diff options
author | Scott Branden <sbranden@broadcom.com> | 2015-03-20 18:06:22 -0700 |
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committer | Rob Herring <robh@kernel.org> | 2015-03-26 12:14:11 -0500 |
commit | 23a71fd616bf77fcc630ea514c469b0dd09cb99c (patch) | |
tree | 9172aa58dea51022af10f8f910dbdf00c120511c /Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt | |
parent | 9697a5595ece52a722d88f25a90ded0028e5e6b4 (diff) | |
download | linux-23a71fd616bf77fcc630ea514c469b0dd09cb99c.tar.bz2 |
dt-bindings: brcm: rationalize Broadcom documentation naming
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>
Diffstat (limited to 'Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt')
-rw-r--r-- | Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt new file mode 100644 index 000000000000..1396078d15ac --- /dev/null +++ b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt @@ -0,0 +1,57 @@ +* 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"; +}; |