int ltc294x_init(void) {
struct i2c_client *client = <c2943_client;
ltc2943_client.addr = LTC2943_ADDRESS;
struct ltc294x_info *info = <c2943_info;
int ret;
u32 prescaler_exp;
s32 r_sense;
info->num_regs = LTC2943_NUM_REGS;
/* r_sense can be negative, when sense+ is connected to the battery
* instead of the sense-. This results in reversed measurements. */
info->r_sense = 20; // in mOhm
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
if (info->num_regs == LTC2943_NUM_REGS) {
if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
info->Qlsb = ((340 * 50000) / r_sense) /
(4096 / (1 << (2*prescaler_exp)));
}
else {
if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
info->Qlsb = ((85 * 50000) / r_sense) /
(128 / (1 << prescaler_exp));
}
info->client = client;
info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
info->supply_desc.properties = ltc294x_properties;
if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties);
else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 1;
else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 2;
else
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 3;
ret = ltc294x_reset(prescaler_exp);
if (ret < 0) {
dev_err(&client->dev, "Communication with chip failed\n");
goto fail_comm;
}
return 0;
fail_comm:
return ret;
}
static int ltc294x_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct power_supply_config psy_cfg = {};
struct ltc294x_info *info;
int ret;
int num;
u32 prescaler_exp;
s32 r_sense;
struct device_node *np;
mutex_lock(<c294x_lock);
ret = idr_alloc(<c294x_id, client, 0, 0, GFP_KERNEL);
mutex_unlock(<c294x_lock);
if (ret < 0)
goto fail_id;
num = ret;
info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
if (info == NULL) {
ret = -ENOMEM;
goto fail_info;
}
i2c_set_clientdata(client, info);
info->num_regs = id->driver_data;
info->supply_desc.name = kasprintf(GFP_KERNEL, "%s-%d", client->name,
num);
if (!info->supply_desc.name) {
ret = -ENOMEM;
goto fail_name;
}
np = of_node_get(client->dev.of_node);
/* r_sense can be negative, when sense+ is connected to the battery
* instead of the sense-. This results in reversed measurements. */
ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
if (ret < 0) {
dev_err(&client->dev,
"Could not find lltc,resistor-sense in devicetree\n");
goto fail_name;
}
info->r_sense = r_sense;
ret = of_property_read_u32(np, "lltc,prescaler-exponent",
&prescaler_exp);
if (ret < 0) {
dev_warn(&client->dev,
"lltc,prescaler-exponent not in devicetree\n");
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
}
if (info->num_regs == LTC2943_NUM_REGS) {
if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
info->Qlsb = ((340 * 50000) / r_sense) /
(4096 / (1 << (2*prescaler_exp)));
} else {
if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
info->Qlsb = ((85 * 50000) / r_sense) /
(128 / (1 << prescaler_exp));
}
info->client = client;
info->id = num;
info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
info->supply_desc.properties = ltc294x_properties;
if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties);
else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 1;
else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 2;
else
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 3;
info->supply_desc.get_property = ltc294x_get_property;
info->supply_desc.set_property = ltc294x_set_property;
info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
info->supply_desc.external_power_changed = NULL;
psy_cfg.drv_data = info;
INIT_DELAYED_WORK(&info->work, ltc294x_work);
ret = ltc294x_reset(info, prescaler_exp);
if (ret < 0) {
dev_err(&client->dev, "Communication with chip failed\n");
goto fail_comm;
}
info->supply = power_supply_register(&client->dev, &info->supply_desc,
&psy_cfg);
if (IS_ERR(info->supply)) {
dev_err(&client->dev, "failed to register ltc2941\n");
ret = PTR_ERR(info->supply);
goto fail_register;
} else {
schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
}
return 0;
fail_register:
kfree(info->supply_desc.name);
fail_comm:
fail_name:
fail_info:
mutex_lock(<c294x_lock);
idr_remove(<c294x_id, num);
mutex_unlock(<c294x_lock);
fail_id:
return ret;
}
static int ltc294x_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ltc294x_platform_data *platform_data;
struct ltc294x_info *info;
int ret;
u32 prescaler_exp;
u8 status;
info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
i2c_set_clientdata(client, info);
platform_data = client->dev.platform_data;
info->id = (enum ltc294x_id)id->driver_data;
info->supply.name = platform_data->name;
/* r_sense can be negative, when sense+ is connected to the battery
* instead of the sense-. This results in reversed measurements. */
info->r_sense = platform_data->r_sense;
prescaler_exp = platform_data->prescaler_exp;
if (info->id == LTC2943_ID) {
if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
info->Qlsb = ((340 * 50000) / info->r_sense) /
(4096 / (1 << (2*prescaler_exp)));
} else {
if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
info->Qlsb = ((85 * 50000) / info->r_sense) /
(128 / (1 << prescaler_exp));
}
/* Read status register to check for LTC2942 */
if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
if (ret < 0) {
dev_err(&client->dev,
"Could not read status register\n");
return ret;
}
if (status & LTC2941_REG_STATUS_CHIP_ID)
info->id = LTC2941_ID;
else
info->id = LTC2942_ID;
}
info->client = client;
info->supply.type = POWER_SUPPLY_TYPE_BATTERY;
info->supply.properties = ltc294x_properties;
switch (info->id) {
case LTC2944_ID:
case LTC2943_ID:
info->supply.num_properties =
ARRAY_SIZE(ltc294x_properties);
break;
case LTC2942_ID:
info->supply.num_properties =
ARRAY_SIZE(ltc294x_properties) - 1;
break;
case LTC2941_ID:
default:
info->supply.num_properties =
ARRAY_SIZE(ltc294x_properties) - 3;
break;
}
info->supply.get_property = ltc294x_get_property;
info->supply.set_property = ltc294x_set_property;
info->supply.property_is_writeable = ltc294x_property_is_writeable;
info->supply.external_power_changed = NULL;
INIT_DELAYED_WORK(&info->work, ltc294x_work);
ret = ltc294x_reset(info, prescaler_exp);
if (ret < 0) {
dev_err(&client->dev, "Communication with chip failed\n");
return ret;
}
ret = power_supply_register(&client->dev, &info->supply);
if (ret) {
dev_err(&client->dev, "failed to register ltc2941\n");
return ret;
} else {
schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
}
return 0;
}
