nand_spl/nand_boot.c

   1 /*
   2  * (C) Copyright 2006-2008
   3  * Stefan Roese, DENX Software Engineering, sr@denx.de.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  18  * MA 02111-1307 USA
  19  */
  20
  21 #include <common.h>
  22 #include <nand.h>
  23
  24 #define CFG_NAND_READ_DELAY \
  25         { volatile int dummy; int i; for (i=0; i<10000; i++) dummy = i; }
  26
  27 static int nand_ecc_pos[] = CFG_NAND_ECCPOS;
  28
  29 extern void board_nand_init(struct nand_chip *nand);
  30
  31 #if (CFG_NAND_PAGE_SIZE <= 512)
  32 /*
  33  * NAND command for small page NAND devices (512)
  34  */
  35 static int nand_command(struct mtd_info *mtd, int block, int page, int offs, u8 cmd)
  36 {
  37         struct nand_chip *this = mtd->priv;
  38         int page_addr = page + block * CFG_NAND_PAGE_COUNT;
  39
  40         if (this->dev_ready)
  41                 this->dev_ready(mtd);
  42         else
  43                 CFG_NAND_READ_DELAY;
  44
  45         /* Begin command latch cycle */
  46         this->hwcontrol(mtd, NAND_CTL_SETCLE);
  47         this->write_byte(mtd, cmd);
  48         /* Set ALE and clear CLE to start address cycle */
  49         this->hwcontrol(mtd, NAND_CTL_CLRCLE);
  50         this->hwcontrol(mtd, NAND_CTL_SETALE);
  51         /* Column address */
  52         this->write_byte(mtd, offs);                                    /* A[7:0] */
  53         this->write_byte(mtd, (uchar)(page_addr & 0xff));               /* A[16:9] */
  54         this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));        /* A[24:17] */
  55 #ifdef CFG_NAND_4_ADDR_CYCLE
  56         /* One more address cycle for devices > 32MiB */
  57         this->write_byte(mtd, (uchar)((page_addr >> 16) & 0x0f));       /* A[xx:25] */
  58 #endif
  59         /* Latch in address */
  60         this->hwcontrol(mtd, NAND_CTL_CLRALE);
  61
  62         /*
  63          * Wait a while for the data to be ready
  64          */
  65         if (this->dev_ready)
  66                 this->dev_ready(mtd);
  67         else
  68                 CFG_NAND_READ_DELAY;
  69
  70         return 0;
  71 }
  72 #else
  73 /*
  74  * NAND command for large page NAND devices (2k)
  75  */
  76 static int nand_command(struct mtd_info *mtd, int block, int page, int offs, u8 cmd)
  77 {
  78         struct nand_chip *this = mtd->priv;
  79         int page_offs = offs;
  80         int page_addr = page + block * CFG_NAND_PAGE_COUNT;
  81
  82         if (this->dev_ready)
  83                 this->dev_ready(mtd);
  84         else
  85                 CFG_NAND_READ_DELAY;
  86
  87         /* Emulate NAND_CMD_READOOB */
  88         if (cmd == NAND_CMD_READOOB) {
  89                 page_offs += CFG_NAND_PAGE_SIZE;
  90                 cmd = NAND_CMD_READ0;
  91         }
  92
  93         /* Begin command latch cycle */
  94         this->hwcontrol(mtd, NAND_CTL_SETCLE);
  95         this->write_byte(mtd, cmd);
  96         /* Set ALE and clear CLE to start address cycle */
  97         this->hwcontrol(mtd, NAND_CTL_CLRCLE);
  98         this->hwcontrol(mtd, NAND_CTL_SETALE);
  99         /* Column address */
 100         this->write_byte(mtd, page_offs & 0xff);                        /* A[7:0] */
 101         this->write_byte(mtd, (uchar)((page_offs >> 8) & 0xff));        /* A[11:9] */
 102         /* Row address */
 103         this->write_byte(mtd, (uchar)(page_addr & 0xff));               /* A[19:12] */
 104         this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));        /* A[27:20] */
 105 #ifdef CFG_NAND_5_ADDR_CYCLE
 106         /* One more address cycle for devices > 128MiB */
 107         this->write_byte(mtd, (uchar)((page_addr >> 16) & 0x0f));       /* A[xx:28] */
 108 #endif
 109         /* Latch in address */
 110         this->hwcontrol(mtd, NAND_CTL_CLRALE);
 111
 112         /* Begin command latch cycle */
 113         this->hwcontrol(mtd, NAND_CTL_SETCLE);
 114         /* Write out the start read command */
 115         this->write_byte(mtd, NAND_CMD_READSTART);
 116         /* End command latch cycle */
 117         this->hwcontrol(mtd, NAND_CTL_CLRCLE);
 118
 119         /*
 120          * Wait a while for the data to be ready
 121          */
 122         if (this->dev_ready)
 123                 this->dev_ready(mtd);
 124         else
 125                 CFG_NAND_READ_DELAY;
 126
 127         return 0;
 128 }
 129 #endif
 130
 131 static int nand_is_bad_block(struct mtd_info *mtd, int block)
 132 {
 133         struct nand_chip *this = mtd->priv;
 134
 135         nand_command(mtd, block, 0, CFG_NAND_BAD_BLOCK_POS, NAND_CMD_READOOB);
 136
 137         /*
 138          * Read one byte
 139          */
 140         if (this->read_byte(mtd) != 0xff)
 141                 return 1;
 142
 143         return 0;
 144 }
 145
 146 static int nand_read_page(struct mtd_info *mtd, int block, int page, uchar *dst)
 147 {
 148         struct nand_chip *this = mtd->priv;
 149         u_char *ecc_calc;
 150         u_char *ecc_code;
 151         u_char *oob_data;
 152         int i;
 153         int eccsize = CFG_NAND_ECCSIZE;
 154         int eccbytes = CFG_NAND_ECCBYTES;
 155         int eccsteps = CFG_NAND_ECCSTEPS;
 156         uint8_t *p = dst;
 157         int stat;
 158
 159         nand_command(mtd, block, page, 0, NAND_CMD_READ0);
 160
 161         /* No malloc available for now, just use some temporary locations
 162          * in SDRAM
 163          */
 164         ecc_calc = (u_char *)(CFG_SDRAM_BASE + 0x10000);
 165         ecc_code = ecc_calc + 0x100;
 166         oob_data = ecc_calc + 0x200;
 167
 168         for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 169                 this->enable_hwecc(mtd, NAND_ECC_READ);
 170                 this->read_buf(mtd, p, eccsize);
 171                 this->calculate_ecc(mtd, p, &ecc_calc[i]);
 172         }
 173         this->read_buf(mtd, oob_data, CFG_NAND_OOBSIZE);
 174
 175         /* Pick the ECC bytes out of the oob data */
 176         for (i = 0; i < CFG_NAND_ECCTOTAL; i++)
 177                 ecc_code[i] = oob_data[nand_ecc_pos[i]];
 178
 179         eccsteps = CFG_NAND_ECCSTEPS;
 180         p = dst;
 181
 182         for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 183                 /* No chance to do something with the possible error message
 184                  * from correct_data(). We just hope that all possible errors
 185                  * are corrected by this routine.
 186                  */
 187                 stat = this->correct_data(mtd, p, &ecc_code[i], &ecc_calc[i]);
 188         }
 189
 190         return 0;
 191 }
 192
 193 static int nand_load(struct mtd_info *mtd, int offs, int uboot_size, uchar *dst)
 194 {
 195         int block;
 196         int blockcopy_count;
 197         int page;
 198
 199         /*
 200          * offs has to be aligned to a block address!
 201          */
 202         block = offs / CFG_NAND_BLOCK_SIZE;
 203         blockcopy_count = 0;
 204
 205         while (blockcopy_count < (uboot_size / CFG_NAND_BLOCK_SIZE)) {
 206                 if (!nand_is_bad_block(mtd, block)) {
 207                         /*
 208                          * Skip bad blocks
 209                          */
 210                         for (page = 0; page < CFG_NAND_PAGE_COUNT; page++) {
 211                                 nand_read_page(mtd, block, page, dst);
 212                                 dst += CFG_NAND_PAGE_SIZE;
 213                         }
 214
 215                         blockcopy_count++;
 216                 }
 217
 218                 block++;
 219         }
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * The main entry for NAND booting. It's necessary that SDRAM is already
 226  * configured and available since this code loads the main U-Boot image
 227  * from NAND into SDRAM and starts it from there.
 228  */
 229 void nand_boot(void)
 230 {
 231         struct nand_chip nand_chip;
 232         nand_info_t nand_info;
 233         int ret;
 234         void (*uboot)(void);
 235
 236         /*
 237          * Init board specific nand support
 238          */
 239         nand_info.priv = &nand_chip;
 240         nand_chip.IO_ADDR_R = nand_chip.IO_ADDR_W = (void  __iomem *)CFG_NAND_BASE;
 241         nand_chip.dev_ready = NULL;     /* preset to NULL */
 242         board_nand_init(&nand_chip);
 243
 244         /*
 245          * Load U-Boot image from NAND into RAM
 246          */
 247         ret = nand_load(&nand_info, CFG_NAND_U_BOOT_OFFS, CFG_NAND_U_BOOT_SIZE,
 248                         (uchar *)CFG_NAND_U_BOOT_DST);
 249
 250         /*
 251          * Jump to U-Boot image
 252          */
 253         uboot = (void (*)(void))CFG_NAND_U_BOOT_START;
 254         (*uboot)();
 255 }