xref: /openbmc/u-boot/post/drivers/i2c.c (revision 713cb680)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 /*
25  * I2C test
26  *
27  * For verifying the I2C bus, a full I2C bus scanning is performed.
28  *
29  * #ifdef CONFIG_SYS_POST_I2C_ADDRS
30  *   The test is considered as passed if all the devices and only the devices
31  *   in the list are found.
32  *   #ifdef CONFIG_SYS_POST_I2C_IGNORES
33  *     Ignore devices listed in CONFIG_SYS_POST_I2C_IGNORES.  These devices
34  *     are optional or not vital to board functionality.
35  *   #endif
36  * #else [ ! CONFIG_SYS_POST_I2C_ADDRS ]
37  *   The test is considered as passed if any I2C device is found.
38  * #endif
39  */
40 
41 #include <common.h>
42 #include <post.h>
43 #include <i2c.h>
44 
45 #if CONFIG_POST & CONFIG_SYS_POST_I2C
46 
47 static int i2c_ignore_device(unsigned int chip)
48 {
49 #ifdef CONFIG_SYS_POST_I2C_IGNORES
50 	const unsigned char i2c_ignore_list[] = CONFIG_SYS_POST_I2C_IGNORES;
51 	int i;
52 
53 	for (i = 0; i < sizeof(i2c_ignore_list); i++)
54 		if (i2c_ignore_list[i] == chip)
55 			return 1;
56 #endif
57 
58 	return 0;
59 }
60 
61 int i2c_post_test (int flags)
62 {
63 	unsigned int i;
64 #ifndef CONFIG_SYS_POST_I2C_ADDRS
65 	/* Start at address 1, address 0 is the general call address */
66 	for (i = 1; i < 128; i++) {
67 		if (i2c_ignore_device(i))
68 			continue;
69 		if (i2c_probe (i) == 0)
70 			return 0;
71 	}
72 
73 	/* No devices found */
74 	return -1;
75 #else
76 	unsigned int ret  = 0;
77 	int j;
78 	unsigned char i2c_addr_list[] = CONFIG_SYS_POST_I2C_ADDRS;
79 
80 	/* Start at address 1, address 0 is the general call address */
81 	for (i = 1; i < 128; i++) {
82 		if (i2c_ignore_device(i))
83 			continue;
84 		if (i2c_probe(i) != 0)
85 			continue;
86 
87 		for (j = 0; j < sizeof(i2c_addr_list); ++j) {
88 			if (i == i2c_addr_list[j]) {
89 				i2c_addr_list[j] = 0xff;
90 				break;
91 			}
92 		}
93 
94 		if (j == sizeof(i2c_addr_list)) {
95 			ret = -1;
96 			post_log("I2C: addr %02x not expected\n", i);
97 		}
98 	}
99 
100 	for (i = 0; i < sizeof(i2c_addr_list); ++i) {
101 		if (i2c_addr_list[i] == 0xff)
102 			continue;
103 		if (i2c_ignore_device(i2c_addr_list[i]))
104 			continue;
105 		post_log("I2C: addr %02x did not respond\n", i2c_addr_list[i]);
106 		ret = -1;
107 	}
108 
109 	return ret;
110 #endif
111 }
112 
113 #endif /* CONFIG_POST & CONFIG_SYS_POST_I2C */
114