drivers/power/supply/z2_battery.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Battery measurement code for Zipit Z2
   4  *
   5  * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/i2c.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/irq.h>
  13 #include <linux/power_supply.h>
  14 #include <linux/slab.h>
  15 #include <linux/z2_battery.h>
  16
  17 #define Z2_DEFAULT_NAME "Z2"
  18
  19 struct z2_charger {
  20         struct z2_battery_info          *info;
  21         struct gpio_desc                *charge_gpiod;
  22         int                             bat_status;
  23         struct i2c_client               *client;
  24         struct power_supply             *batt_ps;
  25         struct power_supply_desc        batt_ps_desc;
  26         struct mutex                    work_lock;
  27         struct work_struct              bat_work;
  28 };
  29
  30 static unsigned long z2_read_bat(struct z2_charger *charger)
  31 {
  32         int data;
  33         data = i2c_smbus_read_byte_data(charger->client,
  34                                         charger->info->batt_I2C_reg);
  35         if (data < 0)
  36                 return 0;
  37
  38         return data * charger->info->batt_mult / charger->info->batt_div;
  39 }
  40
  41 static int z2_batt_get_property(struct power_supply *batt_ps,
  42                             enum power_supply_property psp,
  43                             union power_supply_propval *val)
  44 {
  45         struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  46         struct z2_battery_info *info = charger->info;
  47
  48         switch (psp) {
  49         case POWER_SUPPLY_PROP_STATUS:
  50                 val->intval = charger->bat_status;
  51                 break;
  52         case POWER_SUPPLY_PROP_TECHNOLOGY:
  53                 val->intval = info->batt_tech;
  54                 break;
  55         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  56                 if (info->batt_I2C_reg >= 0)
  57                         val->intval = z2_read_bat(charger);
  58                 else
  59                         return -EINVAL;
  60                 break;
  61         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  62                 if (info->max_voltage >= 0)
  63                         val->intval = info->max_voltage;
  64                 else
  65                         return -EINVAL;
  66                 break;
  67         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  68                 if (info->min_voltage >= 0)
  69                         val->intval = info->min_voltage;
  70                 else
  71                         return -EINVAL;
  72                 break;
  73         case POWER_SUPPLY_PROP_PRESENT:
  74                 val->intval = 1;
  75                 break;
  76         default:
  77                 return -EINVAL;
  78         }
  79
  80         return 0;
  81 }
  82
  83 static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
  84 {
  85         struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  86
  87         schedule_work(&charger->bat_work);
  88 }
  89
  90 static void z2_batt_update(struct z2_charger *charger)
  91 {
  92         int old_status = charger->bat_status;
  93
  94         mutex_lock(&charger->work_lock);
  95
  96         charger->bat_status = charger->charge_gpiod ?
  97                 (gpiod_get_value(charger->charge_gpiod) ?
  98                 POWER_SUPPLY_STATUS_CHARGING :
  99                 POWER_SUPPLY_STATUS_DISCHARGING) :
 100                 POWER_SUPPLY_STATUS_UNKNOWN;
 101
 102         if (old_status != charger->bat_status) {
 103                 pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name,
 104                                 old_status,
 105                                 charger->bat_status);
 106                 power_supply_changed(charger->batt_ps);
 107         }
 108
 109         mutex_unlock(&charger->work_lock);
 110 }
 111
 112 static void z2_batt_work(struct work_struct *work)
 113 {
 114         struct z2_charger *charger;
 115         charger = container_of(work, struct z2_charger, bat_work);
 116         z2_batt_update(charger);
 117 }
 118
 119 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
 120 {
 121         struct z2_charger *charger = devid;
 122         schedule_work(&charger->bat_work);
 123         return IRQ_HANDLED;
 124 }
 125
 126 static int z2_batt_ps_init(struct z2_charger *charger, int props)
 127 {
 128         int i = 0;
 129         enum power_supply_property *prop;
 130         struct z2_battery_info *info = charger->info;
 131
 132         if (charger->charge_gpiod)
 133                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 134         if (info->batt_tech >= 0)
 135                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 136         if (info->batt_I2C_reg >= 0)
 137                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 138         if (info->max_voltage >= 0)
 139                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 140         if (info->min_voltage >= 0)
 141                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 142
 143         prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
 144         if (!prop)
 145                 return -ENOMEM;
 146
 147         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 148         if (charger->charge_gpiod)
 149                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 150         if (info->batt_tech >= 0)
 151                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 152         if (info->batt_I2C_reg >= 0)
 153                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 154         if (info->max_voltage >= 0)
 155                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 156         if (info->min_voltage >= 0)
 157                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 158
 159         if (!info->batt_name) {
 160                 dev_info(&charger->client->dev,
 161                                 "Please consider setting proper battery "
 162                                 "name in platform definition file, falling "
 163                                 "back to name \" Z2_DEFAULT_NAME \"\n");
 164                 charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
 165         } else
 166                 charger->batt_ps_desc.name = info->batt_name;
 167
 168         charger->batt_ps_desc.properties        = prop;
 169         charger->batt_ps_desc.num_properties    = props;
 170         charger->batt_ps_desc.type              = POWER_SUPPLY_TYPE_BATTERY;
 171         charger->batt_ps_desc.get_property      = z2_batt_get_property;
 172         charger->batt_ps_desc.external_power_changed =
 173                                                 z2_batt_ext_power_changed;
 174         charger->batt_ps_desc.use_for_apm       = 1;
 175
 176         return 0;
 177 }
 178
 179 static int z2_batt_probe(struct i2c_client *client,
 180                                 const struct i2c_device_id *id)
 181 {
 182         int ret = 0;
 183         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 184         struct z2_charger *charger;
 185         struct z2_battery_info *info = client->dev.platform_data;
 186         struct power_supply_config psy_cfg = {};
 187
 188         if (info == NULL) {
 189                 dev_err(&client->dev,
 190                         "Please set platform device platform_data"
 191                         " to a valid z2_battery_info pointer!\n");
 192                 return -EINVAL;
 193         }
 194
 195         charger = kzalloc(sizeof(*charger), GFP_KERNEL);
 196         if (charger == NULL)
 197                 return -ENOMEM;
 198
 199         charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
 200         charger->info = info;
 201         charger->client = client;
 202         i2c_set_clientdata(client, charger);
 203         psy_cfg.drv_data = charger;
 204
 205         mutex_init(&charger->work_lock);
 206
 207         charger->charge_gpiod = devm_gpiod_get_optional(&client->dev,
 208                                                         NULL, GPIOD_IN);
 209         if (IS_ERR(charger->charge_gpiod))
 210                 return dev_err_probe(&client->dev,
 211                                      PTR_ERR(charger->charge_gpiod),
 212                                      "failed to get charge GPIO\n");
 213
 214         if (charger->charge_gpiod) {
 215                 gpiod_set_consumer_name(charger->charge_gpiod, "BATT CHRG");
 216
 217                 irq_set_irq_type(gpiod_to_irq(charger->charge_gpiod),
 218                                  IRQ_TYPE_EDGE_BOTH);
 219                 ret = request_irq(gpiod_to_irq(charger->charge_gpiod),
 220                                 z2_charge_switch_irq, 0,
 221                                 "AC Detect", charger);
 222                 if (ret)
 223                         goto err;
 224         }
 225
 226         ret = z2_batt_ps_init(charger, props);
 227         if (ret)
 228                 goto err3;
 229
 230         INIT_WORK(&charger->bat_work, z2_batt_work);
 231
 232         charger->batt_ps = power_supply_register(&client->dev,
 233                                                  &charger->batt_ps_desc,
 234                                                  &psy_cfg);
 235         if (IS_ERR(charger->batt_ps)) {
 236                 ret = PTR_ERR(charger->batt_ps);
 237                 goto err4;
 238         }
 239
 240         schedule_work(&charger->bat_work);
 241
 242         return 0;
 243
 244 err4:
 245         kfree(charger->batt_ps_desc.properties);
 246 err3:
 247         if (charger->charge_gpiod)
 248                 free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
 249 err:
 250         kfree(charger);
 251         return ret;
 252 }
 253
 254 static int z2_batt_remove(struct i2c_client *client)
 255 {
 256         struct z2_charger *charger = i2c_get_clientdata(client);
 257
 258         cancel_work_sync(&charger->bat_work);
 259         power_supply_unregister(charger->batt_ps);
 260
 261         kfree(charger->batt_ps_desc.properties);
 262         if (charger->charge_gpiod)
 263                 free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
 264
 265         kfree(charger);
 266
 267         return 0;
 268 }
 269
 270 #ifdef CONFIG_PM
 271 static int z2_batt_suspend(struct device *dev)
 272 {
 273         struct i2c_client *client = to_i2c_client(dev);
 274         struct z2_charger *charger = i2c_get_clientdata(client);
 275
 276         flush_work(&charger->bat_work);
 277         return 0;
 278 }
 279
 280 static int z2_batt_resume(struct device *dev)
 281 {
 282         struct i2c_client *client = to_i2c_client(dev);
 283         struct z2_charger *charger = i2c_get_clientdata(client);
 284
 285         schedule_work(&charger->bat_work);
 286         return 0;
 287 }
 288
 289 static const struct dev_pm_ops z2_battery_pm_ops = {
 290         .suspend        = z2_batt_suspend,
 291         .resume         = z2_batt_resume,
 292 };
 293
 294 #define Z2_BATTERY_PM_OPS       (&z2_battery_pm_ops)
 295
 296 #else
 297 #define Z2_BATTERY_PM_OPS       (NULL)
 298 #endif
 299
 300 static const struct i2c_device_id z2_batt_id[] = {
 301         { "aer915", 0 },
 302         { }
 303 };
 304 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
 305
 306 static struct i2c_driver z2_batt_driver = {
 307         .driver = {
 308                 .name   = "z2-battery",
 309                 .pm     = Z2_BATTERY_PM_OPS
 310         },
 311         .probe          = z2_batt_probe,
 312         .remove         = z2_batt_remove,
 313         .id_table       = z2_batt_id,
 314 };
 315 module_i2c_driver(z2_batt_driver);
 316
 317 MODULE_LICENSE("GPL");
 318 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
 319 MODULE_DESCRIPTION("Zipit Z2 battery driver");