drivers/acpi/power.c

   1 /*
   2  *  power.c - Overall power driver. Also handles AC adapter device.
   3  *
   4  *  Copyright (C) 2000 Andrew Grover
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/types.h>
  23 #include <linux/proc_fs.h>
  24 #include "acpi.h"
  25 #include "driver.h"
  26
  27 #define _COMPONENT      OS_DEPENDENT
  28         MODULE_NAME     ("power")
  29
  30 int acpi_cmbatt_init(void);
  31 int acpi_cmbatt_terminate(void);
  32
  33 /* ACPI-specific defines */
  34 #define ACPI_AC_ADAPTER_HID     "ACPI0003"
  35
  36 static int ac_count = 0;
  37 static ACPI_HANDLE ac_handle = 0;
  38
  39 /*
  40  * We found a device with the correct HID
  41  */
  42 static ACPI_STATUS
  43 acpi_found_ac_adapter(ACPI_HANDLE handle, u32 level, void *ctx, void **value)
  44 {
  45         ACPI_DEVICE_INFO        info;
  46
  47         if (ac_count > 0) {
  48                 printk(KERN_ERR "AC Adapter: more than one!\n");
  49                 return (AE_OK);
  50         }
  51
  52         if (!ACPI_SUCCESS(acpi_get_object_info(handle, &info))) {
  53                 printk(KERN_ERR "AC Adapter: Could not get AC Adapter object info\n");
  54                 return (AE_OK);
  55         }
  56
  57         if (!(info.valid & ACPI_VALID_STA)) {
  58                 printk(KERN_ERR "AC Adapter: Battery _STA invalid\n");
  59                 return AE_OK;
  60         }
  61
  62         printk(KERN_INFO "AC Adapter: found\n");
  63
  64         ac_handle = handle;
  65
  66         ac_count++;
  67
  68         return AE_OK;
  69 }
  70
  71 static int
  72 proc_read_ac_adapter_status(char *page, char **start, off_t off,
  73                                 int count, int *eof, void *data)
  74 {
  75         ACPI_OBJECT obj;
  76         ACPI_BUFFER buf;
  77
  78         char *p = page;
  79         int len;
  80
  81         buf.length = sizeof(obj);
  82         buf.pointer = &obj;
  83         if (!ACPI_SUCCESS(acpi_evaluate_object(ac_handle, "_PSR", NULL, &buf))
  84                 || obj.type != ACPI_TYPE_NUMBER) {
  85                 p += sprintf(p, "Could not read AC status\n");
  86                 goto end;
  87         }
  88
  89         if (obj.number.value)
  90                 p += sprintf(p, "on-line\n");
  91         else
  92                 p += sprintf(p, "off-line\n");
  93
  94 end:
  95         len = (p - page);
  96         if (len <= off+count) *eof = 1;
  97         *start = page + off;
  98         len -= off;
  99         if (len>count) len = count;
 100         if (len<0) len = 0;
 101         return len;
 102 }
 103
 104 int
 105 acpi_power_init(void)
 106 {
 107         acpi_get_devices(ACPI_AC_ADAPTER_HID,
 108                         acpi_found_ac_adapter,
 109                         NULL,
 110                         NULL);
 111
 112         if (!proc_mkdir("power", NULL))
 113                 return 0;
 114
 115         if (ac_handle) {
 116                 create_proc_read_entry("power/ac", 0, NULL,
 117                         proc_read_ac_adapter_status, NULL);
 118         }
 119
 120         acpi_cmbatt_init();
 121
 122         return 0;
 123 }
 124
 125 int
 126 acpi_power_terminate(void)
 127 {
 128         acpi_cmbatt_terminate();
 129
 130         if (ac_handle) {
 131                 remove_proc_entry("power/ac", NULL);
 132         }
 133
 134         remove_proc_entry("power", NULL);
 135
 136         return 0;
 137 }