Re: [PATCH v9 4/6] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support - linux-kernel-dev

From: linux-kernel-dev@aliel.fr
To: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>,
	Daniel Lezcano <daniel.lezcano@kernel.org>
Cc: linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org,
	linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-pm@vger.kernel.org, mfd@lists.linux.dev,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Lee Jones <lee@kernel.org>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Andi Shyti <andi.shyti@kernel.org>,
	Kevin Hilman <khilman@baylibre.com>,
	Jerome Brunet <jbrunet@baylibre.com>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	Beniamino Galvani <b.galvani@gmail.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Zhang Rui <rui.zhang@intel.com>,
	Lukasz Luba <lukasz.luba@arm.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v9 4/6] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support
Date: Wed, 19 Aug 2026 09:41:15 +0200	[thread overview]
Message-ID: <ef9ca9f8-6cb0-437e-b73d-976059dc6f82@aliel.fr> (raw)
In-Reply-To: <64e146aa-4907-495d-b394-7cecb1727816@oss.qualcomm.com>

On 8/7/26 4:34 AM, Daniel Lezcano wrote:
> On 8/5/26 10:06, Ronald Claveau via B4 Relay wrote:
>> From: Ronald Claveau <linux-kernel-dev@aliel.fr>
>>
>> Replace the hardcoded MAX_LEVEL constant and fan register
>> with values read from platform_data (fan_reg, levels[] and nlevels),
>> as new MCUs need different values.
>>
>> The cooling device's state is stored as an index into levels[],
>> and khadas_mcu_fan_set_level() writes levels[state] to fan_reg,
>> rather than writing the raw state value as before.
>>
>> Optionally acquire and enable a "fan" regulator supply
>> at probe time and on resume,
>> so boards that gate fan power through a regulator are handled.
>>
>> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
>> Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
>> ---
> 
>  * Through which tree this patch should go ? (assuming there is a
> dependency on other patches)
> 

I think this patch should go through MFD as this patch depends on it.

>  * How this will behave with 100 levels with the step wise governor ?
> For a 100ms passive delay and 100 states, it will take 10s before
> reaching the full speed

Yes the VIM4 MCU accept values from 0 to 100, but here I'm giving a list
which is (0, 30, 40, 55, 75, 100), so 5 steps to full speed.

-- 
Best regards,
Ronald

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