This adds a sandbox mailbox implementation (provider), a test client
device, instantiates them both from Sandbox's DT, and adds a DM test
that excercises everything.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org> # v1
A mailbox is a hardware mechanism for transferring small message and/or
notifications between the CPU on which U-Boot runs and some other device
such as an auxilliary CPU running firmware or a hardware module.
This patch defines a standard API that connects mailbox clients to mailbox
providers (drivers). Initially, DT is the only supported method for
connecting the two.
The DT binding specification (mailbox.txt) was taken from Linux kernel
v4.5's Documentation/devicetree/bindings/mailbox/mailbox.txt.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
