[PATCH 2/8 v4] Documentation: bindings: dma: Add binding for dma-channel-mask

John Stultz
2019-01-16T17:11:27Z

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