1 files changed, 382 insertions, 0 deletions

diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c
new file mode 100644
index 0000000..62d4948
--- /dev/null
+++ b/drivers/power/bq27x00_battery.c
@@ -0,0 +1,382 @@
+/*
+ * BQ27x00 battery driver
+ *
+ * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
+ *
+ * This package 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.
+ *
+ * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/idr.h>
+
+#include <linux/i2c.h>
+
+#define DRIVER_VERSION			"1.0.0"
+
+#define BQ27x00_REG_TEMP		0x06
+#define BQ27x00_REG_VOLT		0x08
+#define BQ27x00_REG_RSOC		0x0B /* Relative State-of-Charge */
+#define BQ27x00_REG_AI			0x14
+#define BQ27x00_REG_FLAGS		0x0A
+#define HIGH_BYTE(A)			((A) << 8)
+
+/* If the system has several batteries we need a different name for each
+ * of them...
+ */
+static DEFINE_IDR(battery_id);
+static DEFINE_MUTEX(battery_mutex);
+
+struct bq27x00_device_info;
+struct bq27x00_access_methods {
+	int (*read)(u8 reg, int *rt_value, int b_single,
+		struct bq27x00_device_info *di);
+};
+
+struct bq27x00_device_info {
+	struct device 		*dev;
+	int			id;
+	int			voltage_uV;
+	int			current_uA;
+	int			temp_C;
+	int			charge_rsoc;
+	struct bq27x00_access_methods	*bus;
+	struct power_supply	bat;
+
+	struct i2c_client	*client;
+};
+
+static enum power_supply_property bq27x00_battery_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_TEMP,
+};
+
+/*
+ * Common code for BQ27x00 devices
+ */
+
+static int bq27x00_read(u8 reg, int *rt_value, int b_single,
+			struct bq27x00_device_info *di)
+{
+	int ret;
+
+	ret = di->bus->read(reg, rt_value, b_single, di);
+	*rt_value = be16_to_cpu(*rt_value);
+
+	return ret;
+}
+
+/*
+ * Return the battery temperature in Celcius degrees
+ * Or < 0 if something fails.
+ */
+static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
+{
+	int ret;
+	int temp = 0;
+
+	ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di);
+	if (ret) {
+		dev_err(di->dev, "error reading temperature\n");
+		return ret;
+	}
+
+	return (temp >> 2) - 273;
+}
+
+/*
+ * Return the battery Voltage in milivolts
+ * Or < 0 if something fails.
+ */
+static int bq27x00_battery_voltage(struct bq27x00_device_info *di)
+{
+	int ret;
+	int volt = 0;
+
+	ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di);
+	if (ret) {
+		dev_err(di->dev, "error reading voltage\n");
+		return ret;
+	}
+
+	return volt;
+}
+
+/*
+ * Return the battery average current
+ * Note that current can be negative signed as well
+ * Or 0 if something fails.
+ */
+static int bq27x00_battery_current(struct bq27x00_device_info *di)
+{
+	int ret;
+	int curr = 0;
+	int flags = 0;
+
+	ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di);
+	if (ret) {
+		dev_err(di->dev, "error reading current\n");
+		return 0;
+	}
+	ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
+	if (ret < 0) {
+		dev_err(di->dev, "error reading flags\n");
+		return 0;
+	}
+	if ((flags & (1 << 7)) != 0) {
+		dev_dbg(di->dev, "negative current!\n");
+		return -curr;
+	}
+	return curr;
+}
+
+/*
+ * Return the battery Relative State-of-Charge
+ * Or < 0 if something fails.
+ */
+static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
+{
+	int ret;
+	int rsoc = 0;
+
+	ret = bq27x00_read(BQ27x00_REG_RSOC, &rsoc, 1, di);
+	if (ret) {
+		dev_err(di->dev, "error reading relative State-of-Charge\n");
+		return ret;
+	}
+
+	return rsoc >> 8;
+}
+
+#define to_bq27x00_device_info(x) container_of((x), \
+				struct bq27x00_device_info, bat);
+
+static int bq27x00_battery_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = bq27x00_battery_voltage(di);
+		if (psp == POWER_SUPPLY_PROP_PRESENT)
+			val->intval = val->intval <= 0 ? 0 : 1;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		val->intval = bq27x00_battery_current(di);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = bq27x00_battery_rsoc(di);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = bq27x00_battery_temperature(di);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
+{
+	di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
+	di->bat.properties = bq27x00_battery_props;
+	di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
+	di->bat.get_property = bq27x00_battery_get_property;
+	di->bat.external_power_changed = NULL;
+}
+
+/*
+ * BQ27200 specific code
+ */
+
+static int bq27200_read(u8 reg, int *rt_value, int b_single,
+			struct bq27x00_device_info *di)
+{
+	struct i2c_client *client = di->client;
+	struct i2c_msg msg[1];
+	unsigned char data[2];
+	int err;
+
+	if (!client->adapter)
+		return -ENODEV;
+
+	msg->addr = client->addr;
+	msg->flags = 0;
+	msg->len = 1;
+	msg->buf = data;
+
+	data[0] = reg;
+	err = i2c_transfer(client->adapter, msg, 1);
+
+	if (err >= 0) {
+		if (!b_single)
+			msg->len = 2;
+		else
+			msg->len = 1;
+
+		msg->flags = I2C_M_RD;
+		err = i2c_transfer(client->adapter, msg, 1);
+		if (err >= 0) {
+			if (!b_single)
+				*rt_value = data[1] | HIGH_BYTE(data[0]);
+			else
+				*rt_value = data[0];
+
+			return 0;
+		}
+	}
+	return err;
+}
+
+static int bq27200_battery_probe(struct i2c_client *client,
+				 const struct i2c_device_id *id)
+{
+	char *name;
+	struct bq27x00_device_info *di;
+	struct bq27x00_access_methods *bus;
+	int num;
+	int retval = 0;
+
+	/* Get new ID for the new battery device */
+	retval = idr_pre_get(&battery_id, GFP_KERNEL);
+	if (retval == 0)
+		return -ENOMEM;
+	mutex_lock(&battery_mutex);
+	retval = idr_get_new(&battery_id, client, &num);
+	mutex_unlock(&battery_mutex);
+	if (retval < 0)
+		return retval;
+
+	name = kasprintf(GFP_KERNEL, "bq27200-%d", num);
+	if (!name) {
+		dev_err(&client->dev, "failed to allocate device name\n");
+		retval = -ENOMEM;
+		goto batt_failed_1;
+	}
+
+	di = kzalloc(sizeof(*di), GFP_KERNEL);
+	if (!di) {
+		dev_err(&client->dev, "failed to allocate device info data\n");
+		retval = -ENOMEM;
+		goto batt_failed_2;
+	}
+	di->id = num;
+
+	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
+	if (!bus) {
+		dev_err(&client->dev, "failed to allocate access method "
+					"data\n");
+		retval = -ENOMEM;
+		goto batt_failed_3;
+	}
+
+	i2c_set_clientdata(client, di);
+	di->dev = &client->dev;
+	di->bat.name = name;
+	bus->read = &bq27200_read;
+	di->bus = bus;
+	di->client = client;
+
+	bq27x00_powersupply_init(di);
+
+	retval = power_supply_register(&client->dev, &di->bat);
+	if (retval) {
+		dev_err(&client->dev, "failed to register battery\n");
+		goto batt_failed_4;
+	}
+
+	dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
+
+	return 0;
+
+batt_failed_4:
+	kfree(bus);
+batt_failed_3:
+	kfree(di);
+batt_failed_2:
+	kfree(name);
+batt_failed_1:
+	mutex_lock(&battery_mutex);
+	idr_remove(&battery_id, num);
+	mutex_unlock(&battery_mutex);
+
+	return retval;
+}
+
+static int bq27200_battery_remove(struct i2c_client *client)
+{
+	struct bq27x00_device_info *di = i2c_get_clientdata(client);
+
+	power_supply_unregister(&di->bat);
+
+	kfree(di->bat.name);
+
+	mutex_lock(&battery_mutex);
+	idr_remove(&battery_id, di->id);
+	mutex_unlock(&battery_mutex);
+
+	kfree(di);
+
+	return 0;
+}
+
+/*
+ * Module stuff
+ */
+
+static const struct i2c_device_id bq27200_id[] = {
+	{ "bq27200", 0 },
+	{},
+};
+
+static struct i2c_driver bq27200_battery_driver = {
+	.driver = {
+		.name = "bq27200-battery",
+	},
+	.probe = bq27200_battery_probe,
+	.remove = bq27200_battery_remove,
+	.id_table = bq27200_id,
+};
+
+static int __init bq27x00_battery_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&bq27200_battery_driver);
+	if (ret)
+		printk(KERN_ERR "Unable to register BQ27200 driver\n");
+
+	return ret;
+}
+module_init(bq27x00_battery_init);
+
+static void __exit bq27x00_battery_exit(void)
+{
+	i2c_del_driver(&bq27200_battery_driver);
+}
+module_exit(bq27x00_battery_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
+MODULE_LICENSE("GPL");