Initial import

1 files changed, 475 insertions, 0 deletions

diff --git a/drivers/power/ds2782_battery.c b/drivers/power/ds2782_battery.c
new file mode 100644
index 000000000..ed4d756d2
--- /dev/null
+++ b/drivers/power/ds2782_battery.c
@@ -0,0 +1,475 @@
+/*
+ * I2C client/driver for the Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC
+ *
+ * Copyright (C) 2009 Bluewater Systems Ltd
+ *
+ * Author: Ryan Mallon
+ *
+ * DS2786 added by Yulia Vilensky <vilensky@compulab.co.il>
+ *
+ * UEvent sending added by Evgeny Romanov <romanov@neurosoft.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/swab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+#include <linux/ds2782_battery.h>
+
+#define DS2782_REG_RARC		0x06	/* Remaining active relative capacity */
+
+#define DS278x_REG_VOLT_MSB	0x0c
+#define DS278x_REG_TEMP_MSB	0x0a
+#define DS278x_REG_CURRENT_MSB	0x0e
+
+/* EEPROM Block */
+#define DS2782_REG_RSNSP	0x69	/* Sense resistor value */
+
+/* Current unit measurement in uA for a 1 milli-ohm sense resistor */
+#define DS2782_CURRENT_UNITS	1563
+
+#define DS2786_REG_RARC		0x02	/* Remaining active relative capacity */
+
+#define DS2786_CURRENT_UNITS	25
+
+#define DS278x_DELAY		1000
+
+struct ds278x_info;
+
+struct ds278x_battery_ops {
+	int (*get_battery_current)(struct ds278x_info *info, int *current_uA);
+	int (*get_battery_voltage)(struct ds278x_info *info, int *voltage_uV);
+	int (*get_battery_capacity)(struct ds278x_info *info, int *capacity);
+};
+
+#define to_ds278x_info(x) power_supply_get_drvdata(x)
+
+struct ds278x_info {
+	struct i2c_client	*client;
+	struct power_supply	*battery;
+	struct power_supply_desc	battery_desc;
+	struct ds278x_battery_ops  *ops;
+	struct delayed_work	bat_work;
+	int			id;
+	int                     rsns;
+	int			capacity;
+	int			status;		/* State Of Charge */
+};
+
+static DEFINE_IDR(battery_id);
+static DEFINE_MUTEX(battery_lock);
+
+static inline int ds278x_read_reg(struct ds278x_info *info, int reg, u8 *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(info->client, reg);
+	if (ret < 0) {
+		dev_err(&info->client->dev, "register read failed\n");
+		return ret;
+	}
+
+	*val = ret;
+	return 0;
+}
+
+static inline int ds278x_read_reg16(struct ds278x_info *info, int reg_msb,
+				    s16 *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_word_data(info->client, reg_msb);
+	if (ret < 0) {
+		dev_err(&info->client->dev, "register read failed\n");
+		return ret;
+	}
+
+	*val = swab16(ret);
+	return 0;
+}
+
+static int ds278x_get_temp(struct ds278x_info *info, int *temp)
+{
+	s16 raw;
+	int err;
+
+	/*
+	 * Temperature is measured in units of 0.125 degrees celcius, the
+	 * power_supply class measures temperature in tenths of degrees
+	 * celsius. The temperature value is stored as a 10 bit number, plus
+	 * sign in the upper bits of a 16 bit register.
+	 */
+	err = ds278x_read_reg16(info, DS278x_REG_TEMP_MSB, &raw);
+	if (err)
+		return err;
+	*temp = ((raw / 32) * 125) / 100;
+	return 0;
+}
+
+static int ds2782_get_current(struct ds278x_info *info, int *current_uA)
+{
+	int sense_res;
+	int err;
+	u8 sense_res_raw;
+	s16 raw;
+
+	/*
+	 * The units of measurement for current are dependent on the value of
+	 * the sense resistor.
+	 */
+	err = ds278x_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw);
+	if (err)
+		return err;
+	if (sense_res_raw == 0) {
+		dev_err(&info->client->dev, "sense resistor value is 0\n");
+		return -ENXIO;
+	}
+	sense_res = 1000 / sense_res_raw;
+
+	dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n",
+		sense_res);
+	err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw);
+	if (err)
+		return err;
+	*current_uA = raw * (DS2782_CURRENT_UNITS / sense_res);
+	return 0;
+}
+
+static int ds2782_get_voltage(struct ds278x_info *info, int *voltage_uV)
+{
+	s16 raw;
+	int err;
+
+	/*
+	 * Voltage is measured in units of 4.88mV. The voltage is stored as
+	 * a 10-bit number plus sign, in the upper bits of a 16-bit register
+	 */
+	err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw);
+	if (err)
+		return err;
+	*voltage_uV = (raw / 32) * 4800;
+	return 0;
+}
+
+static int ds2782_get_capacity(struct ds278x_info *info, int *capacity)
+{
+	int err;
+	u8 raw;
+
+	err = ds278x_read_reg(info, DS2782_REG_RARC, &raw);
+	if (err)
+		return err;
+	*capacity = raw;
+	return 0;
+}
+
+static int ds2786_get_current(struct ds278x_info *info, int *current_uA)
+{
+	int err;
+	s16 raw;
+
+	err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw);
+	if (err)
+		return err;
+	*current_uA = (raw / 16) * (DS2786_CURRENT_UNITS / info->rsns);
+	return 0;
+}
+
+static int ds2786_get_voltage(struct ds278x_info *info, int *voltage_uV)
+{
+	s16 raw;
+	int err;
+
+	/*
+	 * Voltage is measured in units of 1.22mV. The voltage is stored as
+	 * a 12-bit number plus sign, in the upper bits of a 16-bit register
+	 */
+	err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw);
+	if (err)
+		return err;
+	*voltage_uV = (raw / 8) * 1220;
+	return 0;
+}
+
+static int ds2786_get_capacity(struct ds278x_info *info, int *capacity)
+{
+	int err;
+	u8 raw;
+
+	err = ds278x_read_reg(info, DS2786_REG_RARC, &raw);
+	if (err)
+		return err;
+	/* Relative capacity is displayed with resolution 0.5 % */
+	*capacity = raw/2 ;
+	return 0;
+}
+
+static int ds278x_get_status(struct ds278x_info *info, int *status)
+{
+	int err;
+	int current_uA;
+	int capacity;
+
+	err = info->ops->get_battery_current(info, &current_uA);
+	if (err)
+		return err;
+
+	err = info->ops->get_battery_capacity(info, &capacity);
+	if (err)
+		return err;
+
+	info->capacity = capacity;
+
+	if (capacity == 100)
+		*status = POWER_SUPPLY_STATUS_FULL;
+	else if (current_uA == 0)
+		*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+	else if (current_uA < 0)
+		*status = POWER_SUPPLY_STATUS_DISCHARGING;
+	else
+		*status = POWER_SUPPLY_STATUS_CHARGING;
+
+	return 0;
+}
+
+static int ds278x_battery_get_property(struct power_supply *psy,
+				       enum power_supply_property prop,
+				       union power_supply_propval *val)
+{
+	struct ds278x_info *info = to_ds278x_info(psy);
+	int ret;
+
+	switch (prop) {
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = ds278x_get_status(info, &val->intval);
+		break;
+
+	case POWER_SUPPLY_PROP_CAPACITY:
+		ret = info->ops->get_battery_capacity(info, &val->intval);
+		break;
+
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = info->ops->get_battery_voltage(info, &val->intval);
+		break;
+
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = info->ops->get_battery_current(info, &val->intval);
+		break;
+
+	case POWER_SUPPLY_PROP_TEMP:
+		ret = ds278x_get_temp(info, &val->intval);
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static void ds278x_bat_update(struct ds278x_info *info)
+{
+	int old_status = info->status;
+	int old_capacity = info->capacity;
+
+	ds278x_get_status(info, &info->status);
+
+	if ((old_status != info->status) || (old_capacity != info->capacity))
+		power_supply_changed(info->battery);
+}
+
+static void ds278x_bat_work(struct work_struct *work)
+{
+	struct ds278x_info *info;
+
+	info = container_of(work, struct ds278x_info, bat_work.work);
+	ds278x_bat_update(info);
+
+	schedule_delayed_work(&info->bat_work, DS278x_DELAY);
+}
+
+static enum power_supply_property ds278x_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_TEMP,
+};
+
+static void ds278x_power_supply_init(struct power_supply_desc *battery)
+{
+	battery->type			= POWER_SUPPLY_TYPE_BATTERY;
+	battery->properties		= ds278x_battery_props;
+	battery->num_properties		= ARRAY_SIZE(ds278x_battery_props);
+	battery->get_property		= ds278x_battery_get_property;
+	battery->external_power_changed	= NULL;
+}
+
+static int ds278x_battery_remove(struct i2c_client *client)
+{
+	struct ds278x_info *info = i2c_get_clientdata(client);
+
+	power_supply_unregister(info->battery);
+	kfree(info->battery_desc.name);
+
+	mutex_lock(&battery_lock);
+	idr_remove(&battery_id, info->id);
+	mutex_unlock(&battery_lock);
+
+	cancel_delayed_work(&info->bat_work);
+
+	kfree(info);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ds278x_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ds278x_info *info = i2c_get_clientdata(client);
+
+	cancel_delayed_work(&info->bat_work);
+	return 0;
+}
+
+static int ds278x_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ds278x_info *info = i2c_get_clientdata(client);
+
+	schedule_delayed_work(&info->bat_work, DS278x_DELAY);
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(ds278x_battery_pm_ops, ds278x_suspend, ds278x_resume);
+
+enum ds278x_num_id {
+	DS2782 = 0,
+	DS2786,
+};
+
+static struct ds278x_battery_ops ds278x_ops[] = {
+	[DS2782] = {
+		.get_battery_current  = ds2782_get_current,
+		.get_battery_voltage  = ds2782_get_voltage,
+		.get_battery_capacity = ds2782_get_capacity,
+	},
+	[DS2786] = {
+		.get_battery_current  = ds2786_get_current,
+		.get_battery_voltage  = ds2786_get_voltage,
+		.get_battery_capacity = ds2786_get_capacity,
+	}
+};
+
+static int ds278x_battery_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct ds278x_platform_data *pdata = client->dev.platform_data;
+	struct power_supply_config psy_cfg = {};
+	struct ds278x_info *info;
+	int ret;
+	int num;
+
+	/*
+	 * ds2786 should have the sense resistor value set
+	 * in the platform data
+	 */
+	if (id->driver_data == DS2786 && !pdata) {
+		dev_err(&client->dev, "missing platform data for ds2786\n");
+		return -EINVAL;
+	}
+
+	/* Get an ID for this battery */
+	mutex_lock(&battery_lock);
+	ret = idr_alloc(&battery_id, client, 0, 0, GFP_KERNEL);
+	mutex_unlock(&battery_lock);
+	if (ret < 0)
+		goto fail_id;
+	num = ret;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		ret = -ENOMEM;
+		goto fail_info;
+	}
+
+	info->battery_desc.name = kasprintf(GFP_KERNEL, "%s-%d",
+					    client->name, num);
+	if (!info->battery_desc.name) {
+		ret = -ENOMEM;
+		goto fail_name;
+	}
+
+	if (id->driver_data == DS2786)
+		info->rsns = pdata->rsns;
+
+	i2c_set_clientdata(client, info);
+	info->client = client;
+	info->id = num;
+	info->ops  = &ds278x_ops[id->driver_data];
+	ds278x_power_supply_init(&info->battery_desc);
+	psy_cfg.drv_data = info;
+
+	info->capacity = 100;
+	info->status = POWER_SUPPLY_STATUS_FULL;
+
+	INIT_DELAYED_WORK(&info->bat_work, ds278x_bat_work);
+
+	info->battery = power_supply_register(&client->dev,
+					      &info->battery_desc, &psy_cfg);
+	if (IS_ERR(info->battery)) {
+		dev_err(&client->dev, "failed to register battery\n");
+		ret = PTR_ERR(info->battery);
+		goto fail_register;
+	} else {
+		schedule_delayed_work(&info->bat_work, DS278x_DELAY);
+	}
+
+	return 0;
+
+fail_register:
+	kfree(info->battery_desc.name);
+fail_name:
+	kfree(info);
+fail_info:
+	mutex_lock(&battery_lock);
+	idr_remove(&battery_id, num);
+	mutex_unlock(&battery_lock);
+fail_id:
+	return ret;
+}
+
+static const struct i2c_device_id ds278x_id[] = {
+	{"ds2782", DS2782},
+	{"ds2786", DS2786},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, ds278x_id);
+
+static struct i2c_driver ds278x_battery_driver = {
+	.driver 	= {
+		.name	= "ds2782-battery",
+		.pm	= &ds278x_battery_pm_ops,
+	},
+	.probe		= ds278x_battery_probe,
+	.remove		= ds278x_battery_remove,
+	.id_table	= ds278x_id,
+};
+module_i2c_driver(ds278x_battery_driver);
+
+MODULE_AUTHOR("Ryan Mallon");
+MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver");
+MODULE_LICENSE("GPL");