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