Merge branch 'akpm'
[linux-2.6/next.git] / drivers / power / max17042_battery.c
blob9a85f905ae6fa6447837a505fc9b305b277f6361
1 /*
2 * Fuel gauge driver for Maxim 17042 / 8966 / 8997
3 * Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
5 * Copyright (C) 2011 Samsung Electronics
6 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * This driver is based on max17040_battery.c
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/i2c.h>
29 #include <linux/mod_devicetable.h>
30 #include <linux/power_supply.h>
31 #include <linux/power/max17042_battery.h>
33 struct max17042_chip {
34 struct i2c_client *client;
35 struct power_supply battery;
36 struct max17042_platform_data *pdata;
39 static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
41 int ret = i2c_smbus_write_word_data(client, reg, value);
43 if (ret < 0)
44 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
46 return ret;
49 static int max17042_read_reg(struct i2c_client *client, u8 reg)
51 int ret = i2c_smbus_read_word_data(client, reg);
53 if (ret < 0)
54 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
56 return ret;
59 static void max17042_set_reg(struct i2c_client *client,
60 struct max17042_reg_data *data, int size)
62 int i;
64 for (i = 0; i < size; i++)
65 max17042_write_reg(client, data[i].addr, data[i].data);
68 static enum power_supply_property max17042_battery_props[] = {
69 POWER_SUPPLY_PROP_PRESENT,
70 POWER_SUPPLY_PROP_CYCLE_COUNT,
71 POWER_SUPPLY_PROP_VOLTAGE_MAX,
72 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
73 POWER_SUPPLY_PROP_VOLTAGE_NOW,
74 POWER_SUPPLY_PROP_VOLTAGE_AVG,
75 POWER_SUPPLY_PROP_CAPACITY,
76 POWER_SUPPLY_PROP_CHARGE_FULL,
77 POWER_SUPPLY_PROP_TEMP,
78 POWER_SUPPLY_PROP_CURRENT_NOW,
79 POWER_SUPPLY_PROP_CURRENT_AVG,
82 static int max17042_get_property(struct power_supply *psy,
83 enum power_supply_property psp,
84 union power_supply_propval *val)
86 struct max17042_chip *chip = container_of(psy,
87 struct max17042_chip, battery);
89 switch (psp) {
90 case POWER_SUPPLY_PROP_PRESENT:
91 val->intval = max17042_read_reg(chip->client,
92 MAX17042_STATUS);
93 if (val->intval & MAX17042_STATUS_BattAbsent)
94 val->intval = 0;
95 else
96 val->intval = 1;
97 break;
98 case POWER_SUPPLY_PROP_CYCLE_COUNT:
99 val->intval = max17042_read_reg(chip->client,
100 MAX17042_Cycles);
101 break;
102 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
103 val->intval = max17042_read_reg(chip->client,
104 MAX17042_MinMaxVolt);
105 val->intval >>= 8;
106 val->intval *= 20000; /* Units of LSB = 20mV */
107 break;
108 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
109 val->intval = max17042_read_reg(chip->client,
110 MAX17042_V_empty);
111 val->intval >>= 7;
112 val->intval *= 10000; /* Units of LSB = 10mV */
113 break;
114 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
115 val->intval = max17042_read_reg(chip->client, MAX17042_VCELL)
116 * 625 / 8;
117 break;
118 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
119 val->intval = max17042_read_reg(chip->client, MAX17042_AvgVCELL)
120 * 625 / 8;
121 break;
122 case POWER_SUPPLY_PROP_CAPACITY:
123 val->intval = max17042_read_reg(chip->client,
124 MAX17042_SOC) / 256;
125 break;
126 case POWER_SUPPLY_PROP_CHARGE_FULL:
127 val->intval = max17042_read_reg(chip->client,
128 MAX17042_RepSOC);
129 if ((val->intval / 256) >= MAX17042_BATTERY_FULL)
130 val->intval = 1;
131 else if (val->intval >= 0)
132 val->intval = 0;
133 break;
134 case POWER_SUPPLY_PROP_TEMP:
135 val->intval = max17042_read_reg(chip->client,
136 MAX17042_TEMP);
137 /* The value is signed. */
138 if (val->intval & 0x8000) {
139 val->intval = (0x7fff & ~val->intval) + 1;
140 val->intval *= -1;
142 /* The value is converted into deci-centigrade scale */
143 /* Units of LSB = 1 / 256 degree Celsius */
144 val->intval = val->intval * 10 / 256;
145 break;
146 case POWER_SUPPLY_PROP_CURRENT_NOW:
147 if (chip->pdata->enable_current_sense) {
148 val->intval = max17042_read_reg(chip->client,
149 MAX17042_Current);
150 if (val->intval & 0x8000) {
151 /* Negative */
152 val->intval = ~val->intval & 0x7fff;
153 val->intval++;
154 val->intval *= -1;
156 val->intval *= 1562500 / chip->pdata->r_sns;
157 } else {
158 return -EINVAL;
160 break;
161 case POWER_SUPPLY_PROP_CURRENT_AVG:
162 if (chip->pdata->enable_current_sense) {
163 val->intval = max17042_read_reg(chip->client,
164 MAX17042_AvgCurrent);
165 if (val->intval & 0x8000) {
166 /* Negative */
167 val->intval = ~val->intval & 0x7fff;
168 val->intval++;
169 val->intval *= -1;
171 val->intval *= 1562500 / chip->pdata->r_sns;
172 } else {
173 return -EINVAL;
175 break;
176 default:
177 return -EINVAL;
179 return 0;
182 static int __devinit max17042_probe(struct i2c_client *client,
183 const struct i2c_device_id *id)
185 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
186 struct max17042_chip *chip;
187 int ret;
189 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
190 return -EIO;
192 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
193 if (!chip)
194 return -ENOMEM;
196 chip->client = client;
197 chip->pdata = client->dev.platform_data;
199 i2c_set_clientdata(client, chip);
201 chip->battery.name = "max17042_battery";
202 chip->battery.type = POWER_SUPPLY_TYPE_BATTERY;
203 chip->battery.get_property = max17042_get_property;
204 chip->battery.properties = max17042_battery_props;
205 chip->battery.num_properties = ARRAY_SIZE(max17042_battery_props);
207 /* When current is not measured,
208 * CURRENT_NOW and CURRENT_AVG properties should be invisible. */
209 if (!chip->pdata->enable_current_sense)
210 chip->battery.num_properties -= 2;
212 if (chip->pdata->r_sns == 0)
213 chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
215 ret = power_supply_register(&client->dev, &chip->battery);
216 if (ret) {
217 dev_err(&client->dev, "failed: power supply register\n");
218 kfree(chip);
219 return ret;
222 /* Initialize registers according to values from the platform data */
223 if (chip->pdata->init_data)
224 max17042_set_reg(client, chip->pdata->init_data,
225 chip->pdata->num_init_data);
227 if (!chip->pdata->enable_current_sense) {
228 max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
229 max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
230 max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
233 return 0;
236 static int __devexit max17042_remove(struct i2c_client *client)
238 struct max17042_chip *chip = i2c_get_clientdata(client);
240 power_supply_unregister(&chip->battery);
241 kfree(chip);
242 return 0;
245 static const struct i2c_device_id max17042_id[] = {
246 { "max17042", 0 },
249 MODULE_DEVICE_TABLE(i2c, max17042_id);
251 static struct i2c_driver max17042_i2c_driver = {
252 .driver = {
253 .name = "max17042",
255 .probe = max17042_probe,
256 .remove = __devexit_p(max17042_remove),
257 .id_table = max17042_id,
260 static int __init max17042_init(void)
262 return i2c_add_driver(&max17042_i2c_driver);
264 module_init(max17042_init);
266 static void __exit max17042_exit(void)
268 i2c_del_driver(&max17042_i2c_driver);
270 module_exit(max17042_exit);
272 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
273 MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
274 MODULE_LICENSE("GPL");