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Date:   Tue, 4 Apr 2023 14:18:24 +0200
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     Ibrahim Tilki <Ibrahim.Tilki@analog.com>, a.zummo@towertech.it,
        jdelvare@suse.com, linux@roeck-us.net, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-rtc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org,
        devicetree@vger.kernel.org,
        Zeynep Arslanbenzer <Zeynep.Arslanbenzer@analog.com>
Subject: Re: [PATCH v5 2/2] dt-bindings: rtc: add max313xx RTCs
Message-ID: <2023040412182450fc4fd1@mail.local>
References: <20230403154342.3108-1-Ibrahim.Tilki@analog.com>
 <20230403154342.3108-3-Ibrahim.Tilki@analog.com>
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 <202304040710049c9cc01a@mail.local>
 <996b49ab-5e2e-76bc-efb1-38c6384871f6@linaro.org>
 <2023040407444619bf5596@mail.local>
 <0fd972bd-c5e7-65cc-6992-09c4c3e88f95@linaro.org>
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On 04/04/2023 12:06:14+0200, Krzysztof Kozlowski wrote:
> On 04/04/2023 11:56, Alexandre Belloni wrote:
> > On 04/04/2023 10:14:33+0200, Krzysztof Kozlowski wrote:
> >> On 04/04/2023 09:44, Alexandre Belloni wrote:
> >>>>
> >>>>> charging will always
> >>>>> enable a diode, select a resistor and then have or not an extra diode.
> >>>>> Figure2 of the MAX31329 datasheet is great.
> >>>>
> >>>> So the diode is in the max313xx? Then why enabling it is a property of
> >>>> DT? Either this should be inferred from compatible or is even a policy,
> >>>> not a DT property. Just because device has a register for something, is
> >>>> not an argument that "something" should be in DT.
> >>>
> >>> Well, it depends on the battery that is installed on the board so it
> >>> makes sense to have it in DT.
> >>
> >> OK, that would be a good reason, but I wonder why? Why choosing diode or
> >> not depends on the battery? Wouldn't you always want to have the diode?
> >>
> > 
> > It limits the maximum current used to charge the battery or supercap to
> > not exceed what is allowed.
> 
> and I still wonder why someone would like to allow exceeding what is
> allowed. IOW, what is the use case to disable the diode?
> 

The battery or supercap is the part defining the current limit. why
would you want to limit the current if you can charge faster?


-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com