linux-kernel - Re: [PATCH v2 00/14] Support ROHM Scalable PMIC family

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Message-ID: <20250410080233.GO372032@google.com>
Date: Thu, 10 Apr 2025 09:02:33 +0100
From: Lee Jones <lee@...nel.org>
To: Matti Vaittinen <mazziesaccount@...il.com>
Cc: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 00/14] Support ROHM Scalable PMIC family

On Tue, 08 Apr 2025, Matti Vaittinen wrote:

> On 04/04/2025 18:43, Lee Jones wrote:
> > On Mon, 24 Mar 2025, Matti Vaittinen wrote:
> > 
> > > Support ROHM BD96802, BD96805 and BD96806 PMICs
> > > 
> > > The ROHM BD96801 [1] and BD96805 [2] are almost identical PMICs what comes
> > > to the digital interface. Main difference is voltage tuning range.
> > > Supporting BD96805 with BD96801 drivers is mostly just a matter of being
> > > able to differentiate the PMICs (done based on the devicetree
> > > compatible) and then providing separate voltage tables.
> > > 
> > > The ROHM BD96802 [3] is a companion PMIC which is intended to be used to
> > > provide more capacity on systems where the BD96801 alone is not
> > > sufficient. Startup sequence of these PMICs can be synchronized in
> > > hardware level, and there seems to be some mechanisms which allow
> > > delivering the companion PMIC (BD96802) status to the main PMIC
> > > (BD96801/BD96805). This patch series does treat the companion PMIC(s) as
> > > individual PMICs and allows using them from software point of view as a
> > > stand alone ICs. From the digital point of view, the BD96802 is a subset
> > > of BD96801, providing only buck1 and buck2 regulators. Please see the
> > > data sheet
> > > 
> > > The ROHM BD96806 [4] is similar to the BD96802, except that it does also
> > > provide different voltage tuning ranges.
> > > 
> > > This series adds basic voltage monitoring and control as well as a
> > > watchdog support for these PMICs using the BD96801 drivers.
> > > 
> > > Similarly to the BD96801, these PMICs too have a few configurations
> > > which can only be done when the PMIC is in STBY state. Similarly to the
> > > BD96801, doing these configurations isn't supported by the driver. The
> > > original BD96801 RFC [5] driver should be able to cover those
> > > configurations, if modified to support these models.
> > > 
> > > [1]: ROHM BD96801 data sheet:
> > > https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator_system/product_brief_bd96801qxx-c-e.pdf
> > > [2]: ROHM BD96805 data sheet:
> > > https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator_system/product_brief_bd96805qxx-c-e.pdf
> > > [3]: ROHM BD96802 data sheet:
> > > https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator_system/product_brief_bd96802qxx-c-e.pdf
> > > [4]: ROHM BD96806 data sheet:
> > > https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator_system/product_brief_bd96806qxx-c-e.pdf
> > > [5]: Original BD96801 RFC:
> > > https://lore.kernel.org/all/cover.1712058690.git.mazziesaccount@gmail.com/
> > > 
> > > Revision history:
> > > 
> > > v1 => v2: MFD driver changes after review by Lee
> > >   - Use enum for chip type instead of picking the data directly from the
> > >     of_match_data.
> > >   - rename "chip data" variable 'cd' to more widely used 'ddata'.
> > >   link to v1:
> > >    https://lore.kernel.org/all/cover.1741864404.git.mazziesaccount@gmail.com/
> 
> > 
> > The MFD stuff looks okay to me now.
> > 
> > Let me know when everything else is ready to go.
> > 
> 
> I'll treat this as an ACK for the V3. Please, let me know if that's not
> Okay.

Acks are tricky because another maintainer might (have have in the past)
assume that they can apply the set with my blessing, this is not the
case.  I used to use `Acked-for-MFD-by: <me>`, but these ended up being
merged.  *face palm*

Anyway, no harm done this time around I think.

-- 
Lee Jones [李琼斯]