linux/drivers/power/wm97xx_battery.c
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   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
  28static struct work_struct bat_work;
  29static DEFINE_MUTEX(work_lock);
  30static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  31static enum power_supply_property *prop;
  32
  33static 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
  43static 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
  53static 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
 100static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
 101{
 102        schedule_work(&bat_work);
 103}
 104
 105static 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
 128static 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
 135static void wm97xx_bat_work(struct work_struct *work)
 136{
 137        wm97xx_bat_update(&bat_ps);
 138}
 139
 140static 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
 147static int wm97xx_bat_suspend(struct device *dev)
 148{
 149        flush_work_sync(&bat_work);
 150        return 0;
 151}
 152
 153static int wm97xx_bat_resume(struct device *dev)
 154{
 155        schedule_work(&bat_work);
 156        return 0;
 157}
 158
 159static const struct dev_pm_ops wm97xx_bat_pm_ops = {
 160        .suspend        = wm97xx_bat_suspend,
 161        .resume         = wm97xx_bat_resume,
 162};
 163#endif
 164
 165static int __devinit 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                goto err3;
 217
 218        prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 219        if (pdata->charge_gpio >= 0)
 220                prop[i++] = POWER_SUPPLY_PROP_STATUS;
 221        if (pdata->batt_tech >= 0)
 222                prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 223        if (pdata->temp_aux >= 0)
 224                prop[i++] = POWER_SUPPLY_PROP_TEMP;
 225        if (pdata->batt_aux >= 0)
 226                prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 227        if (pdata->max_voltage >= 0)
 228                prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 229        if (pdata->min_voltage >= 0)
 230                prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 231
 232        INIT_WORK(&bat_work, wm97xx_bat_work);
 233
 234        if (!pdata->batt_name) {
 235                dev_info(&dev->dev, "Please consider setting proper battery "
 236                                "name in platform definition file, falling "
 237                                "back to name \"wm97xx-batt\"\n");
 238                bat_ps.name = "wm97xx-batt";
 239        } else
 240                bat_ps.name = pdata->batt_name;
 241
 242        bat_ps.properties = prop;
 243        bat_ps.num_properties = props;
 244
 245        ret = power_supply_register(&dev->dev, &bat_ps);
 246        if (!ret)
 247                schedule_work(&bat_work);
 248        else
 249                goto err4;
 250
 251        return 0;
 252err4:
 253        kfree(prop);
 254err3:
 255        if (gpio_is_valid(pdata->charge_gpio))
 256                free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 257err2:
 258        if (gpio_is_valid(pdata->charge_gpio))
 259                gpio_free(pdata->charge_gpio);
 260err:
 261        return ret;
 262}
 263
 264static int __devexit wm97xx_bat_remove(struct platform_device *dev)
 265{
 266        struct wm97xx_pdata *wmdata = dev->dev.platform_data;
 267        struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
 268
 269        if (pdata && gpio_is_valid(pdata->charge_gpio)) {
 270                free_irq(gpio_to_irq(pdata->charge_gpio), dev);
 271                gpio_free(pdata->charge_gpio);
 272        }
 273        cancel_work_sync(&bat_work);
 274        power_supply_unregister(&bat_ps);
 275        kfree(prop);
 276        return 0;
 277}
 278
 279static struct platform_driver wm97xx_bat_driver = {
 280        .driver = {
 281                .name   = "wm97xx-battery",
 282                .owner  = THIS_MODULE,
 283#ifdef CONFIG_PM
 284                .pm     = &wm97xx_bat_pm_ops,
 285#endif
 286        },
 287        .probe          = wm97xx_bat_probe,
 288        .remove         = __devexit_p(wm97xx_bat_remove),
 289};
 290
 291module_platform_driver(wm97xx_bat_driver);
 292
 293MODULE_LICENSE("GPL");
 294MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 295MODULE_DESCRIPTION("WM97xx battery driver");
 296
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