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authorLee Jones <lee.jones@linaro.org>2013-05-03 16:32:12 +0200
committerLinus Walleij <linus.walleij@linaro.org>2013-05-23 21:13:08 +0200
commitfa332de5c6b3891485798adfe3252125457e5377 (patch)
treedf2585098fc3aa7e43144244db4309c4a7a4bfa8 /Documentation/devicetree/bindings/dma
parentdmaengine: ste_dma40: Allow driver to be probe()able when DT is enabled (diff)
downloadlinux-fa332de5c6b3891485798adfe3252125457e5377.tar.xz
linux-fa332de5c6b3891485798adfe3252125457e5377.zip
dmaengine: ste_dma40: Supply full Device Tree parsing support
Using the new DMA DT bindings and API, we can register the DMA40 driver as Device Tree capable. Now, when a client attempts to allocate a channel using the DMA DT bindings via its own node, we are able to parse the request and allocate a channel in the correct manner. Cc: Dan Williams <djbw@fb.com> Cc: Per Forlin <per.forlin@stericsson.com> Cc: Rabin Vincent <rabin@rab.in> Cc: Rob Herring <rob.herring@calxeda.com> Cc: devicetree-discuss@lists.ozlabs.org Acked-by: Vinod Koul <vinod.koul@intel.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings/dma')
-rw-r--r--Documentation/devicetree/bindings/dma/ste-dma40.txt62
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/dma/ste-dma40.txt b/Documentation/devicetree/bindings/dma/ste-dma40.txt
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index 000000000000..2679a873522d
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+* DMA40 DMA Controller
+
+Required properties:
+- compatible: "stericsson,dma40"
+- reg: Address range of the DMAC registers
+- reg-names: Names of the above areas to use during resource look-up
+- interrupt: Should contain the DMAC interrupt number
+- #dma-cells: must be <3>
+
+Optional properties:
+- dma-channels: Number of channels supported by hardware - if not present
+ the driver will attempt to obtain the information from H/W
+
+Example:
+
+ dma: dma-controller@801C0000 {
+ compatible = "stericsson,db8500-dma40", "stericsson,dma40";
+ reg = <0x801C0000 0x1000 0x40010000 0x800>;
+ reg-names = "base", "lcpa";
+ interrupt-parent = <&intc>;
+ interrupts = <0 25 0x4>;
+
+ #dma-cells = <2>;
+ dma-channels = <8>;
+ };
+
+Clients
+Required properties:
+- dmas: Comma separated list of dma channel requests
+- dma-names: Names of the aforementioned requested channels
+
+Each dmas request consists of 4 cells:
+ 1. A phandle pointing to the DMA controller
+ 2. Device Type
+ 3. The DMA request line number (only when 'use fixed channel' is set)
+ 4. A 32bit mask specifying; mode, direction and endianess [NB: This list will grow]
+ 0x00000001: Mode:
+ Logical channel when unset
+ Physical channel when set
+ 0x00000002: Direction:
+ Memory to Device when unset
+ Device to Memory when set
+ 0x00000004: Endianess:
+ Little endian when unset
+ Big endian when set
+ 0x00000008: Use fixed channel:
+ Use automatic channel selection when unset
+ Use DMA request line number when set
+
+Example:
+
+ uart@80120000 {
+ compatible = "arm,pl011", "arm,primecell";
+ reg = <0x80120000 0x1000>;
+ interrupts = <0 11 0x4>;
+
+ dmas = <&dma 13 0 0x2>, /* Logical - DevToMem */
+ <&dma 13 0 0x0>; /* Logical - MemToDev */
+ dma-names = "rx", "rx";
+
+ status = "disabled";
+ };