@@ -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.
@@ -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.
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> --- Documentation/powerpc/dts-bindings/fsl/dma.txt | 13 +++++++++++-- Documentation/powerpc/dts-bindings/fsl/ssi.txt | 20 ++++++++++++++------ 2 files changed, 25 insertions(+), 8 deletions(-)