diff options
author | Timur Tabi <timur@freescale.com> | 2008-10-10 12:52:31 -0400 |
---|---|---|
committer | Kumar Gala <galak@kernel.crashing.org> | 2008-10-13 12:10:00 -0400 |
commit | b56c2768d28425783f895971854577f412ae486f (patch) | |
tree | e015bdccf67d759ea637e85934e6288b43808316 | |
parent | dbe216319f4e4b23a37eeb623c8338fa59ac050e (diff) |
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>
-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 86826df00e64..cc453110fc46 100644 --- a/Documentation/powerpc/dts-bindings/fsl/dma.txt +++ b/Documentation/powerpc/dts-bindings/fsl/dma.txt | |||
@@ -20,7 +20,7 @@ Required properties: | |||
20 | - compatible : compatible list, contains 2 entries, first is | 20 | - compatible : compatible list, contains 2 entries, first is |
21 | "fsl,CHIP-dma-channel", where CHIP is the processor | 21 | "fsl,CHIP-dma-channel", where CHIP is the processor |
22 | (mpc8349, mpc8350, etc.) and the second is | 22 | (mpc8349, mpc8350, etc.) and the second is |
23 | "fsl,elo-dma-channel" | 23 | "fsl,elo-dma-channel". However, see note below. |
24 | - reg : <registers mapping for channel> | 24 | - reg : <registers mapping for channel> |
25 | - cell-index : dma channel index starts at 0. | 25 | - cell-index : dma channel index starts at 0. |
26 | 26 | ||
@@ -82,7 +82,7 @@ Required properties: | |||
82 | - compatible : compatible list, contains 2 entries, first is | 82 | - compatible : compatible list, contains 2 entries, first is |
83 | "fsl,CHIP-dma-channel", where CHIP is the processor | 83 | "fsl,CHIP-dma-channel", where CHIP is the processor |
84 | (mpc8540, mpc8560, etc.) and the second is | 84 | (mpc8540, mpc8560, etc.) and the second is |
85 | "fsl,eloplus-dma-channel" | 85 | "fsl,eloplus-dma-channel". However, see note below. |
86 | - cell-index : dma channel index starts at 0. | 86 | - cell-index : dma channel index starts at 0. |
87 | - reg : <registers mapping for channel> | 87 | - reg : <registers mapping for channel> |
88 | - interrupts : <interrupt mapping for DMA channel IRQ> | 88 | - interrupts : <interrupt mapping for DMA channel IRQ> |
@@ -125,3 +125,12 @@ Example: | |||
125 | interrupts = <17 2>; | 125 | interrupts = <17 2>; |
126 | }; | 126 | }; |
127 | }; | 127 | }; |
128 | |||
129 | Note on DMA channel compatible properties: The compatible property must say | ||
130 | "fsl,elo-dma-channel" or "fsl,eloplus-dma-channel" to be used by the Elo DMA | ||
131 | driver (fsldma). Any DMA channel used by fsldma cannot be used by another | ||
132 | DMA driver, such as the SSI sound drivers for the MPC8610. Therefore, any DMA | ||
133 | channel that should be used for another driver should not use | ||
134 | "fsl,elo-dma-channel" or "fsl,eloplus-dma-channel". For the SSI drivers, for | ||
135 | example, the compatible property should be "fsl,ssi-dma-channel". See ssi.txt | ||
136 | for more information. | ||
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: | |||
24 | "rj-master" - r.j., SSI is clock master | 24 | "rj-master" - r.j., SSI is clock master |
25 | "ac97-slave" - AC97 mode, SSI is clock slave | 25 | "ac97-slave" - AC97 mode, SSI is clock slave |
26 | "ac97-master" - AC97 mode, SSI is clock master | 26 | "ac97-master" - AC97 mode, SSI is clock master |
27 | - fsl,playback-dma: phandle to a DMA node for the DMA channel to use for | 27 | - fsl,playback-dma: phandle to a node for the DMA channel to use for |
28 | playback of audio. This is typically dictated by SOC | 28 | playback of audio. This is typically dictated by SOC |
29 | design. See the notes below. | 29 | design. See the notes below. |
30 | - fsl,capture-dma: phandle to a DMA node for the DMA channel to use for | 30 | - fsl,capture-dma: phandle to a node for the DMA channel to use for |
31 | capture (recording) of audio. This is typically dictated | 31 | capture (recording) of audio. This is typically dictated |
32 | by SOC design. See the notes below. | 32 | by SOC design. See the notes below. |
33 | 33 | ||
34 | Optional properties: | 34 | Optional properties: |
35 | - codec-handle : phandle to a 'codec' node that defines an audio | 35 | - 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 | |||
51 | playback and DMA channel 3 for capture. The developer can choose which | 51 | playback and DMA channel 3 for capture. The developer can choose which |
52 | DMA controller to use, but the channels themselves are hard-wired. The | 52 | DMA controller to use, but the channels themselves are hard-wired. The |
53 | purpose of these two properties is to represent this hardware design. | 53 | purpose of these two properties is to represent this hardware design. |
54 | |||
55 | The device tree nodes for the DMA channels that are referenced by | ||
56 | "fsl,playback-dma" and "fsl,capture-dma" must be marked as compatible with | ||
57 | "fsl,ssi-dma-channel". The SOC-specific compatible string (e.g. | ||
58 | "fsl,mpc8610-dma-channel") can remain. If these nodes are left as | ||
59 | "fsl,elo-dma-channel" or "fsl,eloplus-dma-channel", then the generic Elo DMA | ||
60 | drivers (fsldma) will attempt to use them, and it will conflict with the | ||
61 | sound drivers. | ||