From be37a8b5a371850c6367bc984ee61d9de3eacf6a Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 30 Jun 2014 17:09:45 -0500 Subject: [PATCH] devicetree: bindings: document Broadcom CPU enable method Broadcom mobile SoCs use a ROM-implemented holding pen for controlled boot of secondary cores. A special register is used to communicate to the ROM that a secondary core should start executing kernel code. This enable method is currently used for members of the bcm281xx and bcm21664 SoC families. The use of an enable method also allows the SMP operation vector to be assigned as a result of device tree content for these SoCs. Signed-off-by: Alex Elder Signed-off-by: Matt Porter --- .../bindings/arm/bcm/brcm,bcm11351-cpu-method | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/bcm/brcm,bcm11351-cpu-method diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,bcm11351-cpu-method b/Documentation/devicetree/bindings/arm/bcm/brcm,bcm11351-cpu-method new file mode 100644 index 000000000000..8240c023e202 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/bcm/brcm,bcm11351-cpu-method @@ -0,0 +1,36 @@ +Broadcom Kona Family CPU Enable Method +-------------------------------------- +This binding defines the enable method used for starting secondary +CPUs in the following Broadcom SoCs: + BCM11130, BCM11140, BCM11351, BCM28145, BCM28155, BCM21664 + +The enable method is specified by defining the following required +properties in the "cpus" device tree node: + - enable-method = "brcm,bcm11351-cpu-method"; + - secondary-boot-reg = <...>; + +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. The value written to the register is +formed by encoding the target CPU id into the low bits of the +physical start address it should jump to. + +Example: + cpus { + #address-cells = <1>; + #size-cells = <0>; + enable-method = "brcm,bcm11351-cpu-method"; + secondary-boot-reg = <0x3500417c>; + + cpu0: cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a9"; + reg = <0>; + }; + + cpu1: cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a9"; + reg = <1>; + }; + };