[MTD] [NAND] Blackfin on-chip NAND Flash Controller driver

This is the driver for latest Blackfin on-chip nand flash controller

 - use nand_chip and mtd_info common nand driver interface
 - provide both PIO and dma operation
 - compiled with ezkit bf548 configuration
 - use hardware 1-bit ECC
 - tested with YAFFS2 and can mount YAFFS2 filesystem as rootfs

ChangeLog from try#1
 - use hweight32() instead of count_bits()
 - replace bf54x with bf5xx and BF54X with BF5XX
 - compare against plat->page_size in 2 cases when enable hardware ECC

ChangeLog from try#2
 - passed nand_test suites
 - use cpu_relax() instead of busy wait loop
 - some coding style issue pointed out by Andrew

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

include/asm-blackfin/mach-bf548/dma.h

@@ -55,6 +55,7 @@
 #define CH_SPORT3_RX		20
 #define CH_SPORT3_TX		21
 #define CH_SDH			22
+#define CH_NFC			22
 #define CH_SPI2			23
 
 #define CH_MEM_STREAM0_DEST	24

include/asm-blackfin/nand.h

@@ -0,0 +1,47 @@
+/* linux/include/asm-blackfin/nand.h
+ *
+ * Copyright (c) 2007 Analog Devices, Inc.
+ *	Bryan Wu <bryan.wu@analog.com>
+ *
+ * BF5XX - NAND flash controller platfrom_device info
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* struct bf5xx_nand_platform
+ *
+ * define a interface between platfrom board specific code and
+ * bf54x NFC driver.
+ *
+ * nr_partitions = number of partitions pointed to be partitoons (or zero)
+ * partitions	 = mtd partition list
+ */
+
+#define NFC_PG_SIZE_256		0
+#define NFC_PG_SIZE_512		1
+#define NFC_PG_SIZE_OFFSET	9
+
+#define NFC_NWIDTH_8		0
+#define NFC_NWIDTH_16		1
+#define NFC_NWIDTH_OFFSET	8
+
+#define NFC_RDDLY_OFFSET	4
+#define NFC_WRDLY_OFFSET	0
+
+#define NFC_STAT_NBUSY		1
+
+struct bf5xx_nand_platform {
+	/* NAND chip information */
+	unsigned short		page_size;
+	unsigned short		data_width;
+
+	/* RD/WR strobe delay timing information, all times in SCLK cycles */
+	unsigned short		rd_dly;
+	unsigned short		wr_dly;
+
+	/* NAND MTD partition information */
+	int                     nr_partitions;
+	struct mtd_partition    *partitions;
+};