--- /dev/null
+/*
+ * 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");
projects / linux-2.6-omap-h63xx.git / commitdiff