diff mbox

[PATCH/RFC,2/2] ARM: shmobile: kzm9g: support DDR50 mode with 1.8V VccQ on MMCIF

Message ID Pine.LNX.4.64.1307261748260.22137@axis700.grange (mailing list archive)
State RFC
Headers show

Commit Message

Guennadi Liakhovetski July 26, 2013, 3:51 p.m. UTC
MMCIF on sh73a0 supports the UHS DDR50 mode and on the kzm9g board it can
be used with MMC VccQ = 1.8V. This patch enables them.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
---

This patch is correct AFAICS, but pointless on kzm9g, because (at least on 
my board) th eMMC chip, installed on the board and connected to MMCIF 
doesn't support DDR, so, it cannot be enabled. This patch is therefore 
more of an example how these flags shall be used, than a real use case. If 
it is decided to apply it, it can be applied even before patch 1/2, it 
just won't have any effect at all.

 arch/arm/boot/dts/sh73a0-kzm9g-reference.dts |    1 +
 arch/arm/boot/dts/sh73a0.dtsi                |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

Comments

Simon Horman July 30, 2013, 2:18 a.m. UTC | #1
On Fri, Jul 26, 2013 at 05:51:32PM +0200, Guennadi Liakhovetski wrote:
> MMCIF on sh73a0 supports the UHS DDR50 mode and on the kzm9g board it can
> be used with MMC VccQ = 1.8V. This patch enables them.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
> ---
> 
> This patch is correct AFAICS, but pointless on kzm9g, because (at least on 
> my board) th eMMC chip, installed on the board and connected to MMCIF 
> doesn't support DDR, so, it cannot be enabled. This patch is therefore 
> more of an example how these flags shall be used, than a real use case. If 
> it is decided to apply it, it can be applied even before patch 1/2, it 
> just won't have any effect at all.

Thanks, understood.

At this point I prefer not to apply it as it doesn't have any effect.
I am more than happy to discuss this further if others would
like it applied.

> 
>  arch/arm/boot/dts/sh73a0-kzm9g-reference.dts |    1 +
>  arch/arm/boot/dts/sh73a0.dtsi                |    1 +
>  2 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts b/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
> index b99e890..d90de01 100644
> --- a/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
> +++ b/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
> @@ -191,6 +191,7 @@
>  
>  	bus-width = <8>;
>  	vmmc-supply = <&reg_1p8v>;
> +	ddr-1v8;
>  	status = "okay";
>  };
>  
> diff --git a/arch/arm/boot/dts/sh73a0.dtsi b/arch/arm/boot/dts/sh73a0.dtsi
> index 86e79fe..1146be8 100644
> --- a/arch/arm/boot/dts/sh73a0.dtsi
> +++ b/arch/arm/boot/dts/sh73a0.dtsi
> @@ -186,6 +186,7 @@
>  		interrupts = <0 140 0x4
>  			      0 141 0x4>;
>  		reg-io-width = <4>;
> +		uhs-ddr50;
>  		status = "disabled";
>  	};
>  
> -- 
> 1.7.2.5
> 
> --
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diff mbox

Patch

diff --git a/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts b/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
index b99e890..d90de01 100644
--- a/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
+++ b/arch/arm/boot/dts/sh73a0-kzm9g-reference.dts
@@ -191,6 +191,7 @@ 
 
 	bus-width = <8>;
 	vmmc-supply = <&reg_1p8v>;
+	ddr-1v8;
 	status = "okay";
 };
 
diff --git a/arch/arm/boot/dts/sh73a0.dtsi b/arch/arm/boot/dts/sh73a0.dtsi
index 86e79fe..1146be8 100644
--- a/arch/arm/boot/dts/sh73a0.dtsi
+++ b/arch/arm/boot/dts/sh73a0.dtsi
@@ -186,6 +186,7 @@ 
 		interrupts = <0 140 0x4
 			      0 141 0x4>;
 		reg-io-width = <4>;
+		uhs-ddr50;
 		status = "disabled";
 	};