diff options
| -rw-r--r-- | Documentation/powerpc/dts-bindings/fsl/dma.txt | 13 | ||||
| -rw-r--r-- | Documentation/powerpc/dts-bindings/fsl/ssi.txt | 20 |
2 files changed, 25 insertions, 8 deletions
diff --git a/Documentation/powerpc/dts-bindings/fsl/dma.txt b/Documentation/powerpc/dts-bindings/fsl/dma.txt index 86826df00e6..cc453110fc4 100644 --- a/Documentation/powerpc/dts-bindings/fsl/dma.txt +++ b/Documentation/powerpc/dts-bindings/fsl/dma.txt @@ -20,7 +20,7 @@ Required properties: - compatible : compatible list, contains 2 entries, first is "fsl,CHIP-dma-channel", where CHIP is the processor (mpc8349, mpc8350, etc.) and the second is - "fsl,elo-dma-channel" + "fsl,elo-dma-channel". However, see note below. - reg : <registers mapping for channel> - cell-index : dma channel index starts at 0. @@ -82,7 +82,7 @@ Required properties: - compatible : compatible list, contains 2 entries, first is "fsl,CHIP-dma-channel", where CHIP is the processor (mpc8540, mpc8560, etc.) and the second is - "fsl,eloplus-dma-channel" + "fsl,eloplus-dma-channel". However, see note below. - cell-index : dma channel index starts at 0. - reg : <registers mapping for channel> - interrupts : <interrupt mapping for DMA channel IRQ> @@ -125,3 +125,12 @@ Example: interrupts = <17 2>; }; }; + +Note on DMA channel compatible properties: The compatible property must say +"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel" to be used by the Elo DMA +driver (fsldma). Any DMA channel used by fsldma cannot be used by another +DMA driver, such as the SSI sound drivers for the MPC8610. Therefore, any DMA +channel that should be used for another driver should not use +"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel". For the SSI drivers, for +example, the compatible property should be "fsl,ssi-dma-channel". See ssi.txt +for more information. diff --git a/Documentation/powerpc/dts-bindings/fsl/ssi.txt b/Documentation/powerpc/dts-bindings/fsl/ssi.txt index 5d9841303ca..a2d963998a6 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. |