MTD: NAND: JZ4740: Multi-bank support with autodetection

The platform data can now specify which external memory banks to probe
for NAND chips, and in which order. Banks that contain a NAND are used
and the other banks are freed.

Squashed version of development done in jz-2.6.38 branch.
Original patch by Lars-Peter Clausen with some bug fixes from me.
Thanks to Paul Cercueil for the initial autodetection patch.
Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3560/Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-jz4740/jz4740_nand.h

@@ -19,6 +19,8 @@
 #include <linux/mtd/nand.h>
 #include <linux/mtd/partitions.h>
 
+#define JZ_NAND_NUM_BANKS 4
+
 struct jz_nand_platform_data {
 	int			num_partitions;
 	struct mtd_partition	*partitions;
@@ -27,6 +29,8 @@ struct jz_nand_platform_data {
 
 	unsigned int busy_gpio;
 
+	unsigned char banks[JZ_NAND_NUM_BANKS];
+
 	void (*ident_callback)(struct platform_device *, struct nand_chip *,
 				struct mtd_partition **, int *num_partitions);
 };

arch/mips/jz4740/platform.c

@@ -157,11 +157,29 @@ static struct resource jz4740_nand_resources[] = {
 		.flags	= IORESOURCE_MEM,
 	},
 	{
-		.name	= "bank",
+		.name	= "bank1",
 		.start	= 0x18000000,
 		.end	= 0x180C0000 - 1,
 		.flags = IORESOURCE_MEM,
 	},
+	{
+		.name	= "bank2",
+		.start	= 0x14000000,
+		.end	= 0x140C0000 - 1,
+		.flags = IORESOURCE_MEM,
+	},
+	{
+		.name	= "bank3",
+		.start	= 0x0C000000,
+		.end	= 0x0C0C0000 - 1,
+		.flags = IORESOURCE_MEM,
+	},
+	{
+		.name	= "bank4",
+		.start	= 0x08000000,
+		.end	= 0x080C0000 - 1,
+		.flags = IORESOURCE_MEM,
+	},
 };
 
 struct platform_device jz4740_nand_device = {