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 ) 270