cmd/eeprom.c

   1 /*
   2  * (C) Copyright 2000, 2001
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Support for read and write access to EEPROM like memory devices. This
  10  * includes regular EEPROM as well as  FRAM (ferroelectic nonvolaile RAM).
  11  * FRAM devices read and write data at bus speed. In particular, there is no
  12  * write delay. Also, there is no limit imposed on the number of bytes that can
  13  * be transferred with a single read or write.
  14  *
  15  * Use the following configuration options to ensure no unneeded performance
  16  * degradation (typical for EEPROM) is incured for FRAM memory:
  17  *
  18  * #define CONFIG_SYS_I2C_FRAM
  19  * #undef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
  20  *
  21  */
  22
  23 #include <common.h>
  24 #include <config.h>
  25 #include <command.h>
  26 #include <i2c.h>
  27
  28 #ifndef CONFIG_SYS_I2C_SPEED
  29 #define CONFIG_SYS_I2C_SPEED    50000
  30 #endif
  31
  32 #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
  33 #define CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS   0
  34 #endif
  35
  36 #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_BITS
  37 #define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS       8
  38 #endif
  39
  40 #ifndef I2C_RXTX_LEN
  41 #define I2C_RXTX_LEN    128
  42 #endif
  43
  44 #define EEPROM_PAGE_SIZE        (1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
  45 #define EEPROM_PAGE_OFFSET(x)   ((x) & (EEPROM_PAGE_SIZE - 1))
  46
  47 /*
  48  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 2 (16-bit EEPROM address) offset is
  49  *   0x000nxxxx for EEPROM address selectors at n, offset xxxx in EEPROM.
  50  *
  51  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 (8-bit EEPROM page address) offset is
  52  *   0x00000nxx for EEPROM address selectors and page number at n.
  53  */
  54 #if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
  55 #if !defined(CONFIG_SYS_I2C_EEPROM_ADDR_LEN) || \
  56         (CONFIG_SYS_I2C_EEPROM_ADDR_LEN < 1) || \
  57         (CONFIG_SYS_I2C_EEPROM_ADDR_LEN > 2)
  58 #error CONFIG_SYS_I2C_EEPROM_ADDR_LEN must be 1 or 2
  59 #endif
  60 #endif
  61
  62 __weak int eeprom_write_enable(unsigned dev_addr, int state)
  63 {
  64         return 0;
  65 }
  66
  67 void eeprom_init(int bus)
  68 {
  69         /* SPI EEPROM */
  70 #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
  71         spi_init_f();
  72 #endif
  73
  74         /* I2C EEPROM */
  75 #if defined(CONFIG_HARD_I2C) || defined(CONFIG_SYS_I2C_SOFT)
  76 #if defined(CONFIG_SYS_I2C)
  77         if (bus >= 0)
  78                 i2c_set_bus_num(bus);
  79 #endif
  80         i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
  81 #endif
  82 }
  83
  84 static int eeprom_addr(unsigned dev_addr, unsigned offset, uchar *addr)
  85 {
  86         unsigned blk_off;
  87         int alen;
  88
  89         blk_off = offset & 0xff;        /* block offset */
  90 #if CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1
  91         addr[0] = offset >> 8;          /* block number */
  92         addr[1] = blk_off;              /* block offset */
  93         alen = 2;
  94 #else
  95         addr[0] = offset >> 16;         /* block number */
  96         addr[1] = offset >>  8;         /* upper address octet */
  97         addr[2] = blk_off;              /* lower address octet */
  98         alen = 3;
  99 #endif  /* CONFIG_SYS_I2C_EEPROM_ADDR_LEN */
 100
 101         addr[0] |= dev_addr;            /* insert device address */
 102
 103         return alen;
 104 }
 105
 106 static int eeprom_len(unsigned offset, unsigned end)
 107 {
 108         unsigned len = end - offset;
 109
 110         /*
 111          * For a FRAM device there is no limit on the number of the
 112          * bytes that can be ccessed with the single read or write
 113          * operation.
 114          */
 115 #if !defined(CONFIG_SYS_I2C_FRAM)
 116         unsigned blk_off = offset & 0xff;
 117         unsigned maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off);
 118
 119         if (maxlen > I2C_RXTX_LEN)
 120                 maxlen = I2C_RXTX_LEN;
 121
 122         if (len > maxlen)
 123                 len = maxlen;
 124 #endif
 125
 126         return len;
 127 }
 128
 129 static int eeprom_rw_block(unsigned offset, uchar *addr, unsigned alen,
 130                            uchar *buffer, unsigned len, bool read)
 131 {
 132         int ret = 0;
 133
 134         /* SPI */
 135 #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
 136         if (read)
 137                 spi_read(addr, alen, buffer, len);
 138         else
 139                 spi_write(addr, alen, buffer, len);
 140 #else   /* I2C */
 141
 142 #if defined(CONFIG_SYS_I2C_EEPROM_BUS)
 143         i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
 144 #endif
 145
 146         if (read)
 147                 ret = i2c_read(addr[0], offset, alen - 1, buffer, len);
 148         else
 149                 ret = i2c_write(addr[0], offset, alen - 1, buffer, len);
 150
 151         if (ret)
 152                 ret = 1;
 153 #endif
 154         return ret;
 155 }
 156
 157 static int eeprom_rw(unsigned dev_addr, unsigned offset, uchar *buffer,
 158                      unsigned cnt, bool read)
 159 {
 160         unsigned end = offset + cnt;
 161         unsigned alen, len;
 162         int rcode = 0;
 163         uchar addr[3];
 164
 165         while (offset < end) {
 166                 alen = eeprom_addr(dev_addr, offset, addr);
 167
 168                 len = eeprom_len(offset, end);
 169
 170                 rcode = eeprom_rw_block(offset, addr, alen, buffer, len, read);
 171
 172                 buffer += len;
 173                 offset += len;
 174
 175                 if (!read)
 176                         udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
 177         }
 178
 179         return rcode;
 180 }
 181
 182 int eeprom_read(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
 183 {
 184         /*
 185          * Read data until done or would cross a page boundary.
 186          * We must write the address again when changing pages
 187          * because the next page may be in a different device.
 188          */
 189         return eeprom_rw(dev_addr, offset, buffer, cnt, 1);
 190 }
 191
 192 int eeprom_write(unsigned dev_addr, unsigned offset,
 193                  uchar *buffer, unsigned cnt)
 194 {
 195         int ret;
 196
 197         eeprom_write_enable(dev_addr, 1);
 198
 199         /*
 200          * Write data until done or would cross a write page boundary.
 201          * We must write the address again when changing pages
 202          * because the address counter only increments within a page.
 203          */
 204         ret = eeprom_rw(dev_addr, offset, buffer, cnt, 0);
 205
 206         eeprom_write_enable(dev_addr, 0);
 207         return ret;
 208 }
 209
 210 static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 211 {
 212         const char *const fmt =
 213                 "\nEEPROM @0x%lX %s: addr %08lx  off %04lx  count %ld ... ";
 214         char * const *args = &argv[2];
 215         int rcode;
 216         ulong dev_addr, addr, off, cnt;
 217         int bus_addr;
 218
 219         switch (argc) {
 220 #ifdef CONFIG_SYS_DEF_EEPROM_ADDR
 221         case 5:
 222                 bus_addr = -1;
 223                 dev_addr = CONFIG_SYS_DEF_EEPROM_ADDR;
 224                 break;
 225 #endif
 226         case 6:
 227                 bus_addr = -1;
 228                 dev_addr = simple_strtoul(*args++, NULL, 16);
 229                 break;
 230         case 7:
 231                 bus_addr = simple_strtoul(*args++, NULL, 16);
 232                 dev_addr = simple_strtoul(*args++, NULL, 16);
 233                 break;
 234         default:
 235                 return CMD_RET_USAGE;
 236         }
 237
 238         addr = simple_strtoul(*args++, NULL, 16);
 239         off = simple_strtoul(*args++, NULL, 16);
 240         cnt = simple_strtoul(*args++, NULL, 16);
 241
 242         eeprom_init(bus_addr);
 243
 244         if (strcmp(argv[1], "read") == 0) {
 245                 printf(fmt, dev_addr, argv[1], addr, off, cnt);
 246
 247                 rcode = eeprom_read(dev_addr, off, (uchar *)addr, cnt);
 248
 249                 puts("done\n");
 250                 return rcode;
 251         } else if (strcmp(argv[1], "write") == 0) {
 252                 printf(fmt, dev_addr, argv[1], addr, off, cnt);
 253
 254                 rcode = eeprom_write(dev_addr, off, (uchar *)addr, cnt);
 255
 256                 puts("done\n");
 257                 return rcode;
 258         }
 259
 260         return CMD_RET_USAGE;
 261 }
 262
 263 U_BOOT_CMD(
 264         eeprom, 7,      1,      do_eeprom,
 265         "EEPROM sub-system",
 266         "read  <bus> <devaddr> addr off cnt\n"
 267         "eeprom write <bus> <devaddr> addr off cnt\n"
 268         "       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
 269 )