Initial import

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");