NAND: Add ECC support to NAND booting support in nand_spl/nand_boot.c

The U-Boot NAND booting support is now extended to support ECC
upon loading of the NAND U-Boot image.

Tested on AMCC Sequoia (440EPx) and Bamboo (440EP).

Signed-off-by: Stefan Roese <sr@denx.de>

diff --git a/nand_spl/nand_boot.c b/nand_spl/nand_boot.c
index a136fb7..840a596 100644 (file)
--- a/nand_spl/nand_boot.c
+++ b/nand_spl/nand_boot.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2006
+ * (C) Copyright 2006-2007
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
  * This program is free software; you can redistribute it and/or
@@ -24,27 +24,28 @@
 #define CFG_NAND_READ_DELAY \
        { volatile int dummy; int i; for (i=0; i<10000; i++) dummy = i; }
 
+static int nand_ecc_pos[] = CFG_NAND_ECCPOS;
+
 extern void board_nand_init(struct nand_chip *nand);
-extern void ndfc_hwcontrol(struct mtd_info *mtdinfo, int cmd);
-extern void ndfc_write_byte(struct mtd_info *mtdinfo, u_char byte);
-extern u_char ndfc_read_byte(struct mtd_info *mtdinfo);
-extern int ndfc_dev_ready(struct mtd_info *mtdinfo);
-extern int jump_to_ram(ulong delta);
-extern int jump_to_uboot(ulong addr);
 
-static int nand_is_bad_block(struct mtd_info *mtd, int block)
+static int nand_command(struct mtd_info *mtd, int block, int page, int offs, u8 cmd)
 {
        struct nand_chip *this = mtd->priv;
-       int page_addr = block * CFG_NAND_PAGE_COUNT;
+       int page_addr = page + block * CFG_NAND_PAGE_COUNT;
+
+       if (this->dev_ready)
+               this->dev_ready(mtd);
+       else
+               CFG_NAND_READ_DELAY;
 
        /* Begin command latch cycle */
        this->hwcontrol(mtd, NAND_CTL_SETCLE);
-       this->write_byte(mtd, NAND_CMD_READOOB);
+       this->write_byte(mtd, cmd);
        /* Set ALE and clear CLE to start address cycle */
        this->hwcontrol(mtd, NAND_CTL_CLRCLE);
        this->hwcontrol(mtd, NAND_CTL_SETALE);
        /* Column address */
-       this->write_byte(mtd, CFG_NAND_BAD_BLOCK_POS);                  /* A[7:0] */
+       this->write_byte(mtd, offs);                                    /* A[7:0] */
        this->write_byte(mtd, (uchar)(page_addr & 0xff));               /* A[16:9] */
        this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));        /* A[24:17] */
 #ifdef CFG_NAND_4_ADDR_CYCLE
@@ -62,6 +63,15 @@ static int nand_is_bad_block(struct mtd_info *mtd, int block)
        else
                CFG_NAND_READ_DELAY;
 
+       return 0;
+}
+
+static int nand_is_bad_block(struct mtd_info *mtd, int block)
+{
+       struct nand_chip *this = mtd->priv;
+
+       nand_command(mtd, block, 0, CFG_NAND_BAD_BLOCK_POS, NAND_CMD_READOOB);
+
        /*
         * Read on byte
         */
@@ -74,39 +84,46 @@ static int nand_is_bad_block(struct mtd_info *mtd, int block)
 static int nand_read_page(struct mtd_info *mtd, int block, int page, uchar *dst)
 {
        struct nand_chip *this = mtd->priv;
-       int page_addr = page + block * CFG_NAND_PAGE_COUNT;
+       u_char *ecc_calc;
+       u_char *ecc_code;
+       u_char *oob_data;
        int i;
+       int eccsize = CFG_NAND_ECCSIZE;
+       int eccbytes = CFG_NAND_ECCBYTES;
+       int eccsteps = CFG_NAND_ECCSTEPS;
+       uint8_t *p = dst;
+       int stat;
 
-       /* Begin command latch cycle */
-       this->hwcontrol(mtd, NAND_CTL_SETCLE);
-       this->write_byte(mtd, NAND_CMD_READ0);
-       /* Set ALE and clear CLE to start address cycle */
-       this->hwcontrol(mtd, NAND_CTL_CLRCLE);
-       this->hwcontrol(mtd, NAND_CTL_SETALE);
-       /* Column address */
-       this->write_byte(mtd, 0);                                       /* A[7:0] */
-       this->write_byte(mtd, (uchar)(page_addr & 0xff));               /* A[16:9] */
-       this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));        /* A[24:17] */
-#ifdef CFG_NAND_4_ADDR_CYCLE
-       /* One more address cycle for devices > 32MiB */
-       this->write_byte(mtd, (uchar)((page_addr >> 16) & 0x0f));       /* A[xx:25] */
-#endif
-       /* Latch in address */
-       this->hwcontrol(mtd, NAND_CTL_CLRALE);
+       nand_command(mtd, block, page, 0, NAND_CMD_READ0);
 
-       /*
-        * Wait a while for the data to be ready
+       /* No malloc available for now, just use some temporary locations
+        * in SDRAM
         */
-       if (this->dev_ready)
-               this->dev_ready(mtd);
-       else
-               CFG_NAND_READ_DELAY;
+       ecc_calc = (u_char *)(CFG_SDRAM_BASE + 0x10000);
+       ecc_code = ecc_calc + 0x100;
+       oob_data = ecc_calc + 0x200;
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               this->enable_hwecc(mtd, NAND_ECC_READ);
+               this->read_buf(mtd, p, eccsize);
+               this->calculate_ecc(mtd, p, &ecc_calc[i]);
+       }
+       this->read_buf(mtd, oob_data, CFG_NAND_OOBSIZE);
 
-       /*
-        * Read page into buffer
-        */
-       for (i=0; i<CFG_NAND_PAGE_SIZE; i++)
-               *dst++ = this->read_byte(mtd);
+       /* Pick the ECC bytes out of the oob data */
+       for (i = 0; i < CFG_NAND_ECCTOTAL; i++)
+               ecc_code[i] = oob_data[nand_ecc_pos[i]];
+
+       eccsteps = CFG_NAND_ECCSTEPS;
+       p = dst;
+
+       for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               /* No chance to do something with the possible error message
+                * from correct_data(). We just hope that all possible errors
+                * are corrected by this routine.
+                */
+               stat = this->correct_data(mtd, p, &ecc_code[i], &ecc_calc[i]);
+       }
 
        return 0;
 }