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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/dma/dma.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/devicetree/bindings/dma/dma.txt')
-rw-r--r-- | kernel/Documentation/devicetree/bindings/dma/dma.txt | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/Documentation/devicetree/bindings/dma/dma.txt b/kernel/Documentation/devicetree/bindings/dma/dma.txt new file mode 100644 index 000000000..82104271e --- /dev/null +++ b/kernel/Documentation/devicetree/bindings/dma/dma.txt @@ -0,0 +1,81 @@ +* Generic DMA Controller and DMA request bindings + +Generic binding to provide a way for a driver using DMA Engine to retrieve the +DMA request or channel information that goes from a hardware device to a DMA +controller. + + +* DMA controller + +Required property: +- #dma-cells: Must be at least 1. Used to provide DMA controller + specific information. See DMA client binding below for + more details. + +Optional properties: +- dma-channels: Number of DMA channels supported by the controller. +- dma-requests: Number of DMA request signals supported by the + controller. + +Example: + + dma: dma@48000000 { + compatible = "ti,omap-sdma"; + reg = <0x48000000 0x1000>; + interrupts = <0 12 0x4 + 0 13 0x4 + 0 14 0x4 + 0 15 0x4>; + #dma-cells = <1>; + dma-channels = <32>; + dma-requests = <127>; + }; + + +* DMA client + +Client drivers should specify the DMA property using a phandle to the controller +followed by DMA controller specific data. + +Required property: +- dmas: List of one or more DMA specifiers, each consisting of + - A phandle pointing to DMA controller node + - A number of integer cells, as determined by the + #dma-cells property in the node referenced by phandle + containing DMA controller specific information. This + typically contains a DMA request line number or a + channel number, but can contain any data that is + required for configuring a channel. +- dma-names: Contains one identifier string for each DMA specifier in + the dmas property. The specific strings that can be used + are defined in the binding of the DMA client device. + Multiple DMA specifiers can be used to represent + alternatives and in this case the dma-names for those + DMA specifiers must be identical (see examples). + +Examples: + +1. A device with one DMA read channel, one DMA write channel: + + i2c1: i2c@1 { + ... + dmas = <&dma 2 /* read channel */ + &dma 3>; /* write channel */ + dma-names = "rx", "tx"; + ... + }; + +2. A single read-write channel with three alternative DMA controllers: + + dmas = <&dma1 5 + &dma2 7 + &dma3 2>; + dma-names = "rx-tx", "rx-tx", "rx-tx"; + +3. A device with three channels, one of which has two alternatives: + + dmas = <&dma1 2 /* read channel */ + &dma1 3 /* write channel */ + &dma2 0 /* error read */ + &dma3 0>; /* alternative error read */ + dma-names = "rx", "tx", "error", "error"; |