1 /*
2 * max17040_battery.c
3 * fuel-gauge systems for lithium-ion (Li+) batteries
4 *
5 * Copyright (C) 2009 Samsung Electronics
6 * Minkyu Kang <mk7.kang@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/platform_device.h>
16 #include <linux/mutex.h>
17 #include <linux/err.h>
18 #include <linux/i2c.h>
19 #include <linux/delay.h>
20 #include <linux/power_supply.h>
21 #include <linux/max17040_battery.h>
22 #include <linux/slab.h>
23
24 #define MAX17040_VCELL_MSB 0x02
25 #define MAX17040_VCELL_LSB 0x03
26 #define MAX17040_SOC_MSB 0x04
27 #define MAX17040_SOC_LSB 0x05
28 #define MAX17040_MODE_MSB 0x06
29 #define MAX17040_MODE_LSB 0x07
30 #define MAX17040_VER_MSB 0x08
31 #define MAX17040_VER_LSB 0x09
32 #define MAX17040_RCOMP_MSB 0x0C
33 #define MAX17040_RCOMP_LSB 0x0D
34 #define MAX17040_CMD_MSB 0xFE
35 #define MAX17040_CMD_LSB 0xFF
36
37 #define MAX17040_DELAY 1000
38 #define MAX17040_BATTERY_FULL 95
39
40 struct max17040_chip {
41 struct i2c_client *client;
42 struct delayed_work work;
43 struct power_supply battery;
44 struct max17040_platform_data *pdata;
45
46 /* State Of Connect */
47 int online;
48 /* battery voltage */
49 int vcell;
50 /* battery capacity */
51 int soc;
52 /* State Of Charge */
53 int status;
54 };
55
max17040_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)56 static int max17040_get_property(struct power_supply *psy,
57 enum power_supply_property psp,
58 union power_supply_propval *val)
59 {
60 struct max17040_chip *chip = container_of(psy,
61 struct max17040_chip, battery);
62
63 switch (psp) {
64 case POWER_SUPPLY_PROP_STATUS:
65 val->intval = chip->status;
66 break;
67 case POWER_SUPPLY_PROP_ONLINE:
68 val->intval = chip->online;
69 break;
70 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
71 val->intval = chip->vcell;
72 break;
73 case POWER_SUPPLY_PROP_CAPACITY:
74 val->intval = chip->soc;
75 break;
76 default:
77 return -EINVAL;
78 }
79 return 0;
80 }
81
max17040_write_reg(struct i2c_client * client,int reg,u8 value)82 static int max17040_write_reg(struct i2c_client *client, int reg, u8 value)
83 {
84 int ret;
85
86 ret = i2c_smbus_write_byte_data(client, reg, value);
87
88 if (ret < 0)
89 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
90
91 return ret;
92 }
93
max17040_read_reg(struct i2c_client * client,int reg)94 static int max17040_read_reg(struct i2c_client *client, int reg)
95 {
96 int ret;
97
98 ret = i2c_smbus_read_byte_data(client, reg);
99
100 if (ret < 0)
101 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
102
103 return ret;
104 }
105
max17040_reset(struct i2c_client * client)106 static void max17040_reset(struct i2c_client *client)
107 {
108 max17040_write_reg(client, MAX17040_CMD_MSB, 0x54);
109 max17040_write_reg(client, MAX17040_CMD_LSB, 0x00);
110 }
111
max17040_get_vcell(struct i2c_client * client)112 static void max17040_get_vcell(struct i2c_client *client)
113 {
114 struct max17040_chip *chip = i2c_get_clientdata(client);
115 u8 msb;
116 u8 lsb;
117
118 msb = max17040_read_reg(client, MAX17040_VCELL_MSB);
119 lsb = max17040_read_reg(client, MAX17040_VCELL_LSB);
120
121 chip->vcell = (msb << 4) + (lsb >> 4);
122 }
123
max17040_get_soc(struct i2c_client * client)124 static void max17040_get_soc(struct i2c_client *client)
125 {
126 struct max17040_chip *chip = i2c_get_clientdata(client);
127 u8 msb;
128 u8 lsb;
129
130 msb = max17040_read_reg(client, MAX17040_SOC_MSB);
131 lsb = max17040_read_reg(client, MAX17040_SOC_LSB);
132
133 chip->soc = msb;
134 }
135
max17040_get_version(struct i2c_client * client)136 static void max17040_get_version(struct i2c_client *client)
137 {
138 u8 msb;
139 u8 lsb;
140
141 msb = max17040_read_reg(client, MAX17040_VER_MSB);
142 lsb = max17040_read_reg(client, MAX17040_VER_LSB);
143
144 dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver %d%d\n", msb, lsb);
145 }
146
max17040_get_online(struct i2c_client * client)147 static void max17040_get_online(struct i2c_client *client)
148 {
149 struct max17040_chip *chip = i2c_get_clientdata(client);
150
151 if (chip->pdata->battery_online)
152 chip->online = chip->pdata->battery_online();
153 else
154 chip->online = 1;
155 }
156
max17040_get_status(struct i2c_client * client)157 static void max17040_get_status(struct i2c_client *client)
158 {
159 struct max17040_chip *chip = i2c_get_clientdata(client);
160
161 if (!chip->pdata->charger_online || !chip->pdata->charger_enable) {
162 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
163 return;
164 }
165
166 if (chip->pdata->charger_online()) {
167 if (chip->pdata->charger_enable())
168 chip->status = POWER_SUPPLY_STATUS_CHARGING;
169 else
170 chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
171 } else {
172 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
173 }
174
175 if (chip->soc > MAX17040_BATTERY_FULL)
176 chip->status = POWER_SUPPLY_STATUS_FULL;
177 }
178
max17040_work(struct work_struct * work)179 static void max17040_work(struct work_struct *work)
180 {
181 struct max17040_chip *chip;
182
183 chip = container_of(work, struct max17040_chip, work.work);
184
185 max17040_get_vcell(chip->client);
186 max17040_get_soc(chip->client);
187 max17040_get_online(chip->client);
188 max17040_get_status(chip->client);
189
190 schedule_delayed_work(&chip->work, MAX17040_DELAY);
191 }
192
193 static enum power_supply_property max17040_battery_props[] = {
194 POWER_SUPPLY_PROP_STATUS,
195 POWER_SUPPLY_PROP_ONLINE,
196 POWER_SUPPLY_PROP_VOLTAGE_NOW,
197 POWER_SUPPLY_PROP_CAPACITY,
198 };
199
max17040_probe(struct i2c_client * client,const struct i2c_device_id * id)200 static int __devinit max17040_probe(struct i2c_client *client,
201 const struct i2c_device_id *id)
202 {
203 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
204 struct max17040_chip *chip;
205 int ret;
206
207 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
208 return -EIO;
209
210 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
211 if (!chip)
212 return -ENOMEM;
213
214 chip->client = client;
215 chip->pdata = client->dev.platform_data;
216
217 i2c_set_clientdata(client, chip);
218
219 chip->battery.name = "battery";
220 chip->battery.type = POWER_SUPPLY_TYPE_BATTERY;
221 chip->battery.get_property = max17040_get_property;
222 chip->battery.properties = max17040_battery_props;
223 chip->battery.num_properties = ARRAY_SIZE(max17040_battery_props);
224
225 ret = power_supply_register(&client->dev, &chip->battery);
226 if (ret) {
227 dev_err(&client->dev, "failed: power supply register\n");
228 kfree(chip);
229 return ret;
230 }
231
232 max17040_reset(client);
233 max17040_get_version(client);
234
235 INIT_DELAYED_WORK_DEFERRABLE(&chip->work, max17040_work);
236 schedule_delayed_work(&chip->work, MAX17040_DELAY);
237
238 return 0;
239 }
240
max17040_remove(struct i2c_client * client)241 static int __devexit max17040_remove(struct i2c_client *client)
242 {
243 struct max17040_chip *chip = i2c_get_clientdata(client);
244
245 power_supply_unregister(&chip->battery);
246 cancel_delayed_work(&chip->work);
247 kfree(chip);
248 return 0;
249 }
250
251 #ifdef CONFIG_PM
252
max17040_suspend(struct i2c_client * client,pm_message_t state)253 static int max17040_suspend(struct i2c_client *client,
254 pm_message_t state)
255 {
256 struct max17040_chip *chip = i2c_get_clientdata(client);
257
258 cancel_delayed_work(&chip->work);
259 return 0;
260 }
261
max17040_resume(struct i2c_client * client)262 static int max17040_resume(struct i2c_client *client)
263 {
264 struct max17040_chip *chip = i2c_get_clientdata(client);
265
266 schedule_delayed_work(&chip->work, MAX17040_DELAY);
267 return 0;
268 }
269
270 #else
271
272 #define max17040_suspend NULL
273 #define max17040_resume NULL
274
275 #endif /* CONFIG_PM */
276
277 static const struct i2c_device_id max17040_id[] = {
278 { "max17040", 0 },
279 { }
280 };
281 MODULE_DEVICE_TABLE(i2c, max17040_id);
282
283 static struct i2c_driver max17040_i2c_driver = {
284 .driver = {
285 .name = "max17040",
286 },
287 .probe = max17040_probe,
288 .remove = __devexit_p(max17040_remove),
289 .suspend = max17040_suspend,
290 .resume = max17040_resume,
291 .id_table = max17040_id,
292 };
293
max17040_init(void)294 static int __init max17040_init(void)
295 {
296 return i2c_add_driver(&max17040_i2c_driver);
297 }
298 module_init(max17040_init);
299
max17040_exit(void)300 static void __exit max17040_exit(void)
301 {
302 i2c_del_driver(&max17040_i2c_driver);
303 }
304 module_exit(max17040_exit);
305
306 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
307 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
308 MODULE_LICENSE("GPL");
309