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

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Message-ID: <ddd8882f-05b6-40f0-9a26-ab21d9644364@gmail.com>
Date: Tue, 8 Apr 2025 11:05:21 +0300
From: Matti Vaittinen <mazziesaccount@...il.com>
To: Lee Jones <lee@...nel.org>
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 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.

Yours,
	-- Matti