Re: [PATCH v4 05/10] ARM: dts: sunxi: a80: Add msgbox node

From: Samuel Holland
Date: Tue Aug 20 2019 - 09:17:54 EST


On 8/20/19 3:15 AM, Maxime Ripard wrote:
> On Mon, Aug 19, 2019 at 10:23:06PM -0500, Samuel Holland wrote:
>> The A80 SoC contains a message box that can be used to send messages and
>> interrupts back and forth between the ARM application CPUs and the ARISC
>> coprocessor. Add a device tree node for it.
>> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
> I think you mentionned that crust has been tested only on the A64 and
> the H3/H5, did you test the mailbox on those other SoCs as well?

No, I only have A64/H3/H5, and recently H6, hardware to test. I've looked
through the manuals to verify that the registers are all the same, but I haven't
run the driver on earlier SoCs.

On 32-bit SoCs, where there's no other user of SRAM A2, it should be easy to get
the toy firmware running. All you should need to do is:
1) Update the MMIO base/clock addresses in drivers/msgbox/sunxi-msgbox.c
2) Update the load address in platform/sun50i/include/platform/memory.h
3) Load the firmware to SRAM A2 (can be done from a U-Boot shell)
4) Initialize the reset vector (algorithm is in tools/test.c:109)
5) Deassert AR100 reset (again, these last two steps can be done from U-Boot)