mmc: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs

The Allwinner sunxi mmc host uses dma in bus-master mode using a built-in
designware idmac controller, which is identical to the one found in the mmc-dw
hosts. However the rest of the host is not identical to mmc-dw, it deals with
sending stop commands in hardware which makes it significantly different
from the mmc-dw devices.

Signed-off-by: David Lanzendörfer <david.lanzendoerfer@o2s.ch>
[hdegoede@redhat.com: various cleanups and fixes]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Chris Ball <chris@printf.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/mmc/host/Kconfig

@@ -694,3 +694,10 @@ config MMC_REALTEK_PCI
 	help
 	  Say Y here to include driver code to support SD/MMC card interface
 	  of Realtek PCI-E card reader
+
+config MMC_SUNXI
+	tristate "Allwinner sunxi SD/MMC Host Controller support"
+	depends on ARCH_SUNXI
+	help
+	  This selects support for the SD/MMC Host Controller on
+	  Allwinner sunxi SoCs.

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_SUNXI)		+= sunxi-mmc.o
 
 obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o