77 lines
2.6 KiB
Plaintext
77 lines
2.6 KiB
Plaintext
|
* Freescale enhanced Direct Memory Access(eDMA) Controller
|
||
|
|
|
||
|
|
The eDMA channels have multiplex capability by programmble memory-mapped
|
||
|
|
registers. channels are split into two groups, called DMAMUX0 and DMAMUX1,
|
||
|
|
specific DMA request source can only be multiplexed by any channel of certain
|
||
|
|
group, DMAMUX0 or DMAMUX1, but not both.
|
||
|
|
|
||
|
|
* eDMA Controller
|
||
|
|
Required properties:
|
||
|
|
- compatible :
|
||
|
|
- "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC
|
||
|
|
- reg : Specifies base physical address(s) and size of the eDMA registers.
|
||
|
|
The 1st region is eDMA control register's address and size.
|
||
|
|
The 2nd and the 3rd regions are programmable channel multiplexing
|
||
|
|
control register's address and size.
|
||
|
|
- interrupts : A list of interrupt-specifiers, one for each entry in
|
||
|
|
interrupt-names.
|
||
|
|
- interrupt-names : Should contain:
|
||
|
|
"edma-tx" - the transmission interrupt
|
||
|
|
"edma-err" - the error interrupt
|
||
|
|
- #dma-cells : Must be <2>.
|
||
|
|
The 1st cell specifies the DMAMUX(0 for DMAMUX0 and 1 for DMAMUX1).
|
||
|
|
Specific request source can only be multiplexed by specific channels
|
||
|
|
group called DMAMUX.
|
||
|
|
The 2nd cell specifies the request source(slot) ID.
|
||
|
|
See the SoC's reference manual for all the supported request sources.
|
||
|
|
- dma-channels : Number of channels supported by the controller
|
||
|
|
- clock-names : A list of channel group clock names. Should contain:
|
||
|
|
"dmamux0" - clock name of mux0 group
|
||
|
|
"dmamux1" - clock name of mux1 group
|
||
|
|
- clocks : A list of phandle and clock-specifier pairs, one for each entry in
|
||
|
|
clock-names.
|
||
|
|
|
||
|
|
Optional properties:
|
||
|
|
- big-endian: If present registers and hardware scatter/gather descriptors
|
||
|
|
of the eDMA are implemented in big endian mode, otherwise in little
|
||
|
|
mode.
|
||
|
|
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
|
||
|
|
edma0: dma-controller@40018000 {
|
||
|
|
#dma-cells = <2>;
|
||
|
|
compatible = "fsl,vf610-edma";
|
||
|
|
reg = <0x40018000 0x2000>,
|
||
|
|
<0x40024000 0x1000>,
|
||
|
|
<0x40025000 0x1000>;
|
||
|
|
interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>,
|
||
|
|
<0 9 IRQ_TYPE_LEVEL_HIGH>;
|
||
|
|
interrupt-names = "edma-tx", "edma-err";
|
||
|
|
dma-channels = <32>;
|
||
|
|
clock-names = "dmamux0", "dmamux1";
|
||
|
|
clocks = <&clks VF610_CLK_DMAMUX0>,
|
||
|
|
<&clks VF610_CLK_DMAMUX1>;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
* DMA clients
|
||
|
|
DMA client drivers that uses the DMA function must use the format described
|
||
|
|
in the dma.txt file, using a two-cell specifier for each channel: the 1st
|
||
|
|
specifies the channel group(DMAMUX) in which this request can be multiplexed,
|
||
|
|
and the 2nd specifies the request source.
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
|
||
|
|
sai2: sai@40031000 {
|
||
|
|
compatible = "fsl,vf610-sai";
|
||
|
|
reg = <0x40031000 0x1000>;
|
||
|
|
interrupts = <0 86 IRQ_TYPE_LEVEL_HIGH>;
|
||
|
|
clock-names = "sai";
|
||
|
|
clocks = <&clks VF610_CLK_SAI2>;
|
||
|
|
dma-names = "tx", "rx";
|
||
|
|
dmas = <&edma0 0 21>,
|
||
|
|
<&edma0 0 20>;
|
||
|
|
status = "disabled";
|
||
|
|
};
|