Re: [PATCH RESEND 1/4] dt-bindings: add SMP enable-method for Broadcom NSP

From: Rob Herring
Date: Thu Nov 05 2015 - 15:48:37 EST


On Thu, Nov 05, 2015 at 12:51:18AM -0500, Kapil Hali wrote:
> Add a compatible string "brcm,bcm-nsp-smp" for Broadcom's
> Northstar Plus CPU to the 32-bit ARM CPU device tree binding
> documentation file and create a new binding documentation for
> Northstar Plus CPU pen-release mechanism.
>
> Signed-off-by: Kapil Hali <kapilh@xxxxxxxxxxxx>
> ---
> .../bindings/arm/bcm/brcm,nsp-cpu-method.txt | 36 ++++++++++++++++++++++
> Documentation/devicetree/bindings/arm/cpus.txt | 1 +
> 2 files changed, 37 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/bcm/brcm,nsp-cpu-method.txt
>
> diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,nsp-cpu-method.txt b/Documentation/devicetree/bindings/arm/bcm/brcm,nsp-cpu-method.txt
> new file mode 100644
> index 0000000..8506da7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/bcm/brcm,nsp-cpu-method.txt
> @@ -0,0 +1,36 @@
> +Broadcom Northstar Plus SoC CPU Enable Method
> +---------------------------------------------
> +This binding defines the enable method used for starting secondary
> +CPUs in the following Broadcom SoCs:
> + BCM58522, BCM58525, BCM58535, BCM58622, BCM58623, BCM58625, BCM88312
> +
> +The enable method is specified by defining the following required
> +properties in the "cpus" device tree node:
> + - enable-method = "brcm,bcm-nsp-smp";

This is supposed to be per core.

> + - secondary-boot-reg = <...>;

What happens with more than 2 cores?

> +The secondary-boot-reg property is a u32 value that specifies the
> +physical address of the register used to request the ROM holding pen
> +code release a secondary CPU.
> +
> +Example:
> + cpus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + enable-method = "brcm,bcm-nsp-smp";
> + secondary-boot-reg = <0xffff042c>;
> +
> + cpu0: cpu@0 {
> + device_type = "cpu";
> + compatible = "arm,cortex-a9";
> + next-level-cache = <&L2>;
> + reg = <0>;
> + };
> +
> + cpu1: cpu@1 {
> + device_type = "cpu";
> + compatible = "arm,cortex-a9";
> + next-level-cache = <&L2>;
> + reg = <1>;
> + };
> + };
> diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
> index 91e6e5c..6abe3f3 100644
> --- a/Documentation/devicetree/bindings/arm/cpus.txt
> +++ b/Documentation/devicetree/bindings/arm/cpus.txt
> @@ -191,6 +191,7 @@ nodes to be present and contain the properties described below.
> "allwinner,sun8i-a23"
> "arm,psci"
> "brcm,brahma-b15"
> + "brcm,bcm-nsp-smp"
> "marvell,armada-375-smp"
> "marvell,armada-380-smp"
> "marvell,armada-390-smp"
> --
> 2.1.0
>
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