linux-stable/Documentation/devicetree/bindings/sound/fsl,ssi.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/sound/fsl,ssi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Freescale Synchronous Serial Interface

maintainers:
  - Shengjiu Wang <shengjiu.wang@nxp.com>

description:
  Notes on fsl,playback-dma and fsl,capture-dma
  On SOCs that have an SSI, specific DMA channels are hard-wired for playback
  and capture.  On the MPC8610, for example, SSI1 must use DMA channel 0 for
  playback and DMA channel 1 for capture.  SSI2 must use DMA channel 2 for
  playback and DMA channel 3 for capture.  The developer can choose which
  DMA controller to use, but the channels themselves are hard-wired.  The
  purpose of these two properties is to represent this hardware design.

  The device tree nodes for the DMA channels that are referenced by
  "fsl,playback-dma" and "fsl,capture-dma" must be marked as compatible with
  "fsl,ssi-dma-channel".  The SOC-specific compatible string (e.g.
  "fsl,mpc8610-dma-channel") can remain.  If these nodes are left as
  "fsl,elo-dma-channel" or "fsl,eloplus-dma-channel", then the generic Elo DMA
  drivers (fsldma) will attempt to use them, and it will conflict with the
  sound drivers.

properties:
  compatible:
    oneOf:
      - items:
          - enum:
              - fsl,imx50-ssi
              - fsl,imx53-ssi
          - const: fsl,imx51-ssi
          - const: fsl,imx21-ssi
      - items:
          - enum:
              - fsl,imx25-ssi
              - fsl,imx27-ssi
              - fsl,imx35-ssi
              - fsl,imx51-ssi
          - const: fsl,imx21-ssi
      - items:
          - enum:
              - fsl,imx6q-ssi
              - fsl,imx6sl-ssi
              - fsl,imx6sx-ssi
          - const: fsl,imx51-ssi
      - items:
          - const: fsl,imx21-ssi
      - items:
          - const: fsl,mpc8610-ssi

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  clocks:
    items:
      - description: The ipg clock for register access
      - description: clock for SSI master mode
    minItems: 1

  clock-names:
    items:
      - const: ipg
      - const: baud
    minItems: 1

  dmas:
    oneOf:
      - items:
          - description: DMA controller phandle and request line for RX
          - description: DMA controller phandle and request line for TX
      - items:
          - description: DMA controller phandle and request line for RX0
          - description: DMA controller phandle and request line for TX0
          - description: DMA controller phandle and request line for RX1
          - description: DMA controller phandle and request line for TX1

  dma-names:
    oneOf:
      - items:
          - const: rx
          - const: tx
      - items:
          - const: rx0
          - const: tx0
          - const: rx1
          - const: tx1

  "#sound-dai-cells":
    const: 0
    description: optional, some dts node didn't add it.

  cell-index:
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [0, 1, 2]
    description: The SSI index

  ac97-gpios:
    $ref: /schemas/types.yaml#/definitions/phandle-array
    description: Please refer to soc-ac97link.txt

  codec-handle:
    $ref: /schemas/types.yaml#/definitions/phandle
    description:
      Phandle to a 'codec' node that defines an audio
      codec connected to this SSI.  This node is typically
      a child of an I2C or other control node.

  fsl,fifo-depth:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      The number of elements in the transmit and receive FIFOs.
      This number is the maximum allowed value for SFCSR[TFWM0].
    enum: [8, 15]

  fsl,fiq-stream-filter:
    type: boolean
    description:
      Disabled DMA and use FIQ instead to filter the codec stream.
      This is necessary for some boards where an incompatible codec
      is connected to this SSI, e.g. on pca100 and pcm043.

  fsl,mode:
    $ref: /schemas/types.yaml#/definitions/string
    enum: [ ac97-slave, ac97-master, i2s-slave, i2s-master,
            lj-slave, lj-master, rj-slave, rj-master ]
    description: |
      "ac97-slave" - AC97 mode, SSI is clock slave
      "ac97-master" - AC97 mode, SSI is clock master
      "i2s-slave" - I2S mode, SSI is clock slave
      "i2s-master" - I2S mode, SSI is clock master
      "lj-slave" - Left justified mode, SSI is clock slave
      "lj-master" - Left justified mode, SSI is clock master
      "rj-slave" - Right justified mode, SSI is clock slave
      "rj-master" - Right justified mode, SSI is clock master      

  fsl,ssi-asynchronous:
    type: boolean
    description: If specified, the SSI is to be programmed in asynchronous
      mode.  In this mode, pins SRCK, STCK, SRFS, and STFS must
      all be connected to valid signals.  In synchronous mode,
      SRCK and SRFS are ignored.  Asynchronous mode allows
      playback and capture to use different sample sizes and
      sample rates.  Some drivers may require that SRCK and STCK
      be connected together, and SRFS and STFS be connected
      together.  This would still allow different sample sizes,
      but not different sample rates.

  fsl,playback-dma:
    $ref: /schemas/types.yaml#/definitions/phandle
    description: Phandle to a node for the DMA channel to use for
      playback of audio.  This is typically dictated by SOC
      design. Only used on Power Architecture.

  fsl,capture-dma:
    $ref: /schemas/types.yaml#/definitions/phandle
    description: Phandle to a node for the DMA channel to use for
      capture (recording) of audio.  This is typically dictated
      by SOC design. Only used on Power Architecture.

required:
  - compatible
  - reg
  - interrupts
  - fsl,fifo-depth

allOf:
  - $ref: dai-common.yaml#

unevaluatedProperties: false

examples:
  - |
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/clock/imx6qdl-clock.h>
    ssi@2028000 {
        compatible = "fsl,imx6q-ssi", "fsl,imx51-ssi";
        reg = <0x02028000 0x4000>;
        interrupts = <GIC_SPI 46 IRQ_TYPE_LEVEL_HIGH>;
        clocks = <&clks IMX6QDL_CLK_SSI1_IPG>,
                 <&clks IMX6QDL_CLK_SSI1>;
        clock-names = "ipg", "baud";
        dmas = <&sdma 37 1 0>, <&sdma 38 1 0>;
        dma-names = "rx", "tx";
        #sound-dai-cells = <0>;
        fsl,fifo-depth = <15>;
    };