memory: jz4780-nemc: driver for the NEMC on JZ4780 SoCs

Add a driver for the NAND/External Memory Controller (NEMC) on JZ4780
and later SoCs.

The primary function of this driver is to configure parameters, such
as timings, for external memory devices using data supplied in the
device tree. Devices connected to the NEMC are represented in the DT
as children of the NEMC node, the driver uses optional properties
specified in these child nodes to configure the parameters of each
bank.
Signed-off-by: Alex Smith <alex@alex-smith.me.uk>
Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/memory/Kconfig

@@ -83,6 +83,15 @@ config FSL_IFC
 	bool
 	depends on FSL_SOC
 
+config JZ4780_NEMC
+	bool "Ingenic JZ4780 SoC NEMC driver"
+	default y
+	depends on MACH_JZ4780
+	help
+	  This driver is for the NAND/External Memory Controller (NEMC) in
+	  the Ingenic JZ4780. This controller is used to handle external
+	  memory devices such as NAND and SRAM.
+
 source "drivers/memory/tegra/Kconfig"
 
 endif

drivers/memory/Makefile

@@ -13,5 +13,6 @@ obj-$(CONFIG_FSL_CORENET_CF)	+= fsl-corenet-cf.o
 obj-$(CONFIG_FSL_IFC)		+= fsl_ifc.o
 obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
 obj-$(CONFIG_TEGRA20_MC)	+= tegra20-mc.o
+obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
 
 obj-$(CONFIG_TEGRA_MC)		+= tegra/

include/linux/jz4780-nemc.h

+/*
+ * JZ4780 NAND/external memory controller (NEMC)
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex@alex-smith.me.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __LINUX_JZ4780_NEMC_H__
+#define __LINUX_JZ4780_NEMC_H__
+
+#include <linux/types.h>
+
+struct device;
+
+/*
+ * Number of NEMC banks. Note that there are actually 6, but they are numbered
+ * from 1.
+ */
+#define JZ4780_NEMC_NUM_BANKS	7
+
+/**
+ * enum jz4780_nemc_bank_type - device types which can be connected to a bank
+ * @JZ4780_NEMC_BANK_SRAM: SRAM
+ * @JZ4780_NEMC_BANK_NAND: NAND
+ */
+enum jz4780_nemc_bank_type {
+	JZ4780_NEMC_BANK_SRAM,
+	JZ4780_NEMC_BANK_NAND,
+};
+
+extern unsigned int jz4780_nemc_num_banks(struct device *dev);
+
+extern void jz4780_nemc_set_type(struct device *dev, unsigned int bank,
+				 enum jz4780_nemc_bank_type type);
+extern void jz4780_nemc_assert(struct device *dev, unsigned int bank,
+			       bool assert);
+
+#endif /* __LINUX_JZ4780_NEMC_H__ */