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
);
44 dev_err(&client
->dev
, "%s: err %d\n", __func__
, ret
);
49 static int max17042_read_reg(struct i2c_client
*client
, u8 reg
)
51 int ret
= i2c_smbus_read_word_data(client
, reg
);
54 dev_err(&client
->dev
, "%s: err %d\n", __func__
, ret
);
59 static void max17042_set_reg(struct i2c_client
*client
,
60 struct max17042_reg_data
*data
, int size
)
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
);
90 case POWER_SUPPLY_PROP_PRESENT
:
91 val
->intval
= max17042_read_reg(chip
->client
,
93 if (val
->intval
& MAX17042_STATUS_BattAbsent
)
98 case POWER_SUPPLY_PROP_CYCLE_COUNT
:
99 val
->intval
= max17042_read_reg(chip
->client
,
102 case POWER_SUPPLY_PROP_VOLTAGE_MAX
:
103 val
->intval
= max17042_read_reg(chip
->client
,
104 MAX17042_MinMaxVolt
);
106 val
->intval
*= 20000; /* Units of LSB = 20mV */
108 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN
:
109 val
->intval
= max17042_read_reg(chip
->client
,
112 val
->intval
*= 10000; /* Units of LSB = 10mV */
114 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
115 val
->intval
= max17042_read_reg(chip
->client
,
116 MAX17042_VCELL
) * 83; /* 1000 / 12 = 83 */
118 case POWER_SUPPLY_PROP_VOLTAGE_AVG
:
119 val
->intval
= max17042_read_reg(chip
->client
,
120 MAX17042_AvgVCELL
) * 83;
122 case POWER_SUPPLY_PROP_CAPACITY
:
123 val
->intval
= max17042_read_reg(chip
->client
,
126 case POWER_SUPPLY_PROP_CHARGE_FULL
:
127 val
->intval
= max17042_read_reg(chip
->client
,
129 if ((val
->intval
/ 256) >= MAX17042_BATTERY_FULL
)
131 else if (val
->intval
>= 0)
134 case POWER_SUPPLY_PROP_TEMP
:
135 val
->intval
= max17042_read_reg(chip
->client
,
137 /* The value is signed. */
138 if (val
->intval
& 0x8000) {
139 val
->intval
= (0x7fff & ~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;
146 case POWER_SUPPLY_PROP_CURRENT_NOW
:
147 if (chip
->pdata
->enable_current_sense
) {
148 val
->intval
= max17042_read_reg(chip
->client
,
150 if (val
->intval
& 0x8000) {
152 val
->intval
= ~val
->intval
& 0x7fff;
157 val
->intval
*= 1000000 * 25 / chip
->pdata
->r_sns
;
162 case POWER_SUPPLY_PROP_CURRENT_AVG
:
163 if (chip
->pdata
->enable_current_sense
) {
164 val
->intval
= max17042_read_reg(chip
->client
,
165 MAX17042_AvgCurrent
);
166 if (val
->intval
& 0x8000) {
168 val
->intval
= ~val
->intval
& 0x7fff;
172 val
->intval
*= 1562500 / chip
->pdata
->r_sns
;
183 static int __devinit
max17042_probe(struct i2c_client
*client
,
184 const struct i2c_device_id
*id
)
186 struct i2c_adapter
*adapter
= to_i2c_adapter(client
->dev
.parent
);
187 struct max17042_chip
*chip
;
190 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_WORD_DATA
))
193 chip
= kzalloc(sizeof(*chip
), GFP_KERNEL
);
197 chip
->client
= client
;
198 chip
->pdata
= client
->dev
.platform_data
;
200 i2c_set_clientdata(client
, chip
);
202 chip
->battery
.name
= "max17042_battery";
203 chip
->battery
.type
= POWER_SUPPLY_TYPE_BATTERY
;
204 chip
->battery
.get_property
= max17042_get_property
;
205 chip
->battery
.properties
= max17042_battery_props
;
206 chip
->battery
.num_properties
= ARRAY_SIZE(max17042_battery_props
);
208 /* When current is not measured,
209 * CURRENT_NOW and CURRENT_AVG properties should be invisible. */
210 if (!chip
->pdata
->enable_current_sense
)
211 chip
->battery
.num_properties
-= 2;
213 ret
= power_supply_register(&client
->dev
, &chip
->battery
);
215 dev_err(&client
->dev
, "failed: power supply register\n");
220 /* Initialize registers according to values from the platform data */
221 if (chip
->pdata
->init_data
)
222 max17042_set_reg(client
, chip
->pdata
->init_data
,
223 chip
->pdata
->num_init_data
);
225 if (!chip
->pdata
->enable_current_sense
) {
226 max17042_write_reg(client
, MAX17042_CGAIN
, 0x0000);
227 max17042_write_reg(client
, MAX17042_MiscCFG
, 0x0003);
228 max17042_write_reg(client
, MAX17042_LearnCFG
, 0x0007);
230 if (chip
->pdata
->r_sns
== 0)
231 chip
->pdata
->r_sns
= MAX17042_DEFAULT_SNS_RESISTOR
;
237 static int __devexit
max17042_remove(struct i2c_client
*client
)
239 struct max17042_chip
*chip
= i2c_get_clientdata(client
);
241 power_supply_unregister(&chip
->battery
);
246 static const struct i2c_device_id max17042_id
[] = {
250 MODULE_DEVICE_TABLE(i2c
, max17042_id
);
252 static struct i2c_driver max17042_i2c_driver
= {
256 .probe
= max17042_probe
,
257 .remove
= __devexit_p(max17042_remove
),
258 .id_table
= max17042_id
,
261 static int __init
max17042_init(void)
263 return i2c_add_driver(&max17042_i2c_driver
);
265 module_init(max17042_init
);
267 static void __exit
max17042_exit(void)
269 i2c_del_driver(&max17042_i2c_driver
);
271 module_exit(max17042_exit
);
273 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
274 MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
275 MODULE_LICENSE("GPL");