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

From: Bhupesh Sharma
Date: Thu Jun 03 2021 - 23:41:55 EST


Hi Stephan,

Thanks for the review.

On Fri, 21 May 2021 at 13:41, Stephan Gerhold <stephan@xxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx>
> > Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Andy Gross <agross@xxxxxxxxxx>
> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> > Cc: Stephen Boyd <sboyd@xxxxxxxxxx>
> > Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
> > Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> > Cc: dmaengine@xxxxxxxxxxxxxxx
> > Cc: linux-clk@xxxxxxxxxxxxxxx
> > Cc: linux-crypto@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: bhupesh.linux@xxxxxxxxx
> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> > ---
> > .../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@xxxxxxxxxx>
> > +
> > +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

I did run "make dtbs_check" and I don't remember seeing the issues you reported.
Hmm.. maybe I missed something. Let me recheck and fix issues in v4.

> > + 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

Ok.

> > + 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.

Ok.

Thanks,
Bhupesh