xref: /openbmc/u-boot/board/compulab/common/eeprom.c (revision dfe6f4d6)
1 /*
2  * (C) Copyright 2011 CompuLab, Ltd. <www.compulab.co.il>
3  *
4  * Authors: Nikita Kiryanov <nikita@compulab.co.il>
5  *	    Igor Grinberg <grinberg@compulab.co.il>
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <i2c.h>
12 
13 #ifndef CONFIG_SYS_I2C_EEPROM_ADDR
14 # define CONFIG_SYS_I2C_EEPROM_ADDR	0x50
15 # define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
16 #endif
17 
18 #define EEPROM_LAYOUT_VER_OFFSET	44
19 #define BOARD_SERIAL_OFFSET		20
20 #define BOARD_SERIAL_OFFSET_LEGACY	8
21 #define BOARD_REV_OFFSET		0
22 #define BOARD_REV_OFFSET_LEGACY		6
23 #define BOARD_REV_SIZE			2
24 #define MAC_ADDR_OFFSET			4
25 #define MAC_ADDR_OFFSET_LEGACY		0
26 
27 #define LAYOUT_INVALID	0
28 #define LAYOUT_LEGACY	0xff
29 
30 static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
31 
32 static int cl_eeprom_read(uint offset, uchar *buf, int len)
33 {
34 	return i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
35 			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
36 }
37 
38 static int cl_eeprom_setup_layout(void)
39 {
40 	int res;
41 
42 	if (cl_eeprom_layout != LAYOUT_INVALID)
43 		return 0;
44 
45 	res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
46 			     (uchar *)&cl_eeprom_layout, 1);
47 	if (res) {
48 		cl_eeprom_layout = LAYOUT_INVALID;
49 		return res;
50 	}
51 
52 	if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
53 		cl_eeprom_layout = LAYOUT_LEGACY;
54 
55 	return 0;
56 }
57 
58 void get_board_serial(struct tag_serialnr *serialnr)
59 {
60 	u32 serial[2];
61 	uint offset;
62 
63 	memset(serialnr, 0, sizeof(*serialnr));
64 
65 	if (cl_eeprom_setup_layout())
66 		return;
67 
68 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
69 		BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
70 
71 	if (cl_eeprom_read(offset, (uchar *)serial, 8))
72 		return;
73 
74 	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
75 		serialnr->low = serial[0];
76 		serialnr->high = serial[1];
77 	}
78 }
79 
80 /*
81  * Routine: cl_eeprom_read_mac_addr
82  * Description: read mac address and store it in buf.
83  */
84 int cl_eeprom_read_mac_addr(uchar *buf)
85 {
86 	uint offset;
87 
88 	if (cl_eeprom_setup_layout())
89 		return 0;
90 
91 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
92 			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
93 
94 	return cl_eeprom_read(offset, buf, 6);
95 }
96 
97 /*
98  * Routine: cl_eeprom_get_board_rev
99  * Description: read system revision from eeprom
100  */
101 u32 cl_eeprom_get_board_rev(void)
102 {
103 	u32 rev = 0;
104 	char str[5]; /* Legacy representation can contain at most 4 digits */
105 	uint offset = BOARD_REV_OFFSET_LEGACY;
106 
107 	if (cl_eeprom_setup_layout())
108 		return 0;
109 
110 	if (cl_eeprom_layout != LAYOUT_LEGACY)
111 		offset = BOARD_REV_OFFSET;
112 
113 	if (cl_eeprom_read(offset, (uchar *)&rev, BOARD_REV_SIZE))
114 		return 0;
115 
116 	/*
117 	 * Convert legacy syntactic representation to semantic
118 	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
119 	 */
120 	if (cl_eeprom_layout == LAYOUT_LEGACY) {
121 		sprintf(str, "%x", rev);
122 		rev = simple_strtoul(str, NULL, 10);
123 	}
124 
125 	return rev;
126 };
127