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Message-ID: <58b70e1b-d292-ec45-2309-e237a4a43d0d@loongson.cn>
Date:   Tue, 13 Jun 2023 21:03:23 +0800
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Subject: Re: [ PATCH v2 3/3] ASoC: dt-bindings: Add support for Loongson audio
 card
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To:     Conor Dooley <conor.dooley@microchip.com>
Cc:     Conor Dooley <conor@kernel.org>, krzysztof.kozlowski+dt@linaro.org,
        robh+dt@kernel.org, conor+dt@kernel.org, broonie@kernel.org,
        lgirdwood@gmail.com, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org,
        loongarch@lists.linux.dev, loongson-kernel@lists.loongnix.cn
References: <20230612085614.3039498-1-mengyingkun@loongson.cn>
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 <20230613-zoologist-panorama-a87858bba075@wendy>
 <887f9cc4-6457-9d14-8aef-011ff4c9aeda@loongson.cn>
 <20230613-depletion-garnet-ccc2009111c3@wendy>
From:   Yingkun Meng <mengyingkun@loongson.cn>
In-Reply-To: <20230613-depletion-garnet-ccc2009111c3@wendy>
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On 2023/6/13 20:46, Conor Dooley wrote:
> On Tue, Jun 13, 2023 at 08:38:59PM +0800, Yingkun Meng wrote:
>> On 2023/6/13 20:28, Conor Dooley wrote:
>>> On Tue, Jun 13, 2023 at 08:23:58PM +0800, Yingkun Meng wrote:
>>>> On 2023/6/13 01:24, Conor Dooley wrote:
>>>>> On Mon, Jun 12, 2023 at 04:56:14PM +0800, YingKun Meng wrote:
>>>>>> From: Yingkun Meng <mengyingkun@loongson.cn>
>>>>>>
>>>>>> The audio card uses loongson I2S controller present in
>>>>>> 7axxx/2kxxx chips to transfer audio data.
>>>>>>
>>>>>> On loongson platform, the chip has only one I2S controller.
>>>>>> +description:
>>>>>> +  The binding describes the sound card present in loongson
>>>>>> +  7axxx/2kxxx platform. The sound card is an ASoC component
>>>>>> +  which uses Loongson I2S controller to transfer the audio data.
>>>>>> +
>>>>>> +properties:
>>>>>> +  compatible:
>>>>>> +    const: loongson,ls-audio-card
>>>>> Reviewing sound stuff is beyond my pay grade, so forgive me if I am off
>>>>> the rails here, but this (and the "x"s in the description) look a bit
>>>>> odd. Recently, we've noticed quite a few loongson dt-bindings attempting
>>>>> to use a single compatible for many different chips.
>>>>> Usually you have individual compatibles for the various SoCs with this
>>>>> core, which can fall back to a generic one, rather than just adding a
>>>>> generic compatible for all devices.
>>>>> As far as I know, there's several SoCs fitting 2kxxx, and the format
>>>>> being used elsewhere is "loongson,ls2k1000" etc.
>>>> Currently, Loongson has 2K0500/2K1000LA/2K1500/2K2000 chips.
>>>>
>>>> Here, its' possible to use a single compatible for different chips,
>>>>
>>>> as the audio device is a logical device, not dependent on chip model.
>>> What, may I ask, is a "logical device"?
>>
>> I means it's not a physical one, like "platform bus".
> So it is entirely a software construct? Why does it need a dt-binding
> then? Your commit message says the controller is present on the device!

It's not. The audio device consists of an i2s controller and codec.

The dt-binding is for the audio device, not for i2s controller.

> Confused,
> Conor.