drivers/power/wm97xx_battery.c

   1 /*
   2  * linux/drivers/power/wm97xx_battery.c
   3  *
   4  * Battery measurement code for WM97xx
   5  *
   6  * based on tosa_battery.c
   7  *
   8  * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/power_supply.h>
  21 #include <linux/wm97xx.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/gpio.h>
  25 #include <linux/irq.h>
  26 #include <linux/slab.h>
  27
  28 static DEFINE_MUTEX(bat_lock);
  29 static struct work_struct bat_work;
  30 static struct mutex work_lock;
  31 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  32 static struct wm97xx_batt_info *gpdata;
  33 static enum power_supply_property *prop;
  34
  35 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
  36 {
  37         struct wm97xx_pdata *wmdata = bat_ps->dev->parent->platform_data;
  38         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  39
  40         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev->parent),
  41                                         pdata->batt_aux) * pdata->batt_mult /
  42                                         pdata->batt_div;
  43 }
  44
  45 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
  46 {
  47         struct wm97xx_pdata *wmdata = bat_ps->dev->parent->platform_data;
  48         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  49
  50         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev->parent),
  51                                         pdata->temp_aux) * pdata->temp_mult /
  52                                         pdata->temp_div;
  53 }
  54
  55 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
  56                             enum power_supply_property psp,
  57                             union power_supply_propval *val)
  58 {
  59         struct wm97xx_pdata *wmdata = bat_ps->dev->parent->platform_data;
  60         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  61
  62         switch (psp) {
  63         case POWER_SUPPLY_PROP_STATUS:
  64                 val->intval = bat_status;
  65                 break;
  66         case POWER_SUPPLY_PROP_TECHNOLOGY:
  67                 val->intval = pdata->batt_tech;
  68                 break;
  69         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  70                 if (pdata->batt_aux >= 0)
  71                         val->intval = wm97xx_read_bat(bat_ps);
  72                 else
  73                         return -EINVAL;
  74                 break;
  75         case POWER_SUPPLY_PROP_TEMP:
  76                 if (pdata->temp_aux >= 0)
  77                         val->intval = wm97xx_read_temp(bat_ps);
  78                 else
  79                         return -EINVAL;
  80                 break;
  81         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  82                 if (pdata->max_voltage >= 0)
  83                         val->intval = pdata->max_voltage;
  84                 else
  85                         return -EINVAL;
  86                 break;
  87         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  88                 if (pdata->min_voltage >= 0)
  89                         val->intval = pdata->min_voltage;
  90                 else
  91                         return -EINVAL;
  92                 break;
  93         case POWER_SUPPLY_PROP_PRESENT:
  94                 val->intval = 1;
  95                 break;
  96         default:
  97                 return -EINVAL;
  98         }
  99         return 0;
 100 }
 101
 102 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
 103 {
 104         schedule_work(&bat_work);
 105 }
 106
 107 static void wm97xx_bat_update(struct power_supply *bat_ps)
 108 {
 109         int old_status = bat_status;
 110         struct wm97xx_pdata *wmdata = bat_ps->dev->parent->platform_data;
 111         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 112
 113         mutex_lock(&work_lock);
 114
 115         bat_status = (pdata->charge_gpio >= 0) ?
 116                         (gpio_get_value(pdata->charge_gpio) ?
 117                         POWER_SUPPLY_STATUS_DISCHARGING :
 118                         POWER_SUPPLY_STATUS_CHARGING) :
 119                         POWER_SUPPLY_STATUS_UNKNOWN;
 120
 121         if (old_status != bat_status) {
 122                 pr_debug("%s: %i -> %i\n", bat_ps->name, old_status,
 123                                         bat_status);
 124                 power_supply_changed(bat_ps);
 125         }
 126
 127         mutex_unlock(&work_lock);
 128 }
 129
 130 static struct power_supply bat_ps = {
 131         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 132         .get_property           = wm97xx_bat_get_property,
 133         .external_power_changed = wm97xx_bat_external_power_changed,
 134         .use_for_apm            = 1,
 135 };
 136
 137 static void wm97xx_bat_work(struct work_struct *work)
 138 {
 139         wm97xx_bat_update(&bat_ps);
 140 }
 141
 142 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
 143 {
 144         schedule_work(&bat_work);
 145         return IRQ_HANDLED;
 146 }
 147
 148 #ifdef CONFIG_PM
 149 static int wm97xx_bat_suspend(struct device *dev)
 150 {
 151         flush_scheduled_work();
 152         return 0;
 153 }
 154
 155 static int wm97xx_bat_resume(struct device *dev)
 156 {
 157         schedule_work(&bat_work);
 158         return 0;
 159 }
 160
 161 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
 162         .suspend        = wm97xx_bat_suspend,
 163         .resume         = wm97xx_bat_resume,
 164 };
 165 #endif
 166
 167 static int __devinit wm97xx_bat_probe(struct platform_device *dev)
 168 {
 169         int ret = 0;
 170         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 171         int i = 0;
 172         struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 173         struct wm97xx_batt_pdata *pdata;
 174
 175         if (gpdata) {
 176                 dev_err(&dev->dev, "Do not pass platform_data through "
 177                         "wm97xx_bat_set_pdata!\n");
 178                 return -EINVAL;
 179         }
 180
 181         if (!wmdata) {
 182                 dev_err(&dev->dev, "No platform data supplied\n");
 183                 return -EINVAL;
 184         }
 185
 186         pdata = wmdata->batt_pdata;
 187
 188         if (dev->id != -1)
 189                 return -EINVAL;
 190
 191         mutex_init(&work_lock);
 192
 193         if (!pdata) {
 194                 dev_err(&dev->dev, "No platform_data supplied\n");
 195                 return -EINVAL;
 196         }
 197
 198         if (gpio_is_valid(pdata->charge_gpio)) {
 199                 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
 200                 if (ret)
 201                         goto err;
 202                 ret = gpio_direction_input(pdata->charge_gpio);
 203                 if (ret)
 204                         goto err2;
 205                 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
 206                                 wm97xx_chrg_irq, IRQF_DISABLED,
 207                                 "AC Detect", dev);
 208                 if (ret)
 209                         goto err2;
 210                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 211         }
 212
 213         if (pdata->batt_tech >= 0)
 214                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 215         if (pdata->temp_aux >= 0)
 216                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 217         if (pdata->batt_aux >= 0)
 218                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 219         if (pdata->max_voltage >= 0)
 220                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 221         if (pdata->min_voltage >= 0)
 222                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 223
 224         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 225         if (!prop)
 226                 goto err3;
 227
 228         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 229         if (pdata->charge_gpio >= 0)
 230                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 231         if (pdata->batt_tech >= 0)
 232                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 233         if (pdata->temp_aux >= 0)
 234                 prop[i++] = POWER_SUPPLY_PROP_TEMP;
 235         if (pdata->batt_aux >= 0)
 236                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 237         if (pdata->max_voltage >= 0)
 238                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 239         if (pdata->min_voltage >= 0)
 240                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 241
 242         INIT_WORK(&bat_work, wm97xx_bat_work);
 243
 244         if (!pdata->batt_name) {
 245                 dev_info(&dev->dev, "Please consider setting proper battery "
 246                                 "name in platform definition file, falling "
 247                                 "back to name \"wm97xx-batt\"\n");
 248                 bat_ps.name = "wm97xx-batt";
 249         } else
 250                 bat_ps.name = pdata->batt_name;
 251
 252         bat_ps.properties = prop;
 253         bat_ps.num_properties = props;
 254
 255         ret = power_supply_register(&dev->dev, &bat_ps);
 256         if (!ret)
 257                 schedule_work(&bat_work);
 258         else
 259                 goto err4;
 260
 261         return 0;
 262 err4:
 263         kfree(prop);
 264 err3:
 265         if (gpio_is_valid(pdata->charge_gpio))
 266                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 267 err2:
 268         if (gpio_is_valid(pdata->charge_gpio))
 269                 gpio_free(pdata->charge_gpio);
 270 err:
 271         return ret;
 272 }
 273
 274 static int __devexit wm97xx_bat_remove(struct platform_device *dev)
 275 {
 276         struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 277         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 278
 279         if (pdata && gpio_is_valid(pdata->charge_gpio)) {
 280                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 281                 gpio_free(pdata->charge_gpio);
 282         }
 283         flush_scheduled_work();
 284         power_supply_unregister(&bat_ps);
 285         kfree(prop);
 286         return 0;
 287 }
 288
 289 static struct platform_driver wm97xx_bat_driver = {
 290         .driver = {
 291                 .name   = "wm97xx-battery",
 292                 .owner  = THIS_MODULE,
 293 #ifdef CONFIG_PM
 294                 .pm     = &wm97xx_bat_pm_ops,
 295 #endif
 296         },
 297         .probe          = wm97xx_bat_probe,
 298         .remove         = __devexit_p(wm97xx_bat_remove),
 299 };
 300
 301 static int __init wm97xx_bat_init(void)
 302 {
 303         return platform_driver_register(&wm97xx_bat_driver);
 304 }
 305
 306 static void __exit wm97xx_bat_exit(void)
 307 {
 308         platform_driver_unregister(&wm97xx_bat_driver);
 309 }
 310
 311 /* The interface is deprecated, as well as linux/wm97xx_batt.h */
 312 void wm97xx_bat_set_pdata(struct wm97xx_batt_info *data);
 313
 314 void wm97xx_bat_set_pdata(struct wm97xx_batt_info *data)
 315 {
 316         gpdata = data;
 317 }
 318 EXPORT_SYMBOL_GPL(wm97xx_bat_set_pdata);
 319
 320 module_init(wm97xx_bat_init);
 321 module_exit(wm97xx_bat_exit);
 322
 323 MODULE_LICENSE("GPL");
 324 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 325 MODULE_DESCRIPTION("WM97xx battery driver");