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 static int sc_nand_device_ready(struct mtd_info *mtdinfo);
  22
  23 #define FPGA_NAND_CMD_MASK              (0x7 << 28)
  24 #define FPGA_NAND_CMD_COMMAND           (0x0 << 28)
  25 #define FPGA_NAND_CMD_ADDR              (0x1 << 28)
  26 #define FPGA_NAND_CMD_READ              (0x2 << 28)
  27 #define FPGA_NAND_CMD_WRITE             (0x3 << 28)
  28 #define FPGA_NAND_BUSY                  (0x1 << 15)
  29 #define FPGA_NAND_ENABLE                (0x1 << 31)
  30 #define FPGA_NAND_DATA_SHIFT            16
  31
  32 /**
  33  * sc_nand_write_byte -  write one byte to the chip
  34  * @mtd:        MTD device structure
  35  * @byte:       pointer to data byte to write
  36  */
  37 static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte)
  38 {
  39         sc_nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
  40 }
  41
  42 /**
  43  * sc_nand_write_buf -  write buffer to chip
  44  * @mtd:        MTD device structure
  45  * @buf:        data buffer
  46  * @len:        number of bytes to write
  47  */
  48 static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  49 {
  50         int i;
  51         struct nand_chip *this = mtd->priv;
  52
  53         for (i = 0; i < len; i++) {
  54                 out_be32(this->IO_ADDR_W,
  55                          state | (buf[i] << FPGA_NAND_DATA_SHIFT));
  56         }
  57 }
  58
  59
  60 /**
  61  * sc_nand_read_byte -  read one byte from the chip
  62  * @mtd:        MTD device structure
  63  */
  64 static u_char sc_nand_read_byte(struct mtd_info *mtd)
  65 {
  66         u8 byte;
  67         sc_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
  68         return byte;
  69 }
  70
  71 /**
  72  * sc_nand_read_word -  read one word from the chip
  73  * @mtd:        MTD device structure
  74  */
  75 static u16 sc_nand_read_word(struct mtd_info *mtd)
  76 {
  77         u16 word;
  78         sc_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
  79         return word;
  80 }
  81
  82 /**
  83  * sc_nand_read_buf -  read chip data into buffer
  84  * @mtd:        MTD device structure
  85  * @buf:        buffer to store date
  86  * @len:        number of bytes to read
  87  */
  88 static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
  89 {
  90         int i;
  91         struct nand_chip *this = mtd->priv;
  92         int val;
  93
  94         val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
  95
  96         out_be32(this->IO_ADDR_W, val);
  97         for (i = 0; i < len; i++) {
  98                 buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
  99         }
 100 }
 101
 102 /**
 103  * sc_nand_device_ready - Check the NAND device is ready for next command.
 104  * @mtd:        MTD device structure
 105  */
 106 static int sc_nand_device_ready(struct mtd_info *mtdinfo)
 107 {
 108         struct nand_chip *this = mtdinfo->priv;
 109
 110         if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
 111                 return 0; /* busy */
 112         return 1;
 113 }
 114
 115 /**
 116  * sc_nand_hwcontrol - NAND control functions wrapper.
 117  * @mtd:        MTD device structure
 118  * @cmd:        Command
 119  */
 120 static void sc_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
 121 {
 122         if (ctrl & NAND_CTRL_CHANGE) {
 123                 state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
 124
 125                 switch (ctrl & (NAND_ALE | NAND_CLE)) {
 126                 case 0:
 127                         state |= FPGA_NAND_CMD_WRITE;
 128                         break;
 129
 130                 case NAND_ALE:
 131                         state |= FPGA_NAND_CMD_ADDR;
 132                         break;
 133
 134                 case NAND_CLE:
 135                         state |= FPGA_NAND_CMD_COMMAND;
 136                         break;
 137
 138                 default:
 139                         printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
 140                 }
 141
 142                 if (ctrl & NAND_NCE)
 143                         state |= FPGA_NAND_ENABLE;
 144         }
 145
 146         if (cmd != NAND_CMD_NONE)
 147                 sc_nand_write_byte(mtdinfo, cmd);
 148 }
 149
 150 int board_nand_init(struct nand_chip *nand)
 151 {
 152         nand->cmd_ctrl = sc_nand_hwcontrol;
 153         nand->ecc.mode = NAND_ECC_SOFT;
 154         nand->dev_ready = sc_nand_device_ready;
 155         nand->read_byte = sc_nand_read_byte;
 156         nand->read_word = sc_nand_read_word;
 157         nand->write_buf = sc_nand_write_buf;
 158         nand->read_buf = sc_nand_read_buf;
 159
 160         return 0;
 161 }
 162
 163 #endif