power: Add twl4030_madc battery driver.

This driver is used and tested on gta04 phone. It's using twl4030_madc
(similar to rx51 existing driver). Driver also implement charging and
discharging calibration data so user can define ranges and level.

Signed-off-by: Marek Belisko <marek@goldelico.com>
Signed-off-by: Lukas Märdian <lukas@goldelico.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

4 files changed, 292 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index e8970a65ba52..bb49ab684f9a 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -216,6 +216,13 @@ config BATTERY_S3C_ADC
         help
           Say Y here to enable support for iPAQ h1930/h1940/rx1950 battery
 
+config BATTERY_TWL4030_MADC
+        tristate "TWL4030 MADC battery driver"
+        depends on TWL4030_MADC
+        help
+          Say Y here to enable this dumb driver for batteries managed
+          through the TWL4030 MADC.
+
 config CHARGER_88PM860X
         tristate "Marvell 88PM860x Charger driver"
         depends on MFD_88PM860X && BATTERY_88PM860X
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 4ae45339e32c..a4b74177706f 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_MAX17042)  += max17042_battery.o
 obj-$(CONFIG_BATTERY_Z2)        += z2_battery.o
 obj-$(CONFIG_BATTERY_S3C_ADC)   += s3c_adc_battery.o
+obj-$(CONFIG_BATTERY_TWL4030_MADC)      += twl4030_madc_battery.o
 obj-$(CONFIG_CHARGER_88PM860X)  += 88pm860x_charger.o
 obj-$(CONFIG_CHARGER_PCF50633)  += pcf50633-charger.o
 obj-$(CONFIG_BATTERY_JZ4740)    += jz4740-battery.o
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");
diff --git a/include/linux/power/twl4030_madc_battery.h b/include/linux/power/twl4030_madc_battery.h
new file mode 100644
index 000000000000..23110dc77726
--- /dev/null
+++ b/include/linux/power/twl4030_madc_battery.h
@@ -0,0 +1,39 @@
+/*
+ * Dumb driver for LiIon batteries using TWL4030 madc.
+ *
+ * Copyright 2013 Golden Delicious Computers
+ * Nikolaus Schaller <hns@goldelico.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __TWL4030_MADC_BATTERY_H
+#define __TWL4030_MADC_BATTERY_H
+
+/*
+ * Usually we can assume 100% @ 4.15V and 0% @ 3.3V but curves differ for
+ * charging and discharging!
+ */
+
+struct twl4030_madc_bat_calibration {
+        short voltage;  /* in mV - specify -1 for end of list */
+        short level;    /* in percent (0 .. 100%) */
+};
+
+struct twl4030_madc_bat_platform_data {
+        unsigned int capacity;  /* total capacity in uAh */
+        struct twl4030_madc_bat_calibration *charging;
+        int charging_size;
+        struct twl4030_madc_bat_calibration *discharging;
+        int discharging_size;
+};
+
+#endif