cm-t35: move the eeprom code to common place

Compulab boards use the same eeprom code, so move the eeprom related
code to live under board/compulab/common directory.
Also make several adjustments to eeprom functions namespace, so it will
be generic for compulab boards.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Tested-by: Nikita Kiryanov <nikita@compulab.co.il>
diff --git a/board/compulab/common/eeprom.c b/board/compulab/common/eeprom.c
new file mode 100644
index 0000000..5aa3dbd
--- /dev/null
+++ b/board/compulab/common/eeprom.c
@@ -0,0 +1,121 @@
+/*
+ * (C) Copyright 2011 CompuLab, Ltd. <www.compulab.co.il>
+ *
+ * Authors: Nikita Kiryanov <nikita@compulab.co.il>
+ *	    Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <i2c.h>
+
+#define EEPROM_LAYOUT_VER_OFFSET	44
+#define BOARD_SERIAL_OFFSET		20
+#define BOARD_SERIAL_OFFSET_LEGACY	8
+#define BOARD_REV_OFFSET		0
+#define BOARD_REV_OFFSET_LEGACY		6
+#define BOARD_REV_SIZE			2
+#define MAC_ADDR_OFFSET			4
+#define MAC_ADDR_OFFSET_LEGACY		0
+
+#define LAYOUT_INVALID	0
+#define LAYOUT_LEGACY	0xff
+
+static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
+
+static int cl_eeprom_read(uint offset, uchar *buf, int len)
+{
+	return i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
+			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
+}
+
+static int cl_eeprom_setup_layout(void)
+{
+	int res;
+
+	if (cl_eeprom_layout != LAYOUT_INVALID)
+		return 0;
+
+	res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
+			     (uchar *)&cl_eeprom_layout, 1);
+	if (res) {
+		cl_eeprom_layout = LAYOUT_INVALID;
+		return res;
+	}
+
+	if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
+		cl_eeprom_layout = LAYOUT_LEGACY;
+
+	return 0;
+}
+
+void get_board_serial(struct tag_serialnr *serialnr)
+{
+	u32 serial[2];
+	uint offset;
+
+	memset(serialnr, 0, sizeof(*serialnr));
+
+	if (cl_eeprom_setup_layout())
+		return;
+
+	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
+		BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
+
+	if (cl_eeprom_read(offset, (uchar *)serial, 8))
+		return;
+
+	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
+		serialnr->low = serial[0];
+		serialnr->high = serial[1];
+	}
+}
+
+/*
+ * Routine: cl_eeprom_read_mac_addr
+ * Description: read mac address and store it in buf.
+ */
+int cl_eeprom_read_mac_addr(uchar *buf)
+{
+	uint offset;
+
+	if (cl_eeprom_setup_layout())
+		return 0;
+
+	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
+			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
+
+	return cl_eeprom_read(offset, buf, 6);
+}
+
+/*
+ * Routine: cl_eeprom_get_board_rev
+ * Description: read system revision from eeprom
+ */
+u32 cl_eeprom_get_board_rev(void)
+{
+	u32 rev = 0;
+	char str[5]; /* Legacy representation can contain at most 4 digits */
+	uint offset = BOARD_REV_OFFSET_LEGACY;
+
+	if (cl_eeprom_setup_layout())
+		return 0;
+
+	if (cl_eeprom_layout != LAYOUT_LEGACY)
+		offset = BOARD_REV_OFFSET;
+
+	if (cl_eeprom_read(offset, (uchar *)&rev, BOARD_REV_SIZE))
+		return 0;
+
+	/*
+	 * Convert legacy syntactic representation to semantic
+	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
+	 */
+	if (cl_eeprom_layout == LAYOUT_LEGACY) {
+		sprintf(str, "%x", rev);
+		rev = simple_strtoul(str, NULL, 10);
+	}
+
+	return rev;
+};