drivers/power/supply/generic-adc-battery.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Generic battery driver using IIO
   4  * Copyright (C) 2012, Anish Kumar <yesanishhere@gmail.com>
   5  * Copyright (c) 2023, Sebastian Reichel <sre@kernel.org>
   6  */
   7 #include <linux/interrupt.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/power_supply.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/err.h>
  12 #include <linux/timer.h>
  13 #include <linux/jiffies.h>
  14 #include <linux/errno.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/iio/consumer.h>
  19 #include <linux/iio/types.h>
  20 #include <linux/of.h>
  21 #include <linux/devm-helpers.h>
  22
  23 #define JITTER_DEFAULT 10 /* hope 10ms is enough */
  24
  25 enum gab_chan_type {
  26         GAB_VOLTAGE = 0,
  27         GAB_CURRENT,
  28         GAB_POWER,
  29         GAB_TEMP,
  30         GAB_MAX_CHAN_TYPE
  31 };
  32
  33 /*
  34  * gab_chan_name suggests the standard channel names for commonly used
  35  * channel types.
  36  */
  37 static const char *const gab_chan_name[] = {
  38         [GAB_VOLTAGE]   = "voltage",
  39         [GAB_CURRENT]   = "current",
  40         [GAB_POWER]     = "power",
  41         [GAB_TEMP]      = "temperature",
  42 };
  43
  44 struct gab {
  45         struct power_supply *psy;
  46         struct power_supply_desc psy_desc;
  47         struct iio_channel *channel[GAB_MAX_CHAN_TYPE];
  48         struct delayed_work bat_work;
  49         int status;
  50         struct gpio_desc *charge_finished;
  51 };
  52
  53 static struct gab *to_generic_bat(struct power_supply *psy)
  54 {
  55         return power_supply_get_drvdata(psy);
  56 }
  57
  58 static void gab_ext_power_changed(struct power_supply *psy)
  59 {
  60         struct gab *adc_bat = to_generic_bat(psy);
  61
  62         schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
  63 }
  64
  65 static const enum power_supply_property gab_props[] = {
  66         POWER_SUPPLY_PROP_STATUS,
  67 };
  68
  69 /*
  70  * This properties are set based on the received platform data and this
  71  * should correspond one-to-one with enum chan_type.
  72  */
  73 static const enum power_supply_property gab_dyn_props[] = {
  74         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  75         POWER_SUPPLY_PROP_CURRENT_NOW,
  76         POWER_SUPPLY_PROP_POWER_NOW,
  77         POWER_SUPPLY_PROP_TEMP,
  78 };
  79
  80 static bool gab_charge_finished(struct gab *adc_bat)
  81 {
  82         if (!adc_bat->charge_finished)
  83                 return false;
  84         return gpiod_get_value(adc_bat->charge_finished);
  85 }
  86
  87 static int gab_read_channel(struct gab *adc_bat, enum gab_chan_type channel,
  88                 int *result)
  89 {
  90         int ret;
  91
  92         ret = iio_read_channel_processed(adc_bat->channel[channel], result);
  93         if (ret < 0)
  94                 dev_err(&adc_bat->psy->dev, "read channel error: %d\n", ret);
  95         else
  96                 *result *= 1000;
  97
  98         return ret;
  99 }
 100
 101 static int gab_get_property(struct power_supply *psy,
 102                 enum power_supply_property psp, union power_supply_propval *val)
 103 {
 104         struct gab *adc_bat = to_generic_bat(psy);
 105
 106         switch (psp) {
 107         case POWER_SUPPLY_PROP_STATUS:
 108                 val->intval = adc_bat->status;
 109                 return 0;
 110         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 111                 return gab_read_channel(adc_bat, GAB_VOLTAGE, &val->intval);
 112         case POWER_SUPPLY_PROP_CURRENT_NOW:
 113                 return gab_read_channel(adc_bat, GAB_CURRENT, &val->intval);
 114         case POWER_SUPPLY_PROP_POWER_NOW:
 115                 return gab_read_channel(adc_bat, GAB_POWER, &val->intval);
 116         case POWER_SUPPLY_PROP_TEMP:
 117                 return gab_read_channel(adc_bat, GAB_TEMP, &val->intval);
 118         default:
 119                 return -EINVAL;
 120         }
 121 }
 122
 123 static void gab_work(struct work_struct *work)
 124 {
 125         struct gab *adc_bat;
 126         struct delayed_work *delayed_work;
 127         int status;
 128
 129         delayed_work = to_delayed_work(work);
 130         adc_bat = container_of(delayed_work, struct gab, bat_work);
 131         status = adc_bat->status;
 132
 133         if (!power_supply_am_i_supplied(adc_bat->psy))
 134                 adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
 135         else if (gab_charge_finished(adc_bat))
 136                 adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 137         else
 138                 adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
 139
 140         if (status != adc_bat->status)
 141                 power_supply_changed(adc_bat->psy);
 142 }
 143
 144 static irqreturn_t gab_charged(int irq, void *dev_id)
 145 {
 146         struct gab *adc_bat = dev_id;
 147
 148         schedule_delayed_work(&adc_bat->bat_work,
 149                               msecs_to_jiffies(JITTER_DEFAULT));
 150
 151         return IRQ_HANDLED;
 152 }
 153
 154 static int gab_probe(struct platform_device *pdev)
 155 {
 156         struct gab *adc_bat;
 157         struct power_supply_desc *psy_desc;
 158         struct power_supply_config psy_cfg = {};
 159         enum power_supply_property *properties;
 160         int ret = 0;
 161         int chan;
 162         int index = ARRAY_SIZE(gab_props);
 163         bool any = false;
 164
 165         adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
 166         if (!adc_bat)
 167                 return -ENOMEM;
 168
 169         psy_cfg.of_node = pdev->dev.of_node;
 170         psy_cfg.drv_data = adc_bat;
 171         psy_desc = &adc_bat->psy_desc;
 172         psy_desc->name = dev_name(&pdev->dev);
 173
 174         /* bootup default values for the battery */
 175         adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
 176         psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
 177         psy_desc->get_property = gab_get_property;
 178         psy_desc->external_power_changed = gab_ext_power_changed;
 179
 180         /*
 181          * copying the static properties and allocating extra memory for holding
 182          * the extra configurable properties received from platform data.
 183          */
 184         properties = devm_kcalloc(&pdev->dev,
 185                                   ARRAY_SIZE(gab_props) +
 186                                   ARRAY_SIZE(gab_chan_name),
 187                                   sizeof(*properties),
 188                                   GFP_KERNEL);
 189         if (!properties)
 190                 return -ENOMEM;
 191
 192         memcpy(properties, gab_props, sizeof(gab_props));
 193
 194         /*
 195          * getting channel from iio and copying the battery properties
 196          * based on the channel supported by consumer device.
 197          */
 198         for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 199                 adc_bat->channel[chan] = devm_iio_channel_get(&pdev->dev, gab_chan_name[chan]);
 200                 if (IS_ERR(adc_bat->channel[chan])) {
 201                         ret = PTR_ERR(adc_bat->channel[chan]);
 202                         if (ret != -ENODEV)
 203                                 return dev_err_probe(&pdev->dev, ret, "Failed to get ADC channel %s\n", gab_chan_name[chan]);
 204                         adc_bat->channel[chan] = NULL;
 205                 } else if (adc_bat->channel[chan]) {
 206                         /* copying properties for supported channels only */
 207                         int index2;
 208
 209                         for (index2 = 0; index2 < index; index2++) {
 210                                 if (properties[index2] == gab_dyn_props[chan])
 211                                         break;  /* already known */
 212                         }
 213                         if (index2 == index)    /* really new */
 214                                 properties[index++] = gab_dyn_props[chan];
 215                         any = true;
 216                 }
 217         }
 218
 219         /* none of the channels are supported so let's bail out */
 220         if (!any)
 221                 return dev_err_probe(&pdev->dev, -ENODEV, "Failed to get any ADC channel\n");
 222
 223         /*
 224          * Total number of properties is equal to static properties
 225          * plus the dynamic properties.Some properties may not be set
 226          * as come channels may be not be supported by the device.So
 227          * we need to take care of that.
 228          */
 229         psy_desc->properties = properties;
 230         psy_desc->num_properties = index;
 231
 232         adc_bat->psy = devm_power_supply_register(&pdev->dev, psy_desc, &psy_cfg);
 233         if (IS_ERR(adc_bat->psy))
 234                 return dev_err_probe(&pdev->dev, PTR_ERR(adc_bat->psy), "Failed to register power-supply device\n");
 235
 236         ret = devm_delayed_work_autocancel(&pdev->dev, &adc_bat->bat_work, gab_work);
 237         if (ret)
 238                 return dev_err_probe(&pdev->dev, ret, "Failed to register delayed work\n");
 239
 240         adc_bat->charge_finished = devm_gpiod_get_optional(&pdev->dev, "charged", GPIOD_IN);
 241         if (adc_bat->charge_finished) {
 242                 int irq;
 243
 244                 irq = gpiod_to_irq(adc_bat->charge_finished);
 245                 ret = devm_request_any_context_irq(&pdev->dev, irq, gab_charged,
 246                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 247                                 "battery charged", adc_bat);
 248                 if (ret < 0)
 249                         return dev_err_probe(&pdev->dev, ret, "Failed to register irq\n");
 250         }
 251
 252         platform_set_drvdata(pdev, adc_bat);
 253
 254         /* Schedule timer to check current status */
 255         schedule_delayed_work(&adc_bat->bat_work,
 256                         msecs_to_jiffies(0));
 257         return 0;
 258 }
 259
 260 static int __maybe_unused gab_suspend(struct device *dev)
 261 {
 262         struct gab *adc_bat = dev_get_drvdata(dev);
 263
 264         cancel_delayed_work_sync(&adc_bat->bat_work);
 265         adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
 266         return 0;
 267 }
 268
 269 static int __maybe_unused gab_resume(struct device *dev)
 270 {
 271         struct gab *adc_bat = dev_get_drvdata(dev);
 272
 273         /* Schedule timer to check current status */
 274         schedule_delayed_work(&adc_bat->bat_work,
 275                               msecs_to_jiffies(JITTER_DEFAULT));
 276
 277         return 0;
 278 }
 279
 280 static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
 281
 282 static const struct of_device_id gab_match[] = {
 283         { .compatible = "adc-battery" },
 284         { }
 285 };
 286 MODULE_DEVICE_TABLE(of, gab_match);
 287
 288 static struct platform_driver gab_driver = {
 289         .driver         = {
 290                 .name   = "generic-adc-battery",
 291                 .pm     = &gab_pm_ops,
 292                 .of_match_table = gab_match,
 293         },
 294         .probe          = gab_probe,
 295 };
 296 module_platform_driver(gab_driver);
 297
 298 MODULE_AUTHOR("anish kumar <yesanishhere@gmail.com>");
 299 MODULE_DESCRIPTION("generic battery driver using IIO");
 300 MODULE_LICENSE("GPL");