Re: [PATCH v2 11/13] mmc: sdhci-esdhc-imx: Add sdhc support for i.MXRT series

Giulio Benetti
2021-11-04T02:30:42Z

Hello Rob, Jesse, All,

> Il giorno 4 nov 2021, alle ore 02:05, Rob Herring <robh@kernel.org> ha scritto:
>
> ﻿On Wed, Nov 03, 2021 at 12:30:17AM +0100, Giulio Benetti wrote:
>> Hi Fabio, Jesse, All,
>>
>>> On 11/3/21 12:25 AM, Jesse Taube wrote:
>>>
>>>
>>> On 11/2/21 19:17, Fabio Estevam wrote:
>>>> On Tue, Nov 2, 2021 at 7:57 PM Jesse Taube <mr.bossman075@gmail.com> wrote:
>>>>
>>>>> static struct esdhc_soc_data usdhc_imx8qxp_data = {
>>>>> .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
>>>>> @@ -357,6 +363,7 @@ static const struct of_device_id imx_esdhc_dt_ids[] = {
>>>>> { .compatible = "fsl,imx7ulp-usdhc", .data = &usdhc_imx7ulp_data, },
>>>>> { .compatible = "fsl,imx8qxp-usdhc", .data = &usdhc_imx8qxp_data, },
>>>>> { .compatible = "fsl,imx8mm-usdhc", .data = &usdhc_imx8mm_data, },
>>>>> + { .compatible = "fsl,imxrt-usdhc", .data = &usdhc_imxrt_data, },
>>>>
>>>> I thought Rob suggested to use the SoC name, so this would be:
>>>>
>>> Uh i think that may have been for the UART.
>>>> { .compatible = "fsl,imxrt1050-usdhc", .data = &usdhc_imxrt1050_data, },
>>>>
>>>> The same applies to the other bindings in the series.
>>>>
>>>> This way it would be possible to differentiate between future
>>>> supported i.MX RT devices.
>>>>
>>> This makes sense will do in V3.
>>>
>>
>> If we add every SoC we will end up having a long list for every device
>> driver. At the moment it would be 7 parts:
>> 1) imxrt1020
>> 2) imxrt1024
>> .
>> .
>> .
>> 7) imxrt1170
>
> You don't need a driver update if you use a fallback. When you add
> the 2nd chip, if you think it is 'the same', then you do:
>
> compatible = "fsl,imxrt1024-usdhc", "fsl,imxrt1050-usdhc";
>
> That requires no driver update until the driver needs to handle some
> difference. And when there is a difference, you don't need a DT update.

This solution is pretty fine, we’re going with that then, for this and every driver involved.

Thank you for pointing us.

Best regards
Giulio Benetti
Benetti Engineering sas

>
> You could make "fsl,imxrt-usdhc" the fallback from the start if you are
> adverse to the first way.
>
> Rob