Re: [PATCH] ARM: dts: dra7-evm: Keep all VDD rails always-on

From: Roger Quadros
Date: Mon Nov 03 2014 - 09:43:39 EST


Hi Nishant,

On 10/21/2014 05:38 PM, Nishanth Menon wrote:
> DRA7 Data Manual (SPRS857L - August 2014) section 4.1.1 states: "All
> unused power supply balls must be supplied with the voltages specified
> in the Section 5.2, Recommended Operating Conditions".
>
> This implies that all unused voltage rails for Vayu can never be
> switched off even if the hardware blocks inside that voltage domain is
> unused. Switching off these unused rails may result in stability issues
> on other domains and increased leakage and power-on-hour impacts.
>
> J6eco-evm dts file already considers this, however j6evm-dts file needs
> to be fixed to consider this constraint of the SoC.
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>

Acked-by: Roger Quadros <rogerq@xxxxxx>

I'm assuming that vddshv8 (MMC1 power group) can be switched off.

cheers,
-roger

> ---
>
> Patch is based on v3.18-rc1 tag.
>
> arch/arm/boot/dts/dra7-evm.dts | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts
> index c6ce625..4f4c469 100644
> --- a/arch/arm/boot/dts/dra7-evm.dts
> +++ b/arch/arm/boot/dts/dra7-evm.dts
> @@ -201,6 +201,7 @@
> regulator-name = "smps45";
> regulator-min-microvolt = < 850000>;
> regulator-max-microvolt = <1150000>;
> + regulator-always-on;
> regulator-boot-on;
> };
>
> @@ -209,6 +210,7 @@
> regulator-name = "smps6";
> regulator-min-microvolt = <850000>;
> regulator-max-microvolt = <12500000>;
> + regulator-always-on;
> regulator-boot-on;
> };
>
> @@ -226,6 +228,7 @@
> regulator-name = "smps8";
> regulator-min-microvolt = < 850000>;
> regulator-max-microvolt = <1250000>;
> + regulator-always-on;
> regulator-boot-on;
> };
>
> @@ -252,6 +255,7 @@
> regulator-name = "ldo2";
> regulator-min-microvolt = <3300000>;
> regulator-max-microvolt = <3300000>;
> + regulator-always-on;
> regulator-boot-on;
> };
>
> @@ -269,6 +273,7 @@
> regulator-name = "ldo9";
> regulator-min-microvolt = <1050000>;
> regulator-max-microvolt = <1050000>;
> + regulator-always-on;
> regulator-boot-on;
> };
>
>

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