Re: [PATCH v6 1/6] dt-bindings: remoteproc: Add Xilinx RPU subsystem bindings

Tanmay Shah
2022-06-01T19:07:12Z

Hi Rob,

Thanks for reviews. Please find my comments below:

On 6/1/22 11:42 AM, Rob Herring wrote:
> On Tue, May 31, 2022 at 04:43:05PM -0700, Tanmay Shah wrote:
>> Xilinx ZynqMP platform has dual-core ARM Cortex R5 Realtime Processing
>> Unit(RPU) subsystem. This patch adds dt-bindings for RPU subsystem
>> (cluster).
>>
>> Signed-off-by: Tanmay Shah <tanmay.shah@xilinx.com>
>> ---
>>
>> Changes in v6:
>> - Add maxItems to sram and memory-region property
>>
>> Changes in v5:
>> - Add constraints of the possible values of xlnx,cluster-mode property
>> - fix description of power-domains property for r5 core
>> - Remove reg, address-cells and size-cells properties as it is not required
>> - Fix description of mboxes property
>> - Add description of each memory-region and remove old .txt binding link
>> reference in the description
>>
>> Changes in v4:
>> - Add memory-region, mboxes and mbox-names properties in example
>>
>> Changes in v3:
>> - None
>>
>>
>> .../bindings/remoteproc/xlnx,r5f-rproc.yaml | 129 ++++++++++++++++++
>> include/dt-bindings/power/xlnx-zynqmp-power.h | 6 +
>> 2 files changed, 135 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
>> new file mode 100644
>> index 000000000000..cbff1c201a89
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
>> @@ -0,0 +1,129 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/remoteproc/xlnx,r5f-rproc.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Xilinx R5F processor subsystem
>> +
>> +maintainers:
>> + - Ben Levinsky <ben.levinsky@xilinx.com>
>> + - Tanmay Shah <tanmay.shah@xilinx.com>
>> +
>> +description: |
>> + The Xilinx platforms include a pair of Cortex-R5F processors (RPU) for
>> + real-time processing based on the Cortex-R5F processor core from ARM.
>> + The Cortex-R5F processor implements the Arm v7-R architecture and includes a
>> + floating-point unit that implements the Arm VFPv3 instruction set.
>> +
>> +properties:
>> + compatible:
>> + const: xlnx,zynqmp-r5fss
>> +
>> + xlnx,cluster-mode:
>> + $ref: /schemas/types.yaml#/definitions/uint32
>> + enum: [0, 1, 2]
>> + description: |
>> + The RPU MPCore can operate in split mode(Dual-processor performance), Safety
>> + lock-step mode(Both RPU cores execute the same code in lock-step,
>> + clock-for-clock) or Single CPU mode (RPU core 0 can be held in reset while
>> + core 1 runs normally). The processor does not support dynamic configuration.
>> + Switching between modes is only permitted immediately after a processor reset.
>> + If set to 1 then lockstep mode and if 0 then split mode.
>> + If set to 2 then single CPU mode. When not defined, default will be lockstep mode.
>> +
>> +patternProperties:
>> + "^r5f-[a-f0-9]+$":
>> + type: object
>> + description: |
>> + The RPU is located in the Low Power Domain of the Processor Subsystem.
>> + Each processor includes separate L1 instruction and data caches and
>> + tightly coupled memories (TCM). System memory is cacheable, but the TCM
>> + memory space is non-cacheable.
>> +
>> + Each RPU contains one 64KB memory and two 32KB memories that
>> + are accessed via the TCM A and B port interfaces, for a total of 128KB
>> + per processor. In lock-step mode, the processor has access to 256KB of
>> + TCM memory.
>> +
>> + properties:
>> + compatible:
>> + const: xlnx,zynqmp-r5f
>> +
>> + power-domains:
>> + description: RPU core PM domain specifier
>> + maxItems: 1
>> +
>> + mboxes:
>> + minItems: 1
>> + items:
>> + - description: mailbox channel to send data to RPU
>> + - description: mailbox channel to receive data from RPU
>> +
>> + mbox-names:
>> + minItems: 1
>> + items:
>> + - const: tx
>> + - const: rx
>> +
>> + sram:
>> + $ref: /schemas/types.yaml#/definitions/phandle-array
>> + maxItems: 8
> minItems: 1
> maxItems: 8
> items:
> maxItems: 1

I have posted v7 which adds "minItems: 1".

However, I didn't get items: part. Is it required to have items: now?

Can I add items: part once TCM bindings are posted?

I understand that minItems and maxItems under sram property decides how
many phandles sram can have.

However, maxItems: 1 under items: field what it describes?

Thanks.

>
>> + description: |
>> + phandles to one or more reserved on-chip SRAM regions. Other than TCM,
>> + the RPU can execute instructions and access data from, the OCM memory,
>> + the main DDR memory, and other system memories.
>> +
>> + The regions should be defined as child nodes of the respective SRAM
>> + node, and should be defined as per the generic bindings in,
>> + Documentation/devicetree/bindings/sram/sram.yaml
>> +
>> + memory-region:
>> + description: |
>> + List of phandles to the reserved memory regions associated with the
>> + remoteproc device. This is variable and describes the memories shared with
>> + the remote processor (e.g. remoteproc firmware and carveouts, rpmsg
>> + vrings, ...). This reserved memory region will be allocated on DDR memory.
>> + minItems: 1
>> + maxItems: 8
>> + items:
>> + - description: region used for RPU firmware image section
>> + - description: vdev buffer
>> + - description: vring0
>> + - description: vring1
>> + additionalItems: true
>> +
>> + required:
>> + - compatible
>> + - power-domains
>> +
>> + unevaluatedProperties: false
>> +
>> +required:
>> + - compatible
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + r5fss: r5fss {
>> + compatible = "xlnx,zynqmp-r5fss";
>> + xlnx,cluster-mode = <1>;
>> +
>> + r5f-0 {
>> + compatible = "xlnx,zynqmp-r5f";
>> + power-domains = <&zynqmp_firmware 0x7>;
>> + memory-region = <&rproc_0_fw_image>, <&rpu0vdev0buffer>, <&rpu0vdev0vring0>, <&rpu0vdev0vring1>;
>> + mboxes = <&ipi_mailbox_rpu0 0>, <&ipi_mailbox_rpu0 1>;
>> + mbox-names = "tx", "rx";
>> + };
>> +
>> + r5f-1 {
>> + compatible = "xlnx,zynqmp-r5f";
>> + power-domains = <&zynqmp_firmware 0x8>;
>> + memory-region = <&rproc_1_fw_image>, <&rpu1vdev0buffer>, <&rpu1vdev0vring0>, <&rpu1vdev0vring1>;
>> + mboxes = <&ipi_mailbox_rpu1 0>, <&ipi_mailbox_rpu1 1>;
>> + mbox-names = "tx", "rx";
>> + };
>> + };
>> +...
>> diff --git a/include/dt-bindings/power/xlnx-zynqmp-power.h b/include/dt-bindings/power/xlnx-zynqmp-power.h
>> index 0d9a412fd5e0..618024cbb20d 100644
>> --- a/include/dt-bindings/power/xlnx-zynqmp-power.h
>> +++ b/include/dt-bindings/power/xlnx-zynqmp-power.h
>> @@ -6,6 +6,12 @@
>> #ifndef _DT_BINDINGS_ZYNQMP_POWER_H
>> #define _DT_BINDINGS_ZYNQMP_POWER_H
>>
>> +#define PD_RPU_0 7
>> +#define PD_RPU_1 8
>> +#define PD_R5_0_ATCM 15
>> +#define PD_R5_0_BTCM 16
>> +#define PD_R5_1_ATCM 17
>> +#define PD_R5_1_BTCM 18
>> #define PD_USB_0 22
>> #define PD_USB_1 23
>> #define PD_TTC_0 24
>> --
>> 2.25.1
>>
>>