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 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 (!wmdata) {
 175                 dev_err(&dev->dev, "No platform data supplied\n");
 176                 return -EINVAL;
 177         }
 178
 179         pdata = wmdata->batt_pdata;
 180
 181         if (dev->id != -1)
 182                 return -EINVAL;
 183
 184         mutex_init(&work_lock);
 185
 186         if (!pdata) {
 187                 dev_err(&dev->dev, "No platform_data supplied\n");
 188                 return -EINVAL;
 189         }
 190
 191         if (gpio_is_valid(pdata->charge_gpio)) {
 192                 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
 193                 if (ret)
 194                         goto err;
 195                 ret = gpio_direction_input(pdata->charge_gpio);
 196                 if (ret)
 197                         goto err2;
 198                 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
 199                                 wm97xx_chrg_irq, IRQF_DISABLED,
 200                                 "AC Detect", dev);
 201                 if (ret)
 202                         goto err2;
 203                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 204         }
 205
 206         if (pdata->batt_tech >= 0)
 207                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 208         if (pdata->temp_aux >= 0)
 209                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 210         if (pdata->batt_aux >= 0)
 211                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 212         if (pdata->max_voltage >= 0)
 213                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 214         if (pdata->min_voltage >= 0)
 215                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 216
 217         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 218         if (!prop)
 219                 goto err3;
 220
 221         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 222         if (pdata->charge_gpio >= 0)
 223                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 224         if (pdata->batt_tech >= 0)
 225                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 226         if (pdata->temp_aux >= 0)
 227                 prop[i++] = POWER_SUPPLY_PROP_TEMP;
 228         if (pdata->batt_aux >= 0)
 229                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 230         if (pdata->max_voltage >= 0)
 231                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 232         if (pdata->min_voltage >= 0)
 233                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 234
 235         INIT_WORK(&bat_work, wm97xx_bat_work);
 236
 237         if (!pdata->batt_name) {
 238                 dev_info(&dev->dev, "Please consider setting proper battery "
 239                                 "name in platform definition file, falling "
 240                                 "back to name \"wm97xx-batt\"\n");
 241                 bat_ps.name = "wm97xx-batt";
 242         } else
 243                 bat_ps.name = pdata->batt_name;
 244
 245         bat_ps.properties = prop;
 246         bat_ps.num_properties = props;
 247
 248         ret = power_supply_register(&dev->dev, &bat_ps);
 249         if (!ret)
 250                 schedule_work(&bat_work);
 251         else
 252                 goto err4;
 253
 254         return 0;
 255 err4:
 256         kfree(prop);
 257 err3:
 258         if (gpio_is_valid(pdata->charge_gpio))
 259                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 260 err2:
 261         if (gpio_is_valid(pdata->charge_gpio))
 262                 gpio_free(pdata->charge_gpio);
 263 err:
 264         return ret;
 265 }
 266
 267 static int __devexit wm97xx_bat_remove(struct platform_device *dev)
 268 {
 269         struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 270         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 271
 272         if (pdata && gpio_is_valid(pdata->charge_gpio)) {
 273                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 274                 gpio_free(pdata->charge_gpio);
 275         }
 276         flush_scheduled_work();
 277         power_supply_unregister(&bat_ps);
 278         kfree(prop);
 279         return 0;
 280 }
 281
 282 static struct platform_driver wm97xx_bat_driver = {
 283         .driver = {
 284                 .name   = "wm97xx-battery",
 285                 .owner  = THIS_MODULE,
 286 #ifdef CONFIG_PM
 287                 .pm     = &wm97xx_bat_pm_ops,
 288 #endif
 289         },
 290         .probe          = wm97xx_bat_probe,
 291         .remove         = __devexit_p(wm97xx_bat_remove),
 292 };
 293
 294 static int __init wm97xx_bat_init(void)
 295 {
 296         return platform_driver_register(&wm97xx_bat_driver);
 297 }
 298
 299 static void __exit wm97xx_bat_exit(void)
 300 {
 301         platform_driver_unregister(&wm97xx_bat_driver);
 302 }
 303
 304 module_init(wm97xx_bat_init);
 305 module_exit(wm97xx_bat_exit);
 306
 307 MODULE_LICENSE("GPL");
 308 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 309 MODULE_DESCRIPTION("WM97xx battery driver");