/*
   * i2c-boardinfo.c - collect pre-declarations of I2C devices
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   * MA 02110-1301 USA.
   */
  
  #include <linux/kernel.h>
  #include <linux/i2c.h>
  #include <linux/slab.h>
  #include <linux/export.h>
  #include <linux/rwsem.h>
  
  #include "i2c-core.h"
  
  
  /* These symbols are exported ONLY FOR the i2c core.
   * No other users will be supported.
   */
  DECLARE_RWSEM(__i2c_board_lock);
  EXPORT_SYMBOL_GPL(__i2c_board_lock);
  
  LIST_HEAD(__i2c_board_list);
  EXPORT_SYMBOL_GPL(__i2c_board_list);
  
  int __i2c_first_dynamic_bus_num;
  EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
  
  
  /**
   * i2c_register_board_info - statically declare I2C devices
   * @busnum: identifies the bus to which these devices belong
   * @info: vector of i2c device descriptors
   * @len: how many descriptors in the vector; may be zero to reserve
   *	the specified bus number.
   *
   * Systems using the Linux I2C driver stack can declare tables of board info
   * while they initialize.  This should be done in board-specific init code
   * near arch_initcall() time, or equivalent, before any I2C adapter driver is
   * registered.  For example, mainboard init code could define several devices,
   * as could the init code for each daughtercard in a board stack.
   *
   * The I2C devices will be created later, after the adapter for the relevant
   * bus has been registered.  After that moment, standard driver model tools
   * are used to bind "new style" I2C drivers to the devices.  The bus number
   * for any device declared using this routine is not available for dynamic
   * allocation.
   *
   * The board info passed can safely be __initdata, but be careful of embedded
   * pointers (for platform_data, functions, etc) since that won't be copied.
   */
  int __init
  i2c_register_board_info(int busnum,
  	struct i2c_board_info const *info, unsigned len)
  {
  	int status;
  
  	down_write(&__i2c_board_lock);
  
  	/* dynamic bus numbers will be assigned after the last static one */
  	if (busnum >= __i2c_first_dynamic_bus_num)
  		__i2c_first_dynamic_bus_num = busnum + 1;
  
  	for (status = 0; len; len--, info++) {
  		struct i2c_devinfo	*devinfo;
  
  		devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
  		if (!devinfo) {
  			pr_debug("i2c-core: can't register boardinfo!
  ");
  			status = -ENOMEM;
  			break;
  		}
  
  		devinfo->busnum = busnum;
  		devinfo->board_info = *info;
  		list_add_tail(&devinfo->list, &__i2c_board_list);
  	}
  
  	up_write(&__i2c_board_lock);
  
  	return status;
  }