[Letux-kernel] Fwd: [PATCH v3] dts: omap5: board-common: fix wrong SMPS6 (VDD-DDR3) voltage

H. Nikolaus Schaller hns at goldelico.com
Mon Nov 14 13:57:23 CET 2016


Forgot to forward here because it is OMAP5 only.

And it is a real bummer...

Now the Pyra CPU boards seem to run at 1.25 GHz - but they still freeze at 1.5 GHz.

BR,
Nikolaus


> Anfang der weitergeleiteten Nachricht:
> 
> Von: "H. Nikolaus Schaller" <hns at goldelico.com>
> Betreff: [PATCH v3] dts: omap5: board-common: fix wrong SMPS6 (VDD-DDR3) voltage
> Datum: 14. November 2016 um 12:55:15 MEZ
> An: Benoît Cousson <bcousson at baylibre.com>, Tony Lindgren <tony at atomide.com>, Rob Herring <robh+dt at kernel.org>, Mark Rutland <mark.rutland at arm.com>, Russell King <linux at armlinux.org.uk>
> Kopie: linux-omap at vger.kernel.org, devicetree at vger.kernel.org, linux-kernel at vger.kernel.org, kernel at pyra-handheld.com, "H. Nikolaus Schaller" <hns at goldelico.com>
> 
> DDR3L is usually specified as
> 
> 	JEDEC standard 1.35V(1.28V~1.45V) & 1.5V(1.425V~1.575V)
> 
> Therefore setting smps6 regulator to 1.2V is definitively below
> minimum. It appears that real world chips are more forgiving than
> data sheets indicate, but let's set the regulator right.
> 
> Note: a board that uses other voltages (DDR with 1.5V) can
> overwrite by referencing &smps6_reg.
> 
> Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
> ---
> arch/arm/boot/dts/omap5-board-common.dtsi | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/omap5-board-common.dtsi b/arch/arm/boot/dts/omap5-board-common.dtsi
> index ab60a8e..e4a14d5 100644
> --- a/arch/arm/boot/dts/omap5-board-common.dtsi
> +++ b/arch/arm/boot/dts/omap5-board-common.dtsi
> @@ -476,8 +476,8 @@
> 				smps6_reg: smps6 {
> 					/* VDD_DDR3 - over VDD_SMPS6 */
> 					regulator-name = "smps6";
> -					regulator-min-microvolt = <1200000>;
> -					regulator-max-microvolt = <1200000>;
> +					regulator-min-microvolt = <1350000>;
> +					regulator-max-microvolt = <1350000>;
> 					regulator-always-on;
> 					regulator-boot-on;
> 				};
> -- 
> 2.7.3
> 



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