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, 0); 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 ) 266