#include <linux/devm-helpers.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/power_supply.h>
#include <linux/types.h>
#define REGB_STATUS 0x02
#define REGW_VOLTAGE_NOW 0x20
#define REGW_CURRENT_NOW 0x24
#define REGW_CAPACITY 0x28
#define REGW_CHARGE_NOW 0x2a
#define REGW_CHARGE_FULL 0x2c
#define REGW_CYCLE_COUNT 0x3a
#define REGW_CHARGE_FULL_DESIGN 0x3c
#define REGW_VOLTAGE_MAX_DESIGN 0x3e
#define REGW_SERIAL_NUMBER 0x44
#define REGS_MANUFACTURER 0x46
#define REGS_MODEL_NAME 0x52
#define REGS_TECHNOLOGY 0x5a
#define REGB_ONLINE 0x67
struct srt_ec_device {
struct i2c_client *client;
struct power_supply *bat;
struct power_supply *psy;
struct gpio_desc *enable_gpiod;
struct delayed_work poll_work;
unsigned int technology;
unsigned int capacity;
const char *serial;
char manufacturer[13];
char model_name[10];
};
static const enum power_supply_property srt_bat_power_supply_props[] = {
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CHARGE_NOW,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CYCLE_COUNT,
POWER_SUPPLY_PROP_MANUFACTURER,
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_SERIAL_NUMBER,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
};
static const enum power_supply_property srt_psy_power_supply_props[] = {
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_PRESENT,
};
static int srt_bat_get_value(struct i2c_client *client, int reg, int *val)
{
int ret;
switch (reg) {
case REGW_CHARGE_NOW:
case REGW_CHARGE_FULL_DESIGN:
case REGW_CHARGE_FULL:
case REGW_VOLTAGE_MAX_DESIGN:
case REGW_VOLTAGE_NOW:
ret = i2c_smbus_read_word_data(client, reg);
if (ret < 0)
return ret;
*val = ret * 1000;
break;
case REGW_CURRENT_NOW:
ret = i2c_smbus_read_word_data(client, reg);
if (ret < 0)
return ret;
*val = (s16)ret * 1000;
break;
case REGW_CAPACITY:
case REGW_CYCLE_COUNT:
ret = i2c_smbus_read_word_data(client, reg);
if (ret < 0)
return ret;
*val = ret;
break;
case REGB_STATUS:
ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0)
return ret;
if (ret & BIT(0))
*val = POWER_SUPPLY_STATUS_CHARGING;
else
*val = POWER_SUPPLY_STATUS_DISCHARGING;
break;
case REGB_ONLINE:
ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0)
return ret;
*val = (ret & BIT(1)) >> 1;
break;
default:
return -EINVAL;
}
return 0;
}
static int srt_bat_power_supply_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct srt_ec_device *srt = power_supply_get_drvdata(psy);
struct i2c_client *client = srt->client;
int ret = 0;
switch (psp) {
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = srt->manufacturer;
break;
case POWER_SUPPLY_PROP_MODEL_NAME:
val->strval = srt->model_name;
break;
case POWER_SUPPLY_PROP_SERIAL_NUMBER:
val->strval = srt->serial;
break;
case POWER_SUPPLY_PROP_CAPACITY:
ret = srt_bat_get_value(client, REGW_CAPACITY, &val->intval);
break;
case POWER_SUPPLY_PROP_CHARGE_NOW:
ret = srt_bat_get_value(client, REGW_CHARGE_NOW, &val->intval);
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
ret = srt_bat_get_value(client, REGW_CHARGE_FULL, &val->intval);
break;
case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
ret = srt_bat_get_value(client, REGW_CHARGE_FULL_DESIGN,
&val->intval);
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
ret = srt_bat_get_value(client, REGW_CURRENT_NOW, &val->intval);
break;
case POWER_SUPPLY_PROP_CYCLE_COUNT:
ret = srt_bat_get_value(client, REGW_CYCLE_COUNT, &val->intval);
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = 1;
break;
case POWER_SUPPLY_PROP_ONLINE:
ret = srt_bat_get_value(client, REGB_ONLINE, &val->intval);
break;
case POWER_SUPPLY_PROP_STATUS:
if (srt->capacity < 100)
ret = srt_bat_get_value(client, REGB_STATUS, &val->intval);
else
val->intval = POWER_SUPPLY_STATUS_FULL;
break;
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = srt->technology;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
ret = srt_bat_get_value(client, REGW_VOLTAGE_MAX_DESIGN,
&val->intval);
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
ret = srt_bat_get_value(client, REGW_VOLTAGE_NOW, &val->intval);
break;
default:
return -EINVAL;
}
return ret;
}
static int srt_psy_power_supply_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct srt_ec_device *srt = power_supply_get_drvdata(psy);
struct i2c_client *client = srt->client;
int ret;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
case POWER_SUPPLY_PROP_PRESENT:
ret = i2c_smbus_read_byte_data(client, REGB_ONLINE);
if (ret < 0)
return ret;
val->intval = ret & BIT(0);
break;
default:
return -EINVAL;
}
return 0;
}
static void srt_bat_poll_work(struct work_struct *work)
{
struct srt_ec_device *srt =
container_of(work, struct srt_ec_device, poll_work.work);
int ret, capacity;
ret = srt_bat_get_value(srt->client, REGW_CAPACITY, &capacity);
if (!ret && capacity != srt->capacity) {
srt->capacity = capacity;
power_supply_changed(srt->bat);
}
schedule_delayed_work(&srt->poll_work, 30 * HZ);
}
static irqreturn_t srt_psy_detect_irq(int irq, void *dev_id)
{
struct srt_ec_device *srt = dev_id;
power_supply_changed(srt->psy);
return IRQ_HANDLED;
}
static const struct power_supply_desc srt_bat_power_supply_desc = {
.name = "surface-rt-battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.properties = srt_bat_power_supply_props,
.num_properties = ARRAY_SIZE(srt_bat_power_supply_props),
.get_property = srt_bat_power_supply_get_property,
.external_power_changed = power_supply_changed,
};
static const struct power_supply_desc srt_psy_power_supply_desc = {
.name = "surface-rt-ac-adapter",
.type = POWER_SUPPLY_TYPE_MAINS,
.properties = srt_psy_power_supply_props,
.num_properties = ARRAY_SIZE(srt_psy_power_supply_props),
.get_property = srt_psy_power_supply_get_property,
};
static char *battery_supplied_to[] = { "surface-rt-battery" };
static int srt_ec_probe(struct i2c_client *client)
{
struct power_supply_config bat_cfg = {};
struct power_supply_config psy_cfg = {};
struct device *dev = &client->dev;
struct srt_ec_device *srt;
char str_buf[4];
int ret;
srt = devm_kzalloc(dev, sizeof(*srt), GFP_KERNEL);
if (!srt)
return -ENOMEM;
i2c_set_clientdata(client, srt);
srt->client = client;
srt->enable_gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
if (IS_ERR(srt->enable_gpiod))
return dev_err_probe(dev, PTR_ERR(srt->enable_gpiod),
"failed to get enable gpio\n");
usleep_range(1000, 1500);
ret = i2c_smbus_read_word_data(client, REGW_SERIAL_NUMBER);
if (ret < 0)
return ret;
srt->serial = devm_kasprintf(dev, GFP_KERNEL, "%04x", ret);
if (!srt->serial)
return -ENOMEM;
ret = i2c_smbus_read_i2c_block_data(client, REGS_MANUFACTURER,
sizeof(srt->manufacturer) - 1,
srt->manufacturer);
if (ret < 0)
return ret;
ret = i2c_smbus_read_i2c_block_data(client, REGS_MODEL_NAME,
sizeof(srt->model_name) - 1,
srt->model_name);
if (ret < 0)
return ret;
ret = i2c_smbus_read_i2c_block_data(client, REGS_TECHNOLOGY,
sizeof(str_buf), str_buf);
if (ret < 0)
return ret;
if (!strncmp(str_buf, "LION", 4))
srt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
else
srt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
bat_cfg.drv_data = srt;
bat_cfg.fwnode = dev_fwnode(dev);
srt->bat = devm_power_supply_register(dev, &srt_bat_power_supply_desc,
&bat_cfg);
if (IS_ERR(srt->bat))
return dev_err_probe(dev, PTR_ERR(srt->bat),
"failed to register battery power supply\n");
psy_cfg.drv_data = srt;
psy_cfg.fwnode = dev_fwnode(dev);
psy_cfg.supplied_to = battery_supplied_to;
psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);
srt->psy = devm_power_supply_register(dev, &srt_psy_power_supply_desc,
&psy_cfg);
if (IS_ERR(srt->psy))
return dev_err_probe(dev, PTR_ERR(srt->psy),
"failed to register AC power supply\n");
ret = devm_request_threaded_irq(dev, client->irq, NULL, srt_psy_detect_irq,
IRQF_ONESHOT, client->name, srt);
if (ret < 0)
return dev_err_probe(dev, ret, "failed to request interrupt\n");
ret = devm_delayed_work_autocancel(dev, &srt->poll_work, srt_bat_poll_work);
if (ret < 0)
return ret;
schedule_delayed_work(&srt->poll_work, HZ);
return 0;
}
static int srt_ec_suspend(struct device *dev)
{
struct srt_ec_device *srt = dev_get_drvdata(dev);
cancel_delayed_work_sync(&srt->poll_work);
return 0;
}
static int srt_ec_resume(struct device *dev)
{
struct srt_ec_device *srt = dev_get_drvdata(dev);
schedule_delayed_work(&srt->poll_work, HZ);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(srt_ec_pm_ops, srt_ec_suspend, srt_ec_resume);
static const struct of_device_id srt_ec_of_match[] = {
{ .compatible = "microsoft,surface-rt-ec" },
{ }
};
MODULE_DEVICE_TABLE(of, srt_ec_of_match);
static struct i2c_driver srt_ec_driver = {
.driver = {
.name = "surface-rt-ec",
.of_match_table = srt_ec_of_match,
.pm = &srt_ec_pm_ops,
},
.probe = srt_ec_probe,
};
module_i2c_driver(srt_ec_driver);
MODULE_AUTHOR("Jonas Schwöbel <jonasschwoebel@yahoo.de>");
MODULE_DESCRIPTION("Surface RT Embedded Controller driver");
MODULE_LICENSE("GPL");
