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