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