/*
* Dumb driver for LiIon batteries using TWL4030 madc.
*
* Copyright 2013 Golden Delicious Computers
* Lukas Märdian <lukas@goldelico.com>
*
* Based on dumb driver for gta01 battery
* Copyright 2009 Openmoko, Inc
* Balaji Rao <balajirrao@openmoko.org>
*/
#include <linux/module.h>
#include <linux/param.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/i2c/twl4030-madc.h>
#include <linux/power/twl4030_madc_battery.h>
struct twl4030_madc_battery {
struct power_supply psy;
struct twl4030_madc_bat_platform_data *pdata;
};
static enum power_supply_property twl4030_madc_bat_props[] = {
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_NOW,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
};
static int madc_read(int index)
{
struct twl4030_madc_request req;
int val;
req.channels = index;
req.method = TWL4030_MADC_SW2;
req.type = TWL4030_MADC_WAIT;
req.do_avg = 0;
req.raw = false;
req.func_cb = NULL;
val = twl4030_madc_conversion(&req);
if (val < 0)
return val;
return req.rbuf[ffs(index) - 1];
}
static int twl4030_madc_bat_get_charging_status(void)
{
return (madc_read(TWL4030_MADC_ICHG) > 0) ? 1 : 0;
}
static int twl4030_madc_bat_get_voltage(void)
{
return madc_read(TWL4030_MADC_VBAT);
}
static int twl4030_madc_bat_get_current(void)
{
return madc_read(TWL4030_MADC_ICHG) * 1000;
}
static int twl4030_madc_bat_get_temp(void)
{
return madc_read(TWL4030_MADC_BTEMP) * 10;
}
static int twl4030_madc_bat_voltscale(struct twl4030_madc_battery *bat,
int volt)
{
struct twl4030_madc_bat_calibration *calibration;
int i, res = 0;
/* choose charging curve */
if (twl4030_madc_bat_get_charging_status())
calibration = bat->pdata->charging;
else
calibration = bat->pdata->discharging;
if (volt > calibration[0].voltage) {
res = calibration[0].level;
} else {
for (i = 0; calibration[i+1].voltage >= 0; i++) {
if (volt <= calibration[i].voltage &&
volt >= calibration[i+1].voltage) {
/* interval found - interpolate within range */
res = calibration[i].level -
((calibration[i].voltage - volt) *
(calibration[i].level -
calibration[i+1].level)) /
(calibration[i].voltage -
calibration[i+1].voltage);
break;
}
}
}
return res;
}
static int twl4030_madc_bat_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct twl4030_madc_battery *bat = container_of(psy,
struct twl4030_madc_battery, psy);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
if (twl4030_madc_bat_voltscale(bat,
twl4030_madc_bat_get_voltage()) > 95)
val->intval = POWER_SUPPLY_STATUS_FULL;
else {
if (twl4030_madc_bat_get_charging_status())
val->intval = POWER_SUPPLY_STATUS_CHARGING;
else
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
}
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = twl4030_madc_bat_get_voltage() * 1000;
break;
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
val->intval = twl4030_madc_bat_get_current();
break;
case POWER_SUPPLY_PROP_PRESENT:
/* assume battery is always present */
val->intval = 1;
break;
case POWER_SUPPLY_PROP_CHARGE_NOW: {
int percent = twl4030_madc_bat_voltscale(bat,
twl4030_madc_bat_get_voltage());
val->intval = (percent * bat->pdata->capacity) / 100;
break;
}
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = twl4030_madc_bat_voltscale(bat,
twl4030_madc_bat_get_voltage());
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
val->intval = bat->pdata->capacity;
break;
case POWER_SUPPLY_PROP_TEMP:
val->intval = twl4030_madc_bat_get_temp();
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: {
int percent = twl4030_madc_bat_voltscale(bat,
twl4030_madc_bat_get_voltage());
/* in mAh */
int chg = (percent * (bat->pdata->capacity/1000))/100;
/* assume discharge with 400 mA (ca. 1.5W) */
val->intval = (3600l * chg) / 400;
break;
}
default:
return -EINVAL;
}
return 0;
}
static void twl4030_madc_bat_ext_changed(struct power_supply *psy)
{
struct twl4030_madc_battery *bat = container_of(psy,
struct twl4030_madc_battery, psy);
power_supply_changed(&bat->psy);
}
static int twl4030_cmp(const void *a, const void *b)
{
return ((struct twl4030_madc_bat_calibration *)b)->voltage -
((struct twl4030_madc_bat_calibration *)a)->voltage;
}
static int twl4030_madc_battery_probe(struct platform_device *pdev)
{
struct twl4030_madc_battery *twl4030_madc_bat;
struct twl4030_madc_bat_platform_data *pdata = pdev->dev.platform_data;
twl4030_madc_bat = kzalloc(sizeof(*twl4030_madc_bat), GFP_KERNEL);
if (!twl4030_madc_bat)
return -ENOMEM;
twl4030_madc_bat->psy.name = "twl4030_battery";
twl4030_madc_bat->psy.type = POWER_SUPPLY_TYPE_BATTERY;
twl4030_madc_bat->psy.properties = twl4030_madc_bat_props;
twl4030_madc_bat->psy.num_properties =
ARRAY_SIZE(twl4030_madc_bat_props);
twl4030_madc_bat->psy.get_property = twl4030_madc_bat_get_property;
twl4030_madc_bat->psy.external_power_changed =
twl4030_madc_bat_ext_changed;
/* sort charging and discharging calibration data */
sort(pdata->charging, pdata->charging_size,
sizeof(struct twl4030_madc_bat_calibration),
twl4030_cmp, NULL);
sort(pdata->discharging, pdata->discharging_size,
sizeof(struct twl4030_madc_bat_calibration),
twl4030_cmp, NULL);
twl4030_madc_bat->pdata = pdata;
platform_set_drvdata(pdev, twl4030_madc_bat);
power_supply_register(&pdev->dev, &twl4030_madc_bat->psy);
return 0;
}
static int twl4030_madc_battery_remove(struct platform_device *pdev)
{
struct twl4030_madc_battery *bat = platform_get_drvdata(pdev);
power_supply_unregister(&bat->psy);
kfree(bat);
return 0;
}
static struct platform_driver twl4030_madc_battery_driver = {
.driver = {
.name = "twl4030_madc_battery",
},
.probe = twl4030_madc_battery_probe,
.remove = twl4030_madc_battery_remove,
};
module_platform_driver(twl4030_madc_battery_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>");
MODULE_DESCRIPTION("twl4030_madc battery driver");
