From b56c2768d28425783f895971854577f412ae486f Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Fri, 10 Oct 2008 11:52:31 -0500 Subject: 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 Signed-off-by: Kumar Gala --- Documentation/powerpc/dts-bindings/fsl/ssi.txt | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) (limited to 'Documentation/powerpc/dts-bindings/fsl/ssi.txt') diff --git a/Documentation/powerpc/dts-bindings/fsl/ssi.txt b/Documentation/powerpc/dts-bindings/fsl/ssi.txt index 5d98413..a2d9639 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. -- cgit v1.1