--- /dev/null
+/*
+ * (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'"
+)
projects / oweals / u-boot.git / blobdiff