drivers/power/z2_battery.c

   1 /*
   2  * Battery measurement code for Zipit Z2
   3  *
   4  * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com>
   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 version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/power_supply.h>
  17 #include <linux/i2c.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/gpio.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irq.h>
  23 #include <asm/irq.h>
  24 #include <asm/mach/irq.h>
  25 #include <linux/z2_battery.h>
  26
  27 #define Z2_DEFAULT_NAME "Z2"
  28
  29 struct z2_charger {
  30         struct z2_battery_info  *info;
  31         int                     bat_status;
  32         struct i2c_client       *client;
  33         struct power_supply     batt_ps;
  34         struct mutex            work_lock;
  35         struct work_struct      bat_work;
  36 };
  37
  38 static unsigned long z2_read_bat(struct z2_charger *charger)
  39 {
  40         int data;
  41         data = i2c_smbus_read_byte_data(charger->client,
  42                                         charger->info->batt_I2C_reg);
  43         if (data < 0)
  44                 return 0;
  45
  46         return data * charger->info->batt_mult / charger->info->batt_div;
  47 }
  48
  49 static int z2_batt_get_property(struct power_supply *batt_ps,
  50                             enum power_supply_property psp,
  51                             union power_supply_propval *val)
  52 {
  53         struct z2_charger *charger = container_of(batt_ps, struct z2_charger,
  54                                                 batt_ps);
  55         struct z2_battery_info *info = charger->info;
  56
  57         switch (psp) {
  58         case POWER_SUPPLY_PROP_STATUS:
  59                 val->intval = charger->bat_status;
  60                 break;
  61         case POWER_SUPPLY_PROP_TECHNOLOGY:
  62                 val->intval = info->batt_tech;
  63                 break;
  64         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  65                 if (info->batt_I2C_reg >= 0)
  66                         val->intval = z2_read_bat(charger);
  67                 else
  68                         return -EINVAL;
  69                 break;
  70         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  71                 if (info->max_voltage >= 0)
  72                         val->intval = info->max_voltage;
  73                 else
  74                         return -EINVAL;
  75                 break;
  76         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  77                 if (info->min_voltage >= 0)
  78                         val->intval = info->min_voltage;
  79                 else
  80                         return -EINVAL;
  81                 break;
  82         case POWER_SUPPLY_PROP_PRESENT:
  83                 val->intval = 1;
  84                 break;
  85         default:
  86                 return -EINVAL;
  87         }
  88
  89         return 0;
  90 }
  91
  92 static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
  93 {
  94         struct z2_charger *charger = container_of(batt_ps, struct z2_charger,
  95                                                 batt_ps);
  96         schedule_work(&charger->bat_work);
  97 }
  98
  99 static void z2_batt_update(struct z2_charger *charger)
 100 {
 101         int old_status = charger->bat_status;
 102         struct z2_battery_info *info;
 103
 104         info = charger->info;
 105
 106         mutex_lock(&charger->work_lock);
 107
 108         charger->bat_status = (info->charge_gpio >= 0) ?
 109                 (gpio_get_value(info->charge_gpio) ?
 110                 POWER_SUPPLY_STATUS_CHARGING :
 111                 POWER_SUPPLY_STATUS_DISCHARGING) :
 112                 POWER_SUPPLY_STATUS_UNKNOWN;
 113
 114         if (old_status != charger->bat_status) {
 115                 pr_debug("%s: %i -> %i\n", charger->batt_ps.name, old_status,
 116                         charger->bat_status);
 117                 power_supply_changed(&charger->batt_ps);
 118         }
 119
 120         mutex_unlock(&charger->work_lock);
 121 }
 122
 123 static void z2_batt_work(struct work_struct *work)
 124 {
 125         struct z2_charger *charger;
 126         charger = container_of(work, struct z2_charger, bat_work);
 127         z2_batt_update(charger);
 128 }
 129
 130 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
 131 {
 132         struct z2_charger *charger = devid;
 133         schedule_work(&charger->bat_work);
 134         return IRQ_HANDLED;
 135 }
 136
 137 static int z2_batt_ps_init(struct z2_charger *charger, int props)
 138 {
 139         int i = 0;
 140         enum power_supply_property *prop;
 141         struct z2_battery_info *info = charger->info;
 142
 143         if (info->batt_tech >= 0)
 144                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 145         if (info->batt_I2C_reg >= 0)
 146                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 147         if (info->max_voltage >= 0)
 148                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 149         if (info->min_voltage >= 0)
 150                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 151
 152         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 153         if (!prop)
 154                 return -ENOMEM;
 155
 156         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 157         if (info->charge_gpio >= 0)
 158                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 159         if (info->batt_tech >= 0)
 160                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 161         if (info->batt_I2C_reg >= 0)
 162                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 163         if (info->max_voltage >= 0)
 164                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 165         if (info->min_voltage >= 0)
 166                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 167
 168         if (!info->batt_name) {
 169                 dev_info(&charger->client->dev,
 170                                 "Please consider setting proper battery "
 171                                 "name in platform definition file, falling "
 172                                 "back to name \" Z2_DEFAULT_NAME \"\n");
 173                 charger->batt_ps.name = Z2_DEFAULT_NAME;
 174         } else
 175                 charger->batt_ps.name = info->batt_name;
 176
 177         charger->batt_ps.properties             = prop;
 178         charger->batt_ps.num_properties         = props;
 179         charger->batt_ps.type                   = POWER_SUPPLY_TYPE_BATTERY;
 180         charger->batt_ps.get_property           = z2_batt_get_property;
 181         charger->batt_ps.external_power_changed = z2_batt_ext_power_changed;
 182         charger->batt_ps.use_for_apm            = 1;
 183
 184         return 0;
 185 }
 186
 187 static int __devinit z2_batt_probe(struct i2c_client *client,
 188                                 const struct i2c_device_id *id)
 189 {
 190         int ret = 0;
 191         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 192         struct z2_charger *charger;
 193         struct z2_battery_info *info = client->dev.platform_data;
 194
 195         if (info == NULL) {
 196                 dev_err(&client->dev,
 197                         "Please set platform device platform_data"
 198                         " to a valid z2_battery_info pointer!\n");
 199                 return -EINVAL;
 200         }
 201
 202         charger = kzalloc(sizeof(*charger), GFP_KERNEL);
 203         if (charger == NULL)
 204                 return -ENOMEM;
 205
 206         charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
 207         charger->info = info;
 208         charger->client = client;
 209         i2c_set_clientdata(client, charger);
 210
 211         mutex_init(&charger->work_lock);
 212
 213         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
 214                 ret = gpio_request(info->charge_gpio, "BATT CHRG");
 215                 if (ret)
 216                         goto err;
 217
 218                 ret = gpio_direction_input(info->charge_gpio);
 219                 if (ret)
 220                         goto err2;
 221
 222                 set_irq_type(gpio_to_irq(info->charge_gpio),
 223                                 IRQ_TYPE_EDGE_BOTH);
 224                 ret = request_irq(gpio_to_irq(info->charge_gpio),
 225                                 z2_charge_switch_irq, IRQF_DISABLED,
 226                                 "AC Detect", charger);
 227                 if (ret)
 228                         goto err3;
 229         }
 230
 231         ret = z2_batt_ps_init(charger, props);
 232         if (ret)
 233                 goto err3;
 234
 235         INIT_WORK(&charger->bat_work, z2_batt_work);
 236
 237         ret = power_supply_register(&client->dev, &charger->batt_ps);
 238         if (ret)
 239                 goto err4;
 240
 241         schedule_work(&charger->bat_work);
 242
 243         return 0;
 244
 245 err4:
 246         kfree(charger->batt_ps.properties);
 247 err3:
 248         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
 249                 free_irq(gpio_to_irq(info->charge_gpio), charger);
 250 err2:
 251         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
 252                 gpio_free(info->charge_gpio);
 253 err:
 254         kfree(charger);
 255         return ret;
 256 }
 257
 258 static int __devexit z2_batt_remove(struct i2c_client *client)
 259 {
 260         struct z2_charger *charger = i2c_get_clientdata(client);
 261         struct z2_battery_info *info = charger->info;
 262
 263         flush_scheduled_work();
 264         power_supply_unregister(&charger->batt_ps);
 265
 266         kfree(charger->batt_ps.properties);
 267         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
 268                 free_irq(gpio_to_irq(info->charge_gpio), charger);
 269                 gpio_free(info->charge_gpio);
 270         }
 271
 272         kfree(charger);
 273
 274         return 0;
 275 }
 276
 277 #ifdef CONFIG_PM
 278 static int z2_batt_suspend(struct i2c_client *client, pm_message_t state)
 279 {
 280         flush_scheduled_work();
 281         return 0;
 282 }
 283
 284 static int z2_batt_resume(struct i2c_client *client)
 285 {
 286         struct z2_charger *charger = i2c_get_clientdata(client);
 287
 288         schedule_work(&charger->bat_work);
 289         return 0;
 290 }
 291 #else
 292 #define z2_batt_suspend NULL
 293 #define z2_batt_resume NULL
 294 #endif
 295
 296 static const struct i2c_device_id z2_batt_id[] = {
 297         { "aer915", 0 },
 298         { }
 299 };
 300
 301 static struct i2c_driver z2_batt_driver = {
 302         .driver = {
 303                 .name   = "z2-battery",
 304                 .owner  = THIS_MODULE,
 305         },
 306         .probe          = z2_batt_probe,
 307         .remove         = z2_batt_remove,
 308         .suspend        = z2_batt_suspend,
 309         .resume         = z2_batt_resume,
 310         .id_table       = z2_batt_id,
 311 };
 312
 313 static int __init z2_batt_init(void)
 314 {
 315         return i2c_add_driver(&z2_batt_driver);
 316 }
 317
 318 static void __exit z2_batt_exit(void)
 319 {
 320         i2c_del_driver(&z2_batt_driver);
 321 }
 322
 323 module_init(z2_batt_init);
 324 module_exit(z2_batt_exit);
 325
 326 MODULE_LICENSE("GPL");
 327 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
 328 MODULE_DESCRIPTION("Zipit Z2 battery driver");