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