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

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

[Nishanth Menon]

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@ti.com>
---

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;
 				};
 
-- 
1.7.9.5

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

[Roger Quadros]

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@ti.com>

Acked-by: Roger Quadros <rogerq@ti.com>

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;
>  				};
>  
> 

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

[Tony Lindgren]

* Roger Quadros <rogerq@ti.com> [141103 06:44]:
> 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@ti.com>
> 
> Acked-by: Roger Quadros <rogerq@ti.com>
> 
> I'm assuming that vddshv8 (MMC1 power group) can be switched off.

Applying into omap-for-v3.19/dt thanks.

Tony