Re: [PATCH v3 1/4] dt-bindings: iommu: rockchip: Convert IOMMU to DT schema

[Rob Herring <robh@kernel.org>]

On Tue, May 04, 2021 at 10:41:21AM +0200, Benjamin Gaignard wrote:
> Convert Rockchip IOMMU to DT schema
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> version 2:
>  - Change maintainer
>  - Change reg maxItems
>  - Change interrupt maxItems
> 
>  .../bindings/iommu/rockchip,iommu.txt         | 38 ---------
>  .../bindings/iommu/rockchip,iommu.yaml        | 79 +++++++++++++++++++
>  2 files changed, 79 insertions(+), 38 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
>  create mode 100644 Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt b/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
> deleted file mode 100644
> index 6ecefea1c6f9..000000000000
> --- a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
> +++ /dev/null
> @@ -1,38 +0,0 @@
> -Rockchip IOMMU
> -==============
> -
> -A Rockchip DRM iommu translates io virtual addresses to physical addresses for
> -its master device.  Each slave device is bound to a single master device, and
> -shares its clocks, power domain and irq.
> -
> -Required properties:
> -- compatible      : Should be "rockchip,iommu"
> -- reg             : Address space for the configuration registers
> -- interrupts      : Interrupt specifier for the IOMMU instance
> -- interrupt-names : Interrupt name for the IOMMU instance
> -- #iommu-cells    : Should be <0>.  This indicates the iommu is a
> -                    "single-master" device, and needs no additional information
> -                    to associate with its master device.  See:
> -                    Documentation/devicetree/bindings/iommu/iommu.txt
> -- clocks          : A list of clocks required for the IOMMU to be accessible by
> -                    the host CPU.
> -- clock-names     : Should contain the following:
> -	"iface" - Main peripheral bus clock (PCLK/HCL) (required)
> -	"aclk"  - AXI bus clock (required)
> -
> -Optional properties:
> -- rockchip,disable-mmu-reset : Don't use the mmu reset operation.
> -			       Some mmu instances may produce unexpected results
> -			       when the reset operation is used.
> -
> -Example:
> -
> -	vopl_mmu: iommu@ff940300 {
> -		compatible = "rockchip,iommu";
> -		reg = <0xff940300 0x100>;
> -		interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
> -		interrupt-names = "vopl_mmu";
> -		clocks = <&cru ACLK_VOP1>, <&cru HCLK_VOP1>;
> -		clock-names = "aclk", "iface";
> -		#iommu-cells = <0>;
> -	};
> diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml
> new file mode 100644
> index 000000000000..0db208cf724a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml
> @@ -0,0 +1,79 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iommu/rockchip,iommu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Rockchip IOMMU
> +
> +maintainers:
> +  - Heiko Stuebner <heiko@sntech.de>
> +
> +description: |+
> +  A Rockchip DRM iommu translates io virtual addresses to physical addresses for
> +  its master device. Each slave device is bound to a single master device and
> +  shares its clocks, power domain and irq.
> +
> +  For information on assigning IOMMU controller to its peripheral devices,
> +  see generic IOMMU bindings.
> +
> +properties:
> +  compatible:
> +    const: rockchip,iommu
> +
> +  reg:
> +    minItems: 1
> +    maxItems: 2

What's the 2nd entry? If there's only 1 entry, then you don't have to 
describe what it is. If more than 1, then each entry has to be defined.

> +
> +  interrupts:
> +    minItems: 1
> +    maxItems: 2

Same here, though if interrupt-names defines them, that's good enough.

> +
> +  interrupt-names:
> +    minItems: 1
> +    maxItems: 2

Here we need the values.

> +
> +  clocks:
> +    items:
> +      - description: Core clock
> +      - description: Interface clock
> +
> +  clock-names:
> +    items:
> +      - const: aclk
> +      - const: iface
> +
> +  "#iommu-cells":
> +    const: 0
> +
> +  rockchip,disable-mmu-reset:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description: |
> +      Do not use the mmu reset operation.
> +      Some mmu instances may produce unexpected results
> +      when the reset operation is used.
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - "#iommu-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/rk3399-cru.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    vopl_mmu: iommu@ff940300 {
> +      compatible = "rockchip,iommu";
> +      reg = <0xff940300 0x100>;
> +      interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
> +      interrupt-names = "vopl_mmu";
> +      clocks = <&cru ACLK_VOP1>, <&cru HCLK_VOP1>;
> +      clock-names = "aclk", "iface";
> +      #iommu-cells = <0>;
> +    };
> -- 
> 2.25.1
>