linux-kernel - Re: [PATCH v10 3/3] regulator: axp20x: Add support for AXP313a variant

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Date:   Sun, 2 Apr 2023 14:13:06 +0800
From:   Chen-Yu Tsai <wens@...e.org>
To:     Andre Przywara <andre.przywara@....com>
Cc:     Lee Jones <lee@...nel.org>, Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Martin Botka <martin.botka@...ainline.org>,
        martin.botka1@...il.com, Shengyu Qu <wiagn233@...look.com>,
        Samuel Holland <samuel@...lland.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        linux-sunxi@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v10 3/3] regulator: axp20x: Add support for AXP313a variant

On Sat, Apr 1, 2023 at 8:19 AM Andre Przywara <andre.przywara@....com> wrote:
>
> From: Martin Botka <martin.botka@...ainline.org>
>
> The AXP313a is your typical I2C controlled PMIC, although in a lighter
> fashion compared to the other X-Powers PMICs: it has only three DCDC
> rails, three LDOs, and no battery charging support.
>
> The AXP313a datasheet does not describe a register to change the DCDC
> switching frequency, and talks of it being fixed at 3 MHz. Check that
> the property allowing to change that frequency is absent from the DT,
> and bail out otherwise.
>
> The third LDO, RTCLDO, is fixed, and cannot even be turned on or off,
> programmatically. On top of that, its voltage is customisable (either
> 1.8V or 3.3V), which we cannot describe easily using the existing
> regulator wrapper functions. This should be fixed properly, using
> regulator-{min,max}-microvolt in the DT, but this requires more changes
> to the code. As some other PMICs (AXP2xx, AXP803) seem to paper over the
> same problem as well, we follow suit here and pretend it's a fixed 1.8V
> regulator. A proper fix can follow later. The BSP code seems to ignore
> this regulator altogether.
>
> Describe the AXP313A's voltage settings and switch registers, how the
> voltages are encoded, and connect this to the MFD device via its
> regulator ID.
>
> Signed-off-by: Martin Botka <martin.botka@...ainline.org>
> Signed-off-by: Andre Przywara <andre.przywara@....com>

Reviewed-by: Chen-Yu Tsai <wens@...e.org>