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powerpc: clean up ssi.txt, add definition for fsl,ssi-asynchronous

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Add the definition of the fsl,ssi-asynchronous property to ssi.txt
(documentation of the device tree bindings for the Freescale SSI device).

Also tidy up the layout of ssi.txt.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Timur Tabi 2009-03-11 19:22:04 -05:00 committed by Kumar Gala
parent 393adcacad
commit df4b6806d3
1 changed files with 39 additions and 29 deletions
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68
Documentation/powerpc/dts-bindings/fsl/ssi.txt
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@ -4,46 +4,56 @@ 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, containing "fsl,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.
- interrupt-parent : the phandle for the interrupt controller that
services interrupts for this device.
- fsl,mode : the operating mode for the SSI interface
"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" - l.j. mode, SSI is clock master
"rj-slave" - right-justified mode, SSI is clock slave
"rj-master" - r.j., SSI is clock master
"ac97-slave" - AC97 mode, SSI is clock slave
"ac97-master" - AC97 mode, SSI is clock master
- fsl,playback-dma: phandle to a node for the DMA channel to use for
- compatible: Compatible list, contains "fsl,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.
- interrupt-parent: The phandle for the interrupt controller that
services interrupts for this device.
- fsl,mode: The operating mode for the SSI interface.
"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" - l.j. mode, SSI is clock master
"rj-slave" - right-justified mode, SSI is clock slave
"rj-master" - r.j., SSI is clock master
"ac97-slave" - AC97 mode, SSI is clock slave
"ac97-master" - AC97 mode, SSI is clock master
- 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.
- fsl,capture-dma: phandle to a node for the DMA channel to use for
- 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.
- fsl,fifo-depth: the number of elements in the transmit and receive FIFOs.
- fsl,fifo-depth: The number of elements in the transmit and receive FIFOs.
This number is the maximum allowed value for SFCSR[TFWM0].
- 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.
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.
- 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.
Child 'codec' node required properties:
- compatible : compatible list, contains the name of the codec
- 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.
- 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: