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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> | |
f18c41da | 21 | #include <linux/rwsem.h> |
9c1600ed DB |
22 | |
23 | #include "i2c-core.h" | |
24 | ||
25 | ||
26 | /* These symbols are exported ONLY FOR the i2c core. | |
27 | * No other users will be supported. | |
28 | */ | |
f18c41da | 29 | DECLARE_RWSEM(__i2c_board_lock); |
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30 | EXPORT_SYMBOL_GPL(__i2c_board_lock); |
31 | ||
32 | LIST_HEAD(__i2c_board_list); | |
33 | EXPORT_SYMBOL_GPL(__i2c_board_list); | |
34 | ||
35 | int __i2c_first_dynamic_bus_num; | |
36 | EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num); | |
37 | ||
38 | ||
39 | /** | |
40 | * i2c_register_board_info - statically declare I2C devices | |
41 | * @busnum: identifies the bus to which these devices belong | |
42 | * @info: vector of i2c device descriptors | |
43 | * @len: how many descriptors in the vector; may be zero to reserve | |
44 | * the specified bus number. | |
45 | * | |
46 | * Systems using the Linux I2C driver stack can declare tables of board info | |
47 | * while they initialize. This should be done in board-specific init code | |
48 | * near arch_initcall() time, or equivalent, before any I2C adapter driver is | |
49 | * registered. For example, mainboard init code could define several devices, | |
50 | * as could the init code for each daughtercard in a board stack. | |
51 | * | |
52 | * The I2C devices will be created later, after the adapter for the relevant | |
53 | * bus has been registered. After that moment, standard driver model tools | |
54 | * are used to bind "new style" I2C drivers to the devices. The bus number | |
55 | * for any device declared using this routine is not available for dynamic | |
56 | * allocation. | |
57 | * | |
58 | * The board info passed can safely be __initdata, but be careful of embedded | |
59 | * pointers (for platform_data, functions, etc) since that won't be copied. | |
60 | */ | |
61 | int __init | |
62 | i2c_register_board_info(int busnum, | |
63 | struct i2c_board_info const *info, unsigned len) | |
64 | { | |
65 | int status; | |
66 | ||
f18c41da | 67 | down_write(&__i2c_board_lock); |
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68 | |
69 | /* dynamic bus numbers will be assigned after the last static one */ | |
70 | if (busnum >= __i2c_first_dynamic_bus_num) | |
71 | __i2c_first_dynamic_bus_num = busnum + 1; | |
72 | ||
73 | for (status = 0; len; len--, info++) { | |
74 | struct i2c_devinfo *devinfo; | |
75 | ||
76 | devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL); | |
77 | if (!devinfo) { | |
78 | pr_debug("i2c-core: can't register boardinfo!\n"); | |
79 | status = -ENOMEM; | |
80 | break; | |
81 | } | |
82 | ||
83 | devinfo->busnum = busnum; | |
84 | devinfo->board_info = *info; | |
85 | list_add_tail(&devinfo->list, &__i2c_board_list); | |
86 | } | |
87 | ||
f18c41da | 88 | up_write(&__i2c_board_lock); |
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89 | |
90 | return status; | |
91 | } |