Re: [PATCH v4 2/2] dt-bindings: mailbox: Add Xilinx IPI Mailbox

From: Sudeep Holla
Date: Wed Oct 10 2018 - 05:57:52 EST

On Wed, Oct 10, 2018 at 12:18:32AM -0700, Wendy Liang wrote:
> Xilinx ZynqMP IPI(Inter Processor Interrupt) is a hardware block
> in ZynqMP SoC used for the communication between various processor
> systems.
> Signed-off-by: Wendy Liang <wendy.liang@xxxxxxxxxx>


> +Optional properties:
> +--------------------
> +- method: The method of accessing the IPI agent registers.
> + Permitted values are: "smc" and "hvc". Default is
> + "smc".

You are mixing the hardware messaging based mailbox and the software
"smc/hvc" based mailbox together here. Please keep them separated.
IIUC smc/hvc based mailcox is used for "tx" or too keep it simple in
one direction and hardware based is used for "rx" or the other direction
for communication.

You *should not* mix them as single unit. Also lots of other vendor need
SMC/HVC based mailbox. So make it generic and keep it separate.