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