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