatible is as
specific as it can get.

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
index 16de6434693b..17a2b927af33 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
@@ -33,6 +33,7 @@  properties:
               - samsung,exynos7-pwm
               - samsung,exynosautov9-pwm
               - samsung,exynosautov920-pwm
+              - tesla,fsd-pwm
           - const: samsung,exynos4210-pwm
 
   reg: