Re: [PATCH AUTOSEL 6.12 27/69] mfd: tps6594: Add TI TPS652G1 support

[Sasha Levin <sashal@kernel.org>]

On Mon, Aug 18, 2025 at 08:34:03AM +0200, Michael Walle wrote:
>Hi Sasha,
>
>On Mon Aug 4, 2025 at 2:30 AM CEST, Sasha Levin wrote:
>> From: Michael Walle <mwalle@kernel.org>
>>
>> [ Upstream commit 626bb0a45584d544d84eab909795ccb355062bcc ]
>>
>> The TPS652G1 is a stripped down version of the TPS65224. From a software
>> point of view, it lacks any voltage monitoring, the watchdog, the ESM
>> and the ADC.
>>
>> Signed-off-by: Michael Walle <mwalle@kernel.org>
>> Link: https://lore.kernel.org/r/20250613114518.1772109-2-mwalle@kernel.org
>> Signed-off-by: Lee Jones <lee@kernel.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>>
>> LLM Generated explanations, may be completely bogus:
>>
>> **YES**
>>
>> This commit should be backported to stable kernel trees for the
>> following reasons:
>>
>> 1. **Hardware Enablement (Device ID Addition)**: This patch adds support
>>    for a new PMIC variant (TPS652G1) by adding its device ID and
>>    configuration. According to stable kernel rules, patches that "just
>>    add a device ID" are explicitly allowed for stable backporting.
>>
>> 2. **Self-Contained Changes**: The modifications are isolated to adding
>>    support for the new device without altering existing functionality:
>>    - Adds `TPS652G1` to the `enum pmic_id`
>>    - Adds TPS652G1-specific MFD cells configuration
>>    - Adds device-specific IRQ mappings (subset of TPS65224 IRQs)
>>    - Adds compatible strings "ti,tps652g1" to I2C and SPI device tables
>>    - Properly handles the stripped-down nature of TPS652G1 (no RTC, ADC,
>>      watchdog, ESM)
>>
>> 3. **Low Risk**: The changes follow the existing driver pattern and only
>>    add conditional paths for the new device:
>>   ```c
>>   if (tps->chip_id == TPS65224 || tps->chip_id == TPS652G1)
>>   ```
>>   This ensures existing device support remains unaffected.
>>
>> 4. **User Benefit**: Without this patch, users with TPS652G1 hardware
>>    cannot use their devices on stable kernels. This directly impacts
>>    hardware functionality for affected users.
>>
>> 5. **Proper Implementation**: The patch correctly handles the TPS652G1
>>    as a feature-reduced variant of TPS65224, sharing the same register
>>    layout and CRC handling while properly excluding unsupported
>>    features.
>>
>> The patch is relatively small, follows established driver patterns, and
>> enables essential hardware support without introducing architectural
>> changes or new features beyond device enablement.
>
>While this is correct, the MFD patch on it's own is rather useless,
>as the individual driver implementations are missing. See
>https://lore.kernel.org/all/20250703113153.2447110-1-mwalle@kernel.org/
>
>I don't care too much, I just want to point out, that just having
>this patch might be misleading regarding the support of this PMIC.

Yeah, it doesn't make sense to keep it in. I'll drop it.

Thanks!


-- 
Thanks,
Sasha