linux-kernel - Re: [PATCH] ARM: dts: exynos: Remove unneded always-on for regulators on Peach boards

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Date:	Fri, 20 May 2016 11:54:58 +0200
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Javier Martinez Canillas <javier@....samsung.com>,
	linux-kernel@...r.kernel.org
Cc:	devicetree@...r.kernel.org, Kukjin Kim <kgene@...nel.org>,
	Kumar Gala <galak@...eaurora.org>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	linux-samsung-soc@...r.kernel.org,
	Rob Herring <robh+dt@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Russell King <linux@...linux.org.uk>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] ARM: dts: exynos: Remove unneded always-on for regulators
 on Peach boards

On 05/19/2016 11:52 PM, Javier Martinez Canillas wrote:
> The regulator always-on property should only be used for regulators
> that either can't be disabled or the drivers for the client devices
> are not enabling the regulator and so being disabled due to unused.
> 
> There are some max77802 regulators in the Peach Pit and Pi boards
> that are always-on but shouldn't since they are enabled by drivers:
> 
> BUCK5 is max77802 inl1 supply
> BUCK7 is max77802 inl{2,10} supply
> BUCK9 is max77802 inl{3,4,5,7} supply
> BUCK10 is mmc1 vqmmc supply
> LDO9 is adc vdd supply
> 
> This patch removes the always-on property for these regulators.
> 
> Some regulators should remain always-on even when they are used as
> input supplies, because these regulators are also used by other
> components that are not described in the DT, for example:
> 
> LDO10 is hdmi vdd_osc supply but it's also used as input supply for
> the Exynos5420 temperature sensor.

I don't have the schematics, so just guessing: by temperature sensor do
you mean the tmu_cpu* node (supplying power to VDD_TS01/23/4)?

If yes then you can also change it, like on Odroid XU boards.

> 
> LDO8 is hdmi vdd and vdd_pll supply but it's also used as supply for
> the Exynos5420 Display port.
> 
> BUCK2 and BUCK6 are the vdd supplies for the EAGLE and KFC clusters.
> 
> Signed-off-by: Javier Martinez Canillas <javier@....samsung.com>
> ---
> 
>  arch/arm/boot/dts/exynos5420-peach-pit.dts | 5 -----
>  arch/arm/boot/dts/exynos5800-peach-pi.dts  | 5 -----
>  2 files changed, 10 deletions(-)

Anyway,

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>

Best regards,
Krzysztof