Some dma channels can be reserved for secure mode or other hardware on the SoC, so provide a binding for a bitmask listing the available channels for the kernel to use. This follows the pre-existing bcm,dma-channel-mask binding. Cc: Vinod Koul <vkoul@xxxxxxxxxx> Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Tanglei Han <hantanglei@xxxxxxxxxx> Cc: Zhuangluan Su <suzhuangluan@xxxxxxxxxxxxx> Cc: Ryan Grachek <ryan@xxxxxxxxx> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Cc: dmaengine@xxxxxxxxxxxxxxx Cc: devicetree@xxxxxxxxxxxxxxx Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> --- v3: Renamed to hisi-dma-avail-chan v4: Reworked to generic dma-channel-mask --- Documentation/devicetree/bindings/dma/dma.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt index 6312fb0..eeb4e4d 100644 --- a/Documentation/devicetree/bindings/dma/dma.txt +++ b/Documentation/devicetree/bindings/dma/dma.txt @@ -16,6 +16,9 @@ Optional properties: - dma-channels: Number of DMA channels supported by the controller. - dma-requests: Number of DMA request signals supported by the controller. +- dma-channel-mask: Bitmask of available DMA channels in ascending order + that are not reserved by firmware and are available to + the kernel. i.e. first channel corresponds to LSB. Example: @@ -29,6 +32,7 @@ Example: #dma-cells = <1>; dma-channels = <32>; dma-requests = <127>; + dma-channel-mask = <0xfffe> }; * DMA router -- 2.7.4
