diff options
Diffstat (limited to 'drivers/power/bq20z75.c')
| -rw-r--r-- | drivers/power/bq20z75.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c new file mode 100644 index 000000000000..492da27e1a47 --- /dev/null +++ b/drivers/power/bq20z75.c @@ -0,0 +1,493 @@ +/* + * 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"); |