/* * (C) Copyright 2000, 2001 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. * * SPDX-License-Identifier: GPL-2.0+ */ /* * Support for read and write access to EEPROM like memory devices. This * includes regular EEPROM as well as FRAM (ferroelectic nonvolaile RAM). * FRAM devices read and write data at bus speed. In particular, there is no * write delay. Also, there is no limit imposed on the number of bytes that can * be transferred with a single read or write. * * Use the following configuration options to ensure no unneeded performance * degradation (typical for EEPROM) is incured for FRAM memory: * * #define CONFIG_SYS_I2C_FRAM * #undef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * */ #include <common.h> #include <config.h> #include <command.h> #include <i2c.h> #ifndef CONFIG_SYS_I2C_SPEED #define CONFIG_SYS_I2C_SPEED 50000 #endif #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS #define CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS 0 #endif #ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_BITS #define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS 8 #endif #define EEPROM_PAGE_SIZE (1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS) #define EEPROM_PAGE_OFFSET(x) ((x) & (EEPROM_PAGE_SIZE - 1)) /* * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 2 (16-bit EEPROM address) offset is * 0x000nxxxx for EEPROM address selectors at n, offset xxxx in EEPROM. * * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 (8-bit EEPROM page address) offset is * 0x00000nxx for EEPROM address selectors and page number at n. */ #if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C) #if !defined(CONFIG_SYS_I2C_EEPROM_ADDR_LEN) || \ (CONFIG_SYS_I2C_EEPROM_ADDR_LEN < 1) || \ (CONFIG_SYS_I2C_EEPROM_ADDR_LEN > 2) #error CONFIG_SYS_I2C_EEPROM_ADDR_LEN must be 1 or 2 #endif #endif __weak int eeprom_write_enable(unsigned dev_addr, int state) { return 0; } void eeprom_init(int bus) { /* SPI EEPROM */ #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C) spi_init_f(); #endif /* I2C EEPROM */ #if defined(CONFIG_HARD_I2C) || defined(CONFIG_SYS_I2C_SOFT) #if defined(CONFIG_SYS_I2C) if (bus >= 0) i2c_set_bus_num(bus); #endif i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); #endif } static int eeprom_addr(unsigned dev_addr, unsigned offset, uchar *addr) { unsigned blk_off; int alen; blk_off = offset & 0xff; /* block offset */ #if CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 addr[0] = offset >> 8; /* block number */ addr[1] = blk_off; /* block offset */ alen = 2; #else addr[0] = offset >> 16; /* block number */ addr[1] = offset >> 8; /* upper address octet */ addr[2] = blk_off; /* lower address octet */ alen = 3; #endif /* CONFIG_SYS_I2C_EEPROM_ADDR_LEN */ addr[0] |= dev_addr; /* insert device address */ return alen; } static int eeprom_len(unsigned offset, unsigned end) { unsigned len = end - offset; /* * For a FRAM device there is no limit on the number of the * bytes that can be ccessed with the single read or write * operation. */ #if !defined(CONFIG_SYS_I2C_FRAM) unsigned blk_off = offset & 0xff; unsigned maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off); if (maxlen > I2C_RXTX_LEN) maxlen = I2C_RXTX_LEN; if (len > maxlen) len = maxlen; #endif return len; } static int eeprom_rw_block(unsigned offset, uchar *addr, unsigned alen, uchar *buffer, unsigned len, bool read) { int ret = 0; /* SPI */ #if defined(CONFIG_SPI) && !defined(CONFIG_ENV_EEPROM_IS_ON_I2C) if (read) spi_read(addr, alen, buffer, len); else spi_write(addr, alen, buffer, len); #else /* I2C */ #if defined(CONFIG_SYS_I2C_EEPROM_BUS) i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS); #endif if (read) ret = i2c_read(addr[0], offset, alen - 1, buffer, len); else ret = i2c_write(addr[0], offset, alen - 1, buffer, len); if (ret) ret = 1; #endif return ret; } static int eeprom_rw(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt, bool read) { unsigned end = offset + cnt; unsigned alen, len; int rcode = 0; uchar addr[3]; while (offset < end) { alen = eeprom_addr(dev_addr, offset, addr); len = eeprom_len(offset, end); rcode = eeprom_rw_block(offset, addr, alen, buffer, len, read); buffer += len; offset += len; if (!read) udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000); } return rcode; } int eeprom_read(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt) { /* * Read data until done or would cross a page boundary. * We must write the address again when changing pages * because the next page may be in a different device. */ return eeprom_rw(dev_addr, offset, buffer, cnt, 1); } int eeprom_write(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt) { int ret; eeprom_write_enable(dev_addr, 1); /* * Write data until done or would cross a write page boundary. * We must write the address again when changing pages * because the address counter only increments within a page. */ ret = eeprom_rw(dev_addr, offset, buffer, cnt, 0); eeprom_write_enable(dev_addr, 0); return ret; } static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { const char *const fmt = "\nEEPROM @0x%lX %s: addr %08lx off %04lx count %ld ... "; char * const *args = &argv[2]; int rcode; ulong dev_addr, addr, off, cnt; int bus_addr; switch (argc) { #ifdef CONFIG_SYS_DEF_EEPROM_ADDR case 5: bus_addr = -1; dev_addr = CONFIG_SYS_DEF_EEPROM_ADDR; break; #endif case 6: bus_addr = -1; dev_addr = simple_strtoul(*args++, NULL, 16); break; case 7: bus_addr = simple_strtoul(*args++, NULL, 16); dev_addr = simple_strtoul(*args++, NULL, 16); break; default: return CMD_RET_USAGE; } addr = simple_strtoul(*args++, NULL, 16); off = simple_strtoul(*args++, NULL, 16); cnt = simple_strtoul(*args++, NULL, 16); eeprom_init(bus_addr); if (strcmp(argv[1], "read") == 0) { printf(fmt, dev_addr, argv[1], addr, off, cnt); rcode = eeprom_read(dev_addr, off, (uchar *)addr, cnt); puts("done\n"); return rcode; } else if (strcmp(argv[1], "write") == 0) { printf(fmt, dev_addr, argv[1], addr, off, cnt); rcode = eeprom_write(dev_addr, off, (uchar *)addr, cnt); puts("done\n"); return rcode; } return CMD_RET_USAGE; } U_BOOT_CMD( eeprom, 7, 1, do_eeprom, "EEPROM sub-system", "read <bus> <devaddr> addr off cnt\n" "eeprom write <bus> <devaddr> addr off cnt\n" " - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'" )