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+Freescale Synchronous Serial Interface
+
+The SSI is a serial device that communicates with audio codecs. It can
+be programmed in AC97, I2S, left-justified, or right-justified modes.
+
+Required properties:
+- compatible: Compatible list, should contain one of the following
+ compatibles:
+ fsl,mpc8610-ssi
+ fsl,imx51-ssi
+ fsl,imx35-ssi
+ fsl,imx21-ssi
+- cell-index: The SSI, <0> = SSI1, <1> = SSI2, and so on.
+- reg: Offset and length of the register set for the device.
+- interrupts: <a b> where a is the interrupt number and b is a
+ field that represents an encoding of the sense and
+ level information for the interrupt. This should be
+ encoded based on the information in section 2)
+ depending on the type of interrupt controller you
+ have.
+- fsl,fifo-depth: The number of elements in the transmit and receive FIFOs.
+ This number is the maximum allowed value for SFCSR[TFWM0].
+ - clocks: "ipg" - Required clock for the SSI unit
+ "baud" - Required clock for SSI master mode. Otherwise this
+ clock is not used
+
+Required are also ac97 link bindings if ac97 is used. See
+Documentation/devicetree/bindings/sound/soc-ac97link.txt for the necessary
+bindings.
+
+Optional properties:
+- codec-handle: 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,fiq-stream-filter: Bool property. 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.
+- dmas: Generic dma devicetree binding as described in
+ Documentation/devicetree/bindings/dma/dma.txt.
+- dma-names: Two dmas have to be defined, "tx" and "rx", if fsl,imx-fiq
+ is not defined.
+- fsl,mode: The operating mode for the AC97 interface only.
+ "ac97-slave" - AC97 mode, SSI is clock slave
+ "ac97-master" - AC97 mode, SSI is clock master
+- fsl,ssi-asynchronous:
+ 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: Phandle to a node for the DMA channel to use for
+ playback of audio. This is typically dictated by SOC
+ design. See the notes below.
+ Only used on Power Architecture.
+- fsl,capture-dma: Phandle to a node for the DMA channel to use for
+ capture (recording) of audio. This is typically dictated
+ by SOC design. See the notes below.
+ Only used on Power Architecture.
+
+Child 'codec' node required properties:
+- compatible: Compatible list, contains the name of the codec
+
+Child 'codec' node optional properties:
+- clock-frequency: The frequency of the input clock, which typically comes
+ from an on-board dedicated oscillator.
+
+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.