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         struct z2_battery_info *info;
  94
  95         info = charger->info;
  96
  97         mutex_lock(&charger->work_lock);
  98
  99         charger->bat_status = charger->charge_gpiod ?
 100                 (gpiod_get_value(charger->charge_gpiod) ?
 101                 POWER_SUPPLY_STATUS_CHARGING :
 102                 POWER_SUPPLY_STATUS_DISCHARGING) :
 103                 POWER_SUPPLY_STATUS_UNKNOWN;
 104
 105         if (old_status != charger->bat_status) {
 106                 pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name,
 107                                 old_status,
 108                                 charger->bat_status);
 109                 power_supply_changed(charger->batt_ps);
 110         }
 111
 112         mutex_unlock(&charger->work_lock);
 113 }
 114
 115 static void z2_batt_work(struct work_struct *work)
 116 {
 117         struct z2_charger *charger;
 118         charger = container_of(work, struct z2_charger, bat_work);
 119         z2_batt_update(charger);
 120 }
 121
 122 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
 123 {
 124         struct z2_charger *charger = devid;
 125         schedule_work(&charger->bat_work);
 126         return IRQ_HANDLED;
 127 }
 128
 129 static int z2_batt_ps_init(struct z2_charger *charger, int props)
 130 {
 131         int i = 0;
 132         enum power_supply_property *prop;
 133         struct z2_battery_info *info = charger->info;
 134
 135         if (charger->charge_gpiod)
 136                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 137         if (info->batt_tech >= 0)
 138                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 139         if (info->batt_I2C_reg >= 0)
 140                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 141         if (info->max_voltage >= 0)
 142                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 143         if (info->min_voltage >= 0)
 144                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 145
 146         prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
 147         if (!prop)
 148                 return -ENOMEM;
 149
 150         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 151         if (charger->charge_gpiod)
 152                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 153         if (info->batt_tech >= 0)
 154                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 155         if (info->batt_I2C_reg >= 0)
 156                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 157         if (info->max_voltage >= 0)
 158                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 159         if (info->min_voltage >= 0)
 160                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 161
 162         if (!info->batt_name) {
 163                 dev_info(&charger->client->dev,
 164                                 "Please consider setting proper battery "
 165                                 "name in platform definition file, falling "
 166                                 "back to name \" Z2_DEFAULT_NAME \"\n");
 167                 charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
 168         } else
 169                 charger->batt_ps_desc.name = info->batt_name;
 170
 171         charger->batt_ps_desc.properties        = prop;
 172         charger->batt_ps_desc.num_properties    = props;
 173         charger->batt_ps_desc.type              = POWER_SUPPLY_TYPE_BATTERY;
 174         charger->batt_ps_desc.get_property      = z2_batt_get_property;
 175         charger->batt_ps_desc.external_power_changed =
 176                                                 z2_batt_ext_power_changed;
 177         charger->batt_ps_desc.use_for_apm       = 1;
 178
 179         return 0;
 180 }
 181
 182 static int z2_batt_probe(struct i2c_client *client,
 183                                 const struct i2c_device_id *id)
 184 {
 185         int ret = 0;
 186         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 187         struct z2_charger *charger;
 188         struct z2_battery_info *info = client->dev.platform_data;
 189         struct power_supply_config psy_cfg = {};
 190
 191         if (info == NULL) {
 192                 dev_err(&client->dev,
 193                         "Please set platform device platform_data"
 194                         " to a valid z2_battery_info pointer!\n");
 195                 return -EINVAL;
 196         }
 197
 198         charger = kzalloc(sizeof(*charger), GFP_KERNEL);
 199         if (charger == NULL)
 200                 return -ENOMEM;
 201
 202         charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
 203         charger->info = info;
 204         charger->client = client;
 205         i2c_set_clientdata(client, charger);
 206         psy_cfg.drv_data = charger;
 207
 208         mutex_init(&charger->work_lock);
 209
 210         charger->charge_gpiod = devm_gpiod_get_optional(&client->dev,
 211                                                         NULL, GPIOD_IN);
 212         if (IS_ERR(charger->charge_gpiod))
 213                 return dev_err_probe(&client->dev,
 214                                      PTR_ERR(charger->charge_gpiod),
 215                                      "failed to get charge GPIO\n");
 216
 217         if (charger->charge_gpiod) {
 218                 gpiod_set_consumer_name(charger->charge_gpiod, "BATT CHRG");
 219
 220                 irq_set_irq_type(gpiod_to_irq(charger->charge_gpiod),
 221                                  IRQ_TYPE_EDGE_BOTH);
 222                 ret = request_irq(gpiod_to_irq(charger->charge_gpiod),
 223                                 z2_charge_switch_irq, 0,
 224                                 "AC Detect", charger);
 225                 if (ret)
 226                         goto err;
 227         }
 228
 229         ret = z2_batt_ps_init(charger, props);
 230         if (ret)
 231                 goto err3;
 232
 233         INIT_WORK(&charger->bat_work, z2_batt_work);
 234
 235         charger->batt_ps = power_supply_register(&client->dev,
 236                                                  &charger->batt_ps_desc,
 237                                                  &psy_cfg);
 238         if (IS_ERR(charger->batt_ps)) {
 239                 ret = PTR_ERR(charger->batt_ps);
 240                 goto err4;
 241         }
 242
 243         schedule_work(&charger->bat_work);
 244
 245         return 0;
 246
 247 err4:
 248         kfree(charger->batt_ps_desc.properties);
 249 err3:
 250         if (charger->charge_gpiod)
 251                 free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
 252 err:
 253         kfree(charger);
 254         return ret;
 255 }
 256
 257 static int z2_batt_remove(struct i2c_client *client)
 258 {
 259         struct z2_charger *charger = i2c_get_clientdata(client);
 260
 261         cancel_work_sync(&charger->bat_work);
 262         power_supply_unregister(charger->batt_ps);
 263
 264         kfree(charger->batt_ps_desc.properties);
 265         if (charger->charge_gpiod)
 266                 free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
 267
 268         kfree(charger);
 269
 270         return 0;
 271 }
 272
 273 #ifdef CONFIG_PM
 274 static int z2_batt_suspend(struct device *dev)
 275 {
 276         struct i2c_client *client = to_i2c_client(dev);
 277         struct z2_charger *charger = i2c_get_clientdata(client);
 278
 279         flush_work(&charger->bat_work);
 280         return 0;
 281 }
 282
 283 static int z2_batt_resume(struct device *dev)
 284 {
 285         struct i2c_client *client = to_i2c_client(dev);
 286         struct z2_charger *charger = i2c_get_clientdata(client);
 287
 288         schedule_work(&charger->bat_work);
 289         return 0;
 290 }
 291
 292 static const struct dev_pm_ops z2_battery_pm_ops = {
 293         .suspend        = z2_batt_suspend,
 294         .resume         = z2_batt_resume,
 295 };
 296
 297 #define Z2_BATTERY_PM_OPS       (&z2_battery_pm_ops)
 298
 299 #else
 300 #define Z2_BATTERY_PM_OPS       (NULL)
 301 #endif
 302
 303 static const struct i2c_device_id z2_batt_id[] = {
 304         { "aer915", 0 },
 305         { }
 306 };
 307 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
 308
 309 static struct i2c_driver z2_batt_driver = {
 310         .driver = {
 311                 .name   = "z2-battery",
 312                 .pm     = Z2_BATTERY_PM_OPS
 313         },
 314         .probe          = z2_batt_probe,
 315         .remove         = z2_batt_remove,
 316         .id_table       = z2_batt_id,
 317 };
 318 module_i2c_driver(z2_batt_driver);
 319
 320 MODULE_LICENSE("GPL");
 321 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
 322 MODULE_DESCRIPTION("Zipit Z2 battery driver");