mtd: add bcmring nand driver

Signed-off-by: Leo Hao Chen <leochen@broadcom.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

arch/arm/mach-bcmring/arch.c

@@ -76,9 +76,19 @@ static struct ctl_table bcmring_sysctl_reboot[] = {
 	{}
 };
 
+static struct resource nand_resource[] = {
+	[0] = {
+		.start = MM_ADDR_IO_NAND,
+		.end = MM_ADDR_IO_NAND + 0x1000 - 1,
+		.flags = IORESOURCE_MEM,
+	},
+};
+
 static struct platform_device nand_device = {
 	.name = "bcm-nand",
 	.id = -1,
+	.resource = nand_resource,
+	.num_resources	= ARRAY_SIZE(nand_resource),
 };
 
 static struct platform_device *devices[] __initdata = {

arch/arm/mach-bcmring/include/mach/reg_nand.h

+/*****************************************************************************
+* Copyright 2001 - 2008 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/*
+*
+*****************************************************************************
+*
+*  REG_NAND.h
+*
+*  PURPOSE:
+*
+*     This file contains definitions for the nand registers:
+*
+*  NOTES:
+*
+*****************************************************************************/
+
+#if !defined(__ASM_ARCH_REG_NAND_H)
+#define __ASM_ARCH_REG_NAND_H
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <csp/reg.h>
+#include <mach/reg_umi.h>
+
+/* ---- Constants and Types ---------------------------------------------- */
+
+#define HW_NAND_BASE       MM_IO_BASE_NAND	/* NAND Flash */
+
+/* DMA accesses by the bootstrap need hard nonvirtual addresses */
+#define REG_NAND_CMD            __REG16(HW_NAND_BASE + 0)
+#define REG_NAND_ADDR           __REG16(HW_NAND_BASE + 4)
+
+#define REG_NAND_PHYS_DATA16   (HW_NAND_BASE + 8)
+#define REG_NAND_PHYS_DATA8    (HW_NAND_BASE + 8)
+#define REG_NAND_DATA16         __REG16(REG_NAND_PHYS_DATA16)
+#define REG_NAND_DATA8          __REG8(REG_NAND_PHYS_DATA8)
+
+/* use appropriate offset to make sure it start at the 1K boundary */
+#define REG_NAND_PHYS_DATA_DMA   (HW_NAND_BASE + 0x400)
+#define REG_NAND_DATA_DMA         __REG32(REG_NAND_PHYS_DATA_DMA)
+
+/* Linux DMA requires physical address of the data register */
+#define REG_NAND_DATA16_PADDR    HW_IO_VIRT_TO_PHYS(REG_NAND_PHYS_DATA16)
+#define REG_NAND_DATA8_PADDR     HW_IO_VIRT_TO_PHYS(REG_NAND_PHYS_DATA8)
+#define REG_NAND_DATA_PADDR      HW_IO_VIRT_TO_PHYS(REG_NAND_PHYS_DATA_DMA)
+
+#define NAND_BUS_16BIT()        (0)
+#define NAND_BUS_8BIT()         (!NAND_BUS_16BIT())
+
+/* Register offsets */
+#define REG_NAND_CMD_OFFSET     (0)
+#define REG_NAND_ADDR_OFFSET    (4)
+#define REG_NAND_DATA8_OFFSET   (8)
+
+#endif

arch/arm/mach-bcmring/include/mach/reg_umi.h

+/*****************************************************************************
+* Copyright 2005 - 2008 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/*
+*
+*****************************************************************************
+*
+*  REG_UMI.h
+*
+*  PURPOSE:
+*
+*     This file contains definitions for the nand registers:
+*
+*  NOTES:
+*
+*****************************************************************************/
+
+#if !defined(__ASM_ARCH_REG_UMI_H)
+#define __ASM_ARCH_REG_UMI_H
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <csp/reg.h>
+#include <mach/csp/mm_io.h>
+
+/* ---- Constants and Types ---------------------------------------------- */
+
+/* Unified Memory Interface Ctrl Register */
+#define HW_UMI_BASE       MM_IO_BASE_UMI
+
+/* Flash bank 0 timing and control register */
+#define REG_UMI_FLASH0_TCR         __REG32(HW_UMI_BASE  + 0x00)
+/* Flash bank 1 timing and control register */
+#define REG_UMI_FLASH1_TCR         __REG32(HW_UMI_BASE  + 0x04)
+/* Flash bank 2 timing and control register */
+#define REG_UMI_FLASH2_TCR         __REG32(HW_UMI_BASE  + 0x08)
+/* MMD interface and control register */
+#define REG_UMI_MMD_ICR            __REG32(HW_UMI_BASE  + 0x0c)
+/* NAND timing and control register */
+#define REG_UMI_NAND_TCR           __REG32(HW_UMI_BASE  + 0x18)
+/* NAND ready/chip select register */
+#define REG_UMI_NAND_RCSR          __REG32(HW_UMI_BASE  + 0x1c)
+/* NAND ECC control & status register */
+#define REG_UMI_NAND_ECC_CSR       __REG32(HW_UMI_BASE  + 0x20)
+/* NAND ECC data register XXB2B1B0 */
+#define REG_UMI_NAND_ECC_DATA      __REG32(HW_UMI_BASE  + 0x24)
+/* BCH ECC Parameter N */
+#define REG_UMI_BCH_N              __REG32(HW_UMI_BASE  + 0x40)
+/* BCH ECC Parameter T */
+#define REG_UMI_BCH_K              __REG32(HW_UMI_BASE  + 0x44)
+/* BCH ECC Parameter K */
+#define REG_UMI_BCH_T              __REG32(HW_UMI_BASE  + 0x48)
+/* BCH ECC Contro Status */
+#define REG_UMI_BCH_CTRL_STATUS    __REG32(HW_UMI_BASE  + 0x4C)
+/* BCH WR ECC 31:0 */
+#define REG_UMI_BCH_WR_ECC_0       __REG32(HW_UMI_BASE  + 0x50)
+/* BCH WR ECC 63:32 */
+#define REG_UMI_BCH_WR_ECC_1       __REG32(HW_UMI_BASE  + 0x54)
+/* BCH WR ECC 95:64 */
+#define REG_UMI_BCH_WR_ECC_2       __REG32(HW_UMI_BASE  + 0x58)
+/* BCH WR ECC 127:96 */
+#define REG_UMI_BCH_WR_ECC_3       __REG32(HW_UMI_BASE  + 0x5c)
+/* BCH WR ECC 155:128 */
+#define REG_UMI_BCH_WR_ECC_4       __REG32(HW_UMI_BASE  + 0x60)
+/* BCH Read Error Location 1,0 */
+#define REG_UMI_BCH_RD_ERR_LOC_1_0 __REG32(HW_UMI_BASE  + 0x64)
+/* BCH Read Error Location 3,2 */
+#define REG_UMI_BCH_RD_ERR_LOC_3_2 __REG32(HW_UMI_BASE  + 0x68)
+/* BCH Read Error Location 5,4 */
+#define REG_UMI_BCH_RD_ERR_LOC_5_4 __REG32(HW_UMI_BASE  + 0x6c)
+/* BCH Read Error Location 7,6 */
+#define REG_UMI_BCH_RD_ERR_LOC_7_6 __REG32(HW_UMI_BASE  + 0x70)
+/* BCH Read Error Location 9,8 */
+#define REG_UMI_BCH_RD_ERR_LOC_9_8 __REG32(HW_UMI_BASE  + 0x74)
+/* BCH Read Error Location 11,10 */
+#define REG_UMI_BCH_RD_ERR_LOC_B_A __REG32(HW_UMI_BASE  + 0x78)
+
+/* REG_UMI_FLASH0/1/2_TCR, REG_UMI_SRAM0/1_TCR bits */
+/* Enable wait pin during burst write or read */
+#define REG_UMI_TCR_WAITEN              0x80000000
+/* Enable mem ctrlr to work iwth ext mem of lower freq than AHB clk */
+#define REG_UMI_TCR_LOWFREQ             0x40000000
+/* 1=synch write, 0=async write */
+#define REG_UMI_TCR_MEMTYPE_SYNCWRITE   0x20000000
+/* 1=synch read, 0=async read */
+#define REG_UMI_TCR_MEMTYPE_SYNCREAD    0x10000000
+/* 1=page mode read, 0=normal mode read */
+#define REG_UMI_TCR_MEMTYPE_PAGEREAD    0x08000000
+/* page size/burst size (wrap only) */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_MASK   0x07000000
+/* 4 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_4      0x00000000
+/* 8 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_8      0x01000000
+/* 16 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_16     0x02000000
+/* 32 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_32     0x03000000
+/* 64 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_64     0x04000000
+/* 128 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_128    0x05000000
+/* 256 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_256    0x06000000
+/* 512 word */
+#define REG_UMI_TCR_MEMTYPE_PGSZ_512    0x07000000
+/* Page read access cycle / Burst write latency (n+2 / n+1) */
+#define REG_UMI_TCR_TPRC_TWLC_MASK      0x00f80000
+/* Bus turnaround cycle (n) */
+#define REG_UMI_TCR_TBTA_MASK           0x00070000
+/* Write pulse width cycle (n+1) */
+#define REG_UMI_TCR_TWP_MASK            0x0000f800
+/* Write recovery cycle (n+1) */
+#define REG_UMI_TCR_TWR_MASK            0x00000600
+/* Write address setup cycle (n+1) */
+#define REG_UMI_TCR_TAS_MASK            0x00000180
+/* Output enable delay cycle (n) */
+#define REG_UMI_TCR_TOE_MASK            0x00000060
+/* Read access cycle / Burst read latency (n+2 / n+1) */
+#define REG_UMI_TCR_TRC_TLC_MASK        0x0000001f
+
+/* REG_UMI_MMD_ICR bits */
+/* Flash write protection pin control */
+#define REG_UMI_MMD_ICR_FLASH_WP            0x8000
+/* Extend hold time for sram0, sram1 csn (39 MHz operation) */
+#define REG_UMI_MMD_ICR_XHCS                0x4000
+/* Enable SDRAM 2 interface control */
+#define REG_UMI_MMD_ICR_SDRAM2EN            0x2000
+/* Enable merge of flash banks 0/1 to 512 MBit bank */
+#define REG_UMI_MMD_ICR_INST512             0x1000
+/* Enable merge of flash banks 1/2 to 512 MBit bank */
+#define REG_UMI_MMD_ICR_DATA512             0x0800
+/* Enable SDRAM interface control */
+#define REG_UMI_MMD_ICR_SDRAMEN             0x0400
+/* Polarity of busy state of Burst Wait Signal */
+#define REG_UMI_MMD_ICR_WAITPOL             0x0200
+/* Enable burst clock stopped when not accessing external burst flash/sram */
+#define REG_UMI_MMD_ICR_BCLKSTOP            0x0100
+/* Enable the peri1_csn to replace flash1_csn in 512 Mb flash mode */
+#define REG_UMI_MMD_ICR_PERI1EN             0x0080
+/* Enable the peri2_csn to replace sdram_csn */
+#define REG_UMI_MMD_ICR_PERI2EN             0x0040
+/* Enable the peri3_csn to replace sdram2_csn */
+#define REG_UMI_MMD_ICR_PERI3EN             0x0020
+/* Enable sram bank1 for H/W controlled MRS */
+#define REG_UMI_MMD_ICR_MRSB1               0x0010
+/* Enable sram bank0 for H/W controlled MRS */
+#define REG_UMI_MMD_ICR_MRSB0               0x0008
+/* Polarity for assert3ed state of H/W controlled MRS */
+#define REG_UMI_MMD_ICR_MRSPOL              0x0004
+/* 0: S/W controllable ZZ/MRS/CRE/P-Mode pin */
+/* 1: H/W controlled ZZ/MRS/CRE/P-Mode, same timing as CS */
+#define REG_UMI_MMD_ICR_MRSMODE             0x0002
+/* MRS state for S/W controlled mode */
+#define REG_UMI_MMD_ICR_MRSSTATE            0x0001
+
+/* REG_UMI_NAND_TCR bits */
+/* Enable software to control CS */
+#define REG_UMI_NAND_TCR_CS_SWCTRL          0x80000000
+/* 16-bit nand wordsize if set */
+#define REG_UMI_NAND_TCR_WORD16             0x40000000
+/* Bus turnaround cycle (n) */
+#define REG_UMI_NAND_TCR_TBTA_MASK          0x00070000
+/* Write pulse width cycle (n+1) */
+#define REG_UMI_NAND_TCR_TWP_MASK           0x0000f800
+/* Write recovery cycle (n+1) */
+#define REG_UMI_NAND_TCR_TWR_MASK           0x00000600
+/* Write address setup cycle (n+1) */
+#define REG_UMI_NAND_TCR_TAS_MASK           0x00000180
+/* Output enable delay cycle (n) */
+#define REG_UMI_NAND_TCR_TOE_MASK           0x00000060
+/* Read access cycle (n+2) */
+#define REG_UMI_NAND_TCR_TRC_TLC_MASK       0x0000001f
+
+/* REG_UMI_NAND_RCSR bits */
+/* Status: Ready=1, Busy=0 */
+#define REG_UMI_NAND_RCSR_RDY               0x02
+/* Keep CS asserted during operation */
+#define REG_UMI_NAND_RCSR_CS_ASSERTED       0x01
+
+/* REG_UMI_NAND_ECC_CSR bits */
+/* Interrupt status - read-only */
+#define REG_UMI_NAND_ECC_CSR_NANDINT        0x80000000
+/* Read: Status of ECC done, Write: clear ECC interrupt */
+#define REG_UMI_NAND_ECC_CSR_ECCINT_RAW     0x00800000
+/* Read: Status of R/B, Write: clear R/B interrupt */
+#define REG_UMI_NAND_ECC_CSR_RBINT_RAW      0x00400000
+/* 1 = Enable ECC Interrupt */
+#define REG_UMI_NAND_ECC_CSR_ECCINT_ENABLE  0x00008000
+/* 1 = Assert interrupt at rising edge of R/B_ */
+#define REG_UMI_NAND_ECC_CSR_RBINT_ENABLE   0x00004000
+/* Calculate ECC by 0=512 bytes, 1=256 bytes */
+#define REG_UMI_NAND_ECC_CSR_256BYTE        0x00000080
+/* Enable ECC in hardware */
+#define REG_UMI_NAND_ECC_CSR_ECC_ENABLE     0x00000001
+
+/* REG_UMI_BCH_CTRL_STATUS bits */
+/* Shift to Indicate Number of correctable errors detected */
+#define REG_UMI_BCH_CTRL_STATUS_NB_CORR_ERROR_SHIFT 20
+/* Indicate Number of correctable errors detected */
+#define REG_UMI_BCH_CTRL_STATUS_NB_CORR_ERROR 0x00F00000
+/* Indicate Errors detected during read but uncorrectable */
+#define REG_UMI_BCH_CTRL_STATUS_UNCORR_ERR    0x00080000
+/* Indicate Errors detected during read and are correctable */
+#define REG_UMI_BCH_CTRL_STATUS_CORR_ERR      0x00040000
+/* Flag indicates BCH's ECC status of read process are valid */
+#define REG_UMI_BCH_CTRL_STATUS_RD_ECC_VALID  0x00020000
+/* Flag indicates BCH's ECC status of write process are valid */
+#define REG_UMI_BCH_CTRL_STATUS_WR_ECC_VALID  0x00010000
+/* Pause ECC calculation */
+#define REG_UMI_BCH_CTRL_STATUS_PAUSE_ECC_DEC 0x00000010
+/* Enable Interrupt */
+#define REG_UMI_BCH_CTRL_STATUS_INT_EN        0x00000004
+/* Enable ECC during read */
+#define REG_UMI_BCH_CTRL_STATUS_ECC_RD_EN     0x00000002
+/* Enable ECC during write */
+#define REG_UMI_BCH_CTRL_STATUS_ECC_WR_EN     0x00000001
+/* Mask for location */
+#define REG_UMI_BCH_ERR_LOC_MASK              0x00001FFF
+/* location within a byte */
+#define REG_UMI_BCH_ERR_LOC_BYTE              0x00000007
+/* location within a word */
+#define REG_UMI_BCH_ERR_LOC_WORD              0x00000018
+/* location within a page (512 byte) */
+#define REG_UMI_BCH_ERR_LOC_PAGE              0x00001FE0
+#define REG_UMI_BCH_ERR_LOC_ADDR(index)     (__REG32(HW_UMI_BASE + 0x64 + (index / 2)*4) >> ((index % 2) * 16))
+#endif

drivers/mtd/nand/Kconfig

@@ -203,6 +203,22 @@ config MTD_NAND_S3C2410_CLKSTOP
 	  when the is NAND chip selected or released, but will save
 	  approximately 5mA of power when there is nothing happening.
 
+config MTD_NAND_BCM_UMI
+	tristate "NAND Flash support for BCM Reference Boards"
+	depends on ARCH_BCMRING && MTD_NAND
+	help
+	  This enables the NAND flash controller on the BCM UMI block.
+
+	  No board specfic support is done by this driver, each board
+	  must advertise a platform_device for the driver to attach.
+
+config MTD_NAND_BCM_UMI_HWCS
+	bool "BCM UMI NAND Hardware CS"
+	depends on MTD_NAND_BCM_UMI
+	help
+	  Enable the use of the BCM UMI block's internal CS using NAND.
+	  This should only be used if you know the external NAND CS can toggle.
+
 config MTD_NAND_DISKONCHIP
 	tristate "DiskOnChip 2000, Millennium and Millennium Plus (NAND reimplementation) (EXPERIMENTAL)"
 	depends on EXPERIMENTAL

drivers/mtd/nand/Makefile

@@ -42,5 +42,6 @@ obj-$(CONFIG_MTD_NAND_SOCRATES)		+= socrates_nand.o
 obj-$(CONFIG_MTD_NAND_TXX9NDFMC)	+= txx9ndfmc.o
 obj-$(CONFIG_MTD_NAND_W90P910)		+= w90p910_nand.o
 obj-$(CONFIG_MTD_NAND_NOMADIK)		+= nomadik_nand.o
+obj-$(CONFIG_MTD_NAND_BCM_UMI)		+= bcm_umi_nand.o nand_bcm_umi.o
 
 nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/bcm_umi_bch.c

+/*****************************************************************************
+* Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/* ---- Include Files ---------------------------------------------------- */
+#include "nand_bcm_umi.h"
+
+/* ---- External Variable Declarations ----------------------------------- */
+/* ---- External Function Prototypes ------------------------------------- */
+/* ---- Public Variables ------------------------------------------------- */
+/* ---- Private Constants and Types -------------------------------------- */
+
+/* ---- Private Function Prototypes -------------------------------------- */
+static int bcm_umi_bch_read_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, uint8_t *buf, int page);
+static void bcm_umi_bch_write_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, const uint8_t *buf);
+
+/* ---- Private Variables ------------------------------------------------ */
+
+/*
+** nand_hw_eccoob
+** New oob placement block for use with hardware ecc generation.
+*/
+static struct nand_ecclayout nand_hw_eccoob_512 = {
+	/* Reserve 5 for BI indicator */
+	.oobfree = {
+#if (NAND_ECC_NUM_BYTES > 3)
+		    {.offset = 0, .length = 2}
+#else
+		    {.offset = 0, .length = 5},
+		    {.offset = 6, .length = 7}
+#endif
+		    }
+};
+
+/*
+** We treat the OOB for a 2K page as if it were 4 512 byte oobs,
+** except the BI is at byte 0.
+*/
+static struct nand_ecclayout nand_hw_eccoob_2048 = {
+	/* Reserve 0 as BI indicator */
+	.oobfree = {
+#if (NAND_ECC_NUM_BYTES > 10)
+		    {.offset = 1, .length = 2},
+#elif (NAND_ECC_NUM_BYTES > 7)
+		    {.offset = 1, .length = 5},
+		    {.offset = 16, .length = 6},
+		    {.offset = 32, .length = 6},
+		    {.offset = 48, .length = 6}
+#else
+		    {.offset = 1, .length = 8},
+		    {.offset = 16, .length = 9},
+		    {.offset = 32, .length = 9},
+		    {.offset = 48, .length = 9}
+#endif
+		    }
+};
+
+/* We treat the OOB for a 4K page as if it were 8 512 byte oobs,
+ * except the BI is at byte 0. */
+static struct nand_ecclayout nand_hw_eccoob_4096 = {
+	/* Reserve 0 as BI indicator */
+	.oobfree = {
+#if (NAND_ECC_NUM_BYTES > 10)
+		    {.offset = 1, .length = 2},
+		    {.offset = 16, .length = 3},
+		    {.offset = 32, .length = 3},
+		    {.offset = 48, .length = 3},
+		    {.offset = 64, .length = 3},
+		    {.offset = 80, .length = 3},
+		    {.offset = 96, .length = 3},
+		    {.offset = 112, .length = 3}
+#else
+		    {.offset = 1, .length = 5},
+		    {.offset = 16, .length = 6},
+		    {.offset = 32, .length = 6},
+		    {.offset = 48, .length = 6},
+		    {.offset = 64, .length = 6},
+		    {.offset = 80, .length = 6},
+		    {.offset = 96, .length = 6},
+		    {.offset = 112, .length = 6}
+#endif
+		    }
+};
+
+/* ---- Private Functions ------------------------------------------------ */
+/* ==== Public Functions ================================================= */
+
+/****************************************************************************
+*
+*  bcm_umi_bch_read_page_hwecc - hardware ecc based page read function
+*  @mtd:	mtd info structure
+*  @chip:	nand chip info structure
+*  @buf:	buffer to store read data
+*
+***************************************************************************/
+static int bcm_umi_bch_read_page_hwecc(struct mtd_info *mtd,
+				       struct nand_chip *chip, uint8_t * buf,
+						 int page)
+{
+	int sectorIdx = 0;
+	int eccsize = chip->ecc.size;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *datap = buf;
+	uint8_t eccCalc[NAND_ECC_NUM_BYTES];
+	int sectorOobSize = mtd->oobsize / eccsteps;
+	int stat;
+
+	for (sectorIdx = 0; sectorIdx < eccsteps;
+			sectorIdx++, datap += eccsize) {
+		if (sectorIdx > 0) {
+			/* Seek to page location within sector */
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, sectorIdx * eccsize,
+				      -1);
+		}
+
+		/* Enable hardware ECC before reading the buf */
+		nand_bcm_umi_bch_enable_read_hwecc();
+
+		/* Read in data */
+		bcm_umi_nand_read_buf(mtd, datap, eccsize);
+
+		/* Pause hardware ECC after reading the buf */
+		nand_bcm_umi_bch_pause_read_ecc_calc();
+
+		/* Read the OOB ECC */
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
+			      mtd->writesize + sectorIdx * sectorOobSize, -1);
+		nand_bcm_umi_bch_read_oobEcc(mtd->writesize, eccCalc,
+					     NAND_ECC_NUM_BYTES,
+					     chip->oob_poi +
+					     sectorIdx * sectorOobSize);
+
+		/* Correct any ECC detected errors */
+		stat =
+		    nand_bcm_umi_bch_correct_page(datap, eccCalc,
+						  NAND_ECC_NUM_BYTES);
+
+		/* Update Stats */
+		if (stat < 0) {
+#if defined(NAND_BCM_UMI_DEBUG)
+			printk(KERN_WARNING "%s uncorr_err sectorIdx=%d\n",
+			       __func__, sectorIdx);
+			printk(KERN_WARNING
+			       "%s data %02x %02x %02x %02x "
+					 "%02x %02x %02x %02x\n",
+			       __func__, datap[0], datap[1], datap[2], datap[3],
+			       datap[4], datap[5], datap[6], datap[7]);
+			printk(KERN_WARNING
+			       "%s ecc  %02x %02x %02x %02x "
+					 "%02x %02x %02x %02x %02x %02x "
+					 "%02x %02x %02x\n",
+			       __func__, eccCalc[0], eccCalc[1], eccCalc[2],
+			       eccCalc[3], eccCalc[4], eccCalc[5], eccCalc[6],
+			       eccCalc[7], eccCalc[8], eccCalc[9], eccCalc[10],
+			       eccCalc[11], eccCalc[12]);
+			BUG();
+#endif
+			mtd->ecc_stats.failed++;
+		} else {
+#if defined(NAND_BCM_UMI_DEBUG)
+			if (stat > 0) {
+				printk(KERN_INFO
+				       "%s %d correctable_errors detected\n",
+				       __func__, stat);
+			}
+#endif
+			mtd->ecc_stats.corrected += stat;
+		}
+	}
+	return 0;
+}
+
+/****************************************************************************
+*
+*  bcm_umi_bch_write_page_hwecc - hardware ecc based page write function
+*  @mtd:	mtd info structure
+*  @chip:	nand chip info structure
+*  @buf:	data buffer
+*
+***************************************************************************/
+static void bcm_umi_bch_write_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, const uint8_t *buf)
+{
+	int sectorIdx = 0;
+	int eccsize = chip->ecc.size;
+	int eccsteps = chip->ecc.steps;
+	const uint8_t *datap = buf;
+	uint8_t *oobp = chip->oob_poi;
+	int sectorOobSize = mtd->oobsize / eccsteps;
+
+	for (sectorIdx = 0; sectorIdx < eccsteps;
+	     sectorIdx++, datap += eccsize, oobp += sectorOobSize) {
+		/* Enable hardware ECC before writing the buf */
+		nand_bcm_umi_bch_enable_write_hwecc();
+		bcm_umi_nand_write_buf(mtd, datap, eccsize);
+		nand_bcm_umi_bch_write_oobEcc(mtd->writesize, oobp,
+					      NAND_ECC_NUM_BYTES);
+	}
+
+	bcm_umi_nand_write_buf(mtd, chip->oob_poi, mtd->oobsize);
+}

drivers/mtd/nand/bcm_umi_nand.c

+/*****************************************************************************
+* Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/mach-types.h>
+#include <asm/system.h>
+
+#include <mach/reg_nand.h>
+#include <mach/reg_umi.h>
+
+#include "nand_bcm_umi.h"
+
+#include <mach/memory_settings.h>
+
+#define USE_DMA 1
+#include <mach/dma.h>
+#include <linux/dma-mapping.h>
+#include <linux/completion.h>
+
+/* ---- External Variable Declarations ----------------------------------- */
+/* ---- External Function Prototypes ------------------------------------- */
+/* ---- Public Variables ------------------------------------------------- */
+/* ---- Private Constants and Types -------------------------------------- */
+static const __devinitconst char gBanner[] = KERN_INFO \
+	"BCM UMI MTD NAND Driver: 1.00\n";
+
+#ifdef CONFIG_MTD_PARTITIONS
+const char *part_probes[] = { "cmdlinepart", NULL };
+#endif
+
+#if NAND_ECC_BCH
+static uint8_t scan_ff_pattern[] = { 0xff };
+
+static struct nand_bbt_descr largepage_bbt = {
+	.options = 0,
+	.offs = 0,
+	.len = 1,
+	.pattern = scan_ff_pattern
+};
+#endif
+
+/*
+** Preallocate a buffer to avoid having to do this every dma operation.
+** This is the size of the preallocated coherent DMA buffer.
+*/
+#if USE_DMA
+#define DMA_MIN_BUFLEN	512
+#define DMA_MAX_BUFLEN	PAGE_SIZE
+#define USE_DIRECT_IO(len)	(((len) < DMA_MIN_BUFLEN) || \
+	((len) > DMA_MAX_BUFLEN))
+
+/*
+ * The current NAND data space goes from 0x80001900 to 0x80001FFF,
+ * which is only 0x700 = 1792 bytes long. This is too small for 2K, 4K page
+ * size NAND flash. Need to break the DMA down to multiple 1Ks.
+ *
+ * Need to make sure REG_NAND_DATA_PADDR + DMA_MAX_LEN < 0x80002000
+ */
+#define DMA_MAX_LEN             1024
+
+#else /* !USE_DMA */
+#define DMA_MIN_BUFLEN          0
+#define DMA_MAX_BUFLEN          0
+#define USE_DIRECT_IO(len)      1
+#endif
+/* ---- Private Function Prototypes -------------------------------------- */
+static void bcm_umi_nand_read_buf(struct mtd_info *mtd, u_char * buf, int len);
+static void bcm_umi_nand_write_buf(struct mtd_info *mtd, const u_char * buf,
+				   int len);
+
+/* ---- Private Variables ------------------------------------------------ */
+static struct mtd_info *board_mtd;
+static void __iomem *bcm_umi_io_base;
+static void *virtPtr;
+static dma_addr_t physPtr;
+static struct completion nand_comp;
+
+/* ---- Private Functions ------------------------------------------------ */
+#if NAND_ECC_BCH
+#include "bcm_umi_bch.c"
+#else
+#include "bcm_umi_hamming.c"
+#endif
+
+#if USE_DMA
+
+/* Handler called when the DMA finishes. */
+static void nand_dma_handler(DMA_Device_t dev, int reason, void *userData)
+{
+	complete(&nand_comp);
+}
+
+static int nand_dma_init(void)
+{
+	int rc;
+
+	rc = dma_set_device_handler(DMA_DEVICE_NAND_MEM_TO_MEM,
+		nand_dma_handler, NULL);
+	if (rc != 0) {
+		printk(KERN_ERR "dma_set_device_handler failed: %d\n", rc);
+		return rc;
+	}
+
+	virtPtr =
+	    dma_alloc_coherent(NULL, DMA_MAX_BUFLEN, &physPtr, GFP_KERNEL);
+	if (virtPtr == NULL) {
+		printk(KERN_ERR "NAND - Failed to allocate memory for DMA buffer\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void nand_dma_term(void)
+{
+	if (virtPtr != NULL)
+		dma_free_coherent(NULL, DMA_MAX_BUFLEN, virtPtr, physPtr);
+}
+
+static void nand_dma_read(void *buf, int len)
+{
+	int offset = 0;
+	int tmp_len = 0;
+	int len_left = len;
+	DMA_Handle_t hndl;
+
+	if (virtPtr == NULL)
+		panic("nand_dma_read: virtPtr == NULL\n");
+
+	if ((void *)physPtr == NULL)
+		panic("nand_dma_read: physPtr == NULL\n");
+
+	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
+	if (hndl < 0) {
+		printk(KERN_ERR
+		       "nand_dma_read: unable to allocate dma channel: %d\n",
+		       (int)hndl);
+		panic("\n");
+	}
+
+	while (len_left > 0) {
+		if (len_left > DMA_MAX_LEN) {
+			tmp_len = DMA_MAX_LEN;
+			len_left -= DMA_MAX_LEN;
+		} else {
+			tmp_len = len_left;
+			len_left = 0;
+		}
+
+		init_completion(&nand_comp);
+		dma_transfer_mem_to_mem(hndl, REG_NAND_DATA_PADDR,
+					physPtr + offset, tmp_len);
+		wait_for_completion(&nand_comp);
+
+		offset += tmp_len;
+	}
+
+	dma_free_channel(hndl);
+
+	if (buf != NULL)
+		memcpy(buf, virtPtr, len);
+}
+
+static void nand_dma_write(const void *buf, int len)
+{
+	int offset = 0;
+	int tmp_len = 0;
+	int len_left = len;
+	DMA_Handle_t hndl;
+
+	if (buf == NULL)
+		panic("nand_dma_write: buf == NULL\n");
+
+	if (virtPtr == NULL)
+		panic("nand_dma_write: virtPtr == NULL\n");
+
+	if ((void *)physPtr == NULL)
+		panic("nand_dma_write: physPtr == NULL\n");
+
+	memcpy(virtPtr, buf, len);
+
+
+	hndl = dma_request_channel(DMA_DEVICE_NAND_MEM_TO_MEM);
+	if (hndl < 0) {
+		printk(KERN_ERR
+		       "nand_dma_write: unable to allocate dma channel: %d\n",
+		       (int)hndl);
+		panic("\n");
+	}
+
+	while (len_left > 0) {
+		if (len_left > DMA_MAX_LEN) {
+			tmp_len = DMA_MAX_LEN;
+			len_left -= DMA_MAX_LEN;
+		} else {
+			tmp_len = len_left;
+			len_left = 0;
+		}
+
+		init_completion(&nand_comp);
+		dma_transfer_mem_to_mem(hndl, physPtr + offset,
+					REG_NAND_DATA_PADDR, tmp_len);
+		wait_for_completion(&nand_comp);
+
+		offset += tmp_len;
+	}
+
+	dma_free_channel(hndl);
+}
+
+#endif
+
+static int nand_dev_ready(struct mtd_info *mtd)
+{
+	return nand_bcm_umi_dev_ready();
+}
+
+/****************************************************************************
+*
+*  bcm_umi_nand_inithw
+*
+*   This routine does the necessary hardware (board-specific)
+*   initializations.  This includes setting up the timings, etc.
+*
+***************************************************************************/
+int bcm_umi_nand_inithw(void)
+{
+	/* Configure nand timing parameters */
+	REG_UMI_NAND_TCR &= ~0x7ffff;
+	REG_UMI_NAND_TCR |= HW_CFG_NAND_TCR;
+
+#if !defined(CONFIG_MTD_NAND_BCM_UMI_HWCS)
+	/* enable software control of CS */
+	REG_UMI_NAND_TCR |= REG_UMI_NAND_TCR_CS_SWCTRL;
+#endif
+
+	/* keep NAND chip select asserted */
+	REG_UMI_NAND_RCSR |= REG_UMI_NAND_RCSR_CS_ASSERTED;
+
+	REG_UMI_NAND_TCR &= ~REG_UMI_NAND_TCR_WORD16;
+	/* enable writes to flash */
+	REG_UMI_MMD_ICR |= REG_UMI_MMD_ICR_FLASH_WP;
+
+	writel(NAND_CMD_RESET, bcm_umi_io_base + REG_NAND_CMD_OFFSET);
+	nand_bcm_umi_wait_till_ready();
+
+#if NAND_ECC_BCH
+	nand_bcm_umi_bch_config_ecc(NAND_ECC_NUM_BYTES);
+#endif
+
+	return 0;
+}
+
+/* Used to turn latch the proper register for access. */
+static void bcm_umi_nand_hwcontrol(struct mtd_info *mtd, int cmd,
+				   unsigned int ctrl)
+{
+	/* send command to hardware */
+	struct nand_chip *chip = mtd->priv;
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if (ctrl & NAND_CLE) {
+			chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_CMD_OFFSET;
+			goto CMD;
+		}
+		if (ctrl & NAND_ALE) {
+			chip->IO_ADDR_W =
+			    bcm_umi_io_base + REG_NAND_ADDR_OFFSET;
+			goto CMD;
+		}
+		chip->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
+	}
+
+CMD:
+	/* Send command to chip directly */
+	if (cmd != NAND_CMD_NONE)
+		writeb(cmd, chip->IO_ADDR_W);
+}
+
+static void bcm_umi_nand_write_buf(struct mtd_info *mtd, const u_char * buf,
+				   int len)
+{
+	if (USE_DIRECT_IO(len)) {
+		/* Do it the old way if the buffer is small or too large.
+		 * Probably quicker than starting and checking dma. */
+		int i;
+		struct nand_chip *this = mtd->priv;
+
+		for (i = 0; i < len; i++)
+			writeb(buf[i], this->IO_ADDR_W);
+	}
+#if USE_DMA
+	else
+		nand_dma_write(buf, len);
+#endif
+}
+
+static void bcm_umi_nand_read_buf(struct mtd_info *mtd, u_char * buf, int len)
+{
+	if (USE_DIRECT_IO(len)) {
+		int i;
+		struct nand_chip *this = mtd->priv;
+
+		for (i = 0; i < len; i++)
+			buf[i] = readb(this->IO_ADDR_R);
+	}
+#if USE_DMA
+	else
+		nand_dma_read(buf, len);
+#endif
+}
+
+static uint8_t readbackbuf[NAND_MAX_PAGESIZE];
+static int bcm_umi_nand_verify_buf(struct mtd_info *mtd, const u_char * buf,
+				   int len)
+{
+	/*
+	 * Try to readback page with ECC correction. This is necessary
+	 * for MLC parts which may have permanently stuck bits.
+	 */
+	struct nand_chip *chip = mtd->priv;
+	int ret = chip->ecc.read_page(mtd, chip, readbackbuf, 0);
+	if (ret < 0)
+		return -EFAULT;
+	else {
+		if (memcmp(readbackbuf, buf, len) == 0)
+			return 0;
+
+		return -EFAULT;
+	}
+	return 0;
+}
+
+static int __devinit bcm_umi_nand_probe(struct platform_device *pdev)
+{
+	struct nand_chip *this;
+	struct resource *r;
+	int err = 0;
+
+	printk(gBanner);
+
+	/* Allocate memory for MTD device structure and private data */
+	board_mtd =
+	    kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip),
+		    GFP_KERNEL);
+	if (!board_mtd) {
+		printk(KERN_WARNING
+		       "Unable to allocate NAND MTD device structure.\n");
+		return -ENOMEM;
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!r)
+		return -ENXIO;
+
+	/* map physical adress */
+	bcm_umi_io_base = ioremap(r->start, r->end - r->start + 1);
+
+	if (!bcm_umi_io_base) {
+		printk(KERN_ERR "ioremap to access BCM UMI NAND chip failed\n");
+		kfree(board_mtd);
+		return -EIO;
+	}
+
+	/* Get pointer to private data */
+	this = (struct nand_chip *)(&board_mtd[1]);
+
+	/* Initialize structures */
+	memset((char *)board_mtd, 0, sizeof(struct mtd_info));
+	memset((char *)this, 0, sizeof(struct nand_chip));
+
+	/* Link the private data with the MTD structure */
+	board_mtd->priv = this;
+
+	/* Initialize the NAND hardware.  */
+	if (bcm_umi_nand_inithw() < 0) {
+		printk(KERN_ERR "BCM UMI NAND chip could not be initialized\n");
+		iounmap(bcm_umi_io_base);
+		kfree(board_mtd);
+		return -EIO;
+	}
+
+	/* Set address of NAND IO lines */
+	this->IO_ADDR_W = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
+	this->IO_ADDR_R = bcm_umi_io_base + REG_NAND_DATA8_OFFSET;
+
+	/* Set command delay time, see datasheet for correct value */
+	this->chip_delay = 0;
+	/* Assign the device ready function, if available */
+	this->dev_ready = nand_dev_ready;
+	this->options = 0;
+
+	this->write_buf = bcm_umi_nand_write_buf;
+	this->read_buf = bcm_umi_nand_read_buf;
+	this->verify_buf = bcm_umi_nand_verify_buf;
+
+	this->cmd_ctrl = bcm_umi_nand_hwcontrol;
+	this->ecc.mode = NAND_ECC_HW;
+	this->ecc.size = 512;
+	this->ecc.bytes = NAND_ECC_NUM_BYTES;
+#if NAND_ECC_BCH
+	this->ecc.read_page = bcm_umi_bch_read_page_hwecc;
+	this->ecc.write_page = bcm_umi_bch_write_page_hwecc;
+#else
+	this->ecc.correct = nand_correct_data512;
+	this->ecc.calculate = bcm_umi_hamming_get_hw_ecc;
+	this->ecc.hwctl = bcm_umi_hamming_enable_hwecc;
+#endif
+
+#if USE_DMA
+	err = nand_dma_init();
+	if (err != 0)
+		return err;
+#endif
+
+	/* Figure out the size of the device that we have.
+	 * We need to do this to figure out which ECC
+	 * layout we'll be using.
+	 */
+
+	err = nand_scan_ident(board_mtd, 1);
+	if (err) {
+		printk(KERN_ERR "nand_scan failed: %d\n", err);
+		iounmap(bcm_umi_io_base);
+		kfree(board_mtd);
+		return err;
+	}
+
+	/* Now that we know the nand size, we can setup the ECC layout */
+
+	switch (board_mtd->writesize) {	/* writesize is the pagesize */
+	case 4096:
+		this->ecc.layout = &nand_hw_eccoob_4096;
+		break;
+	case 2048:
+		this->ecc.layout = &nand_hw_eccoob_2048;
+		break;
+	case 512:
+		this->ecc.layout = &nand_hw_eccoob_512;
+		break;
+	default:
+		{
+			printk(KERN_ERR "NAND - Unrecognized pagesize: %d\n",
+					 board_mtd->writesize);
+			return -EINVAL;
+		}
+	}
+
+#if NAND_ECC_BCH
+	if (board_mtd->writesize > 512) {
+		if (this->options & NAND_USE_FLASH_BBT)
+			largepage_bbt.options = NAND_BBT_SCAN2NDPAGE;
+		this->badblock_pattern = &largepage_bbt;
+	}
+#endif
+
+	/* Now finish off the scan, now that ecc.layout has been initialized. */
+
+	err = nand_scan_tail(board_mtd);
+	if (err) {
+		printk(KERN_ERR "nand_scan failed: %d\n", err);
+		iounmap(bcm_umi_io_base);
+		kfree(board_mtd);
+		return err;
+	}
+
+	/* Register the partitions */
+	{
+		int nr_partitions;
+		struct mtd_partition *partition_info;
+
+		board_mtd->name = "bcm_umi-nand";
+		nr_partitions =
+		    parse_mtd_partitions(board_mtd, part_probes,
+					 &partition_info, 0);
+
+		if (nr_partitions <= 0) {
+			printk(KERN_ERR "BCM UMI NAND: Too few partitions - %d\n",
+			       nr_partitions);
+			iounmap(bcm_umi_io_base);
+			kfree(board_mtd);
+			return -EIO;
+		}
+		add_mtd_partitions(board_mtd, partition_info, nr_partitions);
+	}
+
+	/* Return happy */
+	return 0;
+}
+
+static int bcm_umi_nand_remove(struct platform_device *pdev)
+{
+#if USE_DMA
+	nand_dma_term();
+#endif
+
+	/* Release resources, unregister device */
+	nand_release(board_mtd);
+
+	/* unmap physical adress */
+	iounmap(bcm_umi_io_base);
+
+	/* Free the MTD device structure */
+	kfree(board_mtd);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int bcm_umi_nand_suspend(struct platform_device *pdev,
+				pm_message_t state)
+{
+	printk(KERN_ERR "MTD NAND suspend is being called\n");
+	return 0;
+}
+
+static int bcm_umi_nand_resume(struct platform_device *pdev)
+{
+	printk(KERN_ERR "MTD NAND resume is being called\n");
+	return 0;
+}
+#else
+#define bcm_umi_nand_suspend   NULL
+#define bcm_umi_nand_resume    NULL
+#endif
+
+static struct platform_driver nand_driver = {
+	.driver = {
+		   .name = "bcm-nand",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = bcm_umi_nand_probe,
+	.remove = bcm_umi_nand_remove,
+	.suspend = bcm_umi_nand_suspend,
+	.resume = bcm_umi_nand_resume,
+};
+
+static int __init nand_init(void)
+{
+	return platform_driver_register(&nand_driver);
+}
+
+static void __exit nand_exit(void)
+{
+	platform_driver_unregister(&nand_driver);
+}
+
+module_init(nand_init);
+module_exit(nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("BCM UMI MTD NAND driver");

drivers/mtd/nand/nand_bcm_umi.c

+/*****************************************************************************
+* Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <mach/reg_umi.h>
+#include "nand_bcm_umi.h"
+#ifdef BOOT0_BUILD
+#include <uart.h>
+#endif
+
+/* ---- External Variable Declarations ----------------------------------- */
+/* ---- External Function Prototypes ------------------------------------- */
+/* ---- Public Variables ------------------------------------------------- */
+/* ---- Private Constants and Types -------------------------------------- */
+/* ---- Private Function Prototypes -------------------------------------- */
+/* ---- Private Variables ------------------------------------------------ */
+/* ---- Private Functions ------------------------------------------------ */
+
+#if NAND_ECC_BCH
+/****************************************************************************
+*  nand_bch_ecc_flip_bit - Routine to flip an errored bit
+*
+*  PURPOSE:
+*     This is a helper routine that flips the bit (0 -> 1 or 1 -> 0) of the
+*     errored bit specified
+*
+*  PARAMETERS:
+*     datap - Container that holds the 512 byte data
+*     errorLocation - Location of the bit that needs to be flipped
+*
+*  RETURNS:
+*     None
+****************************************************************************/
+static void nand_bcm_umi_bch_ecc_flip_bit(uint8_t *datap, int errorLocation)
+{
+	int locWithinAByte = (errorLocation & REG_UMI_BCH_ERR_LOC_BYTE) >> 0;
+	int locWithinAWord = (errorLocation & REG_UMI_BCH_ERR_LOC_WORD) >> 3;
+	int locWithinAPage = (errorLocation & REG_UMI_BCH_ERR_LOC_PAGE) >> 5;
+
+	uint8_t errorByte = 0;
+	uint8_t byteMask = 1 << locWithinAByte;
+
+	/* BCH uses big endian, need to change the location
+	 * bits to little endian */
+	locWithinAWord = 3 - locWithinAWord;
+
+	errorByte = datap[locWithinAPage * sizeof(uint32_t) + locWithinAWord];
+
+#ifdef BOOT0_BUILD
+	puthexs("\nECC Correct Offset: ",
+		locWithinAPage * sizeof(uint32_t) + locWithinAWord);
+	puthexs(" errorByte:", errorByte);
+	puthex8(" Bit: ", locWithinAByte);
+#endif
+
+	if (errorByte & byteMask) {
+		/* bit needs to be cleared */
+		errorByte &= ~byteMask;
+	} else {
+		/* bit needs to be set */
+		errorByte |= byteMask;
+	}
+
+	/* write back the value with the fixed bit */
+	datap[locWithinAPage * sizeof(uint32_t) + locWithinAWord] = errorByte;
+}
+
+/****************************************************************************
+*  nand_correct_page_bch - Routine to correct bit errors when reading NAND
+*
+*  PURPOSE:
+*     This routine reads the BCH registers to determine if there are any bit
+*     errors during the read of the last 512 bytes of data + ECC bytes.  If
+*     errors exists, the routine fixes it.
+*
+*  PARAMETERS:
+*     datap - Container that holds the 512 byte data
+*
+*  RETURNS:
+*     0 or greater = Number of errors corrected
+*                    (No errors are found or errors have been fixed)
+*    -1 = Error(s) cannot be fixed
+****************************************************************************/
+int nand_bcm_umi_bch_correct_page(uint8_t *datap, uint8_t *readEccData,
+				  int numEccBytes)
+{
+	int numErrors;
+	int errorLocation;
+	int idx;
+	uint32_t regValue;
+
+	/* wait for read ECC to be valid */
+	regValue = nand_bcm_umi_bch_poll_read_ecc_calc();
+
+	/*
+	 * read the control status register to determine if there
+	 * are error'ed bits
+	 * see if errors are correctible
+	 */
+	if ((regValue & REG_UMI_BCH_CTRL_STATUS_UNCORR_ERR) > 0) {
+		int i;
+
+		for (i = 0; i < numEccBytes; i++) {
+			if (readEccData[i] != 0xff) {
+				/* errors cannot be fixed, return -1 */
+				return -1;
+			}
+		}
+		/* If ECC is unprogrammed then we can't correct,
+		 * assume everything OK */
+		return 0;
+	}
+
+	if ((regValue & REG_UMI_BCH_CTRL_STATUS_CORR_ERR) == 0) {
+		/* no errors */
+		return 0;
+	}
+
+	/*
+	 * Fix errored bits by doing the following:
+	 * 1. Read the number of errors in the control and status register
+	 * 2. Read the error location registers that corresponds to the number
+	 *    of errors reported
+	 * 3. Invert the bit in the data
+	 */
+	numErrors = (regValue & REG_UMI_BCH_CTRL_STATUS_NB_CORR_ERROR) >> 20;
+
+	for (idx = 0; idx < numErrors; idx++) {
+		errorLocation =
+		    REG_UMI_BCH_ERR_LOC_ADDR(idx) & REG_UMI_BCH_ERR_LOC_MASK;
+
+		/* Flip bit */
+		nand_bcm_umi_bch_ecc_flip_bit(datap, errorLocation);
+	}
+	/* Errors corrected */
+	return numErrors;
+}
+#endif

drivers/mtd/nand/nand_bcm_umi.h

+/*****************************************************************************
+* Copyright 2003 - 2009 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+#ifndef NAND_BCM_UMI_H
+#define NAND_BCM_UMI_H
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <mach/reg_umi.h>
+#include <mach/reg_nand.h>
+#include <cfg_global.h>
+
+/* ---- Constants and Types ---------------------------------------------- */
+#if (CFG_GLOBAL_CHIP_FAMILY == CFG_GLOBAL_CHIP_FAMILY_BCMRING)
+#define NAND_ECC_BCH (CFG_GLOBAL_CHIP_REV > 0xA0)
+#else
+#define NAND_ECC_BCH 0
+#endif
+
+#define CFG_GLOBAL_NAND_ECC_BCH_NUM_BYTES	13
+
+#if NAND_ECC_BCH
+#ifdef BOOT0_BUILD
+#define NAND_ECC_NUM_BYTES 13
+#else
+#define NAND_ECC_NUM_BYTES CFG_GLOBAL_NAND_ECC_BCH_NUM_BYTES
+#endif
+#else
+#define NAND_ECC_NUM_BYTES 3
+#endif
+
+#define NAND_DATA_ACCESS_SIZE 512
+
+/* ---- Variable Externs ------------------------------------------ */
+/* ---- Function Prototypes --------------------------------------- */
+int nand_bcm_umi_bch_correct_page(uint8_t *datap, uint8_t *readEccData,
+				  int numEccBytes);
+
+/* Check in device is ready */
+static inline int nand_bcm_umi_dev_ready(void)
+{
+	return REG_UMI_NAND_RCSR & REG_UMI_NAND_RCSR_RDY;
+}
+
+/* Wait until device is ready */
+static inline void nand_bcm_umi_wait_till_ready(void)
+{
+	while (nand_bcm_umi_dev_ready() == 0)
+		;
+}
+
+/* Enable Hamming ECC */
+static inline void nand_bcm_umi_hamming_enable_hwecc(void)
+{
+	/* disable and reset ECC, 512 byte page */
+	REG_UMI_NAND_ECC_CSR &= ~(REG_UMI_NAND_ECC_CSR_ECC_ENABLE |
+		REG_UMI_NAND_ECC_CSR_256BYTE);
+	/* enable ECC */
+	REG_UMI_NAND_ECC_CSR |= REG_UMI_NAND_ECC_CSR_ECC_ENABLE;
+}
+
+#if NAND_ECC_BCH
+/* BCH ECC specifics */
+#define ECC_BITS_PER_CORRECTABLE_BIT 13
+
+/* Enable BCH Read ECC */
+static inline void nand_bcm_umi_bch_enable_read_hwecc(void)
+{
+	/* disable and reset ECC */
+	REG_UMI_BCH_CTRL_STATUS = REG_UMI_BCH_CTRL_STATUS_RD_ECC_VALID;
+	/* Turn on ECC */
+	REG_UMI_BCH_CTRL_STATUS = REG_UMI_BCH_CTRL_STATUS_ECC_RD_EN;
+}
+
+/* Enable BCH Write ECC */
+static inline void nand_bcm_umi_bch_enable_write_hwecc(void)
+{
+	/* disable and reset ECC */
+	REG_UMI_BCH_CTRL_STATUS = REG_UMI_BCH_CTRL_STATUS_WR_ECC_VALID;
+	/* Turn on ECC */
+	REG_UMI_BCH_CTRL_STATUS = REG_UMI_BCH_CTRL_STATUS_ECC_WR_EN;
+}
+
+/* Config number of BCH ECC bytes */
+static inline void nand_bcm_umi_bch_config_ecc(uint8_t numEccBytes)
+{
+	uint32_t nValue;
+	uint32_t tValue;
+	uint32_t kValue;
+	uint32_t numBits = numEccBytes * 8;
+
+	/* disable and reset ECC */
+	REG_UMI_BCH_CTRL_STATUS =
+	    REG_UMI_BCH_CTRL_STATUS_WR_ECC_VALID |
+	    REG_UMI_BCH_CTRL_STATUS_RD_ECC_VALID;
+
+	/* Every correctible bit requires 13 ECC bits */
+	tValue = (uint32_t) (numBits / ECC_BITS_PER_CORRECTABLE_BIT);
+
+	/* Total data in number of bits for generating and computing BCH ECC */
+	nValue = (NAND_DATA_ACCESS_SIZE + numEccBytes) * 8;
+
+	/* K parameter is used internally.  K = N - (T * 13) */
+	kValue = nValue - (tValue * ECC_BITS_PER_CORRECTABLE_BIT);
+
+	/* Write the settings */
+	REG_UMI_BCH_N = nValue;
+	REG_UMI_BCH_T = tValue;
+	REG_UMI_BCH_K = kValue;
+}
+
+/* Pause during ECC read calculation to skip bytes in OOB */
+static inline void nand_bcm_umi_bch_pause_read_ecc_calc(void)
+{
+	REG_UMI_BCH_CTRL_STATUS =
+	    REG_UMI_BCH_CTRL_STATUS_ECC_RD_EN |
+	    REG_UMI_BCH_CTRL_STATUS_PAUSE_ECC_DEC;
+}
+
+/* Resume during ECC read calculation after skipping bytes in OOB */
+static inline void nand_bcm_umi_bch_resume_read_ecc_calc(void)
+{
+	REG_UMI_BCH_CTRL_STATUS = REG_UMI_BCH_CTRL_STATUS_ECC_RD_EN;
+}
+
+/* Poll read ECC calc to check when hardware completes */
+static inline uint32_t nand_bcm_umi_bch_poll_read_ecc_calc(void)
+{
+	uint32_t regVal;
+
+	do {
+		/* wait for ECC to be valid */
+		regVal = REG_UMI_BCH_CTRL_STATUS;
+	} while ((regVal & REG_UMI_BCH_CTRL_STATUS_RD_ECC_VALID) == 0);
+
+	return regVal;
+}
+
+/* Poll write ECC calc to check when hardware completes */
+static inline void nand_bcm_umi_bch_poll_write_ecc_calc(void)
+{
+	/* wait for ECC to be valid */
+	while ((REG_UMI_BCH_CTRL_STATUS & REG_UMI_BCH_CTRL_STATUS_WR_ECC_VALID)
+	       == 0)
+		;
+}
+
+/* Read the OOB and ECC, for kernel write OOB to a buffer */
+#if defined(__KERNEL__) && !defined(STANDALONE)
+static inline void nand_bcm_umi_bch_read_oobEcc(uint32_t pageSize,
+	uint8_t *eccCalc, int numEccBytes, uint8_t *oobp)
+#else
+static inline void nand_bcm_umi_bch_read_oobEcc(uint32_t pageSize,
+	uint8_t *eccCalc, int numEccBytes)
+#endif
+{
+	int eccPos = 0;
+	int numToRead = 16;	/* There are 16 bytes per sector in the OOB */
+
+	/* ECC is already paused when this function is called */
+
+	if (pageSize == NAND_DATA_ACCESS_SIZE) {
+		while (numToRead > numEccBytes) {
+			/* skip free oob region */
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp++ = REG_NAND_DATA8;
+#else
+			REG_NAND_DATA8;
+#endif
+			numToRead--;
+		}
+
+		/* read ECC bytes before BI */
+		nand_bcm_umi_bch_resume_read_ecc_calc();
+
+		while (numToRead > 11) {
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp = REG_NAND_DATA8;
+			eccCalc[eccPos++] = *oobp;
+			oobp++;
+#else
+			eccCalc[eccPos++] = REG_NAND_DATA8;
+#endif
+		}
+
+		nand_bcm_umi_bch_pause_read_ecc_calc();
+
+		if (numToRead == 11) {
+			/* read BI */
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp++ = REG_NAND_DATA8;
+#else
+			REG_NAND_DATA8;
+#endif
+			numToRead--;
+		}
+
+		/* read ECC bytes */
+		nand_bcm_umi_bch_resume_read_ecc_calc();
+		while (numToRead) {
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp = REG_NAND_DATA8;
+			eccCalc[eccPos++] = *oobp;
+			oobp++;
+#else
+			eccCalc[eccPos++] = REG_NAND_DATA8;
+#endif
+			numToRead--;
+		}
+	} else {
+		/* skip BI */
+#if defined(__KERNEL__) && !defined(STANDALONE)
+		*oobp++ = REG_NAND_DATA8;
+#else
+		REG_NAND_DATA8;
+#endif
+		numToRead--;
+
+		while (numToRead > numEccBytes) {
+			/* skip free oob region */
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp++ = REG_NAND_DATA8;
+#else
+			REG_NAND_DATA8;
+#endif
+			numToRead--;
+		}
+
+		/* read ECC bytes */
+		nand_bcm_umi_bch_resume_read_ecc_calc();
+		while (numToRead) {
+#if defined(__KERNEL__) && !defined(STANDALONE)
+			*oobp = REG_NAND_DATA8;
+			eccCalc[eccPos++] = *oobp;
+			oobp++;
+#else
+			eccCalc[eccPos++] = REG_NAND_DATA8;
+#endif
+			numToRead--;
+		}
+	}
+}
+
+/* Helper function to write ECC */
+static inline void NAND_BCM_UMI_ECC_WRITE(int numEccBytes, int eccBytePos,
+					  uint8_t *oobp, uint8_t eccVal)
+{
+	if (eccBytePos <= numEccBytes)
+		*oobp = eccVal;
+}
+
+/* Write OOB with ECC */
+static inline void nand_bcm_umi_bch_write_oobEcc(uint32_t pageSize,
+						 uint8_t *oobp, int numEccBytes)
+{
+	uint32_t eccVal = 0xffffffff;
+
+	/* wait for write ECC to be valid */
+	nand_bcm_umi_bch_poll_write_ecc_calc();
+
+	/*
+	 ** Get the hardware ecc from the 32-bit result registers.
+	 ** Read after 512 byte accesses. Format B3B2B1B0
+	 ** where B3 = ecc3, etc.
+	 */
+
+	if (pageSize == NAND_DATA_ACCESS_SIZE) {
+		/* Now fill in the ECC bytes */
+		if (numEccBytes >= 13)
+			eccVal = REG_UMI_BCH_WR_ECC_3;
+
+		/* Usually we skip CM in oob[0,1] */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 15, &oobp[0],
+			(eccVal >> 16) & 0xff);
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 14, &oobp[1],
+			(eccVal >> 8) & 0xff);
+
+		/* Write ECC in oob[2,3,4] */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 13, &oobp[2],
+			eccVal & 0xff);	/* ECC 12 */
+
+		if (numEccBytes >= 9)
+			eccVal = REG_UMI_BCH_WR_ECC_2;
+
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 12, &oobp[3],
+			(eccVal >> 24) & 0xff);	/* ECC11 */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 11, &oobp[4],
+			(eccVal >> 16) & 0xff);	/* ECC10 */
+
+		/* Always Skip BI in oob[5] */
+	} else {
+		/* Always Skip BI in oob[0] */
+
+		/* Now fill in the ECC bytes */
+		if (numEccBytes >= 13)
+			eccVal = REG_UMI_BCH_WR_ECC_3;
+
+		/* Usually skip CM in oob[1,2] */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 15, &oobp[1],
+			(eccVal >> 16) & 0xff);
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 14, &oobp[2],
+			(eccVal >> 8) & 0xff);
+
+		/* Write ECC in oob[3-15] */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 13, &oobp[3],
+			eccVal & 0xff);	/* ECC12 */
+
+		if (numEccBytes >= 9)
+			eccVal = REG_UMI_BCH_WR_ECC_2;
+
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 12, &oobp[4],
+			(eccVal >> 24) & 0xff);	/* ECC11 */
+		NAND_BCM_UMI_ECC_WRITE(numEccBytes, 11, &oobp[5],
+			(eccVal >> 16) & 0xff);	/* ECC10 */
+	}
+
+	/* Fill in the remainder of ECC locations */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 10, &oobp[6],
+		(eccVal >> 8) & 0xff);	/* ECC9 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 9, &oobp[7],
+		eccVal & 0xff);	/* ECC8 */
+
+	if (numEccBytes >= 5)
+		eccVal = REG_UMI_BCH_WR_ECC_1;
+
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 8, &oobp[8],
+		(eccVal >> 24) & 0xff);	/* ECC7 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 7, &oobp[9],
+		(eccVal >> 16) & 0xff);	/* ECC6 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 6, &oobp[10],
+		(eccVal >> 8) & 0xff);	/* ECC5 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 5, &oobp[11],
+		eccVal & 0xff);	/* ECC4 */
+
+	if (numEccBytes >= 1)
+		eccVal = REG_UMI_BCH_WR_ECC_0;
+
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 4, &oobp[12],
+		(eccVal >> 24) & 0xff);	/* ECC3 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 3, &oobp[13],
+		(eccVal >> 16) & 0xff);	/* ECC2 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 2, &oobp[14],
+		(eccVal >> 8) & 0xff);	/* ECC1 */
+	NAND_BCM_UMI_ECC_WRITE(numEccBytes, 1, &oobp[15],
+		eccVal & 0xff);	/* ECC0 */
+}
+#endif
+
+#endif /* NAND_BCM_UMI_H */