/*
* Gas Gauge driver for TI's BQ20Z75
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#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>
enum {
REG_MANUFACTURER_DATA,
REG_TEMPERATURE,
REG_VOLTAGE,
REG_CURRENT,
REG_CAPACITY,
REG_TIME_TO_EMPTY,
REG_TIME_TO_FULL,
REG_STATUS,
REG_CYCLE_COUNT,
REG_SERIAL_NUMBER,
REG_REMAINING_CAPACITY,
REG_FULL_CHARGE_CAPACITY,
REG_DESIGN_CAPACITY,
REG_DESIGN_VOLTAGE,
};
/* manufacturer access defines */
#define MANUFACTURER_ACCESS_STATUS 0x0006
#define MANUFACTURER_ACCESS_SLEEP 0x0011
/* battery status value bits */
#define BATTERY_DISCHARGING 0x40
#define BATTERY_FULL_CHARGED 0x20
#define BATTERY_FULL_DISCHARGED 0x10
#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
.psp = _psp, \
.addr = _addr, \
.min_value = _min_value, \
.max_value = _max_value, \
}
static const struct bq20z75_device_data {
enum power_supply_property psp;
u8 addr;
int min_value;
int max_value;
} bq20z75_data[] = {
[REG_MANUFACTURER_DATA] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
[REG_TEMPERATURE] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
[REG_VOLTAGE] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
[REG_CURRENT] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
32767),
[REG_CAPACITY] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
[REG_REMAINING_CAPACITY] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
[REG_FULL_CHARGE_CAPACITY] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
[REG_TIME_TO_EMPTY] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
65535),
[REG_TIME_TO_FULL] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
65535),
[REG_STATUS] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
[REG_CYCLE_COUNT] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
[REG_DESIGN_CAPACITY] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
65535),
[REG_DESIGN_VOLTAGE] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
65535),
[REG_SERIAL_NUMBER] =
BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
};
static enum power_supply_property bq20z75_properties[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_CYCLE_COUNT,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
POWER_SUPPLY_PROP_SERIAL_NUMBER,
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
POWER_SUPPLY_PROP_ENERGY_NOW,
POWER_SUPPLY_PROP_ENERGY_FULL,
POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
};
struct bq20z75_info {
struct i2c_client *client;
struct power_supply power_supply;
};
static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
{
s32 ret;
ret = i2c_smbus_read_word_data(client, address);
if (ret < 0) {
dev_err(&client->dev,
"%s: i2c read at address 0x%x failed\n",
__func__, address);
return ret;
}
return le16_to_cpu(ret);
}
static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
u16 value)
{
s32 ret;
ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
if (ret < 0) {
dev_err(&client->dev,
"%s: i2c write to address 0x%x failed\n",
__func__, address);
return ret;
}
return 0;
}
static int bq20z75_get_battery_presence_and_health(
struct i2c_client *client, enum power_supply_property psp,
union power_supply_propval *val)
{
s32 ret;
/* Write to ManufacturerAccess with
* ManufacturerAccess command and then
* read the status */
ret = bq20z75_write_word_data(client,
bq20z75_data[REG_MANUFACTURER_DATA].addr,
MANUFACTURER_ACCESS_STATUS);
if (ret < 0)
return ret;
ret = bq20z75_read_word_data(client,
bq20z75_data[REG_MANUFACTURER_DATA].addr);
if (ret < 0)
return ret;
if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
val->intval = 0;
return 0;
}
/* Mask the upper nibble of 2nd byte and
* lower byte of response then
* shift the result by 8 to get status*/
ret &= 0x0F00;
ret >>= 8;
if (psp == POWER_SUPPLY_PROP_PRESENT) {
if (ret == 0x0F)
/* battery removed */
val->intval = 0;
else
val->intval = 1;
} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
if (ret == 0x09)
val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
else if (ret == 0x0B)
val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
else if (ret == 0x0C)
val->intval = POWER_SUPPLY_HEALTH_DEAD;
else
val->intval = POWER_SUPPLY_HEALTH_GOOD;
}
return 0;
}
static int bq20z75_get_battery_property(struct i2c_client *client,
int reg_offset, enum power_supply_property psp,
union power_supply_propval *val)
{
s32 ret;
ret = bq20z75_read_word_data(client,
bq20z75_data[reg_offset].addr);
if (ret < 0)
return ret;
/* returned values are 16 bit */
if (bq20z75_data[reg_offset].min_value < 0)
ret = (s16)ret;
if (ret >= bq20z75_data[reg_offset].min_value &&
ret <= bq20z75_data[reg_offset].max_value) {
val->intval = ret;
if (psp == POWER_SUPPLY_PROP_STATUS) {
if (ret & BATTERY_FULL_CHARGED)
val->intval = POWER_SUPPLY_STATUS_FULL;
else if (ret & BATTERY_FULL_DISCHARGED)
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
else if (ret & BATTERY_DISCHARGING)
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
else
val->intval = POWER_SUPPLY_STATUS_CHARGING;
}
} else {
if (psp == POWER_SUPPLY_PROP_STATUS)
val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
else
val->intval = 0;
}
return 0;
}
static void bq20z75_unit_adjustment(struct i2c_client *client,
enum power_supply_property psp, union power_supply_propval *val)
{
#define BASE_UNIT_CONVERSION 1000
#define BATTERY_MODE_CAP_MULT_WATT (10 * BASE_UNIT_CONVERSION)
#define TIME_UNIT_CONVERSION 600
#define TEMP_KELVIN_TO_CELCIUS 2731
switch (psp) {
case POWER_SUPPLY_PROP_ENERGY_NOW:
case POWER_SUPPLY_PROP_ENERGY_FULL:
case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
val->intval *= BATTERY_MODE_CAP_MULT_WATT;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
case POWER_SUPPLY_PROP_CURRENT_NOW:
val->intval *= BASE_UNIT_CONVERSION;
break;
case POWER_SUPPLY_PROP_TEMP:
/* bq20z75 provides battery tempreture in 0.1°K
* so convert it to 0.1°C */
val->intval -= TEMP_KELVIN_TO_CELCIUS;
val->intval *= 10;
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
val->intval *= TIME_UNIT_CONVERSION;
break;
default:
dev_dbg(&client->dev,
"%s: no need for unit conversion %d\n", __func__, psp);
}
}
static int bq20z75_get_battery_capacity(struct i2c_client *client,
int reg_offset, enum power_supply_property psp,
union power_supply_propval *val)
{
s32 ret;
ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
if (ret < 0)
return ret;
if (psp == POWER_SUPPLY_PROP_CAPACITY) {
/* bq20z75 spec says that this can be >100 %
* even if max value is 100 % */
val->intval = min(ret, 100);
} else
val->intval = ret;
return 0;
}
static char bq20z75_serial[5];
static int bq20z75_get_battery_serial_number(struct i2c_client *client,
union power_supply_propval *val)
{
int ret;
ret = bq20z75_read_word_data(client,
bq20z75_data[REG_SERIAL_NUMBER].addr);
if (ret < 0)
return ret;
ret = sprintf(bq20z75_serial, "%04x", ret);
val->strval = bq20z75_serial;
return 0;
}
static int bq20z75_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
int count;
int ret;
struct bq20z75_info *bq20z75_device = container_of(psy,
struct bq20z75_info, power_supply);
struct i2c_client *client = bq20z75_device->client;
switch (psp) {
case POWER_SUPPLY_PROP_PRESENT:
case POWER_SUPPLY_PROP_HEALTH:
ret = bq20z75_get_battery_presence_and_health(client, psp, val);
if (ret)
return ret;
break;
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
case POWER_SUPPLY_PROP_ENERGY_NOW:
case POWER_SUPPLY_PROP_ENERGY_FULL:
case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
case POWER_SUPPLY_PROP_CAPACITY:
for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
if (psp == bq20z75_data[count].psp)
break;
}
ret = bq20z75_get_battery_capacity(client, count, psp, val);
if (ret)
return ret;
break;
case POWER_SUPPLY_PROP_SERIAL_NUMBER:
ret = bq20z75_get_battery_serial_number(client, val);
if (ret)
return ret;
break;
case POWER_SUPPLY_PROP_STATUS:
case POWER_SUPPLY_PROP_CYCLE_COUNT:
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
case POWER_SUPPLY_PROP_CURRENT_NOW:
case POWER_SUPPLY_PROP_TEMP:
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
if (psp == bq20z75_data[count].psp)
break;
}
ret = bq20z75_get_battery_property(client, count, psp, val);
if (ret)
return ret;
break;
default:
dev_err(&client->dev,
"%s: INVALID property\n", __func__);
return -EINVAL;
}
/* Convert units to match requirements for power supply class */
bq20z75_unit_adjustment(client, psp, val);
dev_dbg(&client->dev,
"%s: property = %d, value = %d\n", __func__, psp, val->intval);
return 0;
}
static int bq20z75_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct bq20z75_info *bq20z75_device;
int rc;
bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
if (!bq20z75_device)
return -ENOMEM;
bq20z75_device->client = client;
bq20z75_device->power_supply.name = "battery";
bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
bq20z75_device->power_supply.properties = bq20z75_properties;
bq20z75_device->power_supply.num_properties =
ARRAY_SIZE(bq20z75_properties);
bq20z75_device->power_supply.get_property = bq20z75_get_property;
i2c_set_clientdata(client, bq20z75_device);
rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
if (rc) {
dev_err(&client->dev,
"%s: Failed to register power supply\n", __func__);
kfree(bq20z75_device);
return rc;
}
dev_info(&client->dev,
"%s: battery gas gauge device registered\n", client->name);
return 0;
}
static int bq20z75_remove(struct i2c_client *client)
{
struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
power_supply_unregister(&bq20z75_device->power_supply);
kfree(bq20z75_device);
bq20z75_device = NULL;
return 0;
}
#if defined CONFIG_PM
static int bq20z75_suspend(struct i2c_client *client,
pm_message_t state)
{
s32 ret;
/* write to manufacturer access with sleep command */
ret = bq20z75_write_word_data(client,
bq20z75_data[REG_MANUFACTURER_DATA].addr,
MANUFACTURER_ACCESS_SLEEP);
if (ret < 0)
return ret;
return 0;
}
#else
#define bq20z75_suspend NULL
#endif
/* any smbus transaction will wake up bq20z75 */
#define bq20z75_resume NULL
static const struct i2c_device_id bq20z75_id[] = {
{ "bq20z75", 0 },
{}
};
static struct i2c_driver bq20z75_battery_driver = {
.probe = bq20z75_probe,
.remove = bq20z75_remove,
.suspend = bq20z75_suspend,
.resume = bq20z75_resume,
.id_table = bq20z75_id,
.driver = {
.name = "bq20z75-battery",
},
};
static int __init bq20z75_battery_init(void)
{
return i2c_add_driver(&bq20z75_battery_driver);
}
module_init(bq20z75_battery_init);
static void __exit bq20z75_battery_exit(void)
{
i2c_del_driver(&bq20z75_battery_driver);
}
module_exit(bq20z75_battery_exit);
MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
MODULE_LICENSE("GPL");
