Thread (36 messages) 36 messages, 4 authors, 2021-07-29

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

From: Stephan Gerhold <stephan@gerhold.net>
Date: 2021-05-21 08:11:09
Also in: dmaengine, linux-arm-msm, linux-clk, linux-devicetree, lkml

Hi,

On Wed, May 19, 2021 at 08:06:44PM +0530, Bhupesh Sharma wrote:
quoted hunk ↗ jump to hunk
Convert Qualcomm BAM DMA devicetree binding to YAML.

Cc: Thara Gopinath <redacted>
Cc: Bjorn Andersson <redacted>
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 <redacted>
---
 .../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
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