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authorMyungJoo Ham <myungjoo.ham@samsung.com>2011-01-14 08:46:11 +0300
committerAnton Vorontsov <cbouatmailru@gmail.com>2011-01-14 18:11:59 +0300
commit359ab9f5b154cbd807a11e22792235f0f36b0cd5 (patch)
tree3500652809c242b75deb5139ded7052c389e0bb4 /drivers/power/max17042_battery.c
parentbf542a4e7b634c2adcba4241a29082f69b0f45dc (diff)
downloadlinux-359ab9f5b154cbd807a11e22792235f0f36b0cd5.tar.xz
power_supply: Add MAX17042 Fuel Gauge Driver
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>
Diffstat (limited to 'drivers/power/max17042_battery.c')
-rw-r--r--drivers/power/max17042_battery.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
new file mode 100644
index 000000000000..c5c8805156cb
--- /dev/null
+++ b/drivers/power/max17042_battery.c
@@ -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");