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 /*
  37  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 2 (16-bit EEPROM address) offset is
  38  *   0x000nxxxx for EEPROM address selectors at n, offset xxxx in EEPROM.
  39  *
  40  * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 (8-bit EEPROM page address) offset is
  41  *   0x00000nxx for EEPROM address selectors and page number at n.
  42  */
  43 #if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
  44 #if !defined(CONFIG_SYS_I2C_EEPROM_ADDR_LEN) || \
  45     (CONFIG_SYS_I2C_EEPROM_ADDR_LEN < 1) || \
  46     (CONFIG_SYS_I2C_EEPROM_ADDR_LEN > 2)
  47 #error CONFIG_SYS_I2C_EEPROM_ADDR_LEN must be 1 or 2
  48 #endif
  49 #endif
  50
  51 __weak int eeprom_write_enable(unsigned dev_addr, int state)
  52 {
  53         return 0;
  54 }
  55
  56 void eeprom_init(void)
  57 {
  58         /* SPI EEPROM */
  59 #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
  60         spi_init_f();
  61 #endif
  62
  63         /* I2C EEPROM */
  64 #if defined(CONFIG_HARD_I2C) || defined(CONFIG_SYS_I2C_SOFT)
  65         i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
  66 #endif
  67 }
  68
  69 static int eeprom_addr(unsigned dev_addr, unsigned offset, uchar *addr)
  70 {
  71         unsigned blk_off;
  72         int alen;
  73
  74         blk_off = offset & 0xff;        /* block offset */
  75 #if CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1
  76         addr[0] = offset >> 8;          /* block number */
  77         addr[1] = blk_off;              /* block offset */
  78         alen = 2;
  79 #else
  80         addr[0] = offset >> 16;         /* block number */
  81         addr[1] = offset >>  8;         /* upper address octet */
  82         addr[2] = blk_off;              /* lower address octet */
  83         alen = 3;
  84 #endif  /* CONFIG_SYS_I2C_EEPROM_ADDR_LEN */
  85
  86         addr[0] |= dev_addr;            /* insert device address */
  87
  88         return alen;
  89 }
  90
  91 static int eeprom_rw_block(unsigned offset, uchar *addr, unsigned alen,
  92                            uchar *buffer, unsigned len, bool read)
  93 {
  94         int ret = 0;
  95
  96         /* SPI */
  97 #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
  98         if (read)
  99                 spi_read(addr, alen, buffer, len);
 100         else
 101                 spi_write(addr, alen, buffer, len);
 102 #else   /* I2C */
 103
 104 #if defined(CONFIG_SYS_I2C_EEPROM_BUS)
 105         i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
 106 #endif
 107
 108         if (read)
 109                 ret = i2c_read(addr[0], offset, alen - 1, buffer, len);
 110         else
 111                 ret = i2c_write(addr[0], offset, alen - 1, buffer, len);
 112
 113         if (ret)
 114                 ret = 1;
 115 #endif
 116         return ret;
 117 }
 118
 119 int eeprom_read (unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
 120 {
 121         unsigned end = offset + cnt;
 122         unsigned blk_off;
 123         int rcode = 0;
 124         uchar addr[3];
 125
 126         /*
 127          * Read data until done or would cross a page boundary.
 128          * We must write the address again when changing pages
 129          * because the next page may be in a different device.
 130          */
 131         while (offset < end) {
 132                 unsigned alen, len;
 133 #if !defined(CONFIG_SYS_I2C_FRAM)
 134                 unsigned maxlen;
 135 #endif
 136
 137                 blk_off = offset & 0xFF;        /* block offset */
 138                 alen = eeprom_addr(dev_addr, offset, addr);
 139
 140                 len = end - offset;
 141
 142                 /*
 143                  * For a FRAM device there is no limit on the number of the
 144                  * bytes that can be ccessed with the single read or write
 145                  * operation.
 146                  */
 147 #if !defined(CONFIG_SYS_I2C_FRAM)
 148                 maxlen = 0x100 - blk_off;
 149                 if (maxlen > I2C_RXTX_LEN)
 150                         maxlen = I2C_RXTX_LEN;
 151                 if (len > maxlen)
 152                         len = maxlen;
 153 #endif
 154
 155                 rcode = eeprom_rw_block(offset, addr, alen, buffer, len, 1);
 156
 157                 buffer += len;
 158                 offset += len;
 159         }
 160
 161         return rcode;
 162 }
 163
 164 int eeprom_write (unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
 165 {
 166         unsigned end = offset + cnt;
 167         unsigned blk_off;
 168         int rcode = 0;
 169         uchar addr[3];
 170
 171         eeprom_write_enable(dev_addr, 1);
 172
 173         /*
 174          * Write data until done or would cross a write page boundary.
 175          * We must write the address again when changing pages
 176          * because the address counter only increments within a page.
 177          */
 178
 179         while (offset < end) {
 180                 unsigned alen, len;
 181 #if !defined(CONFIG_SYS_I2C_FRAM)
 182                 unsigned maxlen;
 183 #endif
 184
 185                 blk_off = offset & 0xFF;        /* block offset */
 186                 alen = eeprom_addr(dev_addr, offset, addr);
 187
 188                 len = end - offset;
 189
 190                 /*
 191                  * For a FRAM device there is no limit on the number of the
 192                  * bytes that can be accessed with the single read or write
 193                  * operation.
 194                  */
 195 #if !defined(CONFIG_SYS_I2C_FRAM)
 196
 197 #if defined(CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
 198
 199 #define EEPROM_PAGE_SIZE        (1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
 200 #define EEPROM_PAGE_OFFSET(x)   ((x) & (EEPROM_PAGE_SIZE - 1))
 201
 202                 maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off);
 203 #else
 204                 maxlen = 0x100 - blk_off;
 205 #endif
 206                 if (maxlen > I2C_RXTX_LEN)
 207                         maxlen = I2C_RXTX_LEN;
 208
 209                 if (len > maxlen)
 210                         len = maxlen;
 211 #endif
 212
 213                 rcode = eeprom_rw_block(offset, addr, alen, buffer, len, 0);
 214
 215                 buffer += len;
 216                 offset += len;
 217
 218                 udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
 219         }
 220
 221         eeprom_write_enable(dev_addr, 0);
 222
 223         return rcode;
 224 }
 225
 226 static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 227 {
 228         const char *const fmt =
 229                 "\nEEPROM @0x%lX %s: addr %08lx  off %04lx  count %ld ... ";
 230         char * const *args = &argv[2];
 231         int rcode;
 232         ulong dev_addr, addr, off, cnt;
 233
 234         switch (argc) {
 235 #ifdef CONFIG_SYS_DEF_EEPROM_ADDR
 236         case 5:
 237                 dev_addr = CONFIG_SYS_DEF_EEPROM_ADDR;
 238                 break;
 239 #endif
 240         case 6:
 241                 dev_addr = simple_strtoul(*args++, NULL, 16);
 242                 break;
 243         default:
 244                 return CMD_RET_USAGE;
 245         }
 246
 247         addr = simple_strtoul(*args++, NULL, 16);
 248         off = simple_strtoul(*args++, NULL, 16);
 249         cnt = simple_strtoul(*args++, NULL, 16);
 250
 251         eeprom_init();
 252
 253         if (strcmp (argv[1], "read") == 0) {
 254                 printf(fmt, dev_addr, argv[1], addr, off, cnt);
 255
 256                 rcode = eeprom_read(dev_addr, off, (uchar *) addr, cnt);
 257
 258                 puts ("done\n");
 259                 return rcode;
 260         } else if (strcmp (argv[1], "write") == 0) {
 261                 printf(fmt, dev_addr, argv[1], addr, off, cnt);
 262
 263                 rcode = eeprom_write(dev_addr, off, (uchar *) addr, cnt);
 264
 265                 puts ("done\n");
 266                 return rcode;
 267         }
 268
 269         return CMD_RET_USAGE;
 270 }
 271
 272 U_BOOT_CMD(
 273         eeprom, 6,      1,      do_eeprom,
 274         "EEPROM sub-system",
 275         "read  devaddr addr off cnt\n"
 276         "eeprom write devaddr addr off cnt\n"
 277         "       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
 278 )