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