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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
9c1600ed | 2 | /* |
950a5097 | 3 | * i2c-boardinfo.c - collect pre-declarations of I2C devices |
9c1600ed DB |
4 | */ |
5 | ||
345df512 | 6 | #include <linux/export.h> |
258d3129 WS |
7 | #include <linux/i2c.h> |
8 | #include <linux/kernel.h> | |
0daaf99d | 9 | #include <linux/property.h> |
f18c41da | 10 | #include <linux/rwsem.h> |
258d3129 | 11 | #include <linux/slab.h> |
9c1600ed DB |
12 | |
13 | #include "i2c-core.h" | |
14 | ||
15 | ||
16 | /* These symbols are exported ONLY FOR the i2c core. | |
17 | * No other users will be supported. | |
18 | */ | |
f18c41da | 19 | DECLARE_RWSEM(__i2c_board_lock); |
9c1600ed DB |
20 | EXPORT_SYMBOL_GPL(__i2c_board_lock); |
21 | ||
22 | LIST_HEAD(__i2c_board_list); | |
23 | EXPORT_SYMBOL_GPL(__i2c_board_list); | |
24 | ||
25 | int __i2c_first_dynamic_bus_num; | |
26 | EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num); | |
27 | ||
28 | ||
29 | /** | |
30 | * i2c_register_board_info - statically declare I2C devices | |
31 | * @busnum: identifies the bus to which these devices belong | |
32 | * @info: vector of i2c device descriptors | |
33 | * @len: how many descriptors in the vector; may be zero to reserve | |
34 | * the specified bus number. | |
35 | * | |
36 | * Systems using the Linux I2C driver stack can declare tables of board info | |
37 | * while they initialize. This should be done in board-specific init code | |
38 | * near arch_initcall() time, or equivalent, before any I2C adapter driver is | |
39 | * registered. For example, mainboard init code could define several devices, | |
40 | * as could the init code for each daughtercard in a board stack. | |
41 | * | |
42 | * The I2C devices will be created later, after the adapter for the relevant | |
43 | * bus has been registered. After that moment, standard driver model tools | |
44 | * are used to bind "new style" I2C drivers to the devices. The bus number | |
45 | * for any device declared using this routine is not available for dynamic | |
46 | * allocation. | |
47 | * | |
48 | * The board info passed can safely be __initdata, but be careful of embedded | |
49 | * pointers (for platform_data, functions, etc) since that won't be copied. | |
50 | */ | |
5abe9b26 | 51 | int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len) |
9c1600ed DB |
52 | { |
53 | int status; | |
54 | ||
f18c41da | 55 | down_write(&__i2c_board_lock); |
9c1600ed DB |
56 | |
57 | /* dynamic bus numbers will be assigned after the last static one */ | |
58 | if (busnum >= __i2c_first_dynamic_bus_num) | |
59 | __i2c_first_dynamic_bus_num = busnum + 1; | |
60 | ||
61 | for (status = 0; len; len--, info++) { | |
62 | struct i2c_devinfo *devinfo; | |
63 | ||
64 | devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL); | |
65 | if (!devinfo) { | |
66 | pr_debug("i2c-core: can't register boardinfo!\n"); | |
67 | status = -ENOMEM; | |
68 | break; | |
69 | } | |
70 | ||
71 | devinfo->busnum = busnum; | |
72 | devinfo->board_info = *info; | |
0daaf99d | 73 | |
4124c4eb DT |
74 | if (info->resources) { |
75 | devinfo->board_info.resources = | |
76 | kmemdup(info->resources, | |
77 | info->num_resources * | |
78 | sizeof(*info->resources), | |
79 | GFP_KERNEL); | |
80 | if (!devinfo->board_info.resources) { | |
81 | status = -ENOMEM; | |
66a7c84d | 82 | kfree(devinfo); |
4124c4eb DT |
83 | break; |
84 | } | |
85 | } | |
86 | ||
9c1600ed DB |
87 | list_add_tail(&devinfo->list, &__i2c_board_list); |
88 | } | |
89 | ||
f18c41da | 90 | up_write(&__i2c_board_lock); |
9c1600ed DB |
91 | |
92 | return status; | |
93 | } |