xref: /openbmc/u-boot/post/drivers/i2c.c (revision dd580801)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * I2C test
10  *
11  * For verifying the I2C bus, a full I2C bus scanning is performed.
12  *
13  * #ifdef CONFIG_SYS_POST_I2C_ADDRS
14  *   The test is considered as passed if all the devices and only the devices
15  *   in the list are found.
16  *   #ifdef CONFIG_SYS_POST_I2C_IGNORES
17  *     Ignore devices listed in CONFIG_SYS_POST_I2C_IGNORES.  These devices
18  *     are optional or not vital to board functionality.
19  *   #endif
20  * #else [ ! CONFIG_SYS_POST_I2C_ADDRS ]
21  *   The test is considered as passed if any I2C device is found.
22  * #endif
23  */
24 
25 #include <common.h>
26 #include <post.h>
27 #include <i2c.h>
28 
29 #if CONFIG_POST & CONFIG_SYS_POST_I2C
30 
31 static int i2c_ignore_device(unsigned int chip)
32 {
33 #ifdef CONFIG_SYS_POST_I2C_IGNORES
34 	const unsigned char i2c_ignore_list[] = CONFIG_SYS_POST_I2C_IGNORES;
35 	int i;
36 
37 	for (i = 0; i < sizeof(i2c_ignore_list); i++)
38 		if (i2c_ignore_list[i] == chip)
39 			return 1;
40 #endif
41 
42 	return 0;
43 }
44 
45 int i2c_post_test (int flags)
46 {
47 	unsigned int i;
48 #ifndef CONFIG_SYS_POST_I2C_ADDRS
49 	/* Start at address 1, address 0 is the general call address */
50 	for (i = 1; i < 128; i++) {
51 		if (i2c_ignore_device(i))
52 			continue;
53 		if (i2c_probe (i) == 0)
54 			return 0;
55 	}
56 
57 	/* No devices found */
58 	return -1;
59 #else
60 	unsigned int ret  = 0;
61 	int j;
62 	unsigned char i2c_addr_list[] = CONFIG_SYS_POST_I2C_ADDRS;
63 
64 	/* Start at address 1, address 0 is the general call address */
65 	for (i = 1; i < 128; i++) {
66 		if (i2c_ignore_device(i))
67 			continue;
68 		if (i2c_probe(i) != 0)
69 			continue;
70 
71 		for (j = 0; j < sizeof(i2c_addr_list); ++j) {
72 			if (i == i2c_addr_list[j]) {
73 				i2c_addr_list[j] = 0xff;
74 				break;
75 			}
76 		}
77 
78 		if (j == sizeof(i2c_addr_list)) {
79 			ret = -1;
80 			post_log("I2C: addr %02x not expected\n", i);
81 		}
82 	}
83 
84 	for (i = 0; i < sizeof(i2c_addr_list); ++i) {
85 		if (i2c_addr_list[i] == 0xff)
86 			continue;
87 		if (i2c_ignore_device(i2c_addr_list[i]))
88 			continue;
89 		post_log("I2C: addr %02x did not respond\n", i2c_addr_list[i]);
90 		ret = -1;
91 	}
92 
93 	return ret;
94 #endif
95 }
96 
97 #endif /* CONFIG_POST & CONFIG_SYS_POST_I2C */
98