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 #include <asm/io.h>
  24
  25 #define CFG_NAND_READ_DELAY \
  26         { volatile int dummy; int i; for (i=0; i<10000; i++) dummy = i; }
  27
  28 static int nand_ecc_pos[] = CFG_NAND_ECCPOS;
  29
  30 extern void board_nand_init(struct nand_chip *nand);
  31
  32 #if (CFG_NAND_PAGE_SIZE <= 512)
  33 /*
  34  * NAND command for small page NAND devices (512)
  35  */
  36 static int nand_command(struct mtd_info *mtd, int block, int page, int offs, u8 cmd)
  37 {
  38         struct nand_chip *this = mtd->priv;
  39         int page_addr = page + block * CFG_NAND_PAGE_COUNT;
  40
  41         if (this->dev_ready)
  42                 while (!this->dev_ready(mtd))
  43                         ;
  44         else
  45                 CFG_NAND_READ_DELAY;
  46
  47         /* Begin command latch cycle */
  48         this->cmd_ctrl(mtd, cmd, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
  49         /* Set ALE and clear CLE to start address cycle */
  50         /* Column address */
  51         this->cmd_ctrl(mtd, offs, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
  52         this->cmd_ctrl(mtd, page_addr & 0xff, 0); /* A[16:9] */
  53         this->cmd_ctrl(mtd, (page_addr >> 8) & 0xff, 0); /* A[24:17] */
  54 #ifdef CFG_NAND_4_ADDR_CYCLE
  55         /* One more address cycle for devices > 32MiB */
  56         this->cmd_ctrl(mtd, (page_addr >> 16) & 0x0f, 0); /* A[28:25] */
  57 #endif
  58         /* Latch in address */
  59         this->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
  60
  61         /*
  62          * Wait a while for the data to be ready
  63          */
  64         if (this->dev_ready)
  65                 while (!this->dev_ready(mtd))
  66                         ;
  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_addr = page + block * CFG_NAND_PAGE_COUNT;
  80
  81         if (this->dev_ready)
  82                 while (!this->dev_ready(mtd))
  83                         ;
  84         else
  85                 CFG_NAND_READ_DELAY;
  86
  87         /* Emulate NAND_CMD_READOOB */
  88         if (cmd == NAND_CMD_READOOB) {
  89                 offs += CFG_NAND_PAGE_SIZE;
  90                 cmd = NAND_CMD_READ0;
  91         }
  92
  93         /* Begin command latch cycle */
  94         this->cmd_ctrl(mtd, cmd, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
  95         /* Set ALE and clear CLE to start address cycle */
  96         /* Column address */
  97         this->cmd_ctrl(mtd, offs & 0xff,
  98                        NAND_CTRL_ALE | NAND_CTRL_CHANGE); /* A[7:0] */
  99         this->cmd_ctrl(mtd, (offs >> 8) & 0xff, 0); /* A[11:9] */
 100         /* Row address */
 101         this->cmd_ctrl(mtd, (page_addr & 0xff), 0); /* A[19:12] */
 102         this->cmd_ctrl(mtd, ((page_addr >> 8) & 0xff), 0); /* A[27:20] */
 103 #ifdef CFG_NAND_5_ADDR_CYCLE
 104         /* One more address cycle for devices > 128MiB */
 105         this->cmd_ctrl(mtd, (page_addr >> 16) & 0x0f, 0); /* A[31:28] */
 106 #endif
 107         /* Latch in address */
 108         this->cmd_ctrl(mtd, NAND_CMD_READSTART,
 109                        NAND_CTRL_CLE | NAND_CTRL_CHANGE);
 110         this->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 111
 112         /*
 113          * Wait a while for the data to be ready
 114          */
 115         if (this->dev_ready)
 116                 while (!this->dev_ready(mtd))
 117                         ;
 118         else
 119                 CFG_NAND_READ_DELAY;
 120
 121         return 0;
 122 }
 123 #endif
 124
 125 static int nand_is_bad_block(struct mtd_info *mtd, int block)
 126 {
 127         struct nand_chip *this = mtd->priv;
 128
 129         nand_command(mtd, block, 0, CFG_NAND_BAD_BLOCK_POS, NAND_CMD_READOOB);
 130
 131         /*
 132          * Read one byte
 133          */
 134         if (readb(this->IO_ADDR_R) != 0xff)
 135                 return 1;
 136
 137         return 0;
 138 }
 139
 140 static int nand_read_page(struct mtd_info *mtd, int block, int page, uchar *dst)
 141 {
 142         struct nand_chip *this = mtd->priv;
 143         u_char *ecc_calc;
 144         u_char *ecc_code;
 145         u_char *oob_data;
 146         int i;
 147         int eccsize = CFG_NAND_ECCSIZE;
 148         int eccbytes = CFG_NAND_ECCBYTES;
 149         int eccsteps = CFG_NAND_ECCSTEPS;
 150         uint8_t *p = dst;
 151         int stat;
 152
 153         nand_command(mtd, block, page, 0, NAND_CMD_READ0);
 154
 155         /* No malloc available for now, just use some temporary locations
 156          * in SDRAM
 157          */
 158         ecc_calc = (u_char *)(CFG_SDRAM_BASE + 0x10000);
 159         ecc_code = ecc_calc + 0x100;
 160         oob_data = ecc_calc + 0x200;
 161
 162         for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 163                 this->ecc.hwctl(mtd, NAND_ECC_READ);
 164                 this->read_buf(mtd, p, eccsize);
 165                 this->ecc.calculate(mtd, p, &ecc_calc[i]);
 166         }
 167         this->read_buf(mtd, oob_data, CFG_NAND_OOBSIZE);
 168
 169         /* Pick the ECC bytes out of the oob data */
 170         for (i = 0; i < CFG_NAND_ECCTOTAL; i++)
 171                 ecc_code[i] = oob_data[nand_ecc_pos[i]];
 172
 173         eccsteps = CFG_NAND_ECCSTEPS;
 174         p = dst;
 175
 176         for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 177                 /* No chance to do something with the possible error message
 178                  * from correct_data(). We just hope that all possible errors
 179                  * are corrected by this routine.
 180                  */
 181                 stat = this->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int nand_load(struct mtd_info *mtd, unsigned int offs,
 188                      unsigned int uboot_size, uchar *dst)
 189 {
 190         unsigned int block, lastblock;
 191         unsigned int page;
 192
 193         /*
 194          * offs has to be aligned to a page address!
 195          */
 196         block = offs / CFG_NAND_BLOCK_SIZE;
 197         lastblock = (offs + uboot_size - 1) / CFG_NAND_BLOCK_SIZE;
 198         page = (offs % CFG_NAND_BLOCK_SIZE) / CFG_NAND_PAGE_SIZE;
 199
 200         while (block <= lastblock) {
 201                 if (!nand_is_bad_block(mtd, block)) {
 202                         /*
 203                          * Skip bad blocks
 204                          */
 205                         while (page < CFG_NAND_PAGE_COUNT) {
 206                                 nand_read_page(mtd, block, page, dst);
 207                                 dst += CFG_NAND_PAGE_SIZE;
 208                                 page++;
 209                         }
 210
 211                         page = 0;
 212                 } else {
 213                         lastblock++;
 214                 }
 215
 216                 block++;
 217         }
 218
 219         return 0;
 220 }
 221
 222 /*
 223  * The main entry for NAND booting. It's necessary that SDRAM is already
 224  * configured and available since this code loads the main U-Boot image
 225  * from NAND into SDRAM and starts it from there.
 226  */
 227 void nand_boot(void)
 228 {
 229         struct nand_chip nand_chip;
 230         nand_info_t nand_info;
 231         int ret;
 232         __attribute__((noreturn)) void (*uboot)(void);
 233
 234         /*
 235          * Init board specific nand support
 236          */
 237         nand_info.priv = &nand_chip;
 238         nand_chip.IO_ADDR_R = nand_chip.IO_ADDR_W = (void  __iomem *)CFG_NAND_BASE;
 239         nand_chip.dev_ready = NULL;     /* preset to NULL */
 240         board_nand_init(&nand_chip);
 241
 242         if (nand_chip.select_chip)
 243                 nand_chip.select_chip(&nand_info, 0);
 244
 245         /*
 246          * Load U-Boot image from NAND into RAM
 247          */
 248         ret = nand_load(&nand_info, CFG_NAND_U_BOOT_OFFS, CFG_NAND_U_BOOT_SIZE,
 249                         (uchar *)CFG_NAND_U_BOOT_DST);
 250
 251         if (nand_chip.select_chip)
 252                 nand_chip.select_chip(&nand_info, -1);
 253
 254         /*
 255          * Jump to U-Boot image
 256          */
 257         uboot = (void *)CFG_NAND_U_BOOT_START;
 258         (*uboot)();
 259 }