board/socrates/nand.c

   1 /*
   2  * (C) Copyright 2008
   3  * Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <common.h>
  25
  26 #if defined(CONFIG_SYS_NAND_BASE)
  27 #include <nand.h>
  28 #include <asm/errno.h>
  29 #include <asm/io.h>
  30
  31 static int state;
  32 static void nand_write_byte(struct mtd_info *mtd, u_char byte);
  33 static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
  34 static u_char nand_read_byte(struct mtd_info *mtd);
  35 static u16 nand_read_word(struct mtd_info *mtd);
  36 static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
  37 static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);
  38 static int nand_device_ready(struct mtd_info *mtdinfo);
  39
  40 #define FPGA_NAND_CMD_MASK              (0x7 << 28)
  41 #define FPGA_NAND_CMD_COMMAND           (0x0 << 28)
  42 #define FPGA_NAND_CMD_ADDR              (0x1 << 28)
  43 #define FPGA_NAND_CMD_READ              (0x2 << 28)
  44 #define FPGA_NAND_CMD_WRITE             (0x3 << 28)
  45 #define FPGA_NAND_BUSY                  (0x1 << 15)
  46 #define FPGA_NAND_ENABLE                (0x1 << 31)
  47 #define FPGA_NAND_DATA_SHIFT            16
  48
  49 /**
  50  * nand_write_byte -  write one byte to the chip
  51  * @mtd:        MTD device structure
  52  * @byte:       pointer to data byte to write
  53  */
  54 static void nand_write_byte(struct mtd_info *mtd, u_char byte)
  55 {
  56         nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
  57 }
  58
  59 /**
  60  * nand_write_buf -  write buffer to chip
  61  * @mtd:        MTD device structure
  62  * @buf:        data buffer
  63  * @len:        number of bytes to write
  64  */
  65 static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  66 {
  67         int i;
  68         struct nand_chip *this = mtd->priv;
  69
  70         for (i = 0; i < len; i++) {
  71                 out_be32(this->IO_ADDR_W,
  72                          state | (buf[i] << FPGA_NAND_DATA_SHIFT));
  73         }
  74 }
  75
  76
  77 /**
  78  * nand_read_byte -  read one byte from the chip
  79  * @mtd:        MTD device structure
  80  */
  81 static u_char nand_read_byte(struct mtd_info *mtd)
  82 {
  83         u8 byte;
  84         nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
  85         return byte;
  86 }
  87
  88 /**
  89  * nand_read_word -  read one word from the chip
  90  * @mtd:        MTD device structure
  91  */
  92 static u16 nand_read_word(struct mtd_info *mtd)
  93 {
  94         u16 word;
  95         nand_read_buf(mtd, (uchar *)&word, sizeof(word));
  96         return word;
  97 }
  98
  99 /**
 100  * nand_read_buf -  read chip data into buffer
 101  * @mtd:        MTD device structure
 102  * @buf:        buffer to store date
 103  * @len:        number of bytes to read
 104  */
 105 static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 106 {
 107         int i;
 108         struct nand_chip *this = mtd->priv;
 109         int val;
 110
 111         val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
 112
 113         out_be32(this->IO_ADDR_W, val);
 114         for (i = 0; i < len; i++) {
 115                 buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
 116         }
 117 }
 118
 119 /**
 120  * nand_verify_buf -  Verify chip data against buffer
 121  * @mtd:        MTD device structure
 122  * @buf:        buffer containing the data to compare
 123  * @len:        number of bytes to compare
 124  */
 125 static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
 126 {
 127         int i;
 128
 129         for (i = 0; i < len; i++) {
 130                 if (buf[i] != nand_read_byte(mtd));
 131                         return -EFAULT;
 132         }
 133         return 0;
 134 }
 135
 136 /**
 137  * nand_device_ready - Check the NAND device is ready for next command.
 138  * @mtd:        MTD device structure
 139  */
 140 static int nand_device_ready(struct mtd_info *mtdinfo)
 141 {
 142         struct nand_chip *this = mtdinfo->priv;
 143
 144         if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
 145                 return 0; /* busy */
 146         return 1;
 147 }
 148
 149 /**
 150  * nand_hwcontrol - NAND control functions wrapper.
 151  * @mtd:        MTD device structure
 152  * @cmd:        Command
 153  */
 154 static void nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
 155 {
 156         if (ctrl & NAND_CTRL_CHANGE) {
 157                 state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
 158
 159                 switch (ctrl & (NAND_ALE | NAND_CLE)) {
 160                 case 0:
 161                         state |= FPGA_NAND_CMD_WRITE;
 162                         break;
 163
 164                 case NAND_ALE:
 165                         state |= FPGA_NAND_CMD_ADDR;
 166                         break;
 167
 168                 case NAND_CLE:
 169                         state |= FPGA_NAND_CMD_COMMAND;
 170                         break;
 171
 172                 default:
 173                         printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
 174                 }
 175
 176                 if (ctrl & NAND_NCE)
 177                         state |= FPGA_NAND_ENABLE;
 178         }
 179
 180         if (cmd != NAND_CMD_NONE)
 181                 nand_write_byte(mtdinfo, cmd);
 182 }
 183
 184 int board_nand_init(struct nand_chip *nand)
 185 {
 186         nand->cmd_ctrl = nand_hwcontrol;
 187         nand->ecc.mode = NAND_ECC_SOFT;
 188         nand->dev_ready = nand_device_ready;
 189         nand->read_byte = nand_read_byte;
 190         nand->read_word = nand_read_word;
 191         nand->write_buf = nand_write_buf;
 192         nand->read_buf = nand_read_buf;
 193         nand->verify_buf = nand_verify_buf;
 194
 195         return 0;
 196 }
 197
 198 #endif