[PATCH v3 2/4] dt-bindings: pwm: amlogic: add new compatible for meson8 pwm type
neil.armstrong at linaro.org
neil.armstrong at linaro.org
Wed Nov 29 08:41:07 PST 2023
Hi,
On 29/11/2023 17:26, Jerome Brunet wrote:
>
> On Wed 29 Nov 2023 at 17:20, Neil Armstrong <neil.armstrong at linaro.org> wrote:
>
>> Hi,
>>
>> On 29/11/2023 14:39, Jerome Brunet wrote:
>>> Add a new compatible for the pwm found in the meson8 to sm1 Amlogic SoCs,
>>> dealing with clocks differently. This does not enable new HW. It is meant
>>> to fix a bad DT ABI for the currently supported HW.
>>> The original clock bindings describe which input the PWM channel
>>> multiplexer should pick among its possible parents, which are
>>> hard-coded in the driver. As such, it is a setting tied to the driver
>>> implementation and does not describe the HW.
>>> The new bindings introduce here describe the clocks input of the PWM
>>> block
>>> as they exist.
>>> The old compatible is deprecated but kept to maintain ABI compatibility.
>>> The SoC specific compatibles introduced match the SoC families supported
>>> by the original bindings.
>>> Signed-off-by: Jerome Brunet <jbrunet at baylibre.com>
>>> ---
>>> .../devicetree/bindings/pwm/pwm-amlogic.yaml | 52 ++++++++++++++++---
>>> 1 file changed, 46 insertions(+), 6 deletions(-)
>>> diff --git a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
>>> b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
>>> index 387976ed36d5..eece390114a3 100644
>>> --- a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
>>> +++ b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
>>> @@ -21,23 +21,35 @@ properties:
>>> - amlogic,meson-g12a-ee-pwm
>>> - amlogic,meson-g12a-ao-pwm-ab
>>> - amlogic,meson-g12a-ao-pwm-cd
>>> - - amlogic,meson-s4-pwm
>>> + deprecated: true
>>> - items:
>>> - const: amlogic,meson-gx-pwm
>>> - const: amlogic,meson-gxbb-pwm
>>> + deprecated: true
>>> - items:
>>> - const: amlogic,meson-gx-ao-pwm
>>> - const: amlogic,meson-gxbb-ao-pwm
>>> + deprecated: true
>>> - items:
>>> - const: amlogic,meson8-pwm
>>> - const: amlogic,meson8b-pwm
>>> + deprecated: true
>>
>> I think deprecated should be moved in a third patch
>
> The complain on v2 was that it was not clear the new binding was making
> the old one obsolete. It looked to me that the deprecation old bindings
> needed to go together with the introduction of the new.
>
> I don't mind one way or the other
>
> Is there a rule somewhere about this ?
Not sure about that, I don't think it's a problem to have both valid
at the same time, setting them deprecated afterwards looks cleaner
to avoid mixing too much changes at the same time.
Neil
>
>>
>>> + - const: amlogic,meson8-pwm-v2
>>> + - items:
>>> + - enum:
>>> + - amlogic,meson8b-pwm-v2
>>> + - amlogic,meson-gxbb-pwm-v2
>>> + - amlogic,meson-axg-pwm-v2
>>> + - amlogic,meson-g12-pwm-v2
>>> + - const: amlogic,meson8-pwm-v2
>>> + - const: amlogic,meson-s4-pwm
>>> reg:
>>> maxItems: 1
>>> clocks:
>>> minItems: 1
>>> - maxItems: 2
>>> + maxItems: 4
>>> clock-names:
>>> minItems: 1
>>> @@ -58,7 +70,6 @@ allOf:
>>> compatible:
>>> contains:
>>> enum:
>>> - - amlogic,meson8-pwm
>>> - amlogic,meson8b-pwm
>>> - amlogic,meson-gxbb-pwm
>>> - amlogic,meson-gxbb-ao-pwm
>>> @@ -67,14 +78,15 @@ allOf:
>>> - amlogic,meson-g12a-ee-pwm
>>> - amlogic,meson-g12a-ao-pwm-ab
>>> - amlogic,meson-g12a-ao-pwm-cd
>>> - - amlogic,meson-gx-pwm
>>> - - amlogic,meson-gx-ao-pwm
>>
>> I don't understand why those entries are removed
>
> It's a mistake. It should not have been added to begin with in
> the first patch. "amlogic,meson-gx-*" must go along with
> "amlogic,meson-gxbb-*" so it matches correctly without it.
>
> I'll fix it
>
>>
>>> then:
>>> - # Historic bindings tied to the driver implementation
>>> + # Obsolete historic bindings tied to the driver implementation
>>> # The clocks provided here are meant to be matched with the input
>>> # known (hard-coded) in the driver and used to select pwm clock
>>> # source. Currently, the linux driver ignores this.
>>> + # This is kept to maintain ABI backward compatibility.
>>
>> Same here, this should go in a third patch
>>
>>> properties:
>>> + clocks:
>>> + maxItems: 2
>>> clock-names:
>>> oneOf:
>>> - items:
>>> @@ -83,6 +95,27 @@ allOf:
>>> - const: clkin0
>>> - const: clkin1
>>> + # Newer binding where clock describe the actual clock inputs of the
>>> pwm
>>> + # block. These are necessary but some inputs may be grounded.
>>> + - if:
>>> + properties:
>>> + compatible:
>>> + contains:
>>> + enum:
>>> + - amlogic,meson8-pwm-v2
>>> + then:
>>> + properties:
>>> + clocks:
>>> + minItems: 1
>>> + items:
>>> + - description: input clock 0 of the pwm block
>>> + - description: input clock 1 of the pwm block
>>> + - description: input clock 2 of the pwm block
>>> + - description: input clock 3 of the pwm block
>>> + clock-names: false
>>> + required:
>>> + - clocks
>>> +
>>> # Newer IP block take a single input per channel, instead of 4 inputs
>>> # for both channels
>>> - if:
>>> @@ -112,6 +145,13 @@ examples:
>>> clock-names = "clkin0", "clkin1";
>>> #pwm-cells = <3>;
>>> };
>>> + - |
>>> + pwm at 2000 {
>>> + compatible = "amlogic,meson8-pwm-v2";
>>> + reg = <0x1000 0x10>;
>>> + clocks = <&xtal>, <0>, <&fdiv4>, <&fdiv5>;
>>> + #pwm-cells = <3>;
>>> + };
>>> - |
>>> pwm at 1000 {
>>> compatible = "amlogic,meson-s4-pwm";
>>
>> Neil
>
>
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