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authorPaul Walmsley <paul.walmsley@sifive.com>2019-05-20 09:19:40 -0700
committerPaul Walmsley <paul.walmsley@sifive.com>2019-06-17 02:03:58 -0700
commit4fd669a8c4873b6ad54e77bc45aa37b03edc5587 (patch)
treea346612019b7b2551e7aadd3d20b01dec1e71b71 /Documentation
parentc7af55981789299547c51caf5db38e6872e7841f (diff)
downloadlinux-4fd669a8c4873b6ad54e77bc45aa37b03edc5587.tar.bz2
dt-bindings: riscv: convert cpu binding to json-schema
At Rob's request, we're starting to migrate our DT binding documentation to json-schema YAML format. Start by converting our cpu binding documentation. While doing so, document more properties and nodes. This includes adding binding documentation support for the E51 and U54 CPU cores ("harts") that are present on this SoC. These cores are described in: https://static.dev.sifive.com/FU540-C000-v1.0.pdf This cpus.yaml file is intended to be a starting point and to evolve over time. It passes dt-doc-validate as of the yaml-bindings commit 4c79d42e9216. This patch was originally based on the ARM json-schema binding documentation as added by commit 672951cbd1b7 ("dt-bindings: arm: Convert cpu binding to json-schema"). Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Paul Walmsley <paul@pwsan.com> Reviewed-by: Rob Herring <robh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-riscv@lists.infradead.org
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diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
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+# SPDX-License-Identifier: (GPL-2.0 OR MIT)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/cpus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V bindings for 'cpus' DT nodes
+
+maintainers:
+ - Paul Walmsley <paul.walmsley@sifive.com>
+ - Palmer Dabbelt <palmer@sifive.com>
+
+allOf:
+ - $ref: /schemas/cpus.yaml#
+
+properties:
+ $nodename:
+ const: cpus
+ description: Container of cpu nodes
+
+ '#address-cells':
+ const: 1
+ description: |
+ A single unsigned 32-bit integer uniquely identifies each RISC-V
+ hart in a system. (See the "reg" node under the "cpu" node,
+ below).
+
+ '#size-cells':
+ const: 0
+
+patternProperties:
+ '^cpu@[0-9a-f]+$':
+ properties:
+ compatible:
+ type: array
+ items:
+ - enum:
+ - sifive,rocket0
+ - sifive,e5
+ - sifive,e51
+ - sifive,u54-mc
+ - sifive,u54
+ - sifive,u5
+ - const: riscv
+ description:
+ Identifies that the hart uses the RISC-V instruction set
+ and identifies the type of the hart.
+
+ mmu-type:
+ allOf:
+ - $ref: "/schemas/types.yaml#/definitions/string"
+ - enum:
+ - riscv,sv32
+ - riscv,sv39
+ - riscv,sv48
+ description:
+ Identifies the MMU address translation mode used on this
+ hart. These values originate from the RISC-V Privileged
+ Specification document, available from
+ https://riscv.org/specifications/
+
+ riscv,isa:
+ allOf:
+ - $ref: "/schemas/types.yaml#/definitions/string"
+ - enum:
+ - rv64imac
+ - rv64imafdc
+ description:
+ Identifies the specific RISC-V instruction set architecture
+ supported by the hart. These are documented in the RISC-V
+ User-Level ISA document, available from
+ https://riscv.org/specifications/
+
+ timebase-frequency:
+ type: integer
+ minimum: 1
+ description:
+ Specifies the clock frequency of the system timer in Hz.
+ This value is common to all harts on a single system image.
+
+ interrupt-controller:
+ type: object
+ description: Describes the CPU's local interrupt controller
+
+ properties:
+ '#interrupt-cells':
+ const: 1
+
+ compatible:
+ const: riscv,cpu-intc
+
+ interrupt-controller: true
+
+ required:
+ - '#interrupt-cells'
+ - compatible
+ - interrupt-controller
+
+ required:
+ - riscv,isa
+ - timebase-frequency
+ - interrupt-controller
+
+examples:
+ - |
+ // Example 1: SiFive Freedom U540G Development Kit
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ timebase-frequency = <1000000>;
+ cpu@0 {
+ clock-frequency = <0>;
+ compatible = "sifive,rocket0", "riscv";
+ device_type = "cpu";
+ i-cache-block-size = <64>;
+ i-cache-sets = <128>;
+ i-cache-size = <16384>;
+ reg = <0>;
+ riscv,isa = "rv64imac";
+ cpu_intc0: interrupt-controller {
+ #interrupt-cells = <1>;
+ compatible = "riscv,cpu-intc";
+ interrupt-controller;
+ };
+ };
+ cpu@1 {
+ clock-frequency = <0>;
+ compatible = "sifive,rocket0", "riscv";
+ d-cache-block-size = <64>;
+ d-cache-sets = <64>;
+ d-cache-size = <32768>;
+ d-tlb-sets = <1>;
+ d-tlb-size = <32>;
+ device_type = "cpu";
+ i-cache-block-size = <64>;
+ i-cache-sets = <64>;
+ i-cache-size = <32768>;
+ i-tlb-sets = <1>;
+ i-tlb-size = <32>;
+ mmu-type = "riscv,sv39";
+ reg = <1>;
+ riscv,isa = "rv64imafdc";
+ tlb-split;
+ cpu_intc1: interrupt-controller {
+ #interrupt-cells = <1>;
+ compatible = "riscv,cpu-intc";
+ interrupt-controller;
+ };
+ };
+ };
+
+ - |
+ // Example 2: Spike ISA Simulator with 1 Hart
+ cpus {
+ cpu@0 {
+ device_type = "cpu";
+ reg = <0>;
+ compatible = "riscv";
+ riscv,isa = "rv64imafdc";
+ mmu-type = "riscv,sv48";
+ interrupt-controller {
+ #interrupt-cells = <1>;
+ interrupt-controller;
+ compatible = "riscv,cpu-intc";
+ };
+ };
+ };
+...