linux/drivers/power/supply/generic-adc-battery.c
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   1/*
   2 * Generic battery driver code using IIO
   3 * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
   4 * based on jz4740-battery.c
   5 * based on s3c_adc_battery.c
   6 *
   7 * This file is subject to the terms and conditions of the GNU General Public
   8 * License.  See the file COPYING in the main directory of this archive for
   9 * more details.
  10 *
  11 */
  12#include <linux/interrupt.h>
  13#include <linux/platform_device.h>
  14#include <linux/power_supply.h>
  15#include <linux/gpio/consumer.h>
  16#include <linux/err.h>
  17#include <linux/timer.h>
  18#include <linux/jiffies.h>
  19#include <linux/errno.h>
  20#include <linux/init.h>
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/iio/consumer.h>
  24#include <linux/iio/types.h>
  25#include <linux/power/generic-adc-battery.h>
  26
  27#define JITTER_DEFAULT 10 /* hope 10ms is enough */
  28
  29enum gab_chan_type {
  30        GAB_VOLTAGE = 0,
  31        GAB_CURRENT,
  32        GAB_POWER,
  33        GAB_MAX_CHAN_TYPE
  34};
  35
  36/*
  37 * gab_chan_name suggests the standard channel names for commonly used
  38 * channel types.
  39 */
  40static const char *const gab_chan_name[] = {
  41        [GAB_VOLTAGE]   = "voltage",
  42        [GAB_CURRENT]   = "current",
  43        [GAB_POWER]             = "power",
  44};
  45
  46struct gab {
  47        struct power_supply             *psy;
  48        struct power_supply_desc        psy_desc;
  49        struct iio_channel      *channel[GAB_MAX_CHAN_TYPE];
  50        struct gab_platform_data        *pdata;
  51        struct delayed_work bat_work;
  52        int     level;
  53        int     status;
  54        bool cable_plugged;
  55        struct gpio_desc *charge_finished;
  56};
  57
  58static struct gab *to_generic_bat(struct power_supply *psy)
  59{
  60        return power_supply_get_drvdata(psy);
  61}
  62
  63static void gab_ext_power_changed(struct power_supply *psy)
  64{
  65        struct gab *adc_bat = to_generic_bat(psy);
  66
  67        schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
  68}
  69
  70static const enum power_supply_property gab_props[] = {
  71        POWER_SUPPLY_PROP_STATUS,
  72        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
  73        POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
  74        POWER_SUPPLY_PROP_CHARGE_NOW,
  75        POWER_SUPPLY_PROP_VOLTAGE_NOW,
  76        POWER_SUPPLY_PROP_CURRENT_NOW,
  77        POWER_SUPPLY_PROP_TECHNOLOGY,
  78        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  79        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  80        POWER_SUPPLY_PROP_MODEL_NAME,
  81};
  82
  83/*
  84 * This properties are set based on the received platform data and this
  85 * should correspond one-to-one with enum chan_type.
  86 */
  87static const enum power_supply_property gab_dyn_props[] = {
  88        POWER_SUPPLY_PROP_VOLTAGE_NOW,
  89        POWER_SUPPLY_PROP_CURRENT_NOW,
  90        POWER_SUPPLY_PROP_POWER_NOW,
  91};
  92
  93static bool gab_charge_finished(struct gab *adc_bat)
  94{
  95        if (!adc_bat->charge_finished)
  96                return false;
  97        return gpiod_get_value(adc_bat->charge_finished);
  98}
  99
 100static int gab_get_status(struct gab *adc_bat)
 101{
 102        struct gab_platform_data *pdata = adc_bat->pdata;
 103        struct power_supply_info *bat_info;
 104
 105        bat_info = &pdata->battery_info;
 106        if (adc_bat->level == bat_info->charge_full_design)
 107                return POWER_SUPPLY_STATUS_FULL;
 108        return adc_bat->status;
 109}
 110
 111static enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
 112{
 113        switch (psp) {
 114        case POWER_SUPPLY_PROP_POWER_NOW:
 115                return GAB_POWER;
 116        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 117                return GAB_VOLTAGE;
 118        case POWER_SUPPLY_PROP_CURRENT_NOW:
 119                return GAB_CURRENT;
 120        default:
 121                WARN_ON(1);
 122                break;
 123        }
 124        return GAB_POWER;
 125}
 126
 127static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
 128                int *result)
 129{
 130        int ret;
 131        int chan_index;
 132
 133        chan_index = gab_prop_to_chan(psp);
 134        ret = iio_read_channel_processed(adc_bat->channel[chan_index],
 135                        result);
 136        if (ret < 0)
 137                pr_err("read channel error\n");
 138        return ret;
 139}
 140
 141static int gab_get_property(struct power_supply *psy,
 142                enum power_supply_property psp, union power_supply_propval *val)
 143{
 144        struct gab *adc_bat;
 145        struct gab_platform_data *pdata;
 146        struct power_supply_info *bat_info;
 147        int result = 0;
 148        int ret = 0;
 149
 150        adc_bat = to_generic_bat(psy);
 151        if (!adc_bat) {
 152                dev_err(&psy->dev, "no battery infos ?!\n");
 153                return -EINVAL;
 154        }
 155        pdata = adc_bat->pdata;
 156        bat_info = &pdata->battery_info;
 157
 158        switch (psp) {
 159        case POWER_SUPPLY_PROP_STATUS:
 160                val->intval = gab_get_status(adc_bat);
 161                break;
 162        case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
 163                val->intval = 0;
 164                break;
 165        case POWER_SUPPLY_PROP_CHARGE_NOW:
 166                val->intval = pdata->cal_charge(result);
 167                break;
 168        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 169        case POWER_SUPPLY_PROP_CURRENT_NOW:
 170        case POWER_SUPPLY_PROP_POWER_NOW:
 171                ret = read_channel(adc_bat, psp, &result);
 172                if (ret < 0)
 173                        goto err;
 174                val->intval = result;
 175                break;
 176        case POWER_SUPPLY_PROP_TECHNOLOGY:
 177                val->intval = bat_info->technology;
 178                break;
 179        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 180                val->intval = bat_info->voltage_min_design;
 181                break;
 182        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 183                val->intval = bat_info->voltage_max_design;
 184                break;
 185        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 186                val->intval = bat_info->charge_full_design;
 187                break;
 188        case POWER_SUPPLY_PROP_MODEL_NAME:
 189                val->strval = bat_info->name;
 190                break;
 191        default:
 192                return -EINVAL;
 193        }
 194err:
 195        return ret;
 196}
 197
 198static void gab_work(struct work_struct *work)
 199{
 200        struct gab *adc_bat;
 201        struct delayed_work *delayed_work;
 202        bool is_plugged;
 203        int status;
 204
 205        delayed_work = to_delayed_work(work);
 206        adc_bat = container_of(delayed_work, struct gab, bat_work);
 207        status = adc_bat->status;
 208
 209        is_plugged = power_supply_am_i_supplied(adc_bat->psy);
 210        adc_bat->cable_plugged = is_plugged;
 211
 212        if (!is_plugged)
 213                adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
 214        else if (gab_charge_finished(adc_bat))
 215                adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 216        else
 217                adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
 218
 219        if (status != adc_bat->status)
 220                power_supply_changed(adc_bat->psy);
 221}
 222
 223static irqreturn_t gab_charged(int irq, void *dev_id)
 224{
 225        struct gab *adc_bat = dev_id;
 226        struct gab_platform_data *pdata = adc_bat->pdata;
 227        int delay;
 228
 229        delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 230        schedule_delayed_work(&adc_bat->bat_work,
 231                        msecs_to_jiffies(delay));
 232        return IRQ_HANDLED;
 233}
 234
 235static int gab_probe(struct platform_device *pdev)
 236{
 237        struct gab *adc_bat;
 238        struct power_supply_desc *psy_desc;
 239        struct power_supply_config psy_cfg = {};
 240        struct gab_platform_data *pdata = pdev->dev.platform_data;
 241        enum power_supply_property *properties;
 242        int ret = 0;
 243        int chan;
 244        int index = ARRAY_SIZE(gab_props);
 245        bool any = false;
 246
 247        adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
 248        if (!adc_bat) {
 249                dev_err(&pdev->dev, "failed to allocate memory\n");
 250                return -ENOMEM;
 251        }
 252
 253        psy_cfg.drv_data = adc_bat;
 254        psy_desc = &adc_bat->psy_desc;
 255        psy_desc->name = pdata->battery_info.name;
 256
 257        /* bootup default values for the battery */
 258        adc_bat->cable_plugged = false;
 259        adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
 260        psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
 261        psy_desc->get_property = gab_get_property;
 262        psy_desc->external_power_changed = gab_ext_power_changed;
 263        adc_bat->pdata = pdata;
 264
 265        /*
 266         * copying the static properties and allocating extra memory for holding
 267         * the extra configurable properties received from platform data.
 268         */
 269        properties = kcalloc(ARRAY_SIZE(gab_props) +
 270                             ARRAY_SIZE(gab_chan_name),
 271                             sizeof(*properties),
 272                             GFP_KERNEL);
 273        if (!properties) {
 274                ret = -ENOMEM;
 275                goto first_mem_fail;
 276        }
 277
 278        memcpy(properties, gab_props, sizeof(gab_props));
 279
 280        /*
 281         * getting channel from iio and copying the battery properties
 282         * based on the channel supported by consumer device.
 283         */
 284        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 285                adc_bat->channel[chan] = iio_channel_get(&pdev->dev,
 286                                                         gab_chan_name[chan]);
 287                if (IS_ERR(adc_bat->channel[chan])) {
 288                        ret = PTR_ERR(adc_bat->channel[chan]);
 289                        adc_bat->channel[chan] = NULL;
 290                } else {
 291                        /* copying properties for supported channels only */
 292                        int index2;
 293
 294                        for (index2 = 0; index2 < index; index2++) {
 295                                if (properties[index2] == gab_dyn_props[chan])
 296                                        break;  /* already known */
 297                        }
 298                        if (index2 == index)    /* really new */
 299                                properties[index++] = gab_dyn_props[chan];
 300                        any = true;
 301                }
 302        }
 303
 304        /* none of the channels are supported so let's bail out */
 305        if (!any) {
 306                ret = -ENODEV;
 307                goto second_mem_fail;
 308        }
 309
 310        /*
 311         * Total number of properties is equal to static properties
 312         * plus the dynamic properties.Some properties may not be set
 313         * as come channels may be not be supported by the device.So
 314         * we need to take care of that.
 315         */
 316        psy_desc->properties = properties;
 317        psy_desc->num_properties = index;
 318
 319        adc_bat->psy = power_supply_register(&pdev->dev, psy_desc, &psy_cfg);
 320        if (IS_ERR(adc_bat->psy)) {
 321                ret = PTR_ERR(adc_bat->psy);
 322                goto err_reg_fail;
 323        }
 324
 325        INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
 326
 327        adc_bat->charge_finished = devm_gpiod_get_optional(&pdev->dev,
 328                                                           "charged", GPIOD_IN);
 329        if (adc_bat->charge_finished) {
 330                int irq;
 331
 332                irq = gpiod_to_irq(adc_bat->charge_finished);
 333                ret = request_any_context_irq(irq, gab_charged,
 334                                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 335                                "battery charged", adc_bat);
 336                if (ret < 0)
 337                        goto gpio_req_fail;
 338        }
 339
 340        platform_set_drvdata(pdev, adc_bat);
 341
 342        /* Schedule timer to check current status */
 343        schedule_delayed_work(&adc_bat->bat_work,
 344                        msecs_to_jiffies(0));
 345        return 0;
 346
 347gpio_req_fail:
 348        power_supply_unregister(adc_bat->psy);
 349err_reg_fail:
 350        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 351                if (adc_bat->channel[chan])
 352                        iio_channel_release(adc_bat->channel[chan]);
 353        }
 354second_mem_fail:
 355        kfree(properties);
 356first_mem_fail:
 357        return ret;
 358}
 359
 360static int gab_remove(struct platform_device *pdev)
 361{
 362        int chan;
 363        struct gab *adc_bat = platform_get_drvdata(pdev);
 364
 365        power_supply_unregister(adc_bat->psy);
 366
 367        if (adc_bat->charge_finished)
 368                free_irq(gpiod_to_irq(adc_bat->charge_finished), adc_bat);
 369
 370        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 371                if (adc_bat->channel[chan])
 372                        iio_channel_release(adc_bat->channel[chan]);
 373        }
 374
 375        kfree(adc_bat->psy_desc.properties);
 376        cancel_delayed_work_sync(&adc_bat->bat_work);
 377        return 0;
 378}
 379
 380static int __maybe_unused gab_suspend(struct device *dev)
 381{
 382        struct gab *adc_bat = dev_get_drvdata(dev);
 383
 384        cancel_delayed_work_sync(&adc_bat->bat_work);
 385        adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
 386        return 0;
 387}
 388
 389static int __maybe_unused gab_resume(struct device *dev)
 390{
 391        struct gab *adc_bat = dev_get_drvdata(dev);
 392        struct gab_platform_data *pdata = adc_bat->pdata;
 393        int delay;
 394
 395        delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 396
 397        /* Schedule timer to check current status */
 398        schedule_delayed_work(&adc_bat->bat_work,
 399                        msecs_to_jiffies(delay));
 400        return 0;
 401}
 402
 403static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
 404
 405static struct platform_driver gab_driver = {
 406        .driver         = {
 407                .name   = "generic-adc-battery",
 408                .pm     = &gab_pm_ops,
 409        },
 410        .probe          = gab_probe,
 411        .remove         = gab_remove,
 412};
 413module_platform_driver(gab_driver);
 414
 415MODULE_AUTHOR("anish kumar <anish198519851985@gmail.com>");
 416MODULE_DESCRIPTION("generic battery driver using IIO");
 417MODULE_LICENSE("GPL");
 418