drivers/power/supply/wm97xx_battery.c

   1 /*
   2  * Battery measurement code for WM97xx
   3  *
   4  * based on tosa_battery.c
   5  *
   6  * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/power_supply.h>
  19 #include <linux/wm97xx.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/gpio.h>
  23 #include <linux/irq.h>
  24 #include <linux/slab.h>
  25
  26 static struct work_struct bat_work;
  27 static DEFINE_MUTEX(work_lock);
  28 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  29 static enum power_supply_property *prop;
  30
  31 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
  32 {
  33         struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
  34         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  35
  36         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
  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         struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
  44         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  45
  46         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
  47                                         pdata->temp_aux) * pdata->temp_mult /
  48                                         pdata->temp_div;
  49 }
  50
  51 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
  52                             enum power_supply_property psp,
  53                             union power_supply_propval *val)
  54 {
  55         struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
  56         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
  57
  58         switch (psp) {
  59         case POWER_SUPPLY_PROP_STATUS:
  60                 val->intval = bat_status;
  61                 break;
  62         case POWER_SUPPLY_PROP_TECHNOLOGY:
  63                 val->intval = pdata->batt_tech;
  64                 break;
  65         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  66                 if (pdata->batt_aux >= 0)
  67                         val->intval = wm97xx_read_bat(bat_ps);
  68                 else
  69                         return -EINVAL;
  70                 break;
  71         case POWER_SUPPLY_PROP_TEMP:
  72                 if (pdata->temp_aux >= 0)
  73                         val->intval = wm97xx_read_temp(bat_ps);
  74                 else
  75                         return -EINVAL;
  76                 break;
  77         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  78                 if (pdata->max_voltage >= 0)
  79                         val->intval = pdata->max_voltage;
  80                 else
  81                         return -EINVAL;
  82                 break;
  83         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  84                 if (pdata->min_voltage >= 0)
  85                         val->intval = pdata->min_voltage;
  86                 else
  87                         return -EINVAL;
  88                 break;
  89         case POWER_SUPPLY_PROP_PRESENT:
  90                 val->intval = 1;
  91                 break;
  92         default:
  93                 return -EINVAL;
  94         }
  95         return 0;
  96 }
  97
  98 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
  99 {
 100         schedule_work(&bat_work);
 101 }
 102
 103 static void wm97xx_bat_update(struct power_supply *bat_ps)
 104 {
 105         int old_status = bat_status;
 106         struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
 107         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 108
 109         mutex_lock(&work_lock);
 110
 111         bat_status = (pdata->charge_gpio >= 0) ?
 112                         (gpio_get_value(pdata->charge_gpio) ?
 113                         POWER_SUPPLY_STATUS_DISCHARGING :
 114                         POWER_SUPPLY_STATUS_CHARGING) :
 115                         POWER_SUPPLY_STATUS_UNKNOWN;
 116
 117         if (old_status != bat_status) {
 118                 pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
 119                                         bat_status);
 120                 power_supply_changed(bat_ps);
 121         }
 122
 123         mutex_unlock(&work_lock);
 124 }
 125
 126 static struct power_supply *bat_psy;
 127 static struct power_supply_desc bat_psy_desc = {
 128         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 129         .get_property           = wm97xx_bat_get_property,
 130         .external_power_changed = wm97xx_bat_external_power_changed,
 131         .use_for_apm            = 1,
 132 };
 133
 134 static void wm97xx_bat_work(struct work_struct *work)
 135 {
 136         wm97xx_bat_update(bat_psy);
 137 }
 138
 139 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
 140 {
 141         schedule_work(&bat_work);
 142         return IRQ_HANDLED;
 143 }
 144
 145 #ifdef CONFIG_PM
 146 static int wm97xx_bat_suspend(struct device *dev)
 147 {
 148         flush_work(&bat_work);
 149         return 0;
 150 }
 151
 152 static int wm97xx_bat_resume(struct device *dev)
 153 {
 154         schedule_work(&bat_work);
 155         return 0;
 156 }
 157
 158 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
 159         .suspend        = wm97xx_bat_suspend,
 160         .resume         = wm97xx_bat_resume,
 161 };
 162 #endif
 163
 164 static int wm97xx_bat_probe(struct platform_device *dev)
 165 {
 166         int ret = 0;
 167         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 168         int i = 0;
 169         struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 170         struct wm97xx_batt_pdata *pdata;
 171
 172         if (!wmdata) {
 173                 dev_err(&dev->dev, "No platform data supplied\n");
 174                 return -EINVAL;
 175         }
 176
 177         pdata = wmdata->batt_pdata;
 178
 179         if (dev->id != -1)
 180                 return -EINVAL;
 181
 182         if (!pdata) {
 183                 dev_err(&dev->dev, "No platform_data supplied\n");
 184                 return -EINVAL;
 185         }
 186
 187         if (gpio_is_valid(pdata->charge_gpio)) {
 188                 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
 189                 if (ret)
 190                         goto err;
 191                 ret = gpio_direction_input(pdata->charge_gpio);
 192                 if (ret)
 193                         goto err2;
 194                 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
 195                                 wm97xx_chrg_irq, 0,
 196                                 "AC Detect", dev);
 197                 if (ret)
 198                         goto err2;
 199                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 200         }
 201
 202         if (pdata->batt_tech >= 0)
 203                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 204         if (pdata->temp_aux >= 0)
 205                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 206         if (pdata->batt_aux >= 0)
 207                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 208         if (pdata->max_voltage >= 0)
 209                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 210         if (pdata->min_voltage >= 0)
 211                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 212
 213         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 214         if (!prop) {
 215                 ret = -ENOMEM;
 216                 goto err3;
 217         }
 218
 219         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 220         if (pdata->charge_gpio >= 0)
 221                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 222         if (pdata->batt_tech >= 0)
 223                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 224         if (pdata->temp_aux >= 0)
 225                 prop[i++] = POWER_SUPPLY_PROP_TEMP;
 226         if (pdata->batt_aux >= 0)
 227                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 228         if (pdata->max_voltage >= 0)
 229                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 230         if (pdata->min_voltage >= 0)
 231                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 232
 233         INIT_WORK(&bat_work, wm97xx_bat_work);
 234
 235         if (!pdata->batt_name) {
 236                 dev_info(&dev->dev, "Please consider setting proper battery "
 237                                 "name in platform definition file, falling "
 238                                 "back to name \"wm97xx-batt\"\n");
 239                 bat_psy_desc.name = "wm97xx-batt";
 240         } else
 241                 bat_psy_desc.name = pdata->batt_name;
 242
 243         bat_psy_desc.properties = prop;
 244         bat_psy_desc.num_properties = props;
 245
 246         bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, NULL);
 247         if (!IS_ERR(bat_psy)) {
 248                 schedule_work(&bat_work);
 249         } else {
 250                 ret = PTR_ERR(bat_psy);
 251                 goto err4;
 252         }
 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 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         cancel_work_sync(&bat_work);
 277         power_supply_unregister(bat_psy);
 278         kfree(prop);
 279         return 0;
 280 }
 281
 282 static struct platform_driver wm97xx_bat_driver = {
 283         .driver = {
 284                 .name   = "wm97xx-battery",
 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");