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