mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 15:13:55 +08:00
23a71fd616
This patchset attempts to standardize the naming of dt-bindings documents based on the Broadcom vendor prefix of brcm. Although there are no guidelines currently present for how to name the dt-bindings document the "vendor,binding.txt" style is in use by some of the other vendors. Acked-by: Lee Jones <lee@kernel.org> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Gregory Fong <gregory.0xf0@gmail.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Scott Branden <sbranden@broadcom.com> Signed-off-by: Rob Herring <robh@kernel.org>
58 lines
1.5 KiB
Plaintext
58 lines
1.5 KiB
Plaintext
* BCM2835 DMA controller
|
|
|
|
The BCM2835 DMA controller has 16 channels in total.
|
|
Only the lower 13 channels have an associated IRQ.
|
|
Some arbitrary channels are used by the firmware
|
|
(1,3,6,7 in the current firmware version).
|
|
The channels 0,2 and 3 have special functionality
|
|
and should not be used by the driver.
|
|
|
|
Required properties:
|
|
- compatible: Should be "brcm,bcm2835-dma".
|
|
- reg: Should contain DMA registers location and length.
|
|
- interrupts: Should contain the DMA interrupts associated
|
|
to the DMA channels in ascending order.
|
|
- #dma-cells: Must be <1>, the cell in the dmas property of the
|
|
client device represents the DREQ number.
|
|
- brcm,dma-channel-mask: Bit mask representing the channels
|
|
not used by the firmware in ascending order,
|
|
i.e. first channel corresponds to LSB.
|
|
|
|
Example:
|
|
|
|
dma: dma@7e007000 {
|
|
compatible = "brcm,bcm2835-dma";
|
|
reg = <0x7e007000 0xf00>;
|
|
interrupts = <1 16>,
|
|
<1 17>,
|
|
<1 18>,
|
|
<1 19>,
|
|
<1 20>,
|
|
<1 21>,
|
|
<1 22>,
|
|
<1 23>,
|
|
<1 24>,
|
|
<1 25>,
|
|
<1 26>,
|
|
<1 27>,
|
|
<1 28>;
|
|
|
|
#dma-cells = <1>;
|
|
brcm,dma-channel-mask = <0x7f35>;
|
|
};
|
|
|
|
DMA clients connected to the BCM2835 DMA controller must use the format
|
|
described in the dma.txt file, using a two-cell specifier for each channel.
|
|
|
|
Example:
|
|
|
|
bcm2835_i2s: i2s@7e203000 {
|
|
compatible = "brcm,bcm2835-i2s";
|
|
reg = < 0x7e203000 0x20>,
|
|
< 0x7e101098 0x02>;
|
|
|
|
dmas = <&dma 2>,
|
|
<&dma 3>;
|
|
dma-names = "tx", "rx";
|
|
};
|