2024-05-01 19:42:26

by Judith Mendez

[permalink] [raw]
Subject: [PATCH] ARM: dts: am335x: Add PRU system events for virtio

From: Nick Saulnier <[email protected]>

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.

Signed-off-by: Nick Saulnier <[email protected]>
Signed-off-by: Suman Anna <[email protected]>
---
arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi b/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
index d6a143abae5f6..d763ed4a15b58 100644
--- a/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
+++ b/arch/arm/boot/dts/ti/omap/am33xx-l4.dtsi
@@ -915,6 +915,9 @@ pru0: pru@34000 {
<0x22400 0x100>;
reg-names = "iram", "control", "debug";
firmware-name = "am335x-pru0-fw";
+ interrupt-parent = <&pruss_intc>;
+ interrupts = <16 2 2>;
+ interrupt-names = "vring";
};

pru1: pru@38000 {
@@ -924,6 +927,9 @@ pru1: pru@38000 {
<0x24400 0x100>;
reg-names = "iram", "control", "debug";
firmware-name = "am335x-pru1-fw";
+ interrupt-parent = <&pruss_intc>;
+ interrupts = <18 3 3>;
+ interrupt-names = "vring";
};

pruss_mdio: mdio@32400 {

base-commit: 4cece764965020c22cff7665b18a012006359095
--
2.43.2



2024-05-06 22:09:50

by Judith Mendez

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

Hi all,

On 5/1/24 2:41 PM, Judith Mendez wrote:
> From: Nick Saulnier <[email protected]>
>
> 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