Re: [PATCH v3 1/3] dt-bindings: dmaengine: Document qcom,gpi dma binding

From: Rob Herring
Date: Tue Sep 29 2020 - 14:44:29 EST


On Wed, Sep 23, 2020 at 12:04:08PM +0530, Vinod Koul wrote:
> Add devicetree binding documentation for GPI DMA controller
> implemented on Qualcomm SoCs
>
> Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
> ---
> .../devicetree/bindings/dma/qcom,gpi.yaml | 86 +++++++++++++++++++
> include/dt-bindings/dma/qcom-gpi.h | 11 +++
> 2 files changed, 97 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/qcom,gpi.yaml
> create mode 100644 include/dt-bindings/dma/qcom-gpi.h
>
> diff --git a/Documentation/devicetree/bindings/dma/qcom,gpi.yaml b/Documentation/devicetree/bindings/dma/qcom,gpi.yaml
> new file mode 100644
> index 000000000000..82f404bc8745
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/qcom,gpi.yaml
> @@ -0,0 +1,86 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/qcom,gpi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Technologies Inc GPI DMA controller
> +
> +maintainers:
> + - Vinod Koul <vkoul@xxxxxxxxxx>
> +
> +description: |
> + QCOM GPI DMA controller provides DMA capabilities for
> + peripheral buses such as I2C, UART, and SPI.
> +
> +allOf:
> + - $ref: "dma-controller.yaml#"
> +
> +properties:
> + compatible:
> + enum:
> + - qcom,gpi-dma

Should be SoC specific.

> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + description:
> + Interrupt lines for each GPII instance

GPII or GPI?

> + maxItems: 13
> +
> + "#dma-cells":
> + const: 3
> + description: >
> + DMA clients must use the format described in dma.txt, giving a phandle
> + to the DMA controller plus the following 3 integer cells:
> + - channel: if set to 0xffffffff, any available channel will be allocated
> + for the client. Otherwise, the exact channel specified will be used.
> + - seid: serial id of the client as defined in the SoC documentation.
> + - client: type of the client as defined in dt-bindings/dma/qcom-gpi.h
> +
> + iommus:
> + maxItems: 1
> +
> + dma-channels:
> + maxItems: 1

Not an array. Is there a maximum number of channels or 2^32 is valid?

> +
> + dma-channel-mask:
> + maxItems: 1

So up to 32 channels?

> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - "#dma-cells"
> + - iommus
> + - dma-channels
> + - dma-channel-mask
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/dma/qcom-gpi.h>
> + gpi_dma0: dma-controller@800000 {
> + compatible = "qcom,gpi-dma";
> + #dma-cells = <3>;
> + reg = <0x00800000 0x60000>;
> + iommus = <&apps_smmu 0x0016 0x0>;
> + dma-channels = <13>;
> + dma-channel-mask = <0xfa>;
> + interrupts = <GIC_SPI 244 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 245 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 246 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 247 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 248 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 249 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 250 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 251 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 252 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 253 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 254 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 255 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 256 IRQ_TYPE_LEVEL_HIGH>;
> + };
> +
> +...
> diff --git a/include/dt-bindings/dma/qcom-gpi.h b/include/dt-bindings/dma/qcom-gpi.h
> new file mode 100644
> index 000000000000..71f79eb7614c
> --- /dev/null
> +++ b/include/dt-bindings/dma/qcom-gpi.h
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (c) 2020, Linaro Ltd. */
> +
> +#ifndef __DT_BINDINGS_DMA_QCOM_GPI_H__
> +#define __DT_BINDINGS_DMA_QCOM_GPI_H__
> +
> +#define QCOM_GPI_SPI 1
> +#define QCOM_GPI_UART 2
> +#define QCOM_GPI_I2C 3
> +
> +#endif /* __DT_BINDINGS_DMA_QCOM_GPI_H__ */
> --
> 2.26.2
>