drivers/acpi/cm_sbs.c

   1 /*
   2  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   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 (at
   7  *  your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful, but
  10  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  General Public License for more details.
  13  *
  14  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/acpi.h>
  21 #include <linux/types.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/seq_file.h>
  24 #include <acpi/acpi_bus.h>
  25 #include <acpi/acpi_drivers.h>
  26
  27 #define PREFIX "ACPI: "
  28
  29 ACPI_MODULE_NAME("cm_sbs");
  30 #define ACPI_AC_CLASS           "ac_adapter"
  31 #define ACPI_BATTERY_CLASS      "battery"
  32 #define _COMPONENT              ACPI_SBS_COMPONENT
  33 static struct proc_dir_entry *acpi_ac_dir;
  34 static struct proc_dir_entry *acpi_battery_dir;
  35
  36 static DEFINE_MUTEX(cm_sbs_mutex);
  37
  38 static int lock_ac_dir_cnt;
  39 static int lock_battery_dir_cnt;
  40
  41 struct proc_dir_entry *acpi_lock_ac_dir(void)
  42 {
  43         mutex_lock(&cm_sbs_mutex);
  44         if (!acpi_ac_dir)
  45                 acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);
  46         if (acpi_ac_dir) {
  47                 lock_ac_dir_cnt++;
  48         } else {
  49                 printk(KERN_ERR PREFIX
  50                                   "Cannot create %s\n", ACPI_AC_CLASS);
  51         }
  52         mutex_unlock(&cm_sbs_mutex);
  53         return acpi_ac_dir;
  54 }
  55 EXPORT_SYMBOL(acpi_lock_ac_dir);
  56
  57 void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)
  58 {
  59         mutex_lock(&cm_sbs_mutex);
  60         if (acpi_ac_dir_param)
  61                 lock_ac_dir_cnt--;
  62         if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {
  63                 remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);
  64                 acpi_ac_dir = NULL;
  65         }
  66         mutex_unlock(&cm_sbs_mutex);
  67 }
  68 EXPORT_SYMBOL(acpi_unlock_ac_dir);
  69
  70 struct proc_dir_entry *acpi_lock_battery_dir(void)
  71 {
  72         mutex_lock(&cm_sbs_mutex);
  73         if (!acpi_battery_dir) {
  74                 acpi_battery_dir =
  75                     proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
  76         }
  77         if (acpi_battery_dir) {
  78                 lock_battery_dir_cnt++;
  79         } else {
  80                 printk(KERN_ERR PREFIX
  81                                   "Cannot create %s\n", ACPI_BATTERY_CLASS);
  82         }
  83         mutex_unlock(&cm_sbs_mutex);
  84         return acpi_battery_dir;
  85 }
  86 EXPORT_SYMBOL(acpi_lock_battery_dir);
  87
  88 void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)
  89 {
  90         mutex_lock(&cm_sbs_mutex);
  91         if (acpi_battery_dir_param)
  92                 lock_battery_dir_cnt--;
  93         if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param
  94             && acpi_battery_dir) {
  95                 remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);
  96                 acpi_battery_dir = NULL;
  97         }
  98         mutex_unlock(&cm_sbs_mutex);
  99         return;
 100 }
 101 EXPORT_SYMBOL(acpi_unlock_battery_dir);