drivers/power/palmtx_battery.c

   1 /*
   2  * linux/drivers/power/palmtx_battery.c
   3  *
   4  * Battery measurement code for Palm T|X Handheld computer
   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 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/power_supply.h>
  18 #include <linux/wm97xx.h>
  19 #include <linux/delay.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/gpio.h>
  23
  24 #include <asm/mach-types.h>
  25 #include <mach/palmtx.h>
  26
  27 static DEFINE_MUTEX(bat_lock);
  28 static struct work_struct bat_work;
  29 struct mutex work_lock;
  30 int bat_status = POWER_SUPPLY_STATUS_DISCHARGING;
  31
  32 static unsigned long palmtx_read_bat(struct power_supply *bat_ps)
  33 {
  34         return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
  35                                     WM97XX_AUX_ID3) * 1000 / 414;
  36 }
  37
  38 static unsigned long palmtx_read_temp(struct power_supply *bat_ps)
  39 {
  40         return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
  41                                     WM97XX_AUX_ID2);
  42 }
  43
  44 static int palmtx_bat_get_property(struct power_supply *bat_ps,
  45                             enum power_supply_property psp,
  46                             union power_supply_propval *val)
  47 {
  48         switch (psp) {
  49         case POWER_SUPPLY_PROP_STATUS:
  50                 val->intval = bat_status;
  51                 break;
  52         case POWER_SUPPLY_PROP_TECHNOLOGY:
  53                 val->intval = POWER_SUPPLY_TECHNOLOGY_LIPO;
  54                 break;
  55         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  56                 val->intval = palmtx_read_bat(bat_ps);
  57                 break;
  58         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  59         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
  60                 val->intval = PALMTX_BAT_MAX_VOLTAGE;
  61                 break;
  62         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
  63                 val->intval = PALMTX_BAT_MIN_VOLTAGE;
  64                 break;
  65         case POWER_SUPPLY_PROP_TEMP:
  66                 val->intval = palmtx_read_temp(bat_ps);
  67                 break;
  68         case POWER_SUPPLY_PROP_PRESENT:
  69                 val->intval = 1;
  70                 break;
  71         default:
  72                 return -EINVAL;
  73         }
  74         return 0;
  75 }
  76
  77 static void palmtx_bat_external_power_changed(struct power_supply *bat_ps)
  78 {
  79         schedule_work(&bat_work);
  80 }
  81
  82 static char *status_text[] = {
  83         [POWER_SUPPLY_STATUS_UNKNOWN] =         "Unknown",
  84         [POWER_SUPPLY_STATUS_CHARGING] =        "Charging",
  85         [POWER_SUPPLY_STATUS_DISCHARGING] =     "Discharging",
  86 };
  87
  88 static void palmtx_bat_update(struct power_supply *bat_ps)
  89 {
  90         int old_status = bat_status;
  91
  92         mutex_lock(&work_lock);
  93
  94         bat_status = gpio_get_value(GPIO_NR_PALMTX_POWER_DETECT) ?
  95                                     POWER_SUPPLY_STATUS_CHARGING :
  96                                     POWER_SUPPLY_STATUS_DISCHARGING;
  97
  98         if (old_status != bat_status) {
  99                 pr_debug("%s %s -> %s\n", bat_ps->name,
 100                                 status_text[old_status],
 101                                 status_text[bat_status]);
 102                 power_supply_changed(bat_ps);
 103         }
 104
 105         mutex_unlock(&work_lock);
 106 }
 107
 108 static enum power_supply_property palmtx_bat_main_props[] = {
 109         POWER_SUPPLY_PROP_STATUS,
 110         POWER_SUPPLY_PROP_TECHNOLOGY,
 111         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 112         POWER_SUPPLY_PROP_VOLTAGE_MAX,
 113         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 114         POWER_SUPPLY_PROP_TEMP,
 115         POWER_SUPPLY_PROP_PRESENT,
 116 };
 117
 118 struct power_supply bat_ps = {
 119         .name                   = "main-battery",
 120         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 121         .properties             = palmtx_bat_main_props,
 122         .num_properties         = ARRAY_SIZE(palmtx_bat_main_props),
 123         .get_property           = palmtx_bat_get_property,
 124         .external_power_changed = palmtx_bat_external_power_changed,
 125         .use_for_apm            = 1,
 126 };
 127
 128 static void palmtx_bat_work(struct work_struct *work)
 129 {
 130         palmtx_bat_update(&bat_ps);
 131 }
 132
 133 #ifdef CONFIG_PM
 134 static int palmtx_bat_suspend(struct platform_device *dev, pm_message_t state)
 135 {
 136         flush_scheduled_work();
 137         return 0;
 138 }
 139
 140 static int palmtx_bat_resume(struct platform_device *dev)
 141 {
 142         schedule_work(&bat_work);
 143         return 0;
 144 }
 145 #else
 146 #define palmtx_bat_suspend NULL
 147 #define palmtx_bat_resume NULL
 148 #endif
 149
 150 static int __devinit palmtx_bat_probe(struct platform_device *dev)
 151 {
 152         int ret = 0;
 153
 154         if (!machine_is_palmtx())
 155                 return -ENODEV;
 156
 157         mutex_init(&work_lock);
 158
 159         INIT_WORK(&bat_work, palmtx_bat_work);
 160
 161         ret = power_supply_register(&dev->dev, &bat_ps);
 162         if (!ret)
 163                 schedule_work(&bat_work);
 164
 165         return ret;
 166 }
 167
 168 static int __devexit palmtx_bat_remove(struct platform_device *dev)
 169 {
 170         power_supply_unregister(&bat_ps);
 171         return 0;
 172 }
 173
 174 static struct platform_driver palmtx_bat_driver = {
 175         .driver.name    = "wm97xx-battery",
 176         .driver.owner   = THIS_MODULE,
 177         .probe          = palmtx_bat_probe,
 178         .remove         = __devexit_p(palmtx_bat_remove),
 179         .suspend        = palmtx_bat_suspend,
 180         .resume         = palmtx_bat_resume,
 181 };
 182
 183 static int __init palmtx_bat_init(void)
 184 {
 185         return platform_driver_register(&palmtx_bat_driver);
 186 }
 187
 188 static void __exit palmtx_bat_exit(void)
 189 {
 190         platform_driver_unregister(&palmtx_bat_driver);
 191 }
 192
 193 module_init(palmtx_bat_init);
 194 module_exit(palmtx_bat_exit);
 195
 196 MODULE_LICENSE("GPL");
 197 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 198 MODULE_DESCRIPTION("Palm T|X battery driver");