Re: [PATCH v3 01/17] dt-bindings: qcom-bam: Convert binding to YAML

[Stephan Gerhold <stephan@gerhold.net>]

Hi,

On Wed, May 19, 2021 at 08:06:44PM +0530, Bhupesh Sharma wrote:
> Convert Qualcomm BAM DMA devicetree binding to YAML.
> 
> Cc: Thara Gopinath <thara.gopinath@linaro.org>
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Andy Gross <agross@kernel.org>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: dmaengine@vger.kernel.org
> Cc: linux-clk@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: bhupesh.linux@gmail.com
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> ---
>  .../devicetree/bindings/dma/qcom_bam_dma.txt  | 50 ----------
>  .../devicetree/bindings/dma/qcom_bam_dma.yaml | 91 +++++++++++++++++++
>  2 files changed, 91 insertions(+), 50 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
>  create mode 100644 Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml
> 
> diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
> deleted file mode 100644
> index cf5b9e44432c..000000000000
> --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
> +++ /dev/null
> @@ -1,50 +0,0 @@
> -QCOM BAM DMA controller
> -
> -Required properties:
> -- compatible: must be one of the following:
> - * "qcom,bam-v1.4.0" for MSM8974, APQ8074 and APQ8084
> - * "qcom,bam-v1.3.0" for APQ8064, IPQ8064 and MSM8960
> - * "qcom,bam-v1.7.0" for MSM8916
> -- reg: Address range for DMA registers
> -- interrupts: Should contain the one interrupt shared by all channels
> -- #dma-cells: must be <1>, the cell in the dmas property of the client device
> -  represents the channel number
> -- clocks: required clock
> -- clock-names: must contain "bam_clk" entry
> -- qcom,ee : indicates the active Execution Environment identifier (0-7) used in
> -  the secure world.
> -- qcom,controlled-remotely : optional, indicates that the bam is controlled by
> -  remote proccessor i.e. execution environment.
> -- num-channels : optional, indicates supported number of DMA channels in a
> -  remotely controlled bam.
> -- qcom,num-ees : optional, indicates supported number of Execution Environments
> -  in a remotely controlled bam.
> -
> -Example:
> -
> -	uart-bam: dma@f9984000 = {
> -		compatible = "qcom,bam-v1.4.0";
> -		reg = <0xf9984000 0x15000>;
> -		interrupts = <0 94 0>;
> -		clocks = <&gcc GCC_BAM_DMA_AHB_CLK>;
> -		clock-names = "bam_clk";
> -		#dma-cells = <1>;
> -		qcom,ee = <0>;
> -	};
> -
> -DMA clients must use the format described in the dma.txt file, using a two cell
> -specifier for each channel.
> -
> -Example:
> -	serial@f991e000 {
> -		compatible = "qcom,msm-uart";
> -		reg = <0xf991e000 0x1000>
> -			<0xf9944000 0x19000>;
> -		interrupts = <0 108 0>;
> -		clocks = <&gcc GCC_BLSP1_UART2_APPS_CLK>,
> -			<&gcc GCC_BLSP1_AHB_CLK>;
> -		clock-names = "core", "iface";
> -
> -		dmas = <&uart-bam 0>, <&uart-bam 1>;
> -		dma-names = "rx", "tx";
> -	};
> diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml b/Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml
> new file mode 100644
> index 000000000000..173e4d7508a6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml
> @@ -0,0 +1,91 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/qcom_bam_dma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: QCOM BAM DMA controller binding
> +
> +maintainers:
> +  - Bhupesh Sharma <bhupesh.sharma@linaro.org>
> +
> +description: |
> +  This document defines the binding for the BAM DMA controller
> +  found on Qualcomm parts.
> +
> +allOf:
> +  - $ref: "dma-controller.yaml#"
> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,bam-v1.4.0
> +      - qcom,bam-v1.3.0
> +      - qcom,bam-v1.7.0
> +
> +  reg:
> +    maxItems: 1
> +    description: Address range of the DMA registers.
> +
> +  clocks:
> +    minItems: 1
> +    maxItems: 8
> +
> +  clock-names:
> +    const: bam_clk
> +
> +  interrupts:
> +    maxItems: 1
> +    description: Single interrupt line shared by all channels.
> +
> +  num-channels:
> +    maxItems: 31

maxItems doesn't seem right here, since num-channels isn't an array.
Perhaps you meant maximum: 31?

Can you check your bindings on the existing device trees with
"make dtbs_check" and make sure that only reasonable errors remain?

This fails on pretty much every device tree:

arch/arm64/boot/dts/qcom/apq8096-db820c.dt.yaml: dma-controller@9184000: num-channels: [[31]] is too short
        From schema: Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml

> +    description: |
> +      Indicates supported number of DMA channels in a remotely controlled bam.
> +
> +  "#dma-cells":
> +    const: 1
> +    description: The single cell represents the channel index.
> +
> +  qcom,ee:
> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description:
> +      Indicates the active Execution Environment identifier (0-7)
> +      used in the secure world.
> +    enum: [0, 1, 2, 3, 4, 5, 6, 7]
> +

bam_dma.c reads this as uint32 and all existing device tree specify it
as uint32. I don't think adding the /bits/ 8 to all existing device
trees is really worth it.

arch/arm64/boot/dts/qcom/apq8096-db820c.dt.yaml: dma-controller@9184000: qcom,ee: missing size tag in [[1]]
        From schema: Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml


> +  qcom,controlled-remotely:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description:
> +      Indicates that the bam is controlled by remote proccessor i.e.
> +      execution environment.
> +
> +  qcom,num-ees:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      Indicates supported number of Execution Environments in a
> +      remotely controlled bam.
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names

clocks is often missing if qcom,controlled-remotely is set, e.g.

		slimbam: dma-controller@9184000 {
			compatible = "qcom,bam-v1.7.0";
			qcom,controlled-remotely;
			reg = <0x09184000 0x32000>;
			num-channels  = <31>;
			interrupts = <0 164 IRQ_TYPE_LEVEL_HIGH>;
			#dma-cells = <1>;
			qcom,ee = <1>;
			qcom,num-ees = <2>;
		};

arch/arm64/boot/dts/qcom/apq8096-db820c.dt.yaml: dma-controller@9184000: 'clocks' is a required property
        From schema: Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml
arch/arm64/boot/dts/qcom/apq8096-db820c.dt.yaml: dma-controller@9184000: 'clock-names' is a required property
        From schema: Documentation/devicetree/bindings/dma/qcom_bam_dma.yaml

You might be able to encode this with an if: statement (clocks required
if qcom,controlled-remotely not specified), not sure.

Stephan