dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / i2c / i2c-boardinfo.c
blob42c25aed671d82f74a9464071c56d1eac0763a28
1 /*
2 * i2c-boardinfo.c - collect pre-declarations of I2C devices
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.
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.
15 #include <linux/kernel.h>
16 #include <linux/i2c.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <linux/rwsem.h>
21 #include "i2c-core.h"
24 /* These symbols are exported ONLY FOR the i2c core.
25 * No other users will be supported.
27 DECLARE_RWSEM(__i2c_board_lock);
28 EXPORT_SYMBOL_GPL(__i2c_board_lock);
30 LIST_HEAD(__i2c_board_list);
31 EXPORT_SYMBOL_GPL(__i2c_board_list);
33 int __i2c_first_dynamic_bus_num;
34 EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
37 /**
38 * i2c_register_board_info - statically declare I2C devices
39 * @busnum: identifies the bus to which these devices belong
40 * @info: vector of i2c device descriptors
41 * @len: how many descriptors in the vector; may be zero to reserve
42 * the specified bus number.
44 * Systems using the Linux I2C driver stack can declare tables of board info
45 * while they initialize. This should be done in board-specific init code
46 * near arch_initcall() time, or equivalent, before any I2C adapter driver is
47 * registered. For example, mainboard init code could define several devices,
48 * as could the init code for each daughtercard in a board stack.
50 * The I2C devices will be created later, after the adapter for the relevant
51 * bus has been registered. After that moment, standard driver model tools
52 * are used to bind "new style" I2C drivers to the devices. The bus number
53 * for any device declared using this routine is not available for dynamic
54 * allocation.
56 * The board info passed can safely be __initdata, but be careful of embedded
57 * pointers (for platform_data, functions, etc) since that won't be copied.
59 int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
61 int status;
63 down_write(&__i2c_board_lock);
65 /* dynamic bus numbers will be assigned after the last static one */
66 if (busnum >= __i2c_first_dynamic_bus_num)
67 __i2c_first_dynamic_bus_num = busnum + 1;
69 for (status = 0; len; len--, info++) {
70 struct i2c_devinfo *devinfo;
72 devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
73 if (!devinfo) {
74 pr_debug("i2c-core: can't register boardinfo!\n");
75 status = -ENOMEM;
76 break;
79 devinfo->busnum = busnum;
80 devinfo->board_info = *info;
81 list_add_tail(&devinfo->list, &__i2c_board_list);
84 up_write(&__i2c_board_lock);
86 return status;