board/socrates/nand.c

   1 /*
   2  * (C) Copyright 2008
   3  * Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9
  10 #if defined(CONFIG_SYS_NAND_BASE)
  11 #include <nand.h>
  12 #include <asm/errno.h>
  13 #include <asm/io.h>
  14
  15 static int state;
  16 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte);
  17 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
  18 static u_char sc_nand_read_byte(struct mtd_info *mtd);
  19 static u16 sc_nand_read_word(struct mtd_info *mtd);
  20 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
  21 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
  22 static int sc_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);
  23 #endif
  24 static int sc_nand_device_ready(struct mtd_info *mtdinfo);
  25
  26 #define FPGA_NAND_CMD_MASK              (0x7 << 28)
  27 #define FPGA_NAND_CMD_COMMAND           (0x0 << 28)
  28 #define FPGA_NAND_CMD_ADDR              (0x1 << 28)
  29 #define FPGA_NAND_CMD_READ              (0x2 << 28)
  30 #define FPGA_NAND_CMD_WRITE             (0x3 << 28)
  31 #define FPGA_NAND_BUSY                  (0x1 << 15)
  32 #define FPGA_NAND_ENABLE                (0x1 << 31)
  33 #define FPGA_NAND_DATA_SHIFT            16
  34
  35 /**
  36  * sc_nand_write_byte -  write one byte to the chip
  37  * @mtd:        MTD device structure
  38  * @byte:       pointer to data byte to write
  39  */
  40 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte)
  41 {
  42         sc_nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
  43 }
  44
  45 /**
  46  * sc_nand_write_buf -  write buffer to chip
  47  * @mtd:        MTD device structure
  48  * @buf:        data buffer
  49  * @len:        number of bytes to write
  50  */
  51 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  52 {
  53         int i;
  54         struct nand_chip *this = mtd->priv;
  55
  56         for (i = 0; i < len; i++) {
  57                 out_be32(this->IO_ADDR_W,
  58                          state | (buf[i] << FPGA_NAND_DATA_SHIFT));
  59         }
  60 }
  61
  62
  63 /**
  64  * sc_nand_read_byte -  read one byte from the chip
  65  * @mtd:        MTD device structure
  66  */
  67 static u_char sc_nand_read_byte(struct mtd_info *mtd)
  68 {
  69         u8 byte;
  70         sc_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
  71         return byte;
  72 }
  73
  74 /**
  75  * sc_nand_read_word -  read one word from the chip
  76  * @mtd:        MTD device structure
  77  */
  78 static u16 sc_nand_read_word(struct mtd_info *mtd)
  79 {
  80         u16 word;
  81         sc_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
  82         return word;
  83 }
  84
  85 /**
  86  * sc_nand_read_buf -  read chip data into buffer
  87  * @mtd:        MTD device structure
  88  * @buf:        buffer to store date
  89  * @len:        number of bytes to read
  90  */
  91 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
  92 {
  93         int i;
  94         struct nand_chip *this = mtd->priv;
  95         int val;
  96
  97         val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
  98
  99         out_be32(this->IO_ADDR_W, val);
 100         for (i = 0; i < len; i++) {
 101                 buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
 102         }
 103 }
 104
 105 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
 106 /**
 107  * sc_nand_verify_buf -  Verify chip data against buffer
 108  * @mtd:        MTD device structure
 109  * @buf:        buffer containing the data to compare
 110  * @len:        number of bytes to compare
 111  */
 112 static int sc_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
 113 {
 114         int i;
 115
 116         for (i = 0; i < len; i++) {
 117                 if (buf[i] != sc_nand_read_byte(mtd));
 118                         return -EFAULT;
 119         }
 120         return 0;
 121 }
 122 #endif
 123
 124 /**
 125  * sc_nand_device_ready - Check the NAND device is ready for next command.
 126  * @mtd:        MTD device structure
 127  */
 128 static int sc_nand_device_ready(struct mtd_info *mtdinfo)
 129 {
 130         struct nand_chip *this = mtdinfo->priv;
 131
 132         if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
 133                 return 0; /* busy */
 134         return 1;
 135 }
 136
 137 /**
 138  * sc_nand_hwcontrol - NAND control functions wrapper.
 139  * @mtd:        MTD device structure
 140  * @cmd:        Command
 141  */
 142 static void sc_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
 143 {
 144         if (ctrl & NAND_CTRL_CHANGE) {
 145                 state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
 146
 147                 switch (ctrl & (NAND_ALE | NAND_CLE)) {
 148                 case 0:
 149                         state |= FPGA_NAND_CMD_WRITE;
 150                         break;
 151
 152                 case NAND_ALE:
 153                         state |= FPGA_NAND_CMD_ADDR;
 154                         break;
 155
 156                 case NAND_CLE:
 157                         state |= FPGA_NAND_CMD_COMMAND;
 158                         break;
 159
 160                 default:
 161                         printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
 162                 }
 163
 164                 if (ctrl & NAND_NCE)
 165                         state |= FPGA_NAND_ENABLE;
 166         }
 167
 168         if (cmd != NAND_CMD_NONE)
 169                 sc_nand_write_byte(mtdinfo, cmd);
 170 }
 171
 172 int board_nand_init(struct nand_chip *nand)
 173 {
 174         nand->cmd_ctrl = sc_nand_hwcontrol;
 175         nand->ecc.mode = NAND_ECC_SOFT;
 176         nand->dev_ready = sc_nand_device_ready;
 177         nand->read_byte = sc_nand_read_byte;
 178         nand->read_word = sc_nand_read_word;
 179         nand->write_buf = sc_nand_write_buf;
 180         nand->read_buf = sc_nand_read_buf;
 181 #if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
 182         nand->verify_buf = sc_nand_verify_buf;
 183 #endif
 184
 185         return 0;
 186 }
 187
 188 #endif