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 = NULL;
  30         struct power_supply *max_charge_bat = NULL;
  31         struct power_supply *max_energy_bat = NULL;
  32         union power_supply_propval full;
  33         int max_charge = 0;
  34         int max_energy = 0;
  35
  36         main_battery = NULL;
  37
  38         list_for_each_entry(dev, &power_supply_class->devices, node) {
  39                 bat = dev_get_drvdata(dev);
  40
  41                 if (bat->use_for_apm) {
  42                         /* nice, we explicitly asked to report this battery. */
  43                         main_battery = bat;
  44                         return;
  45                 }
  46
  47                 if (!PSY_PROP(bat, CHARGE_FULL_DESIGN, &full) ||
  48                                 !PSY_PROP(bat, CHARGE_FULL, &full)) {
  49                         if (full.intval > max_charge) {
  50                                 max_charge_bat = bat;
  51                                 max_charge = full.intval;
  52                         }
  53                 } else if (!PSY_PROP(bat, ENERGY_FULL_DESIGN, &full) ||
  54                                 !PSY_PROP(bat, ENERGY_FULL, &full)) {
  55                         if (full.intval > max_energy) {
  56                                 max_energy_bat = bat;
  57                                 max_energy = full.intval;
  58                         }
  59                 }
  60         }
  61
  62         if ((max_energy_bat && max_charge_bat) &&
  63                         (max_energy_bat != max_charge_bat)) {
  64                 /* try guess battery with more capacity */
  65                 if (!PSY_PROP(max_charge_bat, VOLTAGE_MAX_DESIGN, &full)) {
  66                         if (max_energy > max_charge * full.intval)
  67                                 main_battery = max_energy_bat;
  68                         else
  69                                 main_battery = max_charge_bat;
  70                 } else if (!PSY_PROP(max_energy_bat, VOLTAGE_MAX_DESIGN,
  71                                                                   &full)) {
  72                         if (max_charge > max_energy / full.intval)
  73                                 main_battery = max_charge_bat;
  74                         else
  75                                 main_battery = max_energy_bat;
  76                 } else {
  77                         /* give up, choice any */
  78                         main_battery = max_energy_bat;
  79                 }
  80         } else if (max_charge_bat) {
  81                 main_battery = max_charge_bat;
  82         } else if (max_energy_bat) {
  83                 main_battery = max_energy_bat;
  84         } else {
  85                 /* give up, try the last if any */
  86                 main_battery = bat;
  87         }
  88 }
  89
  90 static int calculate_time(int status)
  91 {
  92         union power_supply_propval charge_full, charge_empty;
  93         union power_supply_propval charge, I;
  94
  95         if (MPSY_PROP(CHARGE_FULL, &charge_full)) {
  96                 /* if battery can't report this property, use design value */
  97                 if (MPSY_PROP(CHARGE_FULL_DESIGN, &charge_full))
  98                         return -1;
  99         }
 100
 101         if (MPSY_PROP(CHARGE_EMPTY, &charge_empty)) {
 102                 /* if battery can't report this property, use design value */
 103                 if (MPSY_PROP(CHARGE_EMPTY_DESIGN, &charge_empty))
 104                         charge_empty.intval = 0;
 105         }
 106
 107         if (MPSY_PROP(CHARGE_AVG, &charge)) {
 108                 /* if battery can't report average value, use momentary */
 109                 if (MPSY_PROP(CHARGE_NOW, &charge))
 110                         return -1;
 111         }
 112
 113         if (MPSY_PROP(CURRENT_AVG, &I)) {
 114                 /* if battery can't report average value, use momentary */
 115                 if (MPSY_PROP(CURRENT_NOW, &I))
 116                         return -1;
 117         }
 118
 119         if (status == POWER_SUPPLY_STATUS_CHARGING)
 120                 return ((charge.intval - charge_full.intval) * 60L) /
 121                        I.intval;
 122         else
 123                 return -((charge.intval - charge_empty.intval) * 60L) /
 124                         I.intval;
 125 }
 126
 127 static int calculate_capacity(int using_charge)
 128 {
 129         enum power_supply_property full_prop, empty_prop;
 130         enum power_supply_property full_design_prop, empty_design_prop;
 131         enum power_supply_property now_prop, avg_prop;
 132         union power_supply_propval empty, full, cur;
 133         int ret;
 134
 135         if (using_charge) {
 136                 full_prop = POWER_SUPPLY_PROP_CHARGE_FULL;
 137                 empty_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
 138                 full_design_prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
 139                 empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN;
 140                 now_prop = POWER_SUPPLY_PROP_CHARGE_NOW;
 141                 avg_prop = POWER_SUPPLY_PROP_CHARGE_AVG;
 142         } else {
 143                 full_prop = POWER_SUPPLY_PROP_ENERGY_FULL;
 144                 empty_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
 145                 full_design_prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
 146                 empty_design_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN;
 147                 now_prop = POWER_SUPPLY_PROP_ENERGY_NOW;
 148                 avg_prop = POWER_SUPPLY_PROP_ENERGY_AVG;
 149         }
 150
 151         if (_MPSY_PROP(full_prop, &full)) {
 152                 /* if battery can't report this property, use design value */
 153                 if (_MPSY_PROP(full_design_prop, &full))
 154                         return -1;
 155         }
 156
 157         if (_MPSY_PROP(avg_prop, &cur)) {
 158                 /* if battery can't report average value, use momentary */
 159                 if (_MPSY_PROP(now_prop, &cur))
 160                         return -1;
 161         }
 162
 163         if (_MPSY_PROP(empty_prop, &empty)) {
 164                 /* if battery can't report this property, use design value */
 165                 if (_MPSY_PROP(empty_design_prop, &empty))
 166                         empty.intval = 0;
 167         }
 168
 169         if (full.intval - empty.intval)
 170                 ret =  ((cur.intval - empty.intval) * 100L) /
 171                        (full.intval - empty.intval);
 172         else
 173                 return -1;
 174
 175         if (ret > 100)
 176                 return 100;
 177         else if (ret < 0)
 178                 return 0;
 179
 180         return ret;
 181 }
 182
 183 static void apm_battery_apm_get_power_status(struct apm_power_info *info)
 184 {
 185         union power_supply_propval status;
 186         union power_supply_propval capacity, time_to_full, time_to_empty;
 187
 188         down(&power_supply_class->sem);
 189         find_main_battery();
 190         if (!main_battery) {
 191                 up(&power_supply_class->sem);
 192                 return;
 193         }
 194
 195         /* status */
 196
 197         if (MPSY_PROP(STATUS, &status))
 198                 status.intval = POWER_SUPPLY_STATUS_UNKNOWN;
 199
 200         /* ac line status */
 201
 202         if ((status.intval == POWER_SUPPLY_STATUS_CHARGING) ||
 203             (status.intval == POWER_SUPPLY_STATUS_NOT_CHARGING) ||
 204             (status.intval == POWER_SUPPLY_STATUS_FULL))
 205                 info->ac_line_status = APM_AC_ONLINE;
 206         else
 207                 info->ac_line_status = APM_AC_OFFLINE;
 208
 209         /* battery life (i.e. capacity, in percents) */
 210
 211         if (MPSY_PROP(CAPACITY, &capacity) == 0) {
 212                 info->battery_life = capacity.intval;
 213         } else {
 214                 /* try calculate using energy */
 215                 info->battery_life = calculate_capacity(0);
 216                 /* if failed try calculate using charge instead */
 217                 if (info->battery_life == -1)
 218                         info->battery_life = calculate_capacity(1);
 219         }
 220
 221         /* charging status */
 222
 223         if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
 224                 info->battery_status = APM_BATTERY_STATUS_CHARGING;
 225         } else {
 226                 if (info->battery_life > 50)
 227                         info->battery_status = APM_BATTERY_STATUS_HIGH;
 228                 else if (info->battery_life > 5)
 229                         info->battery_status = APM_BATTERY_STATUS_LOW;
 230                 else
 231                         info->battery_status = APM_BATTERY_STATUS_CRITICAL;
 232         }
 233         info->battery_flag = info->battery_status;
 234
 235         /* time */
 236
 237         info->units = APM_UNITS_MINS;
 238
 239         if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
 240                 if (!MPSY_PROP(TIME_TO_FULL_AVG, &time_to_full) ||
 241                                 !MPSY_PROP(TIME_TO_FULL_NOW, &time_to_full))
 242                         info->time = time_to_full.intval / 60;
 243                 else
 244                         info->time = calculate_time(status.intval);
 245         } else {
 246                 if (!MPSY_PROP(TIME_TO_EMPTY_AVG, &time_to_empty) ||
 247                                 !MPSY_PROP(TIME_TO_EMPTY_NOW, &time_to_empty))
 248                         info->time = time_to_empty.intval / 60;
 249                 else
 250                         info->time = calculate_time(status.intval);
 251         }
 252
 253         up(&power_supply_class->sem);
 254 }
 255
 256 static int __init apm_battery_init(void)
 257 {
 258         printk(KERN_INFO "APM Battery Driver\n");
 259
 260         apm_get_power_status = apm_battery_apm_get_power_status;
 261         return 0;
 262 }
 263
 264 static void __exit apm_battery_exit(void)
 265 {
 266         apm_get_power_status = NULL;
 267 }
 268
 269 module_init(apm_battery_init);
 270 module_exit(apm_battery_exit);
 271
 272 MODULE_AUTHOR("Eugeny Boger <eugenyboger@dgap.mipt.ru>");
 273 MODULE_DESCRIPTION("APM emulation driver for battery monitoring class");
 274 MODULE_LICENSE("GPL");