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linux-next/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
Stefan Wahren 7eab96f386 dt-bindings: bcm283x: Fix register ranges of bcm2835-i2s
Since 517e7a1537 ("ASoC: bcm2835: move to use the clock framework")
the bcm2835-i2s requires a clock as DT property. Unfortunately
the necessary DT change has never been applied. While we are at it
also fix the first PCM register range to cover the PCM_GRAY register.

This patch only fixes the affected dt-bindings.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
2018-02-22 11:31:31 -08:00

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* 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.
- interrupt-names: Should contain the names of the interrupt
in the form "dmaXX".
Use "dma-shared-all" for the common interrupt line
that is shared by all dma channels.
- #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>,
/* dma channel 11-14 share one irq */
<1 27>,
<1 27>,
<1 27>,
<1 27>,
/* unused shared irq for all channels */
<1 28>;
interrupt-names = "dma0",
"dma1",
"dma2",
"dma3",
"dma4",
"dma5",
"dma6",
"dma7",
"dma8",
"dma9",
"dma10",
"dma11",
"dma12",
"dma13",
"dma14",
"dma-shared-all";
#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 0x24>;
clocks = <&clocks BCM2835_CLOCK_PCM>;
dmas = <&dma 2>,
<&dma 3>;
dma-names = "tx", "rx";
};