On Wed, Mar 7, 2018 at 12:57 PM, Eric Anholt <e...@anholt.net> wrote:
> The VCHIQ communication channel can be provided by BCM283x and Capri
> SoCs, to communicate with the VPU-side OS services.
>
> Signed-off-by: Eric Anholt <e...@anholt.net>
> ---
>
> v2: dropped firmware property, added cache-line-size.
>
> .../bindings/soc/bcm/brcm,bcm2835-vchiq.txt | 28
> ++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-vchiq.txt
>
> diff --git a/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-vchiq.txt
> b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-vchiq.txt
> new file mode 100644
> index 000000000000..cdef4abc5e47
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-vchiq.txt
> @@ -0,0 +1,28 @@
> +Broadcom VCHIQ firmware services
> +
> +Required properties:
> +
> +- compatible: Should be "brcm,bcm2835-vchiq"
> +- reg: Physical base address and length of the doorbell register pair
> +- interrupts: The interrupt number
> + See
> bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt
> +
> +Optional properties:
> +
> +- cache-line-size:
> + Size of L2 cache lines. The VPU firmware detects
> + this property and overrides it with the actual L2
> + cache line size it's using when loading the
> + device-tree. Determines the required alignment of
> + offsets/sizes of VCHIQ pagelists. If missing, the
> + firmware assumes an older kernel using 32-byte
> + alignment.
How is this a VCHIQ property? This is a standard property for cache
nodes, but this is not a cache node.
Is it really a problem to just use a fixed maximum alignment? That
seems to be good enough for all the rest of the kernel.
> +
> +Example:
> +
> +vchiq@7e00b840 {
mailbox@...
> + compatible = "brcm,bcm2835-vchiq";
> + reg = <0x7e00b840 0xf>;
> + interrupts = <0 2>;
> + cache-line-size: <32>;
> +};
> --
> 2.16.2
>
