Re: [PATCH v16 4/5] dt-bindings: remoteproc: Add documentation for ZynqMP R5 rproc bindings

From: Rob Herring
Date: Tue Sep 29 2020 - 14:36:13 EST

On Tue, Sep 22, 2020 at 03:39:29PM -0700, Ben Levinsky wrote:
> Add binding for ZynqMP R5 OpenAMP.
>
> Represent the RPU domain resources in one device node. Each RPU
> processor is a subnode of the top RPU domain node.
>
> Signed-off-by: Jason Wu <j.wu@xxxxxxxxxx>
> Signed-off-by: Wendy Liang <jliang@xxxxxxxxxx>
> Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> Signed-off-by: Ben Levinsky <ben.levinsky@xxxxxxxxxx>
> ---
> v3:
> - update zynqmp_r5 yaml parsing to not raise warnings for extra
> information in children of R5 node. The warning "node has a unit
> name, but no reg or ranges property" will still be raised though
> as this particular node is needed to describe the
> '#address-cells' and '#size-cells' information.
> v4::
> - remove warning '/example-0/rpu@ff9a0000/r5@0:
> node has a unit name, but no reg or ranges property'
> by adding reg to r5 node.
> v5:
> - update device tree sample and yaml parsing to not raise any warnings
> - description for memory-region in yaml parsing
> - compatible string in yaml parsing for TCM
> v6:
> - remove coupling TCM nodes with remoteproc
> - remove mailbox as it is optional not needed
> v7:
> - change lockstep-mode to xlnx,cluster-mode
> v9:
> - show example IPC nodes and tcm bank nodes
> v11:
> - add property meta-memory-regions to illustrate link
> between r5 and TCM banks
> - update so no warnings from 'make dt_binding_check'
> v14:
> - concerns were raised about the new property meta-memory-regions.
> There is no clear direction so for the moment I kept it in the series
> - place IPC nodes in RAM in the reserved memory section
> v15:
> - change lockstep-mode prop as follows: if present, then RPU cluster is in
> lockstep mode. if not present, cluster is in split mode.
> ---
> .../xilinx,zynqmp-r5-remoteproc.yaml | 120 ++++++++++++++++++
> 1 file changed, 120 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/remoteproc/xilinx,zynqmp-r5-remoteproc.yaml
>
> diff --git a/Documentation/devicetree/bindings/remoteproc/xilinx,zynqmp-r5-remoteproc.yaml b/Documentation/devicetree/bindings/remoteproc/xilinx,zynqmp-r5-remoteproc.yaml
> new file mode 100644
> index 000000000000..ce02e425692e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/xilinx,zynqmp-r5-remoteproc.yaml
> @@ -0,0 +1,120 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/remoteproc/xilinx,zynqmp-r5-remoteproc.yaml#";
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
> +
> +title: Xilinx R5 remote processor controller bindings
> +
> +description:
> + This document defines the binding for the remoteproc component that loads and
> + boots firmwares on the Xilinx Zynqmp and Versal family chipset.
> +
> + Note that the Linux has global addressing view of the R5-related memory (TCM)
> + so the absolute address ranges are provided in TCM reg's.

blank line needed.

TCMs specifically I'm concerned about how they are represented in system
DT and here...

> +maintainers:
> + - Ed Mooring <ed.mooring@xxxxxxxxxx>
> + - Ben Levinsky <ben.levinsky@xxxxxxxxxx>
> +
> +properties:
> + compatible:
> + const: "xlnx,zynqmp-r5-remoteproc-1.0"

Don't need quotes.

The use of version numbers was allowed for Xilinx programmable IP. I
don't think this falls into that category.

> +
> + lockstep-mode:
> + description:
> + If this property is present, then the configuration is lock-step.

boolean...

> + Otherwise RPU is split.
> + maxItems: 1

...or an array?

Either way, doesn't work for TI R5.

> +
> + interrupts:
> + description:
> + Interrupt mapping for remoteproc IPI. It is required if the
> + user uses the remoteproc driver with the RPMsg kernel driver.
> + maxItems: 6
> +
> + memory-region:
> + description:
> + collection of memory carveouts used for elf-loading and inter-processor
> + communication.
> + maxItems: 4
> + minItems: 4

Need to define what each region is.

One blank line between properties.

> + meta-memory-regions:
> + description:
> + collection of memories that are not present in the top level memory
> + nodes' mapping. For example, R5s' TCM banks. These banks are needed
> + for R5 firmware meta data such as the R5 firmware's heap and stack

Humm, needs a better explanation.

> + pnode-id:
> + maxItems: 1

What's this?

> + mboxes:
> + maxItems: 2

Need to define what each one is.

> + mbox-names:
> + maxItems: 2

Need to define the names.

> +
> +examples:
> + - |
> + reserved-memory {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges;
> + elf_load: rproc@3ed000000 {
> + no-map;
> + reg = <0x3ed00000 0x40000>;
> + };
> +
> + rpu0vdev0vring0: rpu0vdev0vring0@3ed40000 {
> + no-map;
> + reg = <0x3ed40000 0x4000>;
> + };
> + rpu0vdev0vring1: rpu0vdev0vring1@3ed44000 {
> + no-map;
> + reg = <0x3ed44000 0x4000>;
> + };
> + rpu0vdev0buffer: rpu0vdev0buffer@3ed48000 {
> + no-map;
> + reg = <0x3ed48000 0x100000>;
> + };
> +
> + };
> +
> + /*
> + * Below nodes are required if using TCM to load R5 firmware
> + * if not, then either do not provide nodes are label as disabled in
> + * status property
> + */
> + tcm0a: tcm_0a@ffe00000 {
> + reg = <0xffe00000 0x10000>;
> + pnode-id = <0xf>;
> + no-map;
> + status = "okay";
> + phandle = <0x40>;
> + compatible = "xlnx,tcm";

TCM is a Xilinx specific thing?

> + };
> + tcm0b: tcm_1a@ffe20000 {
> + reg = <0xffe20000 0x10000>;
> + pnode-id = <0x10>;
> + no-map;
> + status = "okay";
> + compatible = "xlnx,tcm";
> + phandle = <0x41>;
> + };
> +
> + rpu {
> + compatible = "xlnx,zynqmp-r5-remoteproc-1.0";
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges;
> + lockstep-mode;
> + r5_0 {
> + ranges;
> + #address-cells = <1>;
> + #size-cells = <1>;
> + memory-region = <&elf_load>,
> + <&rpu0vdev0vring0>,
> + <&rpu0vdev0vring1>,
> + <&rpu0vdev0buffer>;
> + meta-memory-regions = <&tcm_0a>, <&tcm_0b>;
> + pnode-id = <0x7>;
> + };
> + };
> +
> +...
> --
> 2.17.1
>