xref: /openbmc/u-boot/board/compulab/common/eeprom.c (revision ca11db26)
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 	int res;
35 	unsigned int current_i2c_bus = i2c_get_bus_num();
36 
37 	res = i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
38 	if (res < 0)
39 		return res;
40 
41 	res = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
42 			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
43 
44 	i2c_set_bus_num(current_i2c_bus);
45 
46 	return res;
47 }
48 
49 static int cl_eeprom_setup_layout(void)
50 {
51 	int res;
52 
53 	if (cl_eeprom_layout != LAYOUT_INVALID)
54 		return 0;
55 
56 	res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
57 			     (uchar *)&cl_eeprom_layout, 1);
58 	if (res) {
59 		cl_eeprom_layout = LAYOUT_INVALID;
60 		return res;
61 	}
62 
63 	if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
64 		cl_eeprom_layout = LAYOUT_LEGACY;
65 
66 	return 0;
67 }
68 
69 void get_board_serial(struct tag_serialnr *serialnr)
70 {
71 	u32 serial[2];
72 	uint offset;
73 
74 	memset(serialnr, 0, sizeof(*serialnr));
75 
76 	if (cl_eeprom_setup_layout())
77 		return;
78 
79 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
80 		BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
81 
82 	if (cl_eeprom_read(offset, (uchar *)serial, 8))
83 		return;
84 
85 	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
86 		serialnr->low = serial[0];
87 		serialnr->high = serial[1];
88 	}
89 }
90 
91 /*
92  * Routine: cl_eeprom_read_mac_addr
93  * Description: read mac address and store it in buf.
94  */
95 int cl_eeprom_read_mac_addr(uchar *buf)
96 {
97 	uint offset;
98 
99 	if (cl_eeprom_setup_layout())
100 		return 0;
101 
102 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
103 			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
104 
105 	return cl_eeprom_read(offset, buf, 6);
106 }
107 
108 /*
109  * Routine: cl_eeprom_get_board_rev
110  * Description: read system revision from eeprom
111  */
112 u32 cl_eeprom_get_board_rev(void)
113 {
114 	u32 rev = 0;
115 	char str[5]; /* Legacy representation can contain at most 4 digits */
116 	uint offset = BOARD_REV_OFFSET_LEGACY;
117 
118 	if (cl_eeprom_setup_layout())
119 		return 0;
120 
121 	if (cl_eeprom_layout != LAYOUT_LEGACY)
122 		offset = BOARD_REV_OFFSET;
123 
124 	if (cl_eeprom_read(offset, (uchar *)&rev, BOARD_REV_SIZE))
125 		return 0;
126 
127 	/*
128 	 * Convert legacy syntactic representation to semantic
129 	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
130 	 */
131 	if (cl_eeprom_layout == LAYOUT_LEGACY) {
132 		sprintf(str, "%x", rev);
133 		rev = simple_strtoul(str, NULL, 10);
134 	}
135 
136 	return rev;
137 };
138