android_kernel_xiaomi_sm8350/Documentation/powerpc/dts-bindings/fsl/dma.txt
Timur Tabi b56c2768d2 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>
2008-10-13 11:10:00 -05:00

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* Freescale 83xx DMA Controller
Freescale PowerPC 83xx have on chip general purpose DMA controllers.
Required properties:
- compatible : compatible list, contains 2 entries, first is
"fsl,CHIP-dma", where CHIP is the processor
(mpc8349, mpc8360, etc.) and the second is
"fsl,elo-dma"
- reg : <registers mapping for DMA general status reg>
- ranges : Should be defined as specified in 1) to describe the
DMA controller channels.
- cell-index : controller index. 0 for controller @ 0x8100
- interrupts : <interrupt mapping for DMA IRQ>
- interrupt-parent : optional, if needed for interrupt mapping
- DMA channel nodes:
- 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". However, see note below.
- reg : <registers mapping for channel>
- cell-index : dma channel index starts at 0.
Optional properties:
- interrupts : <interrupt mapping for DMA channel IRQ>
(on 83xx this is expected to be identical to
the interrupts property of the parent node)
- interrupt-parent : optional, if needed for interrupt mapping
Example:
dma@82a8 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "fsl,mpc8349-dma", "fsl,elo-dma";
reg = <82a8 4>;
ranges = <0 8100 1a4>;
interrupt-parent = <&ipic>;
interrupts = <47 8>;
cell-index = <0>;
dma-channel@0 {
compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
cell-index = <0>;
reg = <0 80>;
};
dma-channel@80 {
compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
cell-index = <1>;
reg = <80 80>;
};
dma-channel@100 {
compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
cell-index = <2>;
reg = <100 80>;
};
dma-channel@180 {
compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
cell-index = <3>;
reg = <180 80>;
};
};
* Freescale 85xx/86xx DMA Controller
Freescale PowerPC 85xx/86xx have on chip general purpose DMA controllers.
Required properties:
- compatible : compatible list, contains 2 entries, first is
"fsl,CHIP-dma", where CHIP is the processor
(mpc8540, mpc8540, etc.) and the second is
"fsl,eloplus-dma"
- reg : <registers mapping for DMA general status reg>
- cell-index : controller index. 0 for controller @ 0x21000,
1 for controller @ 0xc000
- ranges : Should be defined as specified in 1) to describe the
DMA controller channels.
- DMA channel nodes:
- 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". However, see note below.
- cell-index : dma channel index starts at 0.
- reg : <registers mapping for channel>
- interrupts : <interrupt mapping for DMA channel IRQ>
- interrupt-parent : optional, if needed for interrupt mapping
Example:
dma@21300 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "fsl,mpc8540-dma", "fsl,eloplus-dma";
reg = <21300 4>;
ranges = <0 21100 200>;
cell-index = <0>;
dma-channel@0 {
compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
reg = <0 80>;
cell-index = <0>;
interrupt-parent = <&mpic>;
interrupts = <14 2>;
};
dma-channel@80 {
compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
reg = <80 80>;
cell-index = <1>;
interrupt-parent = <&mpic>;
interrupts = <15 2>;
};
dma-channel@100 {
compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
reg = <100 80>;
cell-index = <2>;
interrupt-parent = <&mpic>;
interrupts = <16 2>;
};
dma-channel@180 {
compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
reg = <180 80>;
cell-index = <3>;
interrupt-parent = <&mpic>;
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.