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path: root/drivers/power/twl4030_madc_battery.c
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Diffstat (limited to 'drivers/power/twl4030_madc_battery.c')
-rw-r--r--drivers/power/twl4030_madc_battery.c278
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");