Quelle  chagall-battery.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/array_size.h>
#include <linux/delay.h>
#include <linux/devm-helpers.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>

#define CHAGALL_REG_LED_AMBER    0x60
#define CHAGALL_REG_LED_WHITE    0x70
#define CHAGALL_REG_BATTERY_TEMPERATURE   0xa2
#define CHAGALL_REG_BATTERY_VOLTAGE   0xa4
#define CHAGALL_REG_BATTERY_CURRENT   0xa6
#define CHAGALL_REG_BATTERY_CAPACITY   0xa8
#define CHAGALL_REG_BATTERY_CHARGING_CURRENT  0xaa
#define CHAGALL_REG_BATTERY_CHARGING_VOLTAGE  0xac
#define CHAGALL_REG_BATTERY_STATUS   0xae
#define   BATTERY_DISCHARGING    BIT(6)
#define   BATTERY_FULL_CHARGED    BIT(5)
#define   BATTERY_FULL_DISCHARGED   BIT(4)
#define CHAGALL_REG_BATTERY_REMAIN_CAPACITY  0xb0
#define CHAGALL_REG_BATTERY_FULL_CAPACITY  0xb2
#define CHAGALL_REG_MAX_COUNT    0xb4

#define CHAGALL_BATTERY_DATA_REFRESH   5000
#define TEMP_CELSIUS_OFFSET    2731

static const struct regmap_config chagall_battery_regmap_config = {
 .reg_bits = 8,
 .val_bits = 8,
 .max_register = CHAGALL_REG_MAX_COUNT,
 .reg_format_endian = REGMAP_ENDIAN_LITTLE,
 .val_format_endian = REGMAP_ENDIAN_LITTLE,
};

struct chagall_battery_data {
 struct regmap *regmap;
 struct led_classdev amber_led;
 struct led_classdev white_led;
 struct power_supply *battery;
 struct delayed_work poll_work;
 u16 last_state;
};

static void chagall_led_set_brightness_amber(struct led_classdev *led,
          enum led_brightness brightness)
{
 struct chagall_battery_data *cg =
  container_of(led, struct chagall_battery_data, amber_led);

 regmap_write(cg->regmap, CHAGALL_REG_LED_AMBER, brightness);
}

static void chagall_led_set_brightness_white(struct led_classdev *led,
          enum led_brightness brightness)
{
 struct chagall_battery_data *cg =
  container_of(led, struct chagall_battery_data, white_led);

 regmap_write(cg->regmap, CHAGALL_REG_LED_WHITE, brightness);
}

static const enum power_supply_property chagall_battery_properties[] = {
 POWER_SUPPLY_PROP_STATUS,
 POWER_SUPPLY_PROP_PRESENT,
 POWER_SUPPLY_PROP_VOLTAGE_NOW,
 POWER_SUPPLY_PROP_VOLTAGE_MAX,
 POWER_SUPPLY_PROP_CURRENT_NOW,
 POWER_SUPPLY_PROP_CURRENT_MAX,
 POWER_SUPPLY_PROP_CAPACITY,
 POWER_SUPPLY_PROP_TEMP,
 POWER_SUPPLY_PROP_CHARGE_FULL,
 POWER_SUPPLY_PROP_CHARGE_NOW,
};

static const unsigned int chagall_battery_prop_offs[] = {
 [POWER_SUPPLY_PROP_STATUS] = CHAGALL_REG_BATTERY_STATUS,
 [POWER_SUPPLY_PROP_VOLTAGE_NOW] = CHAGALL_REG_BATTERY_VOLTAGE,
 [POWER_SUPPLY_PROP_VOLTAGE_MAX] = CHAGALL_REG_BATTERY_CHARGING_VOLTAGE,
 [POWER_SUPPLY_PROP_CURRENT_NOW] = CHAGALL_REG_BATTERY_CURRENT,
 [POWER_SUPPLY_PROP_CURRENT_MAX] = CHAGALL_REG_BATTERY_CHARGING_CURRENT,
 [POWER_SUPPLY_PROP_CAPACITY] = CHAGALL_REG_BATTERY_CAPACITY,
 [POWER_SUPPLY_PROP_TEMP] = CHAGALL_REG_BATTERY_TEMPERATURE,
 [POWER_SUPPLY_PROP_CHARGE_FULL] = CHAGALL_REG_BATTERY_FULL_CAPACITY,
 [POWER_SUPPLY_PROP_CHARGE_NOW] = CHAGALL_REG_BATTERY_REMAIN_CAPACITY,
};

static int chagall_battery_get_value(struct chagall_battery_data *cg,
         enum power_supply_property psp, u32 *val)
{
 if (psp >= ARRAY_SIZE(chagall_battery_prop_offs))
  return -EINVAL;
 if (!chagall_battery_prop_offs[psp])
  return -EINVAL;

 /* Battery data is stored in 2 consecutive registers with little-endian */
 return regmap_bulk_read(cg->regmap, chagall_battery_prop_offs[psp], val, 2);
}

static int chagall_battery_get_status(u32 status_reg)
{
 if (status_reg & BATTERY_FULL_CHARGED)
  return POWER_SUPPLY_STATUS_FULL;
 else if (status_reg & BATTERY_DISCHARGING)
  return POWER_SUPPLY_STATUS_DISCHARGING;
 else
  return POWER_SUPPLY_STATUS_CHARGING;
}

static int chagall_battery_get_property(struct power_supply *psy,
     enum power_supply_property psp,
     union power_supply_propval *val)
{
 struct chagall_battery_data *cg = power_supply_get_drvdata(psy);
 int ret;

 switch (psp) {
 case POWER_SUPPLY_PROP_PRESENT:
  val->intval = 1;
  break;

 default:
  ret = chagall_battery_get_value(cg, psp, &val->intval);
  if (ret)
   return ret;

  switch (psp) {
  case POWER_SUPPLY_PROP_TEMP:
   val->intval -= TEMP_CELSIUS_OFFSET;
   break;

  case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  case POWER_SUPPLY_PROP_CURRENT_MAX:
  case POWER_SUPPLY_PROP_CURRENT_NOW:
  case POWER_SUPPLY_PROP_CHARGE_FULL:
  case POWER_SUPPLY_PROP_CHARGE_NOW:
   val->intval *= 1000;
   break;

  case POWER_SUPPLY_PROP_STATUS:
   val->intval = chagall_battery_get_status(val->intval);
   break;

  default:
   break;
  }

  break;
 }

 return 0;
}

static void chagall_battery_poll_work(struct work_struct *work)
{
 struct chagall_battery_data *cg =
  container_of(work, struct chagall_battery_data, poll_work.work);
 u32 state;
 int ret;

 ret = chagall_battery_get_value(cg, POWER_SUPPLY_PROP_STATUS, &state);
 if (ret)
  return;

 state = chagall_battery_get_status(state);

 if (cg->last_state != state) {
  cg->last_state = state;
  power_supply_changed(cg->battery);
 }

 /* continuously send uevent notification */
 schedule_delayed_work(&cg->poll_work,
         msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
}

static const struct power_supply_desc chagall_battery_desc = {
 .name = "chagall-battery",
 .type = POWER_SUPPLY_TYPE_BATTERY,
 .properties = chagall_battery_properties,
 .num_properties = ARRAY_SIZE(chagall_battery_properties),
 .get_property = chagall_battery_get_property,
 .external_power_changed = power_supply_changed,
};

static int chagall_battery_probe(struct i2c_client *client)
{
 struct chagall_battery_data *cg;
 struct device *dev = &client->dev;
 struct power_supply_config cfg = { };
 int ret;

 cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
 if (!cg)
  return -ENOMEM;

 cfg.drv_data = cg;
 cfg.fwnode = dev_fwnode(dev);

 i2c_set_clientdata(client, cg);

 cg->regmap = devm_regmap_init_i2c(client, &chagall_battery_regmap_config);
 if (IS_ERR(cg->regmap))
  return dev_err_probe(dev, PTR_ERR(cg->regmap), "cannot allocate regmap\n");

 cg->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
 cg->battery = devm_power_supply_register(dev, &chagall_battery_desc, &cfg);
 if (IS_ERR(cg->battery))
  return dev_err_probe(dev, PTR_ERR(cg->battery),
         "failed to register power supply\n");

 cg->amber_led.name = "power::amber";
 cg->amber_led.max_brightness = 1;
 cg->amber_led.flags = LED_CORE_SUSPENDRESUME;
 cg->amber_led.brightness_set = chagall_led_set_brightness_amber;
 cg->amber_led.default_trigger = "chagall-battery-charging";

 ret = devm_led_classdev_register(dev, &cg->amber_led);
 if (ret)
  return dev_err_probe(dev, ret, "failed to register amber LED\n");

 cg->white_led.name = "power::white";
 cg->white_led.max_brightness = 1;
 cg->white_led.flags = LED_CORE_SUSPENDRESUME;
 cg->white_led.brightness_set = chagall_led_set_brightness_white;
 cg->white_led.default_trigger = "chagall-battery-full";

 ret = devm_led_classdev_register(dev, &cg->white_led);
 if (ret)
  return dev_err_probe(dev, ret, "failed to register white LED\n");

 led_set_brightness(&cg->amber_led, LED_OFF);
 led_set_brightness(&cg->white_led, LED_OFF);

 ret = devm_delayed_work_autocancel(dev, &cg->poll_work, chagall_battery_poll_work);
 if (ret)
  return ret;

 schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));

 return 0;
}

static int __maybe_unused chagall_battery_suspend(struct device *dev)
{
 struct i2c_client *client = to_i2c_client(dev);
 struct chagall_battery_data *cg = i2c_get_clientdata(client);

 cancel_delayed_work_sync(&cg->poll_work);

 return 0;
}

static int __maybe_unused chagall_battery_resume(struct device *dev)
{
 struct i2c_client *client = to_i2c_client(dev);
 struct chagall_battery_data *cg = i2c_get_clientdata(client);

 schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));

 return 0;
}

static SIMPLE_DEV_PM_OPS(chagall_battery_pm_ops,
    chagall_battery_suspend, chagall_battery_resume);

static const struct of_device_id chagall_of_match[] = {
 { .compatible = "pegatron,chagall-ec" },
 { }
};
MODULE_DEVICE_TABLE(of, chagall_of_match);

static struct i2c_driver chagall_battery_driver = {
 .driver = {
  .name = "chagall-battery",
  .pm = &chagall_battery_pm_ops,
  .of_match_table = chagall_of_match,
 },
 .probe = chagall_battery_probe,
};
module_i2c_driver(chagall_battery_driver);

MODULE_AUTHOR("Svyatoslav Ryhel ");
MODULE_DESCRIPTION("Pegatron Chagall fuel gauge driver");
MODULE_LICENSE("GPL");