1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
/*
* i2c-boardinfo.c - collect pre-declarations of I2C devices
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include "i2c-core.h"
/* These symbols are exported ONLY FOR the i2c core.
* No other users will be supported.
*/
DECLARE_RWSEM(__i2c_board_lock);
EXPORT_SYMBOL_GPL(__i2c_board_lock);
LIST_HEAD(__i2c_board_list);
EXPORT_SYMBOL_GPL(__i2c_board_list);
int __i2c_first_dynamic_bus_num;
EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
/**
* i2c_register_board_info - statically declare I2C devices
* @busnum: identifies the bus to which these devices belong
* @info: vector of i2c device descriptors
* @len: how many descriptors in the vector; may be zero to reserve
* the specified bus number.
*
* Systems using the Linux I2C driver stack can declare tables of board info
* while they initialize. This should be done in board-specific init code
* near arch_initcall() time, or equivalent, before any I2C adapter driver is
* registered. For example, mainboard init code could define several devices,
* as could the init code for each daughtercard in a board stack.
*
* The I2C devices will be created later, after the adapter for the relevant
* bus has been registered. After that moment, standard driver model tools
* are used to bind "new style" I2C drivers to the devices. The bus number
* for any device declared using this routine is not available for dynamic
* allocation.
*
* The board info passed can safely be __initdata, but be careful of embedded
* pointers (for platform_data, functions, etc) since that won't be copied.
*/
int __init
i2c_register_board_info(int busnum,
struct i2c_board_info const *info, unsigned len)
{
int status;
down_write(&__i2c_board_lock);
/* dynamic bus numbers will be assigned after the last static one */
if (busnum >= __i2c_first_dynamic_bus_num)
__i2c_first_dynamic_bus_num = busnum + 1;
for (status = 0; len; len--, info++) {
struct i2c_devinfo *devinfo;
devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
if (!devinfo) {
pr_debug("i2c-core: can't register boardinfo!\n");
status = -ENOMEM;
break;
}
devinfo->busnum = busnum;
devinfo->board_info = *info;
list_add_tail(&devinfo->list, &__i2c_board_list);
}
up_write(&__i2c_board_lock);
return status;
}
|
