Re: [PATCH V5 1/4] clk: meson: S4: add support for Amlogic S4 SoC PLL clock driver and bindings

[Jerome Brunet <jbrunet@baylibre.com>]

On Mon 28 Nov 2022 at 15:39, Yu Tu <yu.tu@amlogic.com> wrote:

> Hi Jerome,
> 	Thank you for your reply.
>
> On 2022/11/25 17:23, Jerome Brunet wrote:
>> [ EXTERNAL EMAIL ]
>> On Wed 23 Nov 2022 at 14:53, Krzysztof Kozlowski
>> <krzysztof.kozlowski@linaro.org> wrote:
>> 
>>> On 23/11/2022 14:23, Neil Armstrong wrote:
>>>> Hi,
>>>>
>>>> On 23/11/2022 12:16, Yu Tu wrote:
>>>>> Hi Krzysztof,
>>>>>       Thank you for your reply.
>>>>>
>>>>> On 2022/11/23 18:08, Krzysztof Kozlowski wrote:
>>>>>> [ EXTERNAL EMAIL ]
>>>>>>
>>>>>> On 23/11/2022 03:13, Yu Tu wrote:
>>>>>>> Add the S4 PLL clock controller found and bindings in the s4 SoC family.
>>>>>>>
>>>>>>> Signed-off-by: Yu Tu <yu.tu@amlogic.com>
>>>>>>> ---
>>>>>>>    .../bindings/clock/amlogic,s4-pll-clkc.yaml   |  51 +
>>>>>>
>>>>>> This is v5 and still bindings are here? Bindings are always separate
>>>>>> patches. Use subject prefixes matching the subsystem (git log --oneline
>>>>>> -- ...).
>>>>>>
>>>>>> And this was split, wasn't it? What happened here?!?
>>>>>
>>>>> Put bindings and clock driver patch together from Jerome. Maybe you can read this chat history.
>>>>> https://lore.kernel.or/all/1jy1v6z14n.fsf@starbuckisacylon.baylibre.com/
>>>>
>>>> Jerome was asking you to send 2 patchsets, one with :
>>>> - bindings in separate patches
>>>> - drivers in separate patches
>>>> and a second with DT changes.
>> Indeed, this is what was asked. It is aligned with Krzysztof's request.
>
> According to your discussion, I still should send patches in the previous
> way in series. But I'm going to change it like you suggested.
> I don't know, am I getting it right?

3 people tried to explain this already and we all told you the same thing.

* 1 patchset per maintainer: clk and dt
* bindings must be dedicated patches - never mixed with driver code.

I strongly suggest that you take some time to (re)read:
* https://docs.kernel.org/process/submitting-patches.html
* https://docs.kernel.org/devicetree/bindings/submitting-patches.html

If still unclear, please take some time to look at the kernel mailing
list archive and see how others have done the same things.

Thx.

>
>> 
>>>>
>>>> Then when the bindings + clocks patches are merged, a pull request of the bindings
>>>> can be done to me so I can merge it with DT.
>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>>    MAINTAINERS                                   |   1 +
>>>>>>>    drivers/clk/meson/Kconfig                     |  13 +
>>>>>>>    drivers/clk/meson/Makefile                    |   1 +
>>>>>>>    drivers/clk/meson/s4-pll.c                    | 875 ++++++++++++++++++
>>>>>>>    drivers/clk/meson/s4-pll.h                    |  88 ++
>>>>>>>    .../dt-bindings/clock/amlogic,s4-pll-clkc.h   |  30 +
>>>>>>>    7 files changed, 1059 insertions(+)
>>>>>>>    create mode 100644 Documentation/devicetree/bindings/clock/amlogic,s4-pll-clkc.yaml
>>>>>>>    create mode 100644 drivers/clk/meson/s4-pll.c
>>>>>>>    create mode 100644 drivers/clk/meson/s4-pll.h
>>>>>>>    create mode 100644 include/dt-bindings/clock/amlogic,s4-pll-clkc.h
>>>>>>>
>>>>>>> diff --git a/Documentation/devicetree/bindings/clock/amlogic,s4-pll-clkc.yaml b/Documentation/devicetree/bindings/clock/amlogic,s4-pll-clkc.yaml
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..fd517e8ef14f
>>>>>>> --- /dev/null
>>>>>>> +++ b/Documentation/devicetree/bindings/clock/amlogic,s4-pll-clkc.yaml
>>>>>>> @@ -0,0 +1,51 @@
>>>>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>>>>>> +%YAML 1.2
>>>>>>> +---
>>>>>>> +$id: http://devicetree.org/schemas/clock/amlogic,s4-pll-clkc.yaml#
>>>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>>>>> +
>>>>>>> +title: Amlogic Meson S serials PLL Clock Controller
>>>>>>> +
>>>>>>> +maintainers:
>>>>>>> +  - Neil Armstrong <narmstrong@baylibre.com>
>>>>>>> +  - Jerome Brunet <jbrunet@baylibre.com>
>>>>>>> +  - Yu Tu <yu.hu@amlogic.com>
>>>>>>> +
>>>>>> One blank line.
>>>>>
>>>>>    I will delete this, on next version patch.
>>>>>
>>>>>>
>>>>>>> +
>>>>>>> +properties:
>>>>>>> +  compatible:
>>>>>>> +    const: amlogic,s4-pll-clkc
>>>>>>> +
>>>>>>> +  reg:
>>>>>>> +    maxItems: 1
>>>>>>> +
>>>>>>> +  clocks:
>>>>>>> +    maxItems: 1
>>>>>>> +
>>>>>>> +  clock-names:
>>>>>>> +    items:
>>>>>>> +      - const: xtal
>>>>>>> +
>>>>>>> +  "#clock-cells":
>>>>>>> +    const: 1
>>>>>>> +
>>>>>>> +required:
>>>>>>> +  - compatible
>>>>>>> +  - reg
>>>>>>> +  - clocks
>>>>>>> +  - clock-names
>>>>>>> +  - "#clock-cells"
>>>>>>> +
>>>>>>> +additionalProperties: false
>>>>>>> +
>>>>>>> +examples:
>>>>>>> +  - |
>>>>>>> +    clkc_pll: clock-controller@fe008000 {
>>>>>>> +      compatible = "amlogic,s4-pll-clkc";
>>>>>>> +      reg = <0xfe008000 0x1e8>;
>>>>>>> +      clocks = <&xtal>;
>>>>>>> +      clock-names = "xtal";
>>>>>>> +      #clock-cells = <1>;
>>>>>>> +    };
>>>>>>
>>>>>>
>>>>>>> +#endif /* __MESON_S4_PLL_H__ */
>>>>>>> diff --git a/include/dt-bindings/clock/amlogic,s4-pll-clkc.h b/include/dt-bindings/clock/amlogic,s4-pll-clkc.h
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..345f87023886
>>>>>>> --- /dev/null
>>>>>>> +++ b/include/dt-bindings/clock/amlogic,s4-pll-clkc.h
>>>>>>
>>>>>> This belongs to bindings patch, not driver.
>>>>>>
>>>>>>> @@ -0,0 +1,30 @@
>>>>>>> +/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
>>>>>>> +/*
>>>>>>> + * Copyright (c) 2021 Amlogic, Inc. All rights reserved.
>>>>>>> + * Author: Yu Tu <yu.tu@amlogic.com>
>>>>>>> + */
>>>>>>> +
>>>>>>> +#ifndef _DT_BINDINGS_CLOCK_AMLOGIC_S4_PLL_CLKC_H
>>>>>>> +#define _DT_BINDINGS_CLOCK_AMLOGIC_S4_PLL_CLKC_H
>>>>>>> +
>>>>>>> +/*
>>>>>>> + * CLKID index values
>>>>>>> + */
>>>>>>> +
>>>>>>> +#define CLKID_FIXED_PLL            1
>>>>>>> +#define CLKID_FCLK_DIV2            3
>>>>>>
>>>>>> Indexes start from 0 and are incremented by 1. Not by 2.
>>>>>>
>>>>>> NAK.
>>>>>
>>>>> I remember Jerome discussing this with you.You can look at this submission history.
>>>>> https://lore.kernel.org/all/c088e01c-0714-82be-8347-6140daf56640@linaro.org/
>>>>
>>>> Historically we did that by only exposing part of the numbers, controlling which
>>>> clocks were part of the bindings.
>>>>
>>>> But it seems this doesn't make sens anymore, maybe it would be time to put all the
>>>> clock ids in the bindings for this new SoC and break with the previous strategy.
>> Krzysztof and I agreed there is nothing wrong with the current
>> approach, I believe.
>> It does not prevent someone from using an un-exposed clock, sure, or
>> exposing it in the future if necessary.
>> However, I think it clearly shows that an un-exposed element is not
>> expected to be used by an external consumers. It should be enough to
>> trigger a discussion if this expectation is wrong.
>> 
>>>
>>> So the outcome of the previous discussion was somewhere later in that
>>> thread:
>>>
>>>> It is just a choice to not expose some IDs.
>>>> It is not tied to the implementation at all.
>>>> I think we actually follow the rules and the idea behind it.
>>>
>>>
>>> Best regards,
>>> Krzysztof
>> .