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 = power_supply_get_drvdata(psy);
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
max17040_write_reg(struct i2c_client * client,int reg,u8 value)81 static 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
max17040_read_reg(struct i2c_client * client,int reg)93 static 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
max17040_reset(struct i2c_client * client)105 static 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
max17040_get_vcell(struct i2c_client * client)111 static 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
max17040_get_soc(struct i2c_client * client)123 static 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
max17040_get_version(struct i2c_client * client)135 static 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
max17040_get_online(struct i2c_client * client)146 static void max17040_get_online(struct i2c_client *client)
147 {
148 struct max17040_chip *chip = i2c_get_clientdata(client);
149
150 if (chip->pdata && chip->pdata->battery_online)
151 chip->online = chip->pdata->battery_online();
152 else
153 chip->online = 1;
154 }
155
max17040_get_status(struct i2c_client * client)156 static void max17040_get_status(struct i2c_client *client)
157 {
158 struct max17040_chip *chip = i2c_get_clientdata(client);
159
160 if (!chip->pdata || !chip->pdata->charger_online
161 || !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 queue_delayed_work(system_power_efficient_wq, &chip->work,
191 MAX17040_DELAY);
192 }
193
194 static enum power_supply_property max17040_battery_props[] = {
195 POWER_SUPPLY_PROP_STATUS,
196 POWER_SUPPLY_PROP_ONLINE,
197 POWER_SUPPLY_PROP_VOLTAGE_NOW,
198 POWER_SUPPLY_PROP_CAPACITY,
199 };
200
201 static const struct power_supply_desc max17040_battery_desc = {
202 .name = "battery",
203 .type = POWER_SUPPLY_TYPE_BATTERY,
204 .get_property = max17040_get_property,
205 .properties = max17040_battery_props,
206 .num_properties = ARRAY_SIZE(max17040_battery_props),
207 };
208
max17040_probe(struct i2c_client * client,const struct i2c_device_id * id)209 static int max17040_probe(struct i2c_client *client,
210 const struct i2c_device_id *id)
211 {
212 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
213 struct power_supply_config psy_cfg = {};
214 struct max17040_chip *chip;
215
216 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
217 return -EIO;
218
219 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
220 if (!chip)
221 return -ENOMEM;
222
223 chip->client = client;
224 chip->pdata = client->dev.platform_data;
225
226 i2c_set_clientdata(client, chip);
227 psy_cfg.drv_data = chip;
228
229 chip->battery = power_supply_register(&client->dev,
230 &max17040_battery_desc, &psy_cfg);
231 if (IS_ERR(chip->battery)) {
232 dev_err(&client->dev, "failed: power supply register\n");
233 return PTR_ERR(chip->battery);
234 }
235
236 max17040_reset(client);
237 max17040_get_version(client);
238
239 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
240 queue_delayed_work(system_power_efficient_wq, &chip->work,
241 MAX17040_DELAY);
242
243 return 0;
244 }
245
max17040_remove(struct i2c_client * client)246 static int max17040_remove(struct i2c_client *client)
247 {
248 struct max17040_chip *chip = i2c_get_clientdata(client);
249
250 power_supply_unregister(chip->battery);
251 cancel_delayed_work(&chip->work);
252 return 0;
253 }
254
255 #ifdef CONFIG_PM_SLEEP
256
max17040_suspend(struct device * dev)257 static int max17040_suspend(struct device *dev)
258 {
259 struct i2c_client *client = to_i2c_client(dev);
260 struct max17040_chip *chip = i2c_get_clientdata(client);
261
262 cancel_delayed_work(&chip->work);
263 return 0;
264 }
265
max17040_resume(struct device * dev)266 static int max17040_resume(struct device *dev)
267 {
268 struct i2c_client *client = to_i2c_client(dev);
269 struct max17040_chip *chip = i2c_get_clientdata(client);
270
271 queue_delayed_work(system_power_efficient_wq, &chip->work,
272 MAX17040_DELAY);
273 return 0;
274 }
275
276 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
277 #define MAX17040_PM_OPS (&max17040_pm_ops)
278
279 #else
280
281 #define MAX17040_PM_OPS NULL
282
283 #endif /* CONFIG_PM_SLEEP */
284
285 static const struct i2c_device_id max17040_id[] = {
286 { "max17040" },
287 { "max77836-battery" },
288 { }
289 };
290 MODULE_DEVICE_TABLE(i2c, max17040_id);
291
292 static struct i2c_driver max17040_i2c_driver = {
293 .driver = {
294 .name = "max17040",
295 .pm = MAX17040_PM_OPS,
296 },
297 .probe = max17040_probe,
298 .remove = max17040_remove,
299 .id_table = max17040_id,
300 };
301 module_i2c_driver(max17040_i2c_driver);
302
303 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
304 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
305 MODULE_LICENSE("GPL");
306