3 files changed, 389 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 9ce55850271a..b2bd104b9869 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -62,4 +62,10 @@ config BATTERY_PALMTX
         help
           Say Y to enable support for the battery in Palm T|X.
 
+config BATTERY_BQ27x00
+        tristate "BQ27200 battery driver"
+        depends on I2C
+        help
+          Say Y here to enable support for batteries with BQ27200(I2C) chip.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 4706bf8ff459..6cb301b779a7 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_BATTERY_PMU)	+= pmu_battery.o
 obj-$(CONFIG_BATTERY_OLPC)      += olpc_battery.o
 obj-$(CONFIG_BATTERY_TOSA)      += tosa_battery.o
 obj-$(CONFIG_BATTERY_PALMTX)    += palmtx_battery.o
+obj-$(CONFIG_BATTERY_BQ27x00)   += bq27x00_battery.o
diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c
new file mode 100644
index 000000000000..62d4948e8206
--- /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");