Re: [PATCH] ARM: dts: am335x: Add PRU system events for virtio

From: Judith Mendez
Date: Mon May 06 2024 - 18:09:51 EST


Hi all,

On 5/1/24 2:41 PM, Judith Mendez wrote:
From: Nick Saulnier <nsaulnier@xxxxxx>

A PRU system event "vring" has been added to each of the PRU nodes in
the PRU-ICSS remote processor subsystem to enable the virtio/rpmsg
communication between MPU and that PRU core. The additions are done
in the base am33xx-l4.dtsi, and so are inherited by all the AM335x
boards. Do note that PRUSS is available only on all AM3356+ SoCs.

The PRU system events is the preferred approach over using OMAP
mailboxes, as it eliminates an external peripheral access from
the PRU-side, and keeps the interrupt generation internal to the
PRUSS. The difference from MPU would be minimal in using one
versus the other.

Mailboxes can still be used if desired, but currently there is no
support on firmware-side for the SoC to use mailboxes. Either approach
would require that an appropriate firmware image is loaded/booted on
the PRU.

Please ignore this patch,

Thanks,
Judith