drivers/power/apm_power.c

   1 /*
   2  * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
   3  * Copyright © 2007 Eugeny Boger <eugenyboger@dgap.mipt.ru>
   4  *
   5  * Author: Eugeny Boger <eugenyboger@dgap.mipt.ru>
   6  *
   7  * Use consistent with the GNU GPL is permitted,
   8  * provided that this copyright notice is
   9  * preserved in its entirety in all copies and derived works.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/power_supply.h>
  14 #include <linux/apm-emulation.h>
  15
  16 #define PSY_PROP(psy, prop, val) psy->get_property(psy, \
  17                          POWER_SUPPLY_PROP_##prop, val)
  18
  19 #define _MPSY_PROP(prop, val) main_battery->get_property(main_battery, \
  20                                                          prop, val)
  21
  22 #define MPSY_PROP(prop, val) _MPSY_PROP(POWER_SUPPLY_PROP_##prop, val)
  23
  24 static struct power_supply *main_battery;
  25
  26 static void find_main_battery(void)
  27 {
  28         struct device *dev;
  29         struct power_supply *bat, *batm;
  30         union power_supply_propval full;
  31         int max_charge = 0;
  32
  33         main_battery = NULL;
  34         batm = NULL;
  35         list_for_each_entry(dev, &power_supply_class->devices, node) {
  36                 bat = dev_get_drvdata(dev);
  37                 /* If none of battery devices cantains 'use_for_apm' flag,
  38                    choice one with maximum design charge */
  39                 if (!PSY_PROP(bat, CHARGE_FULL_DESIGN, &full)) {
  40                         if (full.intval > max_charge) {
  41                                 batm = bat;
  42                                 max_charge = full.intval;
  43                         }
  44                 }
  45
  46                 if (bat->use_for_apm)
  47                         main_battery = bat;
  48         }
  49         if (!main_battery)
  50                 main_battery = batm;
  51
  52         return;
  53 }
  54
  55 static int calculate_time(int status)
  56 {
  57         union power_supply_propval charge_full, charge_empty;
  58         union power_supply_propval charge, I;
  59
  60         if (MPSY_PROP(CHARGE_FULL, &charge_full)) {
  61                 /* if battery can't report this property, use design value */
  62                 if (MPSY_PROP(CHARGE_FULL_DESIGN, &charge_full))
  63                         return -1;
  64         }
  65
  66         if (MPSY_PROP(CHARGE_EMPTY, &charge_empty)) {
  67                 /* if battery can't report this property, use design value */
  68                 if (MPSY_PROP(CHARGE_EMPTY_DESIGN, &charge_empty))
  69                         charge_empty.intval = 0;
  70         }
  71
  72         if (MPSY_PROP(CHARGE_AVG, &charge)) {
  73                 /* if battery can't report average value, use momentary */
  74                 if (MPSY_PROP(CHARGE_NOW, &charge))
  75                         return -1;
  76         }
  77
  78         if (MPSY_PROP(CURRENT_AVG, &I)) {
  79                 /* if battery can't report average value, use momentary */
  80                 if (MPSY_PROP(CURRENT_NOW, &I))
  81                         return -1;
  82         }
  83
  84         if (status == POWER_SUPPLY_STATUS_CHARGING)
  85                 return ((charge.intval - charge_full.intval) * 60L) /
  86                        I.intval;
  87         else
  88                 return -((charge.intval - charge_empty.intval) * 60L) /
  89                         I.intval;
  90 }
  91
  92 static int calculate_capacity(int using_charge)
  93 {
  94         enum power_supply_property full_prop, empty_prop;
  95         enum power_supply_property full_design_prop, empty_design_prop;
  96         enum power_supply_property now_prop, avg_prop;
  97         union power_supply_propval empty, full, cur;
  98         int ret;
  99
 100         if (using_charge) {
 101                 full_prop = POWER_SUPPLY_PROP_CHARGE_FULL;
 102                 empty_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
 103                 full_design_prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
 104                 empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN;
 105                 now_prop = POWER_SUPPLY_PROP_CHARGE_NOW;
 106                 avg_prop = POWER_SUPPLY_PROP_CHARGE_AVG;
 107         } else {
 108                 full_prop = POWER_SUPPLY_PROP_ENERGY_FULL;
 109                 empty_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
 110                 full_design_prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
 111                 empty_design_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN;
 112                 now_prop = POWER_SUPPLY_PROP_ENERGY_NOW;
 113                 avg_prop = POWER_SUPPLY_PROP_ENERGY_AVG;
 114         }
 115
 116         if (_MPSY_PROP(full_prop, &full)) {
 117                 /* if battery can't report this property, use design value */
 118                 if (_MPSY_PROP(full_design_prop, &full))
 119                         return -1;
 120         }
 121
 122         if (_MPSY_PROP(avg_prop, &cur)) {
 123                 /* if battery can't report average value, use momentary */
 124                 if (_MPSY_PROP(now_prop, &cur))
 125                         return -1;
 126         }
 127
 128         if (_MPSY_PROP(empty_prop, &empty)) {
 129                 /* if battery can't report this property, use design value */
 130                 if (_MPSY_PROP(empty_design_prop, &empty))
 131                         empty.intval = 0;
 132         }
 133
 134         if (full.intval - empty.intval)
 135                 ret =  ((cur.intval - empty.intval) * 100L) /
 136                        (full.intval - empty.intval);
 137         else
 138                 return -1;
 139
 140         if (ret > 100)
 141                 return 100;
 142         else if (ret < 0)
 143                 return 0;
 144
 145         return ret;
 146 }
 147
 148 static void apm_battery_apm_get_power_status(struct apm_power_info *info)
 149 {
 150         union power_supply_propval status;
 151         union power_supply_propval capacity, time_to_full, time_to_empty;
 152
 153         down(&power_supply_class->sem);
 154         find_main_battery();
 155         if (!main_battery) {
 156                 up(&power_supply_class->sem);
 157                 return;
 158         }
 159
 160         /* status */
 161
 162         if (MPSY_PROP(STATUS, &status))
 163                 status.intval = POWER_SUPPLY_STATUS_UNKNOWN;
 164
 165         /* ac line status */
 166
 167         if ((status.intval == POWER_SUPPLY_STATUS_CHARGING) ||
 168             (status.intval == POWER_SUPPLY_STATUS_NOT_CHARGING) ||
 169             (status.intval == POWER_SUPPLY_STATUS_FULL))
 170                 info->ac_line_status = APM_AC_ONLINE;
 171         else
 172                 info->ac_line_status = APM_AC_OFFLINE;
 173
 174         /* battery life (i.e. capacity, in percents) */
 175
 176         if (MPSY_PROP(CAPACITY, &capacity) == 0) {
 177                 info->battery_life = capacity.intval;
 178         } else {
 179                 /* try calculate using energy */
 180                 info->battery_life = calculate_capacity(0);
 181                 /* if failed try calculate using charge instead */
 182                 if (info->battery_life == -1)
 183                         info->battery_life = calculate_capacity(1);
 184         }
 185
 186         /* charging status */
 187
 188         if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
 189                 info->battery_status = APM_BATTERY_STATUS_CHARGING;
 190         } else {
 191                 if (info->battery_life > 50)
 192                         info->battery_status = APM_BATTERY_STATUS_HIGH;
 193                 else if (info->battery_life > 5)
 194                         info->battery_status = APM_BATTERY_STATUS_LOW;
 195                 else
 196                         info->battery_status = APM_BATTERY_STATUS_CRITICAL;
 197         }
 198         info->battery_flag = info->battery_status;
 199
 200         /* time */
 201
 202         info->units = APM_UNITS_MINS;
 203
 204         if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
 205                 if (MPSY_PROP(TIME_TO_FULL_AVG, &time_to_full)) {
 206                         if (MPSY_PROP(TIME_TO_FULL_NOW, &time_to_full))
 207                                 info->time = calculate_time(status.intval);
 208                         else
 209                                 info->time = time_to_full.intval / 60;
 210                 }
 211         } else {
 212                 if (MPSY_PROP(TIME_TO_EMPTY_AVG, &time_to_empty)) {
 213                         if (MPSY_PROP(TIME_TO_EMPTY_NOW, &time_to_empty))
 214                                 info->time = calculate_time(status.intval);
 215                         else
 216                                 info->time = time_to_empty.intval / 60;
 217                 }
 218         }
 219
 220         up(&power_supply_class->sem);
 221         return;
 222 }
 223
 224 static int __init apm_battery_init(void)
 225 {
 226         printk(KERN_INFO "APM Battery Driver\n");
 227
 228         apm_get_power_status = apm_battery_apm_get_power_status;
 229         return 0;
 230 }
 231
 232 static void __exit apm_battery_exit(void)
 233 {
 234         apm_get_power_status = NULL;
 235         return;
 236 }
 237
 238 module_init(apm_battery_init);
 239 module_exit(apm_battery_exit);
 240
 241 MODULE_AUTHOR("Eugeny Boger <eugenyboger@dgap.mipt.ru>");
 242 MODULE_DESCRIPTION("APM emulation driver for battery monitoring class");
 243 MODULE_LICENSE("GPL");