drivers/power/generic-adc-battery.c

   1 /*
   2  * Generic battery driver code using IIO
   3  * Copyright (C) 2012, Anish Kumar <[email protected]>
   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.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
  29 enum 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  */
  40 static const char *const gab_chan_name[] = {
  41         [GAB_VOLTAGE]   = "voltage",
  42         [GAB_CURRENT]   = "current",
  43         [GAB_POWER]             = "power",
  44 };
  45
  46 struct gab {
  47         struct power_supply     psy;
  48         struct iio_channel      *channel[GAB_MAX_CHAN_TYPE];
  49         struct gab_platform_data        *pdata;
  50         struct delayed_work bat_work;
  51         int     level;
  52         int     status;
  53         bool cable_plugged;
  54 };
  55
  56 static struct gab *to_generic_bat(struct power_supply *psy)
  57 {
  58         return container_of(psy, struct gab, psy);
  59 }
  60
  61 static void gab_ext_power_changed(struct power_supply *psy)
  62 {
  63         struct gab *adc_bat = to_generic_bat(psy);
  64
  65         schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
  66 }
  67
  68 static const enum power_supply_property gab_props[] = {
  69         POWER_SUPPLY_PROP_STATUS,
  70         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
  71         POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
  72         POWER_SUPPLY_PROP_CHARGE_NOW,
  73         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  74         POWER_SUPPLY_PROP_CURRENT_NOW,
  75         POWER_SUPPLY_PROP_TECHNOLOGY,
  76         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  77         POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  78         POWER_SUPPLY_PROP_MODEL_NAME,
  79 };
  80
  81 /*
  82  * This properties are set based on the received platform data and this
  83  * should correspond one-to-one with enum chan_type.
  84  */
  85 static const enum power_supply_property gab_dyn_props[] = {
  86         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  87         POWER_SUPPLY_PROP_CURRENT_NOW,
  88         POWER_SUPPLY_PROP_POWER_NOW,
  89 };
  90
  91 static bool gab_charge_finished(struct gab *adc_bat)
  92 {
  93         struct gab_platform_data *pdata = adc_bat->pdata;
  94         bool ret = gpio_get_value(pdata->gpio_charge_finished);
  95         bool inv = pdata->gpio_inverted;
  96
  97         if (!gpio_is_valid(pdata->gpio_charge_finished))
  98                 return false;
  99         return ret ^ inv;
 100 }
 101
 102 static int gab_get_status(struct gab *adc_bat)
 103 {
 104         struct gab_platform_data *pdata = adc_bat->pdata;
 105         struct power_supply_info *bat_info;
 106
 107         bat_info = &pdata->battery_info;
 108         if (adc_bat->level == bat_info->charge_full_design)
 109                 return POWER_SUPPLY_STATUS_FULL;
 110         return adc_bat->status;
 111 }
 112
 113 static enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
 114 {
 115         switch (psp) {
 116         case POWER_SUPPLY_PROP_POWER_NOW:
 117                 return GAB_POWER;
 118         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 119                 return GAB_VOLTAGE;
 120         case POWER_SUPPLY_PROP_CURRENT_NOW:
 121                 return GAB_CURRENT;
 122         default:
 123                 WARN_ON(1);
 124                 break;
 125         }
 126         return GAB_POWER;
 127 }
 128
 129 static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
 130                 int *result)
 131 {
 132         int ret;
 133         int chan_index;
 134
 135         chan_index = gab_prop_to_chan(psp);
 136         ret = iio_read_channel_processed(adc_bat->channel[chan_index],
 137                         result);
 138         if (ret < 0)
 139                 pr_err("read channel error\n");
 140         return ret;
 141 }
 142
 143 static int gab_get_property(struct power_supply *psy,
 144                 enum power_supply_property psp, union power_supply_propval *val)
 145 {
 146         struct gab *adc_bat;
 147         struct gab_platform_data *pdata;
 148         struct power_supply_info *bat_info;
 149         int result = 0;
 150         int ret = 0;
 151
 152         adc_bat = to_generic_bat(psy);
 153         if (!adc_bat) {
 154                 dev_err(psy->dev, "no battery infos ?!\n");
 155                 return -EINVAL;
 156         }
 157         pdata = adc_bat->pdata;
 158         bat_info = &pdata->battery_info;
 159
 160         switch (psp) {
 161         case POWER_SUPPLY_PROP_STATUS:
 162                 gab_get_status(adc_bat);
 163                 break;
 164         case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
 165                 val->intval = 0;
 166                 break;
 167         case POWER_SUPPLY_PROP_CHARGE_NOW:
 168                 val->intval = pdata->cal_charge(result);
 169                 break;
 170         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 171         case POWER_SUPPLY_PROP_CURRENT_NOW:
 172         case POWER_SUPPLY_PROP_POWER_NOW:
 173                 ret = read_channel(adc_bat, psp, &result);
 174                 if (ret < 0)
 175                         goto err;
 176                 val->intval = result;
 177                 break;
 178         case POWER_SUPPLY_PROP_TECHNOLOGY:
 179                 val->intval = bat_info->technology;
 180                 break;
 181         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 182                 val->intval = bat_info->voltage_min_design;
 183                 break;
 184         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 185                 val->intval = bat_info->voltage_max_design;
 186                 break;
 187         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 188                 val->intval = bat_info->charge_full_design;
 189                 break;
 190         case POWER_SUPPLY_PROP_MODEL_NAME:
 191                 val->strval = bat_info->name;
 192                 break;
 193         default:
 194                 return -EINVAL;
 195         }
 196 err:
 197         return ret;
 198 }
 199
 200 static void gab_work(struct work_struct *work)
 201 {
 202         struct gab *adc_bat;
 203         struct gab_platform_data *pdata;
 204         struct delayed_work *delayed_work;
 205         bool is_plugged;
 206         int status;
 207
 208         delayed_work = container_of(work, struct delayed_work, work);
 209         adc_bat = container_of(delayed_work, struct gab, bat_work);
 210         pdata = adc_bat->pdata;
 211         status = adc_bat->status;
 212
 213         is_plugged = power_supply_am_i_supplied(&adc_bat->psy);
 214         adc_bat->cable_plugged = is_plugged;
 215
 216         if (!is_plugged)
 217                 adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
 218         else if (gab_charge_finished(adc_bat))
 219                 adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 220         else
 221                 adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
 222
 223         if (status != adc_bat->status)
 224                 power_supply_changed(&adc_bat->psy);
 225 }
 226
 227 static irqreturn_t gab_charged(int irq, void *dev_id)
 228 {
 229         struct gab *adc_bat = dev_id;
 230         struct gab_platform_data *pdata = adc_bat->pdata;
 231         int delay;
 232
 233         delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 234         schedule_delayed_work(&adc_bat->bat_work,
 235                         msecs_to_jiffies(delay));
 236         return IRQ_HANDLED;
 237 }
 238
 239 static int gab_probe(struct platform_device *pdev)
 240 {
 241         struct gab *adc_bat;
 242         struct power_supply *psy;
 243         struct gab_platform_data *pdata = pdev->dev.platform_data;
 244         enum power_supply_property *properties;
 245         int ret = 0;
 246         int chan;
 247         int index = 0;
 248
 249         adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
 250         if (!adc_bat) {
 251                 dev_err(&pdev->dev, "failed to allocate memory\n");
 252                 return -ENOMEM;
 253         }
 254
 255         psy = &adc_bat->psy;
 256         psy->name = pdata->battery_info.name;
 257
 258         /* bootup default values for the battery */
 259         adc_bat->cable_plugged = false;
 260         adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
 261         psy->type = POWER_SUPPLY_TYPE_BATTERY;
 262         psy->get_property = gab_get_property;
 263         psy->external_power_changed = gab_ext_power_changed;
 264         adc_bat->pdata = pdata;
 265
 266         /*
 267          * copying the static properties and allocating extra memory for holding
 268          * the extra configurable properties received from platform data.
 269          */
 270         psy->properties = kcalloc(ARRAY_SIZE(gab_props) +
 271                                         ARRAY_SIZE(gab_chan_name),
 272                                         sizeof(*psy->properties), GFP_KERNEL);
 273         if (!psy->properties) {
 274                 ret = -ENOMEM;
 275                 goto first_mem_fail;
 276         }
 277
 278         memcpy(psy->properties, gab_props, sizeof(gab_props));
 279         properties = (enum power_supply_property *)
 280                                 ((char *)psy->properties + sizeof(gab_props));
 281
 282         /*
 283          * getting channel from iio and copying the battery properties
 284          * based on the channel supported by consumer device.
 285          */
 286         for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 287                 adc_bat->channel[chan] = iio_channel_get(&pdev->dev,
 288                                                          gab_chan_name[chan]);
 289                 if (IS_ERR(adc_bat->channel[chan])) {
 290                         ret = PTR_ERR(adc_bat->channel[chan]);
 291                         adc_bat->channel[chan] = NULL;
 292                 } else {
 293                         /* copying properties for supported channels only */
 294                         memcpy(properties + sizeof(*(psy->properties)) * index,
 295                                         &gab_dyn_props[chan],
 296                                         sizeof(gab_dyn_props[chan]));
 297                         index++;
 298                 }
 299         }
 300
 301         /* none of the channels are supported so let's bail out */
 302         if (index == 0) {
 303                 ret = -ENODEV;
 304                 goto second_mem_fail;
 305         }
 306
 307         /*
 308          * Total number of properties is equal to static properties
 309          * plus the dynamic properties.Some properties may not be set
 310          * as come channels may be not be supported by the device.So
 311          * we need to take care of that.
 312          */
 313         psy->num_properties = ARRAY_SIZE(gab_props) + index;
 314
 315         ret = power_supply_register(&pdev->dev, psy);
 316         if (ret)
 317                 goto err_reg_fail;
 318
 319         INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
 320
 321         if (gpio_is_valid(pdata->gpio_charge_finished)) {
 322                 int irq;
 323                 ret = gpio_request(pdata->gpio_charge_finished, "charged");
 324                 if (ret)
 325                         goto gpio_req_fail;
 326
 327                 irq = gpio_to_irq(pdata->gpio_charge_finished);
 328                 ret = request_any_context_irq(irq, gab_charged,
 329                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 330                                 "battery charged", adc_bat);
 331                 if (ret < 0)
 332                         goto err_gpio;
 333         }
 334
 335         platform_set_drvdata(pdev, adc_bat);
 336
 337         /* Schedule timer to check current status */
 338         schedule_delayed_work(&adc_bat->bat_work,
 339                         msecs_to_jiffies(0));
 340         return 0;
 341
 342 err_gpio:
 343         gpio_free(pdata->gpio_charge_finished);
 344 gpio_req_fail:
 345         power_supply_unregister(psy);
 346 err_reg_fail:
 347         for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 348                 if (adc_bat->channel[chan])
 349                         iio_channel_release(adc_bat->channel[chan]);
 350         }
 351 second_mem_fail:
 352         kfree(psy->properties);
 353 first_mem_fail:
 354         return ret;
 355 }
 356
 357 static int gab_remove(struct platform_device *pdev)
 358 {
 359         int chan;
 360         struct gab *adc_bat = platform_get_drvdata(pdev);
 361         struct gab_platform_data *pdata = adc_bat->pdata;
 362
 363         power_supply_unregister(&adc_bat->psy);
 364
 365         if (gpio_is_valid(pdata->gpio_charge_finished)) {
 366                 free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
 367                 gpio_free(pdata->gpio_charge_finished);
 368         }
 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.properties);
 376         cancel_delayed_work(&adc_bat->bat_work);
 377         return 0;
 378 }
 379
 380 #ifdef CONFIG_PM
 381 static int gab_suspend(struct device *dev)
 382 {
 383         struct gab *adc_bat = dev_get_drvdata(dev);
 384
 385         cancel_delayed_work_sync(&adc_bat->bat_work);
 386         adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
 387         return 0;
 388 }
 389
 390 static int gab_resume(struct device *dev)
 391 {
 392         struct gab *adc_bat = dev_get_drvdata(dev);
 393         struct gab_platform_data *pdata = adc_bat->pdata;
 394         int delay;
 395
 396         delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 397
 398         /* Schedule timer to check current status */
 399         schedule_delayed_work(&adc_bat->bat_work,
 400                         msecs_to_jiffies(delay));
 401         return 0;
 402 }
 403
 404 static const struct dev_pm_ops gab_pm_ops = {
 405         .suspend        = gab_suspend,
 406         .resume         = gab_resume,
 407 };
 408
 409 #define GAB_PM_OPS       (&gab_pm_ops)
 410 #else
 411 #define GAB_PM_OPS       (NULL)
 412 #endif
 413
 414 static struct platform_driver gab_driver = {
 415         .driver         = {
 416                 .name   = "generic-adc-battery",
 417                 .owner  = THIS_MODULE,
 418                 .pm     = GAB_PM_OPS
 419         },
 420         .probe          = gab_probe,
 421         .remove         = gab_remove,
 422 };
 423 module_platform_driver(gab_driver);
 424
 425 MODULE_AUTHOR("anish kumar <[email protected]>");
 426 MODULE_DESCRIPTION("generic battery driver using IIO");
 427 MODULE_LICENSE("GPL");