diff options
Diffstat (limited to 'drivers/power/twl4030_madc_battery.c')
| -rw-r--r-- | drivers/power/twl4030_madc_battery.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/power/twl4030_madc_battery.c b/drivers/power/twl4030_madc_battery.c new file mode 100644 index 000000000000..7ef445a6cfa6 --- /dev/null +++ b/drivers/power/twl4030_madc_battery.c @@ -0,0 +1,245 @@ +/* + * 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"); |