mmc: moxart: Add MOXA ART SD/MMC driver

Add SD/MMC driver for MOXA ART SoCs.

The "MOXA ART MMC controller" is likely a faraday "ftsdc010",
a controller with support in U-Boot:

http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/mmc/ftsdc010_mci.cSigned-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

Documentation/devicetree/bindings/mmc/moxa,moxart-mmc.txt

+MOXA ART MMC Host Controller Interface
+
+  Inherits from mmc binding[1].
+
+  [1] Documentation/devicetree/bindings/mmc/mmc.txt
+
+Required properties:
+
+- compatible :	Must be "moxa,moxart-mmc" or "faraday,ftsdc010"
+- reg :		Should contain registers location and length
+- interrupts :	Should contain the interrupt number
+- clocks :	Should contain phandle for the clock feeding the MMC controller
+
+Optional properties:
+
+- dmas :	Should contain two DMA channels, line request number must be 5 for
+		both channels
+- dma-names :	Must be "tx", "rx"
+
+Example:
+
+	mmc: mmc@98e00000 {
+		compatible = "moxa,moxart-mmc";
+		reg = <0x98e00000 0x5C>;
+		interrupts = <5 0>;
+		clocks = <&clk_apb>;
+		dmas =  <&dma 5>,
+			<&dma 5>;
+		dma-names = "tx", "rx";
+	};

drivers/mmc/host/Kconfig

@@ -283,6 +283,15 @@ config MMC_SDHCI_BCM2835
 
 	  If unsure, say N.
 
+config MMC_MOXART
+	tristate "MOXART SD/MMC Host Controller support"
+	depends on ARCH_MOXART && MMC
+	help
+	  This selects support for the MOXART SD/MMC Host Controller.
+	  MOXA provides one multi-functional card reader which can
+	  be found on some embedded hardware such as UC-7112-LX.
+	  If you have a controller with this interface, say Y here.
+
 config MMC_OMAP
 	tristate "TI OMAP Multimedia Card Interface support"
 	depends on ARCH_OMAP

drivers/mmc/host/Makefile

@@ -50,6 +50,7 @@ obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_VUB300)	+= vub300.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
 obj-$(CONFIG_MMC_WMT)		+= wmt-sdmmc.o
+obj-$(CONFIG_MMC_MOXART)	+= moxart-mmc.o
 
 obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o
 obj-$(CONFIG_MMC_REALTEK_USB)	+= rtsx_usb_sdmmc.o