dmaengine: Add MOXA ART DMA engine driver

The MOXA ART SoC has a DMA controller capable of offloading expensive
memory operations, such as large copies. This patch adds support for
the controller including four channels. Two of these are used to
handle MMC copy on the UC-7112-LX hardware. The remaining two can be
used in a future audio driver or client application.

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/dma/moxa,moxart-dma.txt b/Documentation/devicetree/bindings/dma/moxa,moxart-dma.txt
new file mode 100644
index 000000000000..8a9f3559335b
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/moxa,moxart-dma.txt
@@ -0,0 +1,45 @@
+MOXA ART DMA Controller
+
+See dma.txt first
+
+Required properties:
+
+- compatible :  Must be "moxa,moxart-dma"
+- reg :         Should contain registers location and length
+- interrupts :  Should contain an interrupt-specifier for the sole
+                interrupt generated by the device
+- #dma-cells :  Should be 1, a single cell holding a line request number
+
+Example:
+
+        dma: dma@90500000 {
+                compatible = "moxa,moxart-dma";
+                reg = <0x90500080 0x40>;
+                interrupts = <24 0>;
+                #dma-cells = <1>;
+        };
+
+
+Clients:
+
+DMA clients connected to the MOXA ART DMA controller must use the format
+described in the dma.txt file, using a two-cell specifier for each channel:
+a phandle plus one integer cells.
+The two cells in order are:
+
+1. A phandle pointing to the DMA controller.
+2. Peripheral identifier for the hardware handshaking interface.
+
+Example:
+Use specific request line passing from dma
+For example, MMC request line is 5
+
+        sdhci: sdhci@98e00000 {
+                compatible = "moxa,moxart-sdhci";
+                reg = <0x98e00000 0x5C>;
+                interrupts = <5 0>;
+                clocks = <&clk_apb>;
+                dmas =  <&dma 5>,
+                        <&dma 5>;
+                dma-names = "tx", "rx";
+        };