xref: /openbmc/u-boot/board/compulab/common/eeprom.c (revision 52422e37)
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 #ifndef CONFIG_SYS_I2C_EEPROM_BUS
19 #define CONFIG_SYS_I2C_EEPROM_BUS	0
20 #endif
21 
22 #define EEPROM_LAYOUT_VER_OFFSET	44
23 #define BOARD_SERIAL_OFFSET		20
24 #define BOARD_SERIAL_OFFSET_LEGACY	8
25 #define BOARD_REV_OFFSET		0
26 #define BOARD_REV_OFFSET_LEGACY		6
27 #define BOARD_REV_SIZE			2
28 #define MAC_ADDR_OFFSET			4
29 #define MAC_ADDR_OFFSET_LEGACY		0
30 
31 #define LAYOUT_INVALID	0
32 #define LAYOUT_LEGACY	0xff
33 
34 static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
35 
36 static int cl_eeprom_read(uint offset, uchar *buf, int len)
37 {
38 	int res;
39 	unsigned int current_i2c_bus = i2c_get_bus_num();
40 
41 	res = i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
42 	if (res < 0)
43 		return res;
44 
45 	res = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
46 			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
47 
48 	i2c_set_bus_num(current_i2c_bus);
49 
50 	return res;
51 }
52 
53 static int cl_eeprom_setup_layout(void)
54 {
55 	int res;
56 
57 	if (cl_eeprom_layout != LAYOUT_INVALID)
58 		return 0;
59 
60 	res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
61 			     (uchar *)&cl_eeprom_layout, 1);
62 	if (res) {
63 		cl_eeprom_layout = LAYOUT_INVALID;
64 		return res;
65 	}
66 
67 	if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
68 		cl_eeprom_layout = LAYOUT_LEGACY;
69 
70 	return 0;
71 }
72 
73 void get_board_serial(struct tag_serialnr *serialnr)
74 {
75 	u32 serial[2];
76 	uint offset;
77 
78 	memset(serialnr, 0, sizeof(*serialnr));
79 
80 	if (cl_eeprom_setup_layout())
81 		return;
82 
83 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
84 		BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
85 
86 	if (cl_eeprom_read(offset, (uchar *)serial, 8))
87 		return;
88 
89 	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
90 		serialnr->low = serial[0];
91 		serialnr->high = serial[1];
92 	}
93 }
94 
95 /*
96  * Routine: cl_eeprom_read_mac_addr
97  * Description: read mac address and store it in buf.
98  */
99 int cl_eeprom_read_mac_addr(uchar *buf)
100 {
101 	uint offset;
102 
103 	if (cl_eeprom_setup_layout())
104 		return 0;
105 
106 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
107 			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
108 
109 	return cl_eeprom_read(offset, buf, 6);
110 }
111 
112 /*
113  * Routine: cl_eeprom_get_board_rev
114  * Description: read system revision from eeprom
115  */
116 u32 cl_eeprom_get_board_rev(void)
117 {
118 	u32 rev = 0;
119 	char str[5]; /* Legacy representation can contain at most 4 digits */
120 	uint offset = BOARD_REV_OFFSET_LEGACY;
121 
122 	if (cl_eeprom_setup_layout())
123 		return 0;
124 
125 	if (cl_eeprom_layout != LAYOUT_LEGACY)
126 		offset = BOARD_REV_OFFSET;
127 
128 	if (cl_eeprom_read(offset, (uchar *)&rev, BOARD_REV_SIZE))
129 		return 0;
130 
131 	/*
132 	 * Convert legacy syntactic representation to semantic
133 	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
134 	 */
135 	if (cl_eeprom_layout == LAYOUT_LEGACY) {
136 		sprintf(str, "%x", rev);
137 		rev = simple_strtoul(str, NULL, 10);
138 	}
139 
140 	return rev;
141 };
142