Messages in this thread Patch in this message | | | From | John Stultz <> | Subject | [PATCH 2/8 v4] Documentation: bindings: dma: Add binding for dma-channel-mask | Date | Wed, 16 Jan 2019 09:10:23 -0800 |
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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@kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Tanglei Han <hantanglei@huawei.com> Cc: Zhuangluan Su <suzhuangluan@hisilicon.com> Cc: Ryan Grachek <ryan@edited.us> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: dmaengine@vger.kernel.org Cc: devicetree@vger.kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org> --- 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
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