diff options
| author | Timur Tabi <timur@freescale.com> | 2008-10-10 18:52:31 +0200 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2008-10-13 18:10:00 +0200 |
| commit | b56c2768d28425783f895971854577f412ae486f (patch) | |
| tree | e015bdccf67d759ea637e85934e6288b43808316 /Documentation/powerpc/dts-bindings/fsl/ssi.txt | |
| parent | powerpc: disable CHRP and PMAC support in various defconfigs (diff) | |
| download | linux-b56c2768d28425783f895971854577f412ae486f.tar.xz linux-b56c2768d28425783f895971854577f412ae486f.zip | |
powerpc: document the "fsl,ssi-dma-channel" compatible property
The "fsl,ssi-dma-channel" compatible property is used to specify a DMA channel
on the Freescale Elo DMA controller that should be used exclusively by the
Freescale SSI audio controller. When a property is marked as such, the Elo
DMA driver will ignore it, and so it will be available for the sound drivers.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'Documentation/powerpc/dts-bindings/fsl/ssi.txt')
| -rw-r--r-- | Documentation/powerpc/dts-bindings/fsl/ssi.txt | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/powerpc/dts-bindings/fsl/ssi.txt b/Documentation/powerpc/dts-bindings/fsl/ssi.txt index 5d9841303cae..a2d963998a65 100644 --- a/Documentation/powerpc/dts-bindings/fsl/ssi.txt +++ b/Documentation/powerpc/dts-bindings/fsl/ssi.txt @@ -24,12 +24,12 @@ Required properties: "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 DMA 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 DMA node for the DMA channel to use for - capture (recording) of audio. This is typically dictated - by SOC design. See the notes below. +- 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 + capture (recording) of audio. This is typically dictated + by SOC design. See the notes below. Optional properties: - codec-handle : phandle to a 'codec' node that defines an audio @@ -51,3 +51,11 @@ 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. |