#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/bitops.h>
#include <linux/devm-helpers.h>
#define SBS_CHARGER_REG_SPEC_INFO 0x11
#define SBS_CHARGER_REG_STATUS 0x13
#define SBS_CHARGER_REG_ALARM_WARNING 0x16
#define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(0)
#define SBS_CHARGER_STATUS_RES_COLD BIT(9)
#define SBS_CHARGER_STATUS_RES_HOT BIT(10)
#define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14)
#define SBS_CHARGER_STATUS_AC_PRESENT BIT(15)
#define SBS_CHARGER_POLL_TIME 500
struct sbs_info {
struct i2c_client *client;
struct power_supply *power_supply;
struct regmap *regmap;
struct delayed_work work;
unsigned int last_state;
};
static int sbs_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct sbs_info *chip = power_supply_get_drvdata(psy);
unsigned int reg;
reg = chip->last_state;
switch (psp) {
case POWER_SUPPLY_PROP_PRESENT:
val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT);
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT);
break;
case POWER_SUPPLY_PROP_STATUS:
val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT))
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
else if (reg & SBS_CHARGER_STATUS_AC_PRESENT &&
!(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED))
val->intval = POWER_SUPPLY_STATUS_CHARGING;
else
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
break;
case POWER_SUPPLY_PROP_HEALTH:
if (reg & SBS_CHARGER_STATUS_RES_COLD)
val->intval = POWER_SUPPLY_HEALTH_COLD;
if (reg & SBS_CHARGER_STATUS_RES_HOT)
val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
else
val->intval = POWER_SUPPLY_HEALTH_GOOD;
break;
default:
return -EINVAL;
}
return 0;
}
static int sbs_check_state(struct sbs_info *chip)
{
unsigned int reg;
int ret;
ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®);
if (!ret && reg != chip->last_state) {
chip->last_state = reg;
power_supply_changed(chip->power_supply);
return 1;
}
return 0;
}
static void sbs_delayed_work(struct work_struct *work)
{
struct sbs_info *chip = container_of(work, struct sbs_info, work.work);
sbs_check_state(chip);
schedule_delayed_work(&chip->work,
msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
}
static irqreturn_t sbs_irq_thread(int irq, void *data)
{
struct sbs_info *chip = data;
int ret;
ret = sbs_check_state(chip);
return ret ? IRQ_HANDLED : IRQ_NONE;
}
static enum power_supply_property sbs_properties[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_HEALTH,
};
static bool sbs_readable_reg(struct device *dev, unsigned int reg)
{
return reg >= SBS_CHARGER_REG_SPEC_INFO;
}
static bool sbs_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case SBS_CHARGER_REG_STATUS:
return true;
}
return false;
}
static const struct regmap_config sbs_regmap = {
.reg_bits = 8,
.val_bits = 16,
.max_register = SBS_CHARGER_REG_ALARM_WARNING,
.readable_reg = sbs_readable_reg,
.volatile_reg = sbs_volatile_reg,
.val_format_endian = REGMAP_ENDIAN_LITTLE,
};
static const struct power_supply_desc sbs_default_desc = {
.type = POWER_SUPPLY_TYPE_MAINS,
.properties = sbs_properties,
.num_properties = ARRAY_SIZE(sbs_properties),
.get_property = sbs_get_property,
};
static int sbs_probe(struct i2c_client *client)
{
struct power_supply_config psy_cfg = {};
struct power_supply_desc *sbs_desc;
struct sbs_info *chip;
int ret, val;
sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc,
sizeof(*sbs_desc), GFP_KERNEL);
if (!sbs_desc)
return -ENOMEM;
sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s",
dev_name(&client->dev));
if (!sbs_desc->name)
return -ENOMEM;
chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->client = client;
psy_cfg.fwnode = dev_fwnode(&client->dev);
psy_cfg.drv_data = chip;
i2c_set_clientdata(client, chip);
chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap);
if (IS_ERR(chip->regmap))
return PTR_ERR(chip->regmap);
ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val);
if (ret)
return dev_err_probe(&client->dev, ret, "Failed to get device status\n");
chip->last_state = val;
chip->power_supply = devm_power_supply_register(&client->dev, sbs_desc, &psy_cfg);
if (IS_ERR(chip->power_supply))
return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply),
"Failed to register power supply\n");
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, sbs_irq_thread,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
dev_name(&client->dev), chip);
if (ret)
return dev_err_probe(&client->dev, ret, "Failed to request irq\n");
} else {
ret = devm_delayed_work_autocancel(&client->dev, &chip->work,
sbs_delayed_work);
if (ret)
return dev_err_probe(&client->dev, ret,
"Failed to init work for polling\n");
schedule_delayed_work(&chip->work,
msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
}
dev_info(&client->dev,
"%s: smart charger device registered\n", client->name);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id sbs_dt_ids[] = {
{ .compatible = "sbs,sbs-charger" },
{ },
};
MODULE_DEVICE_TABLE(of, sbs_dt_ids);
#endif
static const struct i2c_device_id sbs_id[] = {
{ .name = "sbs-charger" },
{ }
};
MODULE_DEVICE_TABLE(i2c, sbs_id);
static struct i2c_driver sbs_driver = {
.probe = sbs_probe,
.id_table = sbs_id,
.driver = {
.name = "sbs-charger",
.of_match_table = of_match_ptr(sbs_dt_ids),
},
};
module_i2c_driver(sbs_driver);
MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
MODULE_DESCRIPTION("SBS smart charger driver");
MODULE_LICENSE("GPL v2");
