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 power_supply_desc        batt_ps_desc;
  29         struct mutex                    work_lock;
  30         struct work_struct              bat_work;
  31 };
  32
  33 static unsigned long z2_read_bat(struct z2_charger *charger)
  34 {
  35         int data;
  36         data = i2c_smbus_read_byte_data(charger->client,
  37                                         charger->info->batt_I2C_reg);
  38         if (data < 0)
  39                 return 0;
  40
  41         return data * charger->info->batt_mult / charger->info->batt_div;
  42 }
  43
  44 static int z2_batt_get_property(struct power_supply *batt_ps,
  45                             enum power_supply_property psp,
  46                             union power_supply_propval *val)
  47 {
  48         struct z2_charger *charger = power_supply_get_drvdata(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 = power_supply_get_drvdata(batt_ps);
  89
  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->desc->name,
 110                                 old_status,
 111                                 charger->bat_status);
 112                 power_supply_changed(charger->batt_ps);
 113         }
 114
 115         mutex_unlock(&charger->work_lock);
 116 }
 117
 118 static void z2_batt_work(struct work_struct *work)
 119 {
 120         struct z2_charger *charger;
 121         charger = container_of(work, struct z2_charger, bat_work);
 122         z2_batt_update(charger);
 123 }
 124
 125 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
 126 {
 127         struct z2_charger *charger = devid;
 128         schedule_work(&charger->bat_work);
 129         return IRQ_HANDLED;
 130 }
 131
 132 static int z2_batt_ps_init(struct z2_charger *charger, int props)
 133 {
 134         int i = 0;
 135         enum power_supply_property *prop;
 136         struct z2_battery_info *info = charger->info;
 137
 138         if (info->charge_gpio >= 0)
 139                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 140         if (info->batt_tech >= 0)
 141                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 142         if (info->batt_I2C_reg >= 0)
 143                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 144         if (info->max_voltage >= 0)
 145                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 146         if (info->min_voltage >= 0)
 147                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 148
 149         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 150         if (!prop)
 151                 return -ENOMEM;
 152
 153         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 154         if (info->charge_gpio >= 0)
 155                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 156         if (info->batt_tech >= 0)
 157                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 158         if (info->batt_I2C_reg >= 0)
 159                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 160         if (info->max_voltage >= 0)
 161                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 162         if (info->min_voltage >= 0)
 163                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 164
 165         if (!info->batt_name) {
 166                 dev_info(&charger->client->dev,
 167                                 "Please consider setting proper battery "
 168                                 "name in platform definition file, falling "
 169                                 "back to name \" Z2_DEFAULT_NAME \"\n");
 170                 charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
 171         } else
 172                 charger->batt_ps_desc.name = info->batt_name;
 173
 174         charger->batt_ps_desc.properties        = prop;
 175         charger->batt_ps_desc.num_properties    = props;
 176         charger->batt_ps_desc.type              = POWER_SUPPLY_TYPE_BATTERY;
 177         charger->batt_ps_desc.get_property      = z2_batt_get_property;
 178         charger->batt_ps_desc.external_power_changed =
 179                                                 z2_batt_ext_power_changed;
 180         charger->batt_ps_desc.use_for_apm       = 1;
 181
 182         return 0;
 183 }
 184
 185 static int z2_batt_probe(struct i2c_client *client,
 186                                 const struct i2c_device_id *id)
 187 {
 188         int ret = 0;
 189         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 190         struct z2_charger *charger;
 191         struct z2_battery_info *info = client->dev.platform_data;
 192         struct power_supply_config psy_cfg = {};
 193
 194         if (info == NULL) {
 195                 dev_err(&client->dev,
 196                         "Please set platform device platform_data"
 197                         " to a valid z2_battery_info pointer!\n");
 198                 return -EINVAL;
 199         }
 200
 201         charger = kzalloc(sizeof(*charger), GFP_KERNEL);
 202         if (charger == NULL)
 203                 return -ENOMEM;
 204
 205         charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
 206         charger->info = info;
 207         charger->client = client;
 208         i2c_set_clientdata(client, charger);
 209         psy_cfg.drv_data = 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                 irq_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, 0,
 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         charger->batt_ps = power_supply_register(&client->dev,
 238                                                  &charger->batt_ps_desc,
 239                                                  &psy_cfg);
 240         if (IS_ERR(charger->batt_ps)) {
 241                 ret = PTR_ERR(charger->batt_ps);
 242                 goto err4;
 243         }
 244
 245         schedule_work(&charger->bat_work);
 246
 247         return 0;
 248
 249 err4:
 250         kfree(charger->batt_ps_desc.properties);
 251 err3:
 252         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
 253                 free_irq(gpio_to_irq(info->charge_gpio), charger);
 254 err2:
 255         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
 256                 gpio_free(info->charge_gpio);
 257 err:
 258         kfree(charger);
 259         return ret;
 260 }
 261
 262 static int z2_batt_remove(struct i2c_client *client)
 263 {
 264         struct z2_charger *charger = i2c_get_clientdata(client);
 265         struct z2_battery_info *info = charger->info;
 266
 267         cancel_work_sync(&charger->bat_work);
 268         power_supply_unregister(charger->batt_ps);
 269
 270         kfree(charger->batt_ps_desc.properties);
 271         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
 272                 free_irq(gpio_to_irq(info->charge_gpio), charger);
 273                 gpio_free(info->charge_gpio);
 274         }
 275
 276         kfree(charger);
 277
 278         return 0;
 279 }
 280
 281 #ifdef CONFIG_PM
 282 static int z2_batt_suspend(struct device *dev)
 283 {
 284         struct i2c_client *client = to_i2c_client(dev);
 285         struct z2_charger *charger = i2c_get_clientdata(client);
 286
 287         flush_work(&charger->bat_work);
 288         return 0;
 289 }
 290
 291 static int z2_batt_resume(struct device *dev)
 292 {
 293         struct i2c_client *client = to_i2c_client(dev);
 294         struct z2_charger *charger = i2c_get_clientdata(client);
 295
 296         schedule_work(&charger->bat_work);
 297         return 0;
 298 }
 299
 300 static const struct dev_pm_ops z2_battery_pm_ops = {
 301         .suspend        = z2_batt_suspend,
 302         .resume         = z2_batt_resume,
 303 };
 304
 305 #define Z2_BATTERY_PM_OPS       (&z2_battery_pm_ops)
 306
 307 #else
 308 #define Z2_BATTERY_PM_OPS       (NULL)
 309 #endif
 310
 311 static const struct i2c_device_id z2_batt_id[] = {
 312         { "aer915", 0 },
 313         { }
 314 };
 315 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
 316
 317 static struct i2c_driver z2_batt_driver = {
 318         .driver = {
 319                 .name   = "z2-battery",
 320                 .owner  = THIS_MODULE,
 321                 .pm     = Z2_BATTERY_PM_OPS
 322         },
 323         .probe          = z2_batt_probe,
 324         .remove         = z2_batt_remove,
 325         .id_table       = z2_batt_id,
 326 };
 327 module_i2c_driver(z2_batt_driver);
 328
 329 MODULE_LICENSE("GPL");
 330 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
 331 MODULE_DESCRIPTION("Zipit Z2 battery driver");