471 lines
10 KiB
C
471 lines
10 KiB
C
/*
|
|
* BQ27x00 battery driver
|
|
*
|
|
* Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
|
|
* Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
|
|
*
|
|
* Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
|
|
*
|
|
* This package is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/param.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/power_supply.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/i2c.h>
|
|
#include <asm/unaligned.h>
|
|
|
|
#define DRIVER_VERSION "1.1.0"
|
|
|
|
#define BQ27x00_REG_TEMP 0x06
|
|
#define BQ27x00_REG_VOLT 0x08
|
|
#define BQ27x00_REG_AI 0x14
|
|
#define BQ27x00_REG_FLAGS 0x0A
|
|
#define BQ27x00_REG_TTE 0x16
|
|
#define BQ27x00_REG_TTF 0x18
|
|
#define BQ27x00_REG_TTECP 0x26
|
|
|
|
#define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
|
|
#define BQ27000_FLAG_CHGS BIT(7)
|
|
|
|
#define BQ27500_REG_SOC 0x2c
|
|
#define BQ27500_FLAG_DSC BIT(0)
|
|
#define BQ27500_FLAG_FC BIT(9)
|
|
|
|
/* If the system has several batteries we need a different name for each
|
|
* of them...
|
|
*/
|
|
static DEFINE_IDR(battery_id);
|
|
static DEFINE_MUTEX(battery_mutex);
|
|
|
|
struct bq27x00_device_info;
|
|
struct bq27x00_access_methods {
|
|
int (*read)(u8 reg, int *rt_value, int b_single,
|
|
struct bq27x00_device_info *di);
|
|
};
|
|
|
|
enum bq27x00_chip { BQ27000, BQ27500 };
|
|
|
|
struct bq27x00_device_info {
|
|
struct device *dev;
|
|
int id;
|
|
struct bq27x00_access_methods *bus;
|
|
struct power_supply bat;
|
|
enum bq27x00_chip chip;
|
|
|
|
struct i2c_client *client;
|
|
};
|
|
|
|
static enum power_supply_property bq27x00_battery_props[] = {
|
|
POWER_SUPPLY_PROP_STATUS,
|
|
POWER_SUPPLY_PROP_PRESENT,
|
|
POWER_SUPPLY_PROP_VOLTAGE_NOW,
|
|
POWER_SUPPLY_PROP_CURRENT_NOW,
|
|
POWER_SUPPLY_PROP_CAPACITY,
|
|
POWER_SUPPLY_PROP_TEMP,
|
|
POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
|
|
POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
|
|
POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
|
|
};
|
|
|
|
/*
|
|
* Common code for BQ27x00 devices
|
|
*/
|
|
|
|
static int bq27x00_read(u8 reg, int *rt_value, int b_single,
|
|
struct bq27x00_device_info *di)
|
|
{
|
|
return di->bus->read(reg, rt_value, b_single, di);
|
|
}
|
|
|
|
/*
|
|
* Return the battery temperature in tenths of degree Celsius
|
|
* Or < 0 if something fails.
|
|
*/
|
|
static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
|
|
{
|
|
int ret;
|
|
int temp = 0;
|
|
|
|
ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di);
|
|
if (ret) {
|
|
dev_err(di->dev, "error reading temperature\n");
|
|
return ret;
|
|
}
|
|
|
|
if (di->chip == BQ27500)
|
|
return temp - 2731;
|
|
else
|
|
return ((temp >> 2) - 273) * 10;
|
|
}
|
|
|
|
/*
|
|
* Return the battery Voltage in milivolts
|
|
* Or < 0 if something fails.
|
|
*/
|
|
static int bq27x00_battery_voltage(struct bq27x00_device_info *di)
|
|
{
|
|
int ret;
|
|
int volt = 0;
|
|
|
|
ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di);
|
|
if (ret) {
|
|
dev_err(di->dev, "error reading voltage\n");
|
|
return ret;
|
|
}
|
|
|
|
return volt * 1000;
|
|
}
|
|
|
|
/*
|
|
* Return the battery average current
|
|
* Note that current can be negative signed as well
|
|
* Or 0 if something fails.
|
|
*/
|
|
static int bq27x00_battery_current(struct bq27x00_device_info *di)
|
|
{
|
|
int ret;
|
|
int curr = 0;
|
|
int flags = 0;
|
|
|
|
ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di);
|
|
if (ret) {
|
|
dev_err(di->dev, "error reading current\n");
|
|
return 0;
|
|
}
|
|
|
|
if (di->chip == BQ27500) {
|
|
/* bq27500 returns signed value */
|
|
curr = (int)(s16)curr;
|
|
} else {
|
|
ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
|
|
if (ret < 0) {
|
|
dev_err(di->dev, "error reading flags\n");
|
|
return 0;
|
|
}
|
|
if (flags & BQ27000_FLAG_CHGS) {
|
|
dev_dbg(di->dev, "negative current!\n");
|
|
curr = -curr;
|
|
}
|
|
}
|
|
|
|
return curr * 1000;
|
|
}
|
|
|
|
/*
|
|
* Return the battery Relative State-of-Charge
|
|
* Or < 0 if something fails.
|
|
*/
|
|
static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
|
|
{
|
|
int ret;
|
|
int rsoc = 0;
|
|
|
|
if (di->chip == BQ27500)
|
|
ret = bq27x00_read(BQ27500_REG_SOC, &rsoc, 0, di);
|
|
else
|
|
ret = bq27x00_read(BQ27000_REG_RSOC, &rsoc, 1, di);
|
|
if (ret) {
|
|
dev_err(di->dev, "error reading relative State-of-Charge\n");
|
|
return ret;
|
|
}
|
|
|
|
return rsoc;
|
|
}
|
|
|
|
static int bq27x00_battery_status(struct bq27x00_device_info *di,
|
|
union power_supply_propval *val)
|
|
{
|
|
int flags = 0;
|
|
int status;
|
|
int ret;
|
|
|
|
ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
|
|
if (ret < 0) {
|
|
dev_err(di->dev, "error reading flags\n");
|
|
return ret;
|
|
}
|
|
|
|
if (di->chip == BQ27500) {
|
|
if (flags & BQ27500_FLAG_FC)
|
|
status = POWER_SUPPLY_STATUS_FULL;
|
|
else if (flags & BQ27500_FLAG_DSC)
|
|
status = POWER_SUPPLY_STATUS_DISCHARGING;
|
|
else
|
|
status = POWER_SUPPLY_STATUS_CHARGING;
|
|
} else {
|
|
if (flags & BQ27000_FLAG_CHGS)
|
|
status = POWER_SUPPLY_STATUS_CHARGING;
|
|
else
|
|
status = POWER_SUPPLY_STATUS_DISCHARGING;
|
|
}
|
|
|
|
val->intval = status;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Read a time register.
|
|
* Return < 0 if something fails.
|
|
*/
|
|
static int bq27x00_battery_time(struct bq27x00_device_info *di, int reg,
|
|
union power_supply_propval *val)
|
|
{
|
|
int tval = 0;
|
|
int ret;
|
|
|
|
ret = bq27x00_read(reg, &tval, 0, di);
|
|
if (ret) {
|
|
dev_err(di->dev, "error reading register %02x\n", reg);
|
|
return ret;
|
|
}
|
|
|
|
if (tval == 65535)
|
|
return -ENODATA;
|
|
|
|
val->intval = tval * 60;
|
|
return 0;
|
|
}
|
|
|
|
#define to_bq27x00_device_info(x) container_of((x), \
|
|
struct bq27x00_device_info, bat);
|
|
|
|
static int bq27x00_battery_get_property(struct power_supply *psy,
|
|
enum power_supply_property psp,
|
|
union power_supply_propval *val)
|
|
{
|
|
int ret = 0;
|
|
struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
|
|
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_STATUS:
|
|
ret = bq27x00_battery_status(di, val);
|
|
break;
|
|
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
|
|
case POWER_SUPPLY_PROP_PRESENT:
|
|
val->intval = bq27x00_battery_voltage(di);
|
|
if (psp == POWER_SUPPLY_PROP_PRESENT)
|
|
val->intval = val->intval <= 0 ? 0 : 1;
|
|
break;
|
|
case POWER_SUPPLY_PROP_CURRENT_NOW:
|
|
val->intval = bq27x00_battery_current(di);
|
|
break;
|
|
case POWER_SUPPLY_PROP_CAPACITY:
|
|
val->intval = bq27x00_battery_rsoc(di);
|
|
break;
|
|
case POWER_SUPPLY_PROP_TEMP:
|
|
val->intval = bq27x00_battery_temperature(di);
|
|
break;
|
|
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
|
|
ret = bq27x00_battery_time(di, BQ27x00_REG_TTE, val);
|
|
break;
|
|
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
|
|
ret = bq27x00_battery_time(di, BQ27x00_REG_TTECP, val);
|
|
break;
|
|
case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
|
|
ret = bq27x00_battery_time(di, BQ27x00_REG_TTF, val);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
|
|
{
|
|
di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
|
|
di->bat.properties = bq27x00_battery_props;
|
|
di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
|
|
di->bat.get_property = bq27x00_battery_get_property;
|
|
di->bat.external_power_changed = NULL;
|
|
}
|
|
|
|
/*
|
|
* i2c specific code
|
|
*/
|
|
|
|
static int bq27x00_read_i2c(u8 reg, int *rt_value, int b_single,
|
|
struct bq27x00_device_info *di)
|
|
{
|
|
struct i2c_client *client = di->client;
|
|
struct i2c_msg msg[1];
|
|
unsigned char data[2];
|
|
int err;
|
|
|
|
if (!client->adapter)
|
|
return -ENODEV;
|
|
|
|
msg->addr = client->addr;
|
|
msg->flags = 0;
|
|
msg->len = 1;
|
|
msg->buf = data;
|
|
|
|
data[0] = reg;
|
|
err = i2c_transfer(client->adapter, msg, 1);
|
|
|
|
if (err >= 0) {
|
|
if (!b_single)
|
|
msg->len = 2;
|
|
else
|
|
msg->len = 1;
|
|
|
|
msg->flags = I2C_M_RD;
|
|
err = i2c_transfer(client->adapter, msg, 1);
|
|
if (err >= 0) {
|
|
if (!b_single)
|
|
*rt_value = get_unaligned_le16(data);
|
|
else
|
|
*rt_value = data[0];
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int bq27x00_battery_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
char *name;
|
|
struct bq27x00_device_info *di;
|
|
struct bq27x00_access_methods *bus;
|
|
int num;
|
|
int retval = 0;
|
|
|
|
/* Get new ID for the new battery device */
|
|
retval = idr_pre_get(&battery_id, GFP_KERNEL);
|
|
if (retval == 0)
|
|
return -ENOMEM;
|
|
mutex_lock(&battery_mutex);
|
|
retval = idr_get_new(&battery_id, client, &num);
|
|
mutex_unlock(&battery_mutex);
|
|
if (retval < 0)
|
|
return retval;
|
|
|
|
name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
|
|
if (!name) {
|
|
dev_err(&client->dev, "failed to allocate device name\n");
|
|
retval = -ENOMEM;
|
|
goto batt_failed_1;
|
|
}
|
|
|
|
di = kzalloc(sizeof(*di), GFP_KERNEL);
|
|
if (!di) {
|
|
dev_err(&client->dev, "failed to allocate device info data\n");
|
|
retval = -ENOMEM;
|
|
goto batt_failed_2;
|
|
}
|
|
di->id = num;
|
|
di->chip = id->driver_data;
|
|
|
|
bus = kzalloc(sizeof(*bus), GFP_KERNEL);
|
|
if (!bus) {
|
|
dev_err(&client->dev, "failed to allocate access method "
|
|
"data\n");
|
|
retval = -ENOMEM;
|
|
goto batt_failed_3;
|
|
}
|
|
|
|
i2c_set_clientdata(client, di);
|
|
di->dev = &client->dev;
|
|
di->bat.name = name;
|
|
bus->read = &bq27x00_read_i2c;
|
|
di->bus = bus;
|
|
di->client = client;
|
|
|
|
bq27x00_powersupply_init(di);
|
|
|
|
retval = power_supply_register(&client->dev, &di->bat);
|
|
if (retval) {
|
|
dev_err(&client->dev, "failed to register battery\n");
|
|
goto batt_failed_4;
|
|
}
|
|
|
|
dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
|
|
|
|
return 0;
|
|
|
|
batt_failed_4:
|
|
kfree(bus);
|
|
batt_failed_3:
|
|
kfree(di);
|
|
batt_failed_2:
|
|
kfree(name);
|
|
batt_failed_1:
|
|
mutex_lock(&battery_mutex);
|
|
idr_remove(&battery_id, num);
|
|
mutex_unlock(&battery_mutex);
|
|
|
|
return retval;
|
|
}
|
|
|
|
static int bq27x00_battery_remove(struct i2c_client *client)
|
|
{
|
|
struct bq27x00_device_info *di = i2c_get_clientdata(client);
|
|
|
|
power_supply_unregister(&di->bat);
|
|
|
|
kfree(di->bat.name);
|
|
|
|
mutex_lock(&battery_mutex);
|
|
idr_remove(&battery_id, di->id);
|
|
mutex_unlock(&battery_mutex);
|
|
|
|
kfree(di);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Module stuff
|
|
*/
|
|
|
|
static const struct i2c_device_id bq27x00_id[] = {
|
|
{ "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
|
|
{ "bq27500", BQ27500 },
|
|
{},
|
|
};
|
|
|
|
static struct i2c_driver bq27x00_battery_driver = {
|
|
.driver = {
|
|
.name = "bq27x00-battery",
|
|
},
|
|
.probe = bq27x00_battery_probe,
|
|
.remove = bq27x00_battery_remove,
|
|
.id_table = bq27x00_id,
|
|
};
|
|
|
|
static int __init bq27x00_battery_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = i2c_add_driver(&bq27x00_battery_driver);
|
|
if (ret)
|
|
printk(KERN_ERR "Unable to register BQ27x00 driver\n");
|
|
|
|
return ret;
|
|
}
|
|
module_init(bq27x00_battery_init);
|
|
|
|
static void __exit bq27x00_battery_exit(void)
|
|
{
|
|
i2c_del_driver(&bq27x00_battery_driver);
|
|
}
|
|
module_exit(bq27x00_battery_exit);
|
|
|
|
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
|
|
MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
|
|
MODULE_LICENSE("GPL");
|