i2c-boardinfo.c

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/*
 * 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);


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!\n");
            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;
}