linux-kernel - Re: [PATCH v1] max77663-rtc: pass rtc address from device tree node if exists

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Date:   Wed, 8 Mar 2023 11:49:35 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     Svyatoslav Ryhel <clamor95@...il.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        linux-kernel@...r.kernel.org, linux-rtc@...r.kernel.org
Subject: Re: [PATCH v1] max77663-rtc: pass rtc address from device tree node
 if exists

On 08/03/2023 10:42, Alexandre Belloni wrote:
> On 08/03/2023 10:14:22+0100, Krzysztof Kozlowski wrote:
>> On 08/03/2023 10:11, Krzysztof Kozlowski wrote:
>>> On 08/03/2023 09:58, Svyatoslav Ryhel wrote:
>>>> I would love to, but max77663 uses max77686 rtc
>>>> https://github.com/torvalds/linux/blob/master/drivers/mfd/max77620.c#L123
>>>> how to handle this?
>>>
>>> Don't top post.
>>>
>>> Hm, so it seems max7763 is already documented via max77620. I missed
>>> that. Add the new property to max77620, not to max77686 RTC. It does not
>>> look like RTC's property, but the PMIC's.
>>
>> To clarify - the I2C address selection for regmap is in max77686 RTC,
>> but I meant DT property.
>>
>> Different thing is that we do not pass addresses as property fields.
>> These should be devices on the I2C bus rather... unless you are aware of
>> existing property like this?
>>
> 
> I'd say that the RTC should have been modeled as a discrete component
> from the beginning instead of using an i2c dummy device

Yeah, exactly. Current design was working for existing use
cases/devices, but has limits, thus RTC should be reworked. Actually
even for oldest PMIC max77686, the RTC was a separate device on I2C bus.
We just made it for simplicity part of PMIC.

Best regards,
Krzysztof