target/linux/ar7/files/arch/mips/ar7/gpio.c

   1 /*
   2  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #include <linux/module.h>
  21
  22 #include <asm/ar7/gpio.h>
  23
  24 static const char *ar7_gpio_list[TITAN_GPIO_MAX];
  25
  26 int gpio_request(unsigned gpio, const char *label)
  27 {
  28         if (gpio >= (ar7_is_titan() ? TITAN_GPIO_MAX : AR7_GPIO_MAX))
  29                 return -EINVAL;
  30
  31         if (ar7_gpio_list[gpio])
  32                 return -EBUSY;
  33
  34         if (label) {
  35                 ar7_gpio_list[gpio] = label;
  36         } else {
  37                 ar7_gpio_list[gpio] = "busy";
  38         }
  39
  40         return 0;
  41 }
  42 EXPORT_SYMBOL(gpio_request);
  43
  44 void gpio_free(unsigned gpio)
  45 {
  46         BUG_ON(!ar7_gpio_list[gpio]);
  47         ar7_gpio_list[gpio] = NULL;
  48 }
  49 EXPORT_SYMBOL(gpio_free);