diff options
Diffstat (limited to 'drivers/power/twl4030_madc_battery.c')
| -rw-r--r-- | drivers/power/twl4030_madc_battery.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/power/twl4030_madc_battery.c b/drivers/power/twl4030_madc_battery.c new file mode 100644 index 000000000..f5817e422 --- /dev/null +++ b/drivers/power/twl4030_madc_battery.c @@ -0,0 +1,278 @@ +/* + * 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> +#include <linux/iio/consumer.h> + +struct twl4030_madc_battery { + struct power_supply *psy; + struct twl4030_madc_bat_platform_data *pdata; + struct iio_channel *channel_temp; + struct iio_channel *channel_ichg; + struct iio_channel *channel_vbat; +}; + +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(struct iio_channel *channel) +{ + int val, err; + err = iio_read_channel_processed(channel, &val); + if (err < 0) + return err; + + return val; +} + +static int twl4030_madc_bat_get_charging_status(struct twl4030_madc_battery *bt) +{ + return (madc_read(bt->channel_ichg) > 0) ? 1 : 0; +} + +static int twl4030_madc_bat_get_voltage(struct twl4030_madc_battery *bt) +{ + return madc_read(bt->channel_vbat); +} + +static int twl4030_madc_bat_get_current(struct twl4030_madc_battery *bt) +{ + return madc_read(bt->channel_ichg) * 1000; +} + +static int twl4030_madc_bat_get_temp(struct twl4030_madc_battery *bt) +{ + return madc_read(bt->channel_temp) * 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(bat)) + 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 = power_supply_get_drvdata(psy); + + switch (psp) { + case POWER_SUPPLY_PROP_STATUS: + if (twl4030_madc_bat_voltscale(bat, + twl4030_madc_bat_get_voltage(bat)) > 95) + val->intval = POWER_SUPPLY_STATUS_FULL; + else { + if (twl4030_madc_bat_get_charging_status(bat)) + 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(bat) * 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(bat); + 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(bat)); + 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(bat)); + 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(bat); + break; + case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: { + int percent = twl4030_madc_bat_voltscale(bat, + twl4030_madc_bat_get_voltage(bat)); + /* 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) +{ + power_supply_changed(psy); +} + +static const struct power_supply_desc twl4030_madc_bat_desc = { + .name = "twl4030_battery", + .type = POWER_SUPPLY_TYPE_BATTERY, + .properties = twl4030_madc_bat_props, + .num_properties = ARRAY_SIZE(twl4030_madc_bat_props), + .get_property = twl4030_madc_bat_get_property, + .external_power_changed = twl4030_madc_bat_ext_changed, + +}; + +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; + struct power_supply_config psy_cfg = {}; + int ret = 0; + + twl4030_madc_bat = devm_kzalloc(&pdev->dev, sizeof(*twl4030_madc_bat), + GFP_KERNEL); + if (!twl4030_madc_bat) + return -ENOMEM; + + twl4030_madc_bat->channel_temp = iio_channel_get(&pdev->dev, "temp"); + if (IS_ERR(twl4030_madc_bat->channel_temp)) { + ret = PTR_ERR(twl4030_madc_bat->channel_temp); + goto err; + } + + twl4030_madc_bat->channel_ichg = iio_channel_get(&pdev->dev, "ichg"); + if (IS_ERR(twl4030_madc_bat->channel_ichg)) { + ret = PTR_ERR(twl4030_madc_bat->channel_ichg); + goto err_temp; + } + + twl4030_madc_bat->channel_vbat = iio_channel_get(&pdev->dev, "vbat"); + if (IS_ERR(twl4030_madc_bat->channel_vbat)) { + ret = PTR_ERR(twl4030_madc_bat->channel_vbat); + goto err_ichg; + } + + /* 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); + psy_cfg.drv_data = twl4030_madc_bat; + twl4030_madc_bat->psy = power_supply_register(&pdev->dev, + &twl4030_madc_bat_desc, + &psy_cfg); + if (IS_ERR(twl4030_madc_bat->psy)) { + ret = PTR_ERR(twl4030_madc_bat->psy); + goto err_vbat; + } + + return 0; + +err_vbat: + iio_channel_release(twl4030_madc_bat->channel_vbat); +err_ichg: + iio_channel_release(twl4030_madc_bat->channel_ichg); +err_temp: + iio_channel_release(twl4030_madc_bat->channel_temp); +err: + return ret; +} + +static int twl4030_madc_battery_remove(struct platform_device *pdev) +{ + struct twl4030_madc_battery *bat = platform_get_drvdata(pdev); + + power_supply_unregister(bat->psy); + + iio_channel_release(bat->channel_vbat); + iio_channel_release(bat->channel_ichg); + iio_channel_release(bat->channel_temp); + + 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"); +MODULE_ALIAS("platform:twl4030_madc_battery"); |