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