xref: /openbmc/u-boot/board/compulab/common/eeprom.c (revision ad3098f7)
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 #include "eeprom.h"
13 
14 #ifndef CONFIG_SYS_I2C_EEPROM_ADDR
15 # define CONFIG_SYS_I2C_EEPROM_ADDR	0x50
16 # define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
17 #endif
18 
19 #ifndef CONFIG_SYS_I2C_EEPROM_BUS
20 #define CONFIG_SYS_I2C_EEPROM_BUS	0
21 #endif
22 
23 #define EEPROM_LAYOUT_VER_OFFSET	44
24 #define BOARD_SERIAL_OFFSET		20
25 #define BOARD_SERIAL_OFFSET_LEGACY	8
26 #define BOARD_REV_OFFSET		0
27 #define BOARD_REV_OFFSET_LEGACY		6
28 #define BOARD_REV_SIZE			2
29 #define PRODUCT_NAME_OFFSET		128
30 #define PRODUCT_NAME_SIZE		16
31 #define MAC_ADDR_OFFSET			4
32 #define MAC_ADDR_OFFSET_LEGACY		0
33 
34 #define LAYOUT_INVALID	0
35 #define LAYOUT_LEGACY	0xff
36 
37 static int cl_eeprom_bus;
38 static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
39 
40 static int cl_eeprom_read(uint offset, uchar *buf, int len)
41 {
42 	int res;
43 	unsigned int current_i2c_bus = i2c_get_bus_num();
44 
45 	res = i2c_set_bus_num(cl_eeprom_bus);
46 	if (res < 0)
47 		return res;
48 
49 	res = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
50 			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
51 
52 	i2c_set_bus_num(current_i2c_bus);
53 
54 	return res;
55 }
56 
57 static int cl_eeprom_setup(uint eeprom_bus)
58 {
59 	int res;
60 
61 	/*
62 	 * We know the setup was already done when the layout is set to a valid
63 	 * value and we're using the same bus as before.
64 	 */
65 	if (cl_eeprom_layout != LAYOUT_INVALID && eeprom_bus == cl_eeprom_bus)
66 		return 0;
67 
68 	cl_eeprom_bus = eeprom_bus;
69 	res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
70 			     (uchar *)&cl_eeprom_layout, 1);
71 	if (res) {
72 		cl_eeprom_layout = LAYOUT_INVALID;
73 		return res;
74 	}
75 
76 	if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
77 		cl_eeprom_layout = LAYOUT_LEGACY;
78 
79 	return 0;
80 }
81 
82 void get_board_serial(struct tag_serialnr *serialnr)
83 {
84 	u32 serial[2];
85 	uint offset;
86 
87 	memset(serialnr, 0, sizeof(*serialnr));
88 
89 	if (cl_eeprom_setup(CONFIG_SYS_I2C_EEPROM_BUS))
90 		return;
91 
92 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
93 		BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
94 
95 	if (cl_eeprom_read(offset, (uchar *)serial, 8))
96 		return;
97 
98 	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
99 		serialnr->low = serial[0];
100 		serialnr->high = serial[1];
101 	}
102 }
103 
104 /*
105  * Routine: cl_eeprom_read_mac_addr
106  * Description: read mac address and store it in buf.
107  */
108 int cl_eeprom_read_mac_addr(uchar *buf, uint eeprom_bus)
109 {
110 	uint offset;
111 	int err;
112 
113 	err = cl_eeprom_setup(eeprom_bus);
114 	if (err)
115 		return err;
116 
117 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
118 			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
119 
120 	return cl_eeprom_read(offset, buf, 6);
121 }
122 
123 static u32 board_rev;
124 
125 /*
126  * Routine: cl_eeprom_get_board_rev
127  * Description: read system revision from eeprom
128  */
129 u32 cl_eeprom_get_board_rev(uint eeprom_bus)
130 {
131 	char str[5]; /* Legacy representation can contain at most 4 digits */
132 	uint offset = BOARD_REV_OFFSET_LEGACY;
133 
134 	if (board_rev)
135 		return board_rev;
136 
137 	if (cl_eeprom_setup(eeprom_bus))
138 		return 0;
139 
140 	if (cl_eeprom_layout != LAYOUT_LEGACY)
141 		offset = BOARD_REV_OFFSET;
142 
143 	if (cl_eeprom_read(offset, (uchar *)&board_rev, BOARD_REV_SIZE))
144 		return 0;
145 
146 	/*
147 	 * Convert legacy syntactic representation to semantic
148 	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
149 	 */
150 	if (cl_eeprom_layout == LAYOUT_LEGACY) {
151 		sprintf(str, "%x", board_rev);
152 		board_rev = simple_strtoul(str, NULL, 10);
153 	}
154 
155 	return board_rev;
156 };
157 
158 /*
159  * Routine: cl_eeprom_get_board_rev
160  * Description: read system revision from eeprom
161  *
162  * @buf: buffer to store the product name
163  * @eeprom_bus: i2c bus num of the eeprom
164  *
165  * @return: 0 on success, < 0 on failure
166  */
167 int cl_eeprom_get_product_name(uchar *buf, uint eeprom_bus)
168 {
169 	int err;
170 
171 	if (buf == NULL)
172 		return -EINVAL;
173 
174 	err = cl_eeprom_setup(eeprom_bus);
175 	if (err)
176 		return err;
177 
178 	err = cl_eeprom_read(PRODUCT_NAME_OFFSET, buf, PRODUCT_NAME_SIZE);
179 	if (!err) /* Protect ourselves from invalid data (unterminated str) */
180 		buf[PRODUCT_NAME_SIZE - 1] = '\0';
181 
182 	return err;
183 }
184