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 */
28DEFINE_MUTEX(__i2c_board_lock);
29EXPORT_SYMBOL_GPL(__i2c_board_lock);
30
31LIST_HEAD(__i2c_board_list);
32EXPORT_SYMBOL_GPL(__i2c_board_list);
33
34int __i2c_first_dynamic_bus_num;
35EXPORT_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 */
60int __init
61i2c_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