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/*
* (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
/*
* 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(void)
{
/* 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)
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_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;
}
int eeprom_read (unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
{
unsigned end = offset + cnt;
unsigned blk_off;
int rcode = 0;
uchar addr[3];
/*
* 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.
*/
while (offset < end) {
unsigned alen, len;
#if !defined(CONFIG_SYS_I2C_FRAM)
unsigned maxlen;
#endif
blk_off = offset & 0xFF; /* block offset */
alen = eeprom_addr(dev_addr, offset, addr);
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)
maxlen = 0x100 - blk_off;
if (maxlen > I2C_RXTX_LEN)
maxlen = I2C_RXTX_LEN;
if (len > maxlen)
len = maxlen;
#endif
rcode = eeprom_rw_block(offset, addr, alen, buffer, len, 1);
buffer += len;
offset += len;
}
return rcode;
}
int eeprom_write (unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
{
unsigned end = offset + cnt;
unsigned blk_off;
int rcode = 0;
uchar addr[3];
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.
*/
while (offset < end) {
unsigned alen, len;
#if !defined(CONFIG_SYS_I2C_FRAM)
unsigned maxlen;
#endif
blk_off = offset & 0xFF; /* block offset */
alen = eeprom_addr(dev_addr, offset, addr);
len = end - offset;
/*
* For a FRAM device there is no limit on the number of the
* bytes that can be accessed with the single read or write
* operation.
*/
#if !defined(CONFIG_SYS_I2C_FRAM)
#if defined(CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
#define EEPROM_PAGE_SIZE (1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
#define EEPROM_PAGE_OFFSET(x) ((x) & (EEPROM_PAGE_SIZE - 1))
maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off);
#else
maxlen = 0x100 - blk_off;
#endif
if (maxlen > I2C_RXTX_LEN)
maxlen = I2C_RXTX_LEN;
if (len > maxlen)
len = maxlen;
#endif
rcode = eeprom_rw_block(offset, addr, alen, buffer, len, 0);
buffer += len;
offset += len;
#if defined(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS)
udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
#endif
}
eeprom_write_enable(dev_addr, 0);
return rcode;
}
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;
switch (argc) {
#ifdef CONFIG_SYS_DEF_EEPROM_ADDR
case 5:
dev_addr = CONFIG_SYS_DEF_EEPROM_ADDR;
break;
#endif
case 6:
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);
# if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
eeprom_init ();
# endif /* !CONFIG_SPI */
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, 6, 1, do_eeprom,
"EEPROM sub-system",
"read devaddr addr off cnt\n"
"eeprom write devaddr addr off cnt\n"
" - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
)
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