Re: [PATCH v5 1/2] dt-bindings: remoteproc: document AMD MicroBlaze/V BRAM-based rproc
From: Ben Levinsky
Date: Fri Jul 10 2026 - 10:56:49 EST
Hi Mathieu
Though 2/2 got NAK, will you still review this ?
If not I will bump rev and update patch 2/2.
Thank you
Ben
On 7/9/26 7:57 AM, Ben Levinsky wrote:
> Describe an AMD MicroBlaze/V BRAM-based remote processor controlled
> through the remoteproc framework.
>
> The binding models a soft-core processor subsystem instantiated in AMD
> programmable logic and using dual-port BRAM for firmware storage and
> execution. The remoteproc device is represented as a child node whose
> reg property describes the firmware memory window in the processor-local
> address space. The parent bus node provides standard devicetree address
> translation through ranges so Linux can access the same BRAM through the
> system physical address space.
>
> A clock input feeds the soft-core processor subsystem, and an active-low
> reset GPIO holds the processor in reset until firmware loading completes.
> The firmware-name property is optional.
>
> Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Signed-off-by: Ben Levinsky <ben.levinsky@xxxxxxx>
> ---
> .../bindings/remoteproc/amd,bram-rproc.yaml | 105 ++++++++++++++++++
> 1 file changed, 105 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/remoteproc/amd,bram-rproc.yaml
>
> diff --git a/Documentation/devicetree/bindings/remoteproc/amd,bram-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/amd,bram-rproc.yaml
> new file mode 100644
> index 000000000000..c0359f447ea8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/amd,bram-rproc.yaml
> @@ -0,0 +1,105 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/remoteproc/amd,bram-rproc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AMD MicroBlaze/V BRAM-based Remote Processor
> +
> +maintainers:
> + - Ben Levinsky <ben.levinsky@xxxxxxx>
> +
> +description: |
> + Soft-core processor subsystem instantiated in AMD programmable logic and
> + using dual-port BRAM for firmware storage and execution.
> +
> + Hardware Architecture:
> +
> + Host (PS) Programmable Logic (PL)
> + ========= ======================
> +
> + AXI Interface -----------------> AXI BRAM Controller (Host Port)
> + |
> + | Port A
> + v
> + +-----------------+
> + | Dual-Port BRAM |
> + | (shared memory) |
> + +-----------------+
> + ^
> + | Port B
> + |
> + AXI BRAM Controller (Soft-core Port)
> + ^
> + | LMB
> + |
> + Soft-core CPU (MicroBlaze/V)
> +
> + GPIO --------------------------> Proc Sys Reset ----> CPU Reset Signal
> +
> + Clock -------------------------> Clock Distribution -> CPU Clock
> +
> + Memory Architecture:
> +
> + The dual-port BRAM allows simultaneous access from both processors:
> + - Port A: Connected to the host AXI BRAM controller for firmware loading
> + - Port B: Connected to the soft-core local memory bus for execution
> +
> + The reg property describes the executable BRAM window in the processor-local
> + address space. The parent bus node translates that window to the system
> + physical address space by using standard devicetree address translation
> + through ranges. A clock input and a reset GPIO control the subsystem.
> +
> +properties:
> + compatible:
> + oneOf:
> + - const: xlnx,zynqmp-bram-rproc
> + - items:
> + - enum:
> + - amd,versal2-bram-rproc
> + - xlnx,versal-bram-rproc
> + - xlnx,versal-net-bram-rproc
> + - const: xlnx,zynqmp-bram-rproc
> +
> + reg:
> + maxItems: 1
> + description:
> + Processor-local address and size of the BRAM firmware memory window,
> + as seen by the soft-core processor (typically 0x0 for reset vector).
> + The parent bus ranges property must translate this window to the
> + corresponding system physical address.
> +
> + clocks:
> + maxItems: 1
> + description:
> + Clock input for the soft-core processor subsystem.
> +
> + firmware-name:
> + maxItems: 1
> + description:
> + Name of the firmware ELF file to load.
> +
> + reset-gpios:
> + maxItems: 1
> + description:
> + GPIO specifier controlling the soft-core reset input.
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - reset-gpios
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + remoteproc@0 {
> + compatible = "xlnx,zynqmp-bram-rproc";
> + reg = <0x0 0x40000>;
> + clocks = <&pl_clk>;
> + firmware-name = "firmware.elf";
> + reset-gpios = <&gpio0 0 GPIO_ACTIVE_LOW>;
> + };
> +...