Freescale eLBC FCM NAND driver
authorScott Wood <scottwood@freescale.com>
Fri, 21 Mar 2008 21:12:51 +0000 (16:12 -0500)
committerScott Wood <scottwood@freescale.com>
Tue, 12 Aug 2008 16:31:25 +0000 (11:31 -0500)
This is a driver for the Flash Control Machine of the enhanched Local Bus
Controller found on some Freescale chips (such as the mpc8313 and the
mpc8379).

Signed-off-by: Scott Wood <scottwood@freescale.com>
drivers/mtd/nand/Makefile
drivers/mtd/nand/fsl_elbc_nand.c [new file with mode: 0644]

index 7bd22a0c9d790fa3260a54504cb19253647dbc3e..ffb3169594513f7620f90cea3aea6c0d8d69a0c4 100644 (file)
@@ -32,6 +32,7 @@ COBJS-y += nand_ecc.o
 COBJS-y += nand_bbt.o
 COBJS-y += nand_util.o
 
+COBJS-$(CONFIG_NAND_FSL_ELBC) += fsl_elbc_nand.o
 COBJS-y += fsl_upm.o
 
 COBJS  := $(COBJS-y)
diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
new file mode 100644 (file)
index 0000000..c1644c0
--- /dev/null
@@ -0,0 +1,759 @@
+/* Freescale Enhanced Local Bus Controller FCM NAND driver
+ *
+ * Copyright (c) 2006-2008 Freescale Semiconductor
+ *
+ * Authors: Nick Spence <nick.spence@freescale.com>,
+ *          Scott Wood <scottwood@freescale.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+
+#include <asm/io.h>
+#include <asm/errno.h>
+
+#ifdef VERBOSE_DEBUG
+#define DEBUG_ELBC
+#define vdbg(format, arg...) printf("DEBUG: " format, ##arg)
+#else
+#define vdbg(format, arg...) do {} while (0)
+#endif
+
+/* Can't use plain old DEBUG because the linux mtd
+ * headers define it as a macro.
+ */
+#ifdef DEBUG_ELBC
+#define dbg(format, arg...) printf("DEBUG: " format, ##arg)
+#else
+#define dbg(format, arg...) do {} while (0)
+#endif
+
+#define MAX_BANKS 8
+#define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */
+#define FCM_TIMEOUT_MSECS 10 /* Maximum number of mSecs to wait for FCM */
+
+#define LTESR_NAND_MASK (LTESR_FCT | LTESR_PAR | LTESR_CC)
+
+struct fsl_elbc_ctrl;
+
+/* mtd information per set */
+
+struct fsl_elbc_mtd {
+       struct mtd_info mtd;
+       struct nand_chip chip;
+       struct fsl_elbc_ctrl *ctrl;
+
+       struct device *dev;
+       int bank;               /* Chip select bank number           */
+       u8 __iomem *vbase;      /* Chip select base virtual address  */
+       int page_size;          /* NAND page size (0=512, 1=2048)    */
+       unsigned int fmr;       /* FCM Flash Mode Register value     */
+};
+
+/* overview of the fsl elbc controller */
+
+struct fsl_elbc_ctrl {
+       struct nand_hw_control controller;
+       struct fsl_elbc_mtd *chips[MAX_BANKS];
+
+       /* device info */
+       lbus83xx_t *regs;
+       u8 __iomem *addr;        /* Address of assigned FCM buffer        */
+       unsigned int page;       /* Last page written to / read from      */
+       unsigned int read_bytes; /* Number of bytes read during command   */
+       unsigned int column;     /* Saved column from SEQIN               */
+       unsigned int index;      /* Pointer to next byte to 'read'        */
+       unsigned int status;     /* status read from LTESR after last op  */
+       unsigned int mdr;        /* UPM/FCM Data Register value           */
+       unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
+       unsigned int oob;        /* Non zero if operating on OOB data     */
+       uint8_t *oob_poi;        /* Place to write ECC after read back    */
+};
+
+/* These map to the positions used by the FCM hardware ECC generator */
+
+/* Small Page FLASH with FMR[ECCM] = 0 */
+static struct nand_ecclayout fsl_elbc_oob_sp_eccm0 = {
+       .eccbytes = 3,
+       .eccpos = {6, 7, 8},
+       .oobfree = { {0, 5}, {9, 7} },
+       .oobavail = 12,
+};
+
+/* Small Page FLASH with FMR[ECCM] = 1 */
+static struct nand_ecclayout fsl_elbc_oob_sp_eccm1 = {
+       .eccbytes = 3,
+       .eccpos = {8, 9, 10},
+       .oobfree = { {0, 5}, {6, 2}, {11, 5} },
+       .oobavail = 12,
+};
+
+/* Large Page FLASH with FMR[ECCM] = 0 */
+static struct nand_ecclayout fsl_elbc_oob_lp_eccm0 = {
+       .eccbytes = 12,
+       .eccpos = {6, 7, 8, 22, 23, 24, 38, 39, 40, 54, 55, 56},
+       .oobfree = { {1, 5}, {9, 13}, {25, 13}, {41, 13}, {57, 7} },
+       .oobavail = 48,
+};
+
+/* Large Page FLASH with FMR[ECCM] = 1 */
+static struct nand_ecclayout fsl_elbc_oob_lp_eccm1 = {
+       .eccbytes = 12,
+       .eccpos = {8, 9, 10, 24, 25, 26, 40, 41, 42, 56, 57, 58},
+       .oobfree = { {1, 7}, {11, 13}, {27, 13}, {43, 13}, {59, 5} },
+       .oobavail = 48,
+};
+
+/*=================================*/
+
+/*
+ * Set up the FCM hardware block and page address fields, and the fcm
+ * structure addr field to point to the correct FCM buffer in memory
+ */
+static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       lbus83xx_t *lbc = ctrl->regs;
+       int buf_num;
+
+       ctrl->page = page_addr;
+
+       out_be32(&lbc->fbar,
+                page_addr >> (chip->phys_erase_shift - chip->page_shift));
+
+       if (priv->page_size) {
+               out_be32(&lbc->fpar,
+                        ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
+                        (oob ? FPAR_LP_MS : 0) | column);
+               buf_num = (page_addr & 1) << 2;
+       } else {
+               out_be32(&lbc->fpar,
+                        ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
+                        (oob ? FPAR_SP_MS : 0) | column);
+               buf_num = page_addr & 7;
+       }
+
+       ctrl->addr = priv->vbase + buf_num * 1024;
+       ctrl->index = column;
+
+       /* for OOB data point to the second half of the buffer */
+       if (oob)
+               ctrl->index += priv->page_size ? 2048 : 512;
+
+       vdbg("set_addr: bank=%d, ctrl->addr=0x%p (0x%p), "
+            "index %x, pes %d ps %d\n",
+            buf_num, ctrl->addr, priv->vbase, ctrl->index,
+            chip->phys_erase_shift, chip->page_shift);
+}
+
+/*
+ * execute FCM command and wait for it to complete
+ */
+static int fsl_elbc_run_command(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       lbus83xx_t *lbc = ctrl->regs;
+       long long end_tick;
+       u32 ltesr;
+
+       /* Setup the FMR[OP] to execute without write protection */
+       out_be32(&lbc->fmr, priv->fmr | 3);
+       if (ctrl->use_mdr)
+               out_be32(&lbc->mdr, ctrl->mdr);
+
+       vdbg("fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
+            in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
+       vdbg("fsl_elbc_run_command: fbar=%08x fpar=%08x "
+            "fbcr=%08x bank=%d\n",
+            in_be32(&lbc->fbar), in_be32(&lbc->fpar),
+            in_be32(&lbc->fbcr), priv->bank);
+
+       /* execute special operation */
+       out_be32(&lbc->lsor, priv->bank);
+
+       /* wait for FCM complete flag or timeout */
+       end_tick = usec2ticks(FCM_TIMEOUT_MSECS * 1000) + get_ticks();
+
+       ltesr = 0;
+       while (end_tick > get_ticks()) {
+               ltesr = in_be32(&lbc->ltesr);
+               if (ltesr & LTESR_CC)
+                       break;
+       }
+
+       ctrl->status = ltesr & LTESR_NAND_MASK;
+       out_be32(&lbc->ltesr, ctrl->status);
+       out_be32(&lbc->lteatr, 0);
+
+       /* store mdr value in case it was needed */
+       if (ctrl->use_mdr)
+               ctrl->mdr = in_be32(&lbc->mdr);
+
+       ctrl->use_mdr = 0;
+
+       vdbg("fsl_elbc_run_command: stat=%08x mdr=%08x fmr=%08x\n",
+            ctrl->status, ctrl->mdr, in_be32(&lbc->fmr));
+
+       /* returns 0 on success otherwise non-zero) */
+       return ctrl->status == LTESR_CC ? 0 : -EIO;
+}
+
+static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
+{
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       lbus83xx_t *lbc = ctrl->regs;
+
+       if (priv->page_size) {
+               out_be32(&lbc->fir,
+                        (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                        (FIR_OP_CA  << FIR_OP1_SHIFT) |
+                        (FIR_OP_PA  << FIR_OP2_SHIFT) |
+                        (FIR_OP_CW1 << FIR_OP3_SHIFT) |
+                        (FIR_OP_RBW << FIR_OP4_SHIFT));
+
+               out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
+                                   (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
+       } else {
+               out_be32(&lbc->fir,
+                        (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                        (FIR_OP_CA  << FIR_OP1_SHIFT) |
+                        (FIR_OP_PA  << FIR_OP2_SHIFT) |
+                        (FIR_OP_RBW << FIR_OP3_SHIFT));
+
+               if (oob)
+                       out_be32(&lbc->fcr,
+                                NAND_CMD_READOOB << FCR_CMD0_SHIFT);
+               else
+                       out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
+       }
+}
+
+/* cmdfunc send commands to the FCM */
+static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
+                             int column, int page_addr)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       lbus83xx_t *lbc = ctrl->regs;
+
+       ctrl->use_mdr = 0;
+
+       /* clear the read buffer */
+       ctrl->read_bytes = 0;
+       if (command != NAND_CMD_PAGEPROG)
+               ctrl->index = 0;
+
+       switch (command) {
+       /* READ0 and READ1 read the entire buffer to use hardware ECC. */
+       case NAND_CMD_READ1:
+               column += 256;
+
+       /* fall-through */
+       case NAND_CMD_READ0:
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
+                    " 0x%x, column: 0x%x.\n", page_addr, column);
+
+               out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
+               set_addr(mtd, 0, page_addr, 0);
+
+               ctrl->read_bytes = mtd->writesize + mtd->oobsize;
+               ctrl->index += column;
+
+               fsl_elbc_do_read(chip, 0);
+               fsl_elbc_run_command(mtd);
+               return;
+
+       /* READOOB reads only the OOB because no ECC is performed. */
+       case NAND_CMD_READOOB:
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
+                    " 0x%x, column: 0x%x.\n", page_addr, column);
+
+               out_be32(&lbc->fbcr, mtd->oobsize - column);
+               set_addr(mtd, column, page_addr, 1);
+
+               ctrl->read_bytes = mtd->writesize + mtd->oobsize;
+
+               fsl_elbc_do_read(chip, 1);
+               fsl_elbc_run_command(mtd);
+
+               return;
+
+       /* READID must read all 5 possible bytes while CEB is active */
+       case NAND_CMD_READID:
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_READID.\n");
+
+               out_be32(&lbc->fir, (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                                   (FIR_OP_UA  << FIR_OP1_SHIFT) |
+                                   (FIR_OP_RBW << FIR_OP2_SHIFT));
+               out_be32(&lbc->fcr, NAND_CMD_READID << FCR_CMD0_SHIFT);
+               /* 5 bytes for manuf, device and exts */
+               out_be32(&lbc->fbcr, 5);
+               ctrl->read_bytes = 5;
+               ctrl->use_mdr = 1;
+               ctrl->mdr = 0;
+
+               set_addr(mtd, 0, 0, 0);
+               fsl_elbc_run_command(mtd);
+               return;
+
+       /* ERASE1 stores the block and page address */
+       case NAND_CMD_ERASE1:
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
+                    "page_addr: 0x%x.\n", page_addr);
+               set_addr(mtd, 0, page_addr, 0);
+               return;
+
+       /* ERASE2 uses the block and page address from ERASE1 */
+       case NAND_CMD_ERASE2:
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");
+
+               out_be32(&lbc->fir,
+                        (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                        (FIR_OP_PA  << FIR_OP1_SHIFT) |
+                        (FIR_OP_CM1 << FIR_OP2_SHIFT));
+
+               out_be32(&lbc->fcr,
+                        (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
+                        (NAND_CMD_ERASE2 << FCR_CMD1_SHIFT));
+
+               out_be32(&lbc->fbcr, 0);
+               ctrl->read_bytes = 0;
+
+               fsl_elbc_run_command(mtd);
+               return;
+
+       /* SEQIN sets up the addr buffer and all registers except the length */
+       case NAND_CMD_SEQIN: {
+               u32 fcr;
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG, "
+                    "page_addr: 0x%x, column: 0x%x.\n",
+                    page_addr, column);
+
+               ctrl->column = column;
+               ctrl->oob = 0;
+
+               if (priv->page_size) {
+                       fcr = (NAND_CMD_SEQIN << FCR_CMD0_SHIFT) |
+                             (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT);
+
+                       out_be32(&lbc->fir,
+                                (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                                (FIR_OP_CA  << FIR_OP1_SHIFT) |
+                                (FIR_OP_PA  << FIR_OP2_SHIFT) |
+                                (FIR_OP_WB  << FIR_OP3_SHIFT) |
+                                (FIR_OP_CW1 << FIR_OP4_SHIFT));
+               } else {
+                       fcr = (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT) |
+                             (NAND_CMD_SEQIN << FCR_CMD2_SHIFT);
+
+                       out_be32(&lbc->fir,
+                                (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                                (FIR_OP_CM2 << FIR_OP1_SHIFT) |
+                                (FIR_OP_CA  << FIR_OP2_SHIFT) |
+                                (FIR_OP_PA  << FIR_OP3_SHIFT) |
+                                (FIR_OP_WB  << FIR_OP4_SHIFT) |
+                                (FIR_OP_CW1 << FIR_OP5_SHIFT));
+
+                       if (column >= mtd->writesize) {
+                               /* OOB area --> READOOB */
+                               column -= mtd->writesize;
+                               fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
+                               ctrl->oob = 1;
+                       } else if (column < 256) {
+                               /* First 256 bytes --> READ0 */
+                               fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
+                       } else {
+                               /* Second 256 bytes --> READ1 */
+                               fcr |= NAND_CMD_READ1 << FCR_CMD0_SHIFT;
+                       }
+               }
+
+               out_be32(&lbc->fcr, fcr);
+               set_addr(mtd, column, page_addr, ctrl->oob);
+               return;
+       }
+
+       /* PAGEPROG reuses all of the setup from SEQIN and adds the length */
+       case NAND_CMD_PAGEPROG: {
+               int full_page;
+               vdbg("fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
+                    "writing %d bytes.\n", ctrl->index);
+
+               /* if the write did not start at 0 or is not a full page
+                * then set the exact length, otherwise use a full page
+                * write so the HW generates the ECC.
+                */
+               if (ctrl->oob || ctrl->column != 0 ||
+                   ctrl->index != mtd->writesize + mtd->oobsize) {
+                       out_be32(&lbc->fbcr, ctrl->index);
+                       full_page = 0;
+               } else {
+                       out_be32(&lbc->fbcr, 0);
+                       full_page = 1;
+               }
+
+               fsl_elbc_run_command(mtd);
+
+               /* Read back the page in order to fill in the ECC for the
+                * caller.  Is this really needed?
+                */
+               if (full_page && ctrl->oob_poi) {
+                       out_be32(&lbc->fbcr, 3);
+                       set_addr(mtd, 6, page_addr, 1);
+
+                       ctrl->read_bytes = mtd->writesize + 9;
+
+                       fsl_elbc_do_read(chip, 1);
+                       fsl_elbc_run_command(mtd);
+
+                       memcpy_fromio(ctrl->oob_poi + 6,
+                                     &ctrl->addr[ctrl->index], 3);
+                       ctrl->index += 3;
+               }
+
+               ctrl->oob_poi = NULL;
+               return;
+       }
+
+       /* CMD_STATUS must read the status byte while CEB is active */
+       /* Note - it does not wait for the ready line */
+       case NAND_CMD_STATUS:
+               out_be32(&lbc->fir,
+                        (FIR_OP_CM0 << FIR_OP0_SHIFT) |
+                        (FIR_OP_RBW << FIR_OP1_SHIFT));
+               out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
+               out_be32(&lbc->fbcr, 1);
+               set_addr(mtd, 0, 0, 0);
+               ctrl->read_bytes = 1;
+
+               fsl_elbc_run_command(mtd);
+
+               /* The chip always seems to report that it is
+                * write-protected, even when it is not.
+                */
+               out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
+               return;
+
+       /* RESET without waiting for the ready line */
+       case NAND_CMD_RESET:
+               dbg("fsl_elbc_cmdfunc: NAND_CMD_RESET.\n");
+               out_be32(&lbc->fir, FIR_OP_CM0 << FIR_OP0_SHIFT);
+               out_be32(&lbc->fcr, NAND_CMD_RESET << FCR_CMD0_SHIFT);
+               fsl_elbc_run_command(mtd);
+               return;
+
+       default:
+               printf("fsl_elbc_cmdfunc: error, unsupported command 0x%x.\n",
+                       command);
+       }
+}
+
+static void fsl_elbc_select_chip(struct mtd_info *mtd, int chip)
+{
+       /* The hardware does not seem to support multiple
+        * chips per bank.
+        */
+}
+
+/*
+ * Write buf to the FCM Controller Data Buffer
+ */
+static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       unsigned int bufsize = mtd->writesize + mtd->oobsize;
+
+       if (len < 0) {
+               printf("write_buf of %d bytes", len);
+               ctrl->status = 0;
+               return;
+       }
+
+       if ((unsigned int)len > bufsize - ctrl->index) {
+               printf("write_buf beyond end of buffer "
+                      "(%d requested, %u available)\n",
+                      len, bufsize - ctrl->index);
+               len = bufsize - ctrl->index;
+       }
+
+       memcpy_toio(&ctrl->addr[ctrl->index], buf, len);
+       ctrl->index += len;
+}
+
+/*
+ * read a byte from either the FCM hardware buffer if it has any data left
+ * otherwise issue a command to read a single byte.
+ */
+static u8 fsl_elbc_read_byte(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+
+       /* If there are still bytes in the FCM, then use the next byte. */
+       if (ctrl->index < ctrl->read_bytes)
+               return in_8(&ctrl->addr[ctrl->index++]);
+
+       printf("read_byte beyond end of buffer\n");
+       return ERR_BYTE;
+}
+
+/*
+ * Read from the FCM Controller Data Buffer
+ */
+static void fsl_elbc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       int avail;
+
+       if (len < 0)
+               return;
+
+       avail = min((unsigned int)len, ctrl->read_bytes - ctrl->index);
+       memcpy_fromio(buf, &ctrl->addr[ctrl->index], avail);
+       ctrl->index += avail;
+
+       if (len > avail)
+               printf("read_buf beyond end of buffer "
+                      "(%d requested, %d available)\n",
+                      len, avail);
+}
+
+/*
+ * Verify buffer against the FCM Controller Data Buffer
+ */
+static int fsl_elbc_verify_buf(struct mtd_info *mtd,
+                               const u_char *buf, int len)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       int i;
+
+       if (len < 0) {
+               printf("write_buf of %d bytes", len);
+               return -EINVAL;
+       }
+
+       if ((unsigned int)len > ctrl->read_bytes - ctrl->index) {
+               printf("verify_buf beyond end of buffer "
+                      "(%d requested, %u available)\n",
+                      len, ctrl->read_bytes - ctrl->index);
+
+               ctrl->index = ctrl->read_bytes;
+               return -EINVAL;
+       }
+
+       for (i = 0; i < len; i++)
+               if (in_8(&ctrl->addr[ctrl->index + i]) != buf[i])
+                       break;
+
+       ctrl->index += len;
+       return i == len && ctrl->status == LTESR_CC ? 0 : -EIO;
+}
+
+/* This function is called after Program and Erase Operations to
+ * check for success or failure.
+ */
+static int fsl_elbc_wait(struct mtd_info *mtd, struct nand_chip *chip)
+{
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+       lbus83xx_t *lbc = ctrl->regs;
+
+       if (ctrl->status != LTESR_CC)
+               return NAND_STATUS_FAIL;
+
+       /* Use READ_STATUS command, but wait for the device to be ready */
+       ctrl->use_mdr = 0;
+       out_be32(&lbc->fir,
+                (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+                (FIR_OP_RBW << FIR_OP1_SHIFT));
+       out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
+       out_be32(&lbc->fbcr, 1);
+       set_addr(mtd, 0, 0, 0);
+       ctrl->read_bytes = 1;
+
+       fsl_elbc_run_command(mtd);
+
+       if (ctrl->status != LTESR_CC)
+               return NAND_STATUS_FAIL;
+
+       /* The chip always seems to report that it is
+        * write-protected, even when it is not.
+        */
+       out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
+       return fsl_elbc_read_byte(mtd);
+}
+
+static int fsl_elbc_read_page(struct mtd_info *mtd,
+                              struct nand_chip *chip,
+                              uint8_t *buf)
+{
+       fsl_elbc_read_buf(mtd, buf, mtd->writesize);
+       fsl_elbc_read_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       if (fsl_elbc_wait(mtd, chip) & NAND_STATUS_FAIL)
+               mtd->ecc_stats.failed++;
+
+       return 0;
+}
+
+/* ECC will be calculated automatically, and errors will be detected in
+ * waitfunc.
+ */
+static void fsl_elbc_write_page(struct mtd_info *mtd,
+                                struct nand_chip *chip,
+                                const uint8_t *buf)
+{
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_ctrl *ctrl = priv->ctrl;
+
+       fsl_elbc_write_buf(mtd, buf, mtd->writesize);
+       fsl_elbc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       ctrl->oob_poi = chip->oob_poi;
+}
+
+static struct fsl_elbc_ctrl *elbc_ctrl;
+
+static void fsl_elbc_ctrl_init(void)
+{
+       immap_t *im = (immap_t *)CFG_IMMR;
+
+       elbc_ctrl = kzalloc(sizeof(*elbc_ctrl), GFP_KERNEL);
+       if (!elbc_ctrl)
+               return;
+
+       elbc_ctrl->regs = &im->lbus;
+
+       /* clear event registers */
+       out_be32(&elbc_ctrl->regs->ltesr, LTESR_NAND_MASK);
+       out_be32(&elbc_ctrl->regs->lteatr, 0);
+
+       /* Enable interrupts for any detected events */
+       out_be32(&elbc_ctrl->regs->lteir, LTESR_NAND_MASK);
+
+       elbc_ctrl->read_bytes = 0;
+       elbc_ctrl->index = 0;
+       elbc_ctrl->addr = NULL;
+}
+
+int board_nand_init(struct nand_chip *nand)
+{
+       struct fsl_elbc_mtd *priv;
+       uint32_t br, or;
+
+       if (!elbc_ctrl) {
+               fsl_elbc_ctrl_init();
+               if (!elbc_ctrl)
+                       return -1;
+       }
+
+       priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->ctrl = elbc_ctrl;
+       priv->vbase = nand->IO_ADDR_R;
+
+       /* Find which chip select it is connected to.  It'd be nice
+        * if we could pass more than one datum to the NAND driver...
+        */
+       for (priv->bank = 0; priv->bank < MAX_BANKS; priv->bank++) {
+               br = in_be32(&elbc_ctrl->regs->bank[priv->bank].br);
+               or = in_be32(&elbc_ctrl->regs->bank[priv->bank].or);
+
+               if ((br & BR_V) && (br & BR_MSEL) == BR_MS_FCM &&
+                   (br & or & BR_BA) == (phys_addr_t)nand->IO_ADDR_R)
+                       break;
+       }
+
+       if (priv->bank >= MAX_BANKS) {
+               printf("fsl_elbc_nand: address did not match any "
+                      "chip selects\n");
+               return -ENODEV;
+       }
+
+       elbc_ctrl->chips[priv->bank] = priv;
+
+       /* fill in nand_chip structure */
+       /* set up function call table */
+       nand->read_byte = fsl_elbc_read_byte;
+       nand->write_buf = fsl_elbc_write_buf;
+       nand->read_buf = fsl_elbc_read_buf;
+       nand->verify_buf = fsl_elbc_verify_buf;
+       nand->select_chip = fsl_elbc_select_chip;
+       nand->cmdfunc = fsl_elbc_cmdfunc;
+       nand->waitfunc = fsl_elbc_wait;
+
+       /* set up nand options */
+       nand->options = NAND_NO_READRDY | NAND_NO_AUTOINCR;
+
+       nand->controller = &elbc_ctrl->controller;
+       nand->priv = priv;
+
+       nand->ecc.read_page = fsl_elbc_read_page;
+       nand->ecc.write_page = fsl_elbc_write_page;
+
+       /* If CS Base Register selects full hardware ECC then use it */
+       if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
+               nand->ecc.mode = NAND_ECC_HW;
+
+               nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
+                                  &fsl_elbc_oob_sp_eccm1 :
+                                  &fsl_elbc_oob_sp_eccm0;
+
+               nand->ecc.size = 512;
+               nand->ecc.bytes = 3;
+               nand->ecc.steps = 1;
+       } else {
+               /* otherwise fall back to default software ECC */
+               nand->ecc.mode = NAND_ECC_SOFT;
+       }
+
+       priv->fmr = (15 << FMR_CWTO_SHIFT) | (2 << FMR_AL_SHIFT);
+
+       /* adjust Option Register and ECC to match Flash page size */
+       if (or & OR_FCM_PGS) {
+               priv->page_size = 1;
+
+               /* adjust ecc setup if needed */
+               if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
+                       nand->ecc.steps = 4;
+                       nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
+                                          &fsl_elbc_oob_lp_eccm1 :
+                                          &fsl_elbc_oob_lp_eccm0;
+               }
+       }
+
+       return 0;
+}