power_supply: Add MAX17042 Fuel Gauge Driver
authorMyungJoo Ham <myungjoo.ham@samsung.com>
Fri, 14 Jan 2011 05:46:11 +0000 (14:46 +0900)
committerAnton Vorontsov <cbouatmailru@gmail.com>
Fri, 14 Jan 2011 15:11:59 +0000 (18:11 +0300)
The MAX17042 is a fuel gauge with an I2C interface for lithium-ion
betteries. Unlike its predecessor MAX17040, MAX17042 uses 16bit
registers. Besides, MAX17042 has much more features than MAX17040; e.g.,
a thermistor, current and current accumulation measurement, battery
internal resistance estimate, average values of measurement, and others.

This patch implements a driver for MAX17042.
In this initial release, we have implemented the most basic features of
a fuel gauge: measure the battery capacity and voltage.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/max17042_battery.c [new file with mode: 0644]
include/linux/power/max17042_battery.h [new file with mode: 0644]

index 32165295cb1bda069553fa0077a24bc77f0e96cb..61bf5d724139c80a93fd86350dd7ebb46f9eb8c0 100644 (file)
@@ -136,6 +136,16 @@ config BATTERY_MAX17040
          in handheld and portable equipment. The MAX17040 is configured
          to operate with a single lithium cell
 
+config BATTERY_MAX17042
+       tristate "Maxim MAX17042/8997/8966 Fuel Gauge"
+       depends on I2C
+       help
+         MAX17042 is fuel-gauge systems for lithium-ion (Li+) batteries
+         in handheld and portable equipment. The MAX17042 is configured
+         to operate with a single lithium cell. MAX8997 and MAX8966 are
+         multi-function devices that include fuel gauages that are compatible
+         with MAX17042.
+
 config BATTERY_Z2
        tristate "Z2 battery driver"
        depends on I2C && MACH_ZIPIT2
index 545459f9f35695865a7369fd56ff22dabbb0d4bc..8385bfae872836bf367e937b1f627cbe82c39421 100644 (file)
@@ -25,6 +25,7 @@ obj-$(CONFIG_BATTERY_BQ20Z75) += bq20z75.o
 obj-$(CONFIG_BATTERY_BQ27x00)  += bq27x00_battery.o
 obj-$(CONFIG_BATTERY_DA9030)   += da9030_battery.o
 obj-$(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_CHARGER_PCF50633) += pcf50633-charger.o
diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
new file mode 100644 (file)
index 0000000..c5c8805
--- /dev/null
@@ -0,0 +1,239 @@
+/*
+ * Fuel gauge driver for Maxim 17042 / 8966 / 8997
+ *  Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This driver is based on max17040_battery.c
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/power_supply.h>
+#include <linux/power/max17042_battery.h>
+
+enum max17042_register {
+       MAX17042_STATUS         = 0x00,
+       MAX17042_VALRT_Th       = 0x01,
+       MAX17042_TALRT_Th       = 0x02,
+       MAX17042_SALRT_Th       = 0x03,
+       MAX17042_AtRate         = 0x04,
+       MAX17042_RepCap         = 0x05,
+       MAX17042_RepSOC         = 0x06,
+       MAX17042_Age            = 0x07,
+       MAX17042_TEMP           = 0x08,
+       MAX17042_VCELL          = 0x09,
+       MAX17042_Current        = 0x0A,
+       MAX17042_AvgCurrent     = 0x0B,
+       MAX17042_Qresidual      = 0x0C,
+       MAX17042_SOC            = 0x0D,
+       MAX17042_AvSOC          = 0x0E,
+       MAX17042_RemCap         = 0x0F,
+       MAX17402_FullCAP        = 0x10,
+       MAX17042_TTE            = 0x11,
+       MAX17042_V_empty        = 0x12,
+
+       MAX17042_RSLOW          = 0x14,
+
+       MAX17042_AvgTA          = 0x16,
+       MAX17042_Cycles         = 0x17,
+       MAX17042_DesignCap      = 0x18,
+       MAX17042_AvgVCELL       = 0x19,
+       MAX17042_MinMaxTemp     = 0x1A,
+       MAX17042_MinMaxVolt     = 0x1B,
+       MAX17042_MinMaxCurr     = 0x1C,
+       MAX17042_CONFIG         = 0x1D,
+       MAX17042_ICHGTerm       = 0x1E,
+       MAX17042_AvCap          = 0x1F,
+       MAX17042_ManName        = 0x20,
+       MAX17042_DevName        = 0x21,
+       MAX17042_DevChem        = 0x22,
+
+       MAX17042_TempNom        = 0x24,
+       MAX17042_TempCold       = 0x25,
+       MAX17042_TempHot        = 0x26,
+       MAX17042_AIN            = 0x27,
+       MAX17042_LearnCFG       = 0x28,
+       MAX17042_SHFTCFG        = 0x29,
+       MAX17042_RelaxCFG       = 0x2A,
+       MAX17042_MiscCFG        = 0x2B,
+       MAX17042_TGAIN          = 0x2C,
+       MAx17042_TOFF           = 0x2D,
+       MAX17042_CGAIN          = 0x2E,
+       MAX17042_COFF           = 0x2F,
+
+       MAX17042_Q_empty        = 0x33,
+       MAX17042_T_empty        = 0x34,
+
+       MAX17042_RCOMP0         = 0x38,
+       MAX17042_TempCo         = 0x39,
+       MAX17042_Rx             = 0x3A,
+       MAX17042_T_empty0       = 0x3B,
+       MAX17042_TaskPeriod     = 0x3C,
+       MAX17042_FSTAT          = 0x3D,
+
+       MAX17042_SHDNTIMER      = 0x3F,
+
+       MAX17042_VFRemCap       = 0x4A,
+
+       MAX17042_QH             = 0x4D,
+       MAX17042_QL             = 0x4E,
+};
+
+struct max17042_chip {
+       struct i2c_client *client;
+       struct power_supply battery;
+       struct max17042_platform_data *pdata;
+};
+
+static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
+{
+       int ret = i2c_smbus_write_word_data(client, reg, value);
+
+       if (ret < 0)
+               dev_err(&client->dev, "%s: err %d\n", __func__, ret);
+
+       return ret;
+}
+
+static int max17042_read_reg(struct i2c_client *client, u8 reg)
+{
+       int ret = i2c_smbus_read_word_data(client, reg);
+
+       if (ret < 0)
+               dev_err(&client->dev, "%s: err %d\n", __func__, ret);
+
+       return ret;
+}
+
+static enum power_supply_property max17042_battery_props[] = {
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_VOLTAGE_AVG,
+       POWER_SUPPLY_PROP_CAPACITY,
+};
+
+static int max17042_get_property(struct power_supply *psy,
+                           enum power_supply_property psp,
+                           union power_supply_propval *val)
+{
+       struct max17042_chip *chip = container_of(psy,
+                               struct max17042_chip, battery);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+               val->intval = max17042_read_reg(chip->client,
+                               MAX17042_VCELL) * 83; /* 1000 / 12 = 83 */
+               break;
+       case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+               val->intval = max17042_read_reg(chip->client,
+                               MAX17042_AvgVCELL) * 83;
+               break;
+       case POWER_SUPPLY_PROP_CAPACITY:
+               val->intval = max17042_read_reg(chip->client,
+                               MAX17042_SOC) / 256;
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static int __devinit max17042_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+       struct max17042_chip *chip;
+       int ret;
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
+               return -EIO;
+
+       chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       chip->client = client;
+       chip->pdata = client->dev.platform_data;
+
+       i2c_set_clientdata(client, chip);
+
+       chip->battery.name              = "max17042_battery";
+       chip->battery.type              = POWER_SUPPLY_TYPE_BATTERY;
+       chip->battery.get_property      = max17042_get_property;
+       chip->battery.properties        = max17042_battery_props;
+       chip->battery.num_properties    = ARRAY_SIZE(max17042_battery_props);
+
+       ret = power_supply_register(&client->dev, &chip->battery);
+       if (ret) {
+               dev_err(&client->dev, "failed: power supply register\n");
+               i2c_set_clientdata(client, NULL);
+               kfree(chip);
+               return ret;
+       }
+
+       if (!chip->pdata->enable_current_sense) {
+               max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
+               max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
+               max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
+       }
+
+       return 0;
+}
+
+static int __devexit max17042_remove(struct i2c_client *client)
+{
+       struct max17042_chip *chip = i2c_get_clientdata(client);
+
+       power_supply_unregister(&chip->battery);
+       i2c_set_clientdata(client, NULL);
+       kfree(chip);
+       return 0;
+}
+
+static const struct i2c_device_id max17042_id[] = {
+       { "max17042", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, max17042_id);
+
+static struct i2c_driver max17042_i2c_driver = {
+       .driver = {
+               .name   = "max17042",
+       },
+       .probe          = max17042_probe,
+       .remove         = __devexit_p(max17042_remove),
+       .id_table       = max17042_id,
+};
+
+static int __init max17042_init(void)
+{
+       return i2c_add_driver(&max17042_i2c_driver);
+}
+module_init(max17042_init);
+
+static void __exit max17042_exit(void)
+{
+       i2c_del_driver(&max17042_i2c_driver);
+}
+module_exit(max17042_exit);
+
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/power/max17042_battery.h b/include/linux/power/max17042_battery.h
new file mode 100644 (file)
index 0000000..7995deb
--- /dev/null
@@ -0,0 +1,30 @@
+/*
+ * Fuel gauge driver for Maxim 17042 / 8966 / 8997
+ *  Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef __MAX17042_BATTERY_H_
+#define __MAX17042_BATTERY_H_
+
+struct max17042_platform_data {
+       bool enable_current_sense;
+};
+
+#endif /* __MAX17042_BATTERY_H_ */