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/wm97xx_batt.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 *pdata;
  32 static enum power_supply_property *prop;
  33
  34 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
  35 {
  36         return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
  37                                         pdata->batt_aux) * pdata->batt_mult /
  38                                         pdata->batt_div;
  39 }
  40
  41 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
  42 {
  43         return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
  44                                         pdata->temp_aux) * pdata->temp_mult /
  45                                         pdata->temp_div;
  46 }
  47
  48 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
  49                             enum power_supply_property psp,
  50                             union power_supply_propval *val)
  51 {
  52         switch (psp) {
  53         case POWER_SUPPLY_PROP_STATUS:
  54                 val->intval = bat_status;
  55                 break;
  56         case POWER_SUPPLY_PROP_TECHNOLOGY:
  57                 val->intval = pdata->batt_tech;
  58                 break;
  59         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  60                 if (pdata->batt_aux >= 0)
  61                         val->intval = wm97xx_read_bat(bat_ps);
  62                 else
  63                         return -EINVAL;
  64                 break;
  65         case POWER_SUPPLY_PROP_TEMP:
  66                 if (pdata->temp_aux >= 0)
  67                         val->intval = wm97xx_read_temp(bat_ps);
  68                 else
  69                         return -EINVAL;
  70                 break;
  71         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  72                 if (pdata->max_voltage >= 0)
  73                         val->intval = pdata->max_voltage;
  74                 else
  75                         return -EINVAL;
  76                 break;
  77         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  78                 if (pdata->min_voltage >= 0)
  79                         val->intval = pdata->min_voltage;
  80                 else
  81                         return -EINVAL;
  82                 break;
  83         case POWER_SUPPLY_PROP_PRESENT:
  84                 val->intval = 1;
  85                 break;
  86         default:
  87                 return -EINVAL;
  88         }
  89         return 0;
  90 }
  91
  92 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
  93 {
  94         schedule_work(&bat_work);
  95 }
  96
  97 static void wm97xx_bat_update(struct power_supply *bat_ps)
  98 {
  99         int old_status = bat_status;
 100
 101         mutex_lock(&work_lock);
 102
 103         bat_status = (pdata->charge_gpio >= 0) ?
 104                         (gpio_get_value(pdata->charge_gpio) ?
 105                         POWER_SUPPLY_STATUS_DISCHARGING :
 106                         POWER_SUPPLY_STATUS_CHARGING) :
 107                         POWER_SUPPLY_STATUS_UNKNOWN;
 108
 109         if (old_status != bat_status) {
 110                 pr_debug("%s: %i -> %i\n", bat_ps->name, old_status,
 111                                         bat_status);
 112                 power_supply_changed(bat_ps);
 113         }
 114
 115         mutex_unlock(&work_lock);
 116 }
 117
 118 static struct power_supply bat_ps = {
 119         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 120         .get_property           = wm97xx_bat_get_property,
 121         .external_power_changed = wm97xx_bat_external_power_changed,
 122         .use_for_apm            = 1,
 123 };
 124
 125 static void wm97xx_bat_work(struct work_struct *work)
 126 {
 127         wm97xx_bat_update(&bat_ps);
 128 }
 129
 130 #ifdef CONFIG_PM
 131 static int wm97xx_bat_suspend(struct platform_device *dev, pm_message_t state)
 132 {
 133         flush_scheduled_work();
 134         return 0;
 135 }
 136
 137 static int wm97xx_bat_resume(struct platform_device *dev)
 138 {
 139         schedule_work(&bat_work);
 140         return 0;
 141 }
 142 #else
 143 #define wm97xx_bat_suspend NULL
 144 #define wm97xx_bat_resume NULL
 145 #endif
 146
 147 static int __devinit wm97xx_bat_probe(struct platform_device *dev)
 148 {
 149         int ret = 0;
 150         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 151         int i = 0;
 152
 153         if (dev->id != -1)
 154                 return -EINVAL;
 155
 156         mutex_init(&work_lock);
 157
 158         if (!pdata) {
 159                 dev_err(&dev->dev, "Please use wm97xx_bat_set_pdata\n");
 160                 return -EINVAL;
 161         }
 162
 163         if (pdata->charge_gpio >= 0 && gpio_is_valid(pdata->charge_gpio)) {
 164                 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
 165                 if (ret)
 166                         goto err;
 167                 ret = gpio_direction_input(pdata->charge_gpio);
 168                 if (ret)
 169                         goto err2;
 170                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 171         }
 172
 173         if (pdata->batt_tech >= 0)
 174                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 175         if (pdata->temp_aux >= 0)
 176                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 177         if (pdata->batt_aux >= 0)
 178                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 179         if (pdata->max_voltage >= 0)
 180                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 181         if (pdata->min_voltage >= 0)
 182                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 183
 184         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 185         if (!prop)
 186                 goto err2;
 187
 188         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 189         if (pdata->charge_gpio >= 0)
 190                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 191         if (pdata->batt_tech >= 0)
 192                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 193         if (pdata->temp_aux >= 0)
 194                 prop[i++] = POWER_SUPPLY_PROP_TEMP;
 195         if (pdata->batt_aux >= 0)
 196                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 197         if (pdata->max_voltage >= 0)
 198                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 199         if (pdata->min_voltage >= 0)
 200                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 201
 202         INIT_WORK(&bat_work, wm97xx_bat_work);
 203
 204         if (!pdata->batt_name) {
 205                 dev_info(&dev->dev, "Please consider setting proper battery "
 206                                 "name in platform definition file, falling "
 207                                 "back to name \"wm97xx-batt\"\n");
 208                 bat_ps.name = "wm97xx-batt";
 209         } else
 210                 bat_ps.name = pdata->batt_name;
 211
 212         bat_ps.properties = prop;
 213         bat_ps.num_properties = props;
 214
 215         ret = power_supply_register(&dev->dev, &bat_ps);
 216         if (!ret)
 217                 schedule_work(&bat_work);
 218         else
 219                 goto err3;
 220
 221         return 0;
 222 err3:
 223         kfree(prop);
 224 err2:
 225         gpio_free(pdata->charge_gpio);
 226 err:
 227         return ret;
 228 }
 229
 230 static int __devexit wm97xx_bat_remove(struct platform_device *dev)
 231 {
 232         if (pdata && pdata->charge_gpio && pdata->charge_gpio >= 0)
 233                 gpio_free(pdata->charge_gpio);
 234         flush_scheduled_work();
 235         power_supply_unregister(&bat_ps);
 236         kfree(prop);
 237         return 0;
 238 }
 239
 240 static struct platform_driver wm97xx_bat_driver = {
 241         .driver = {
 242                 .name   = "wm97xx-battery",
 243                 .owner  = THIS_MODULE,
 244         },
 245         .probe          = wm97xx_bat_probe,
 246         .remove         = __devexit_p(wm97xx_bat_remove),
 247         .suspend        = wm97xx_bat_suspend,
 248         .resume         = wm97xx_bat_resume,
 249 };
 250
 251 static int __init wm97xx_bat_init(void)
 252 {
 253         return platform_driver_register(&wm97xx_bat_driver);
 254 }
 255
 256 static void __exit wm97xx_bat_exit(void)
 257 {
 258         platform_driver_unregister(&wm97xx_bat_driver);
 259 }
 260
 261 void __init wm97xx_bat_set_pdata(struct wm97xx_batt_info *data)
 262 {
 263         pdata = data;
 264 }
 265 EXPORT_SYMBOL_GPL(wm97xx_bat_set_pdata);
 266
 267 module_init(wm97xx_bat_init);
 268 module_exit(wm97xx_bat_exit);
 269
 270 MODULE_LICENSE("GPL");
 271 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 272 MODULE_DESCRIPTION("WM97xx battery driver");