1/*
2 * i2c-boardinfo.c - 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
15#include <linux/export.h>
16#include <linux/i2c.h>
17#include <linux/kernel.h>
18#include <linux/property.h>
19#include <linux/rwsem.h>
20#include <linux/slab.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 */
28DECLARE_RWSEM(__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 * Device properties are deep-copied though.
60 */
61int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
62{
63 int status;
64
65 down_write(&__i2c_board_lock);
66
67 /* dynamic bus numbers will be assigned after the last static one */
68 if (busnum >= __i2c_first_dynamic_bus_num)
69 __i2c_first_dynamic_bus_num = busnum + 1;
70
71 for (status = 0; len; len--, info++) {
72 struct i2c_devinfo *devinfo;
73
74 devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
75 if (!devinfo) {
76 pr_debug("i2c-core: can't register boardinfo!\n");
77 status = -ENOMEM;
78 break;
79 }
80
81 devinfo->busnum = busnum;
82 devinfo->board_info = *info;
83
84 if (info->properties) {
85 devinfo->board_info.properties =
86 property_entries_dup(info->properties);
87 if (IS_ERR(devinfo->board_info.properties)) {
88 status = PTR_ERR(devinfo->board_info.properties);
89 kfree(devinfo);
90 break;
91 }
92 }
93
94 if (info->resources) {
95 devinfo->board_info.resources =
96 kmemdup(info->resources,
97 info->num_resources *
98 sizeof(*info->resources),
99 GFP_KERNEL);
100 if (!devinfo->board_info.resources) {
101 status = -ENOMEM;
102 kfree(devinfo);
103 break;
104 }
105 }
106
107 list_add_tail(&devinfo->list, &__i2c_board_list);
108 }
109
110 up_write(&__i2c_board_lock);
111
112 return status;
113}
114