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