diff options
Diffstat (limited to 'cmd/eeprom.c')
| -rw-r--r-- | cmd/eeprom.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/cmd/eeprom.c b/cmd/eeprom.c new file mode 100644 index 0000000000..571240a99b --- /dev/null +++ b/cmd/eeprom.c @@ -0,0 +1,265 @@ +/* + * (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'" +) |