mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
well as the hardware BCH controller. DMA is not currently implemented.

While older 47xx SoCs also have a BCH controller, they are incompatible
with the one in the 4780 due to differing register/bit positions, which
would make implementing a common driver for them quite messy.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Brian: fixed a few small mistakes]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/Kconfig

@@ -519,6 +519,13 @@ config MTD_NAND_JZ4740
 	help
 		Enables support for NAND Flash on JZ4740 SoC based boards.
 
+config MTD_NAND_JZ4780
+	tristate "Support for NAND on JZ4780 SoC"
+	depends on MACH_JZ4780 && JZ4780_NEMC
+	help
+	  Enables support for NAND Flash connected to the NEMC on JZ4780 SoC
+	  based boards, using the BCH controller for hardware error correction.
+
 config MTD_NAND_FSMC
 	tristate "Support for NAND on ST Micros FSMC"
 	depends on PLAT_SPEAR || ARCH_NOMADIK || ARCH_U8500 || MACH_U300

drivers/mtd/nand/Makefile

@@ -49,6 +49,7 @@ obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
 obj-$(CONFIG_MTD_NAND_VF610_NFC)	+= vf610_nfc.o
 obj-$(CONFIG_MTD_NAND_RICOH)		+= r852.o
 obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
+obj-$(CONFIG_MTD_NAND_JZ4780)		+= jz4780_nand.o jz4780_bch.o
 obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
 obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/