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->desc->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_psy;
 129 static struct power_supply_desc bat_psy_desc = {
 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_psy);
 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_work(&bat_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 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         if (!pdata) {
 185                 dev_err(&dev->dev, "No platform_data supplied\n");
 186                 return -EINVAL;
 187         }
 188
 189         if (gpio_is_valid(pdata->charge_gpio)) {
 190                 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
 191                 if (ret)
 192                         goto err;
 193                 ret = gpio_direction_input(pdata->charge_gpio);
 194                 if (ret)
 195                         goto err2;
 196                 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
 197                                 wm97xx_chrg_irq, 0,
 198                                 "AC Detect", dev);
 199                 if (ret)
 200                         goto err2;
 201                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 202         }
 203
 204         if (pdata->batt_tech >= 0)
 205                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 206         if (pdata->temp_aux >= 0)
 207                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 208         if (pdata->batt_aux >= 0)
 209                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 210         if (pdata->max_voltage >= 0)
 211                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 212         if (pdata->min_voltage >= 0)
 213                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 214
 215         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
 216         if (!prop) {
 217                 ret = -ENOMEM;
 218                 goto err3;
 219         }
 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_psy_desc.name = "wm97xx-batt";
 242         } else
 243                 bat_psy_desc.name = pdata->batt_name;
 244
 245         bat_psy_desc.properties = prop;
 246         bat_psy_desc.num_properties = props;
 247
 248         bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, NULL);
 249         if (!IS_ERR(bat_psy)) {
 250                 schedule_work(&bat_work);
 251         } else {
 252                 ret = PTR_ERR(bat_psy);
 253                 goto err4;
 254         }
 255
 256         return 0;
 257 err4:
 258         kfree(prop);
 259 err3:
 260         if (gpio_is_valid(pdata->charge_gpio))
 261                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 262 err2:
 263         if (gpio_is_valid(pdata->charge_gpio))
 264                 gpio_free(pdata->charge_gpio);
 265 err:
 266         return ret;
 267 }
 268
 269 static int wm97xx_bat_remove(struct platform_device *dev)
 270 {
 271         struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 272         struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 273
 274         if (pdata && gpio_is_valid(pdata->charge_gpio)) {
 275                 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 276                 gpio_free(pdata->charge_gpio);
 277         }
 278         cancel_work_sync(&bat_work);
 279         power_supply_unregister(bat_psy);
 280         kfree(prop);
 281         return 0;
 282 }
 283
 284 static struct platform_driver wm97xx_bat_driver = {
 285         .driver = {
 286                 .name   = "wm97xx-battery",
 287 #ifdef CONFIG_PM
 288                 .pm     = &wm97xx_bat_pm_ops,
 289 #endif
 290         },
 291         .probe          = wm97xx_bat_probe,
 292         .remove         = wm97xx_bat_remove,
 293 };
 294
 295 module_platform_driver(wm97xx_bat_driver);
 296
 297 MODULE_LICENSE("GPL");
 298 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 299 MODULE_DESCRIPTION("WM97xx battery driver");