1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2016-2019 The Linux Foundation. All rights reserved.
4 * Copyright (c) 2023, Linaro Limited
5 */
6 #include <linux/delay.h>
7 #include <linux/i2c.h>
8 #include <linux/power_supply.h>
9 #include <linux/regmap.h>
10
11 #define REG_BATID 0x00 /* This one is very unclear */
12 #define BATID_101 0x0101 /* 107kOhm */
13 #define BATID_102 0x0102 /* 10kOhm */
14 #define REG_TEMPERATURE 0x06
15 #define REG_VOLTAGE 0x08
16 #define REG_FLAGS 0x0a
17 #define MM8013_FLAG_OTC BIT(15)
18 #define MM8013_FLAG_OTD BIT(14)
19 #define MM8013_FLAG_BATHI BIT(13)
20 #define MM8013_FLAG_BATLOW BIT(12)
21 #define MM8013_FLAG_CHG_INH BIT(11)
22 #define MM8013_FLAG_FC BIT(9)
23 #define MM8013_FLAG_CHG BIT(8)
24 #define MM8013_FLAG_OCC BIT(6)
25 #define MM8013_FLAG_ODC BIT(5)
26 #define MM8013_FLAG_OT BIT(4)
27 #define MM8013_FLAG_UT BIT(3)
28 #define MM8013_FLAG_DSG BIT(0)
29 #define REG_FULL_CHARGE_CAPACITY 0x0e
30 #define REG_NOMINAL_CHARGE_CAPACITY 0x0c
31 #define REG_AVERAGE_CURRENT 0x14
32 #define REG_AVERAGE_TIME_TO_EMPTY 0x16
33 #define REG_AVERAGE_TIME_TO_FULL 0x18
34 #define REG_MAX_LOAD_CURRENT 0x1e
35 #define REG_CYCLE_COUNT 0x2a
36 #define REG_STATE_OF_CHARGE 0x2c
37 #define REG_DESIGN_CAPACITY 0x3c
38 /* TODO: 0x62-0x68 seem to contain 'MM8013C' in a length-prefixed, non-terminated string */
39
40 #define DECIKELVIN_TO_DECIDEGC(t) (t - 2731)
41
42 struct mm8013_chip {
43 struct i2c_client *client;
44 struct regmap *regmap;
45 };
46
mm8013_checkdevice(struct mm8013_chip * chip)47 static int mm8013_checkdevice(struct mm8013_chip *chip)
48 {
49 int battery_id, ret;
50 u32 val;
51
52 ret = regmap_write(chip->regmap, REG_BATID, 0x0008);
53 if (ret < 0)
54 return ret;
55
56 ret = regmap_read(chip->regmap, REG_BATID, &val);
57 if (ret < 0)
58 return ret;
59
60 if (val == BATID_102)
61 battery_id = 2;
62 else if (val == BATID_101)
63 battery_id = 1;
64 else
65 return -EINVAL;
66
67 dev_dbg(&chip->client->dev, "battery_id: %d\n", battery_id);
68
69 return 0;
70 }
71
72 static enum power_supply_property mm8013_battery_props[] = {
73 POWER_SUPPLY_PROP_CAPACITY,
74 POWER_SUPPLY_PROP_CHARGE_FULL,
75 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
76 POWER_SUPPLY_PROP_CHARGE_NOW,
77 POWER_SUPPLY_PROP_CURRENT_MAX,
78 POWER_SUPPLY_PROP_CURRENT_NOW,
79 POWER_SUPPLY_PROP_CYCLE_COUNT,
80 POWER_SUPPLY_PROP_HEALTH,
81 POWER_SUPPLY_PROP_PRESENT,
82 POWER_SUPPLY_PROP_STATUS,
83 POWER_SUPPLY_PROP_TEMP,
84 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
85 POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
86 POWER_SUPPLY_PROP_VOLTAGE_NOW,
87 };
88
mm8013_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)89 static int mm8013_get_property(struct power_supply *psy,
90 enum power_supply_property psp,
91 union power_supply_propval *val)
92 {
93 struct mm8013_chip *chip = psy->drv_data;
94 int ret = 0;
95 u32 regval;
96
97 switch (psp) {
98 case POWER_SUPPLY_PROP_CAPACITY:
99 ret = regmap_read(chip->regmap, REG_STATE_OF_CHARGE, ®val);
100 if (ret < 0)
101 return ret;
102
103 val->intval = regval;
104 break;
105 case POWER_SUPPLY_PROP_CHARGE_FULL:
106 ret = regmap_read(chip->regmap, REG_FULL_CHARGE_CAPACITY, ®val);
107 if (ret < 0)
108 return ret;
109
110 val->intval = 1000 * regval;
111 break;
112 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
113 ret = regmap_read(chip->regmap, REG_DESIGN_CAPACITY, ®val);
114 if (ret < 0)
115 return ret;
116
117 val->intval = 1000 * regval;
118 break;
119 case POWER_SUPPLY_PROP_CHARGE_NOW:
120 ret = regmap_read(chip->regmap, REG_NOMINAL_CHARGE_CAPACITY, ®val);
121 if (ret < 0)
122 return ret;
123
124 val->intval = 1000 * regval;
125 break;
126 case POWER_SUPPLY_PROP_CURRENT_MAX:
127 ret = regmap_read(chip->regmap, REG_MAX_LOAD_CURRENT, ®val);
128 if (ret < 0)
129 return ret;
130
131 val->intval = -1000 * (s16)regval;
132 break;
133 case POWER_SUPPLY_PROP_CURRENT_NOW:
134 ret = regmap_read(chip->regmap, REG_AVERAGE_CURRENT, ®val);
135 if (ret < 0)
136 return ret;
137
138 val->intval = -1000 * (s16)regval;
139 break;
140 case POWER_SUPPLY_PROP_CYCLE_COUNT:
141 ret = regmap_read(chip->regmap, REG_CYCLE_COUNT, ®val);
142 if (ret < 0)
143 return ret;
144
145 val->intval = regval;
146 break;
147 case POWER_SUPPLY_PROP_HEALTH:
148 ret = regmap_read(chip->regmap, REG_FLAGS, ®val);
149 if (ret < 0)
150 return ret;
151
152 if (regval & MM8013_FLAG_UT)
153 val->intval = POWER_SUPPLY_HEALTH_COLD;
154 else if (regval & (MM8013_FLAG_ODC | MM8013_FLAG_OCC))
155 val->intval = POWER_SUPPLY_HEALTH_OVERCURRENT;
156 else if (regval & (MM8013_FLAG_BATLOW))
157 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
158 else if (regval & MM8013_FLAG_BATHI)
159 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
160 else if (regval & (MM8013_FLAG_OT | MM8013_FLAG_OTD | MM8013_FLAG_OTC))
161 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
162 else
163 val->intval = POWER_SUPPLY_HEALTH_GOOD;
164 break;
165 case POWER_SUPPLY_PROP_PRESENT:
166 ret = regmap_read(chip->regmap, REG_TEMPERATURE, ®val);
167 if (ret < 0)
168 return ret;
169
170 val->intval = ((s16)regval > 0);
171 break;
172 case POWER_SUPPLY_PROP_STATUS:
173 ret = regmap_read(chip->regmap, REG_FLAGS, ®val);
174 if (ret < 0)
175 return ret;
176
177 if (regval & MM8013_FLAG_DSG)
178 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
179 else if (regval & MM8013_FLAG_CHG_INH)
180 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
181 else if (regval & MM8013_FLAG_CHG)
182 val->intval = POWER_SUPPLY_STATUS_CHARGING;
183 else if (regval & MM8013_FLAG_FC)
184 val->intval = POWER_SUPPLY_STATUS_FULL;
185 else
186 val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
187 break;
188 case POWER_SUPPLY_PROP_TEMP:
189 ret = regmap_read(chip->regmap, REG_TEMPERATURE, ®val);
190 if (ret < 0)
191 return ret;
192
193 val->intval = DECIKELVIN_TO_DECIDEGC(regval);
194 break;
195 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
196 ret = regmap_read(chip->regmap, REG_AVERAGE_TIME_TO_EMPTY, ®val);
197 if (ret < 0)
198 return ret;
199
200 /* The estimation is not yet ready */
201 if (regval == U16_MAX)
202 return -ENODATA;
203
204 val->intval = regval;
205 break;
206 case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
207 ret = regmap_read(chip->regmap, REG_AVERAGE_TIME_TO_FULL, ®val);
208 if (ret < 0)
209 return ret;
210
211 /* The estimation is not yet ready */
212 if (regval == U16_MAX)
213 return -ENODATA;
214
215 val->intval = regval;
216 break;
217 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
218 ret = regmap_read(chip->regmap, REG_VOLTAGE, ®val);
219 if (ret < 0)
220 return ret;
221
222 val->intval = 1000 * regval;
223 break;
224 default:
225 return -EINVAL;
226 }
227
228 return 0;
229 }
230
231 static const struct power_supply_desc mm8013_desc = {
232 .name = "mm8013",
233 .type = POWER_SUPPLY_TYPE_BATTERY,
234 .properties = mm8013_battery_props,
235 .num_properties = ARRAY_SIZE(mm8013_battery_props),
236 .get_property = mm8013_get_property,
237 };
238
239 static const struct regmap_config mm8013_regmap_config = {
240 .reg_bits = 8,
241 .val_bits = 16,
242 .max_register = 0x68,
243 .use_single_read = true,
244 .use_single_write = true,
245 .val_format_endian = REGMAP_ENDIAN_LITTLE,
246 };
247
mm8013_probe(struct i2c_client * client)248 static int mm8013_probe(struct i2c_client *client)
249 {
250 struct power_supply_config psy_cfg = {};
251 struct device *dev = &client->dev;
252 struct power_supply *psy;
253 struct mm8013_chip *chip;
254 int ret = 0;
255
256 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
257 return dev_err_probe(dev, -EIO,
258 "I2C_FUNC_SMBUS_WORD_DATA not supported\n");
259
260 chip = devm_kzalloc(dev, sizeof(struct mm8013_chip), GFP_KERNEL);
261 if (!chip)
262 return -ENOMEM;
263
264 chip->client = client;
265
266 chip->regmap = devm_regmap_init_i2c(client, &mm8013_regmap_config);
267 if (IS_ERR(chip->regmap)) {
268 ret = PTR_ERR(chip->regmap);
269 return dev_err_probe(dev, ret, "Couldn't initialize regmap\n");
270 }
271
272 ret = mm8013_checkdevice(chip);
273 if (ret)
274 return dev_err_probe(dev, ret, "MM8013 not found\n");
275
276 psy_cfg.drv_data = chip;
277 psy_cfg.of_node = dev->of_node;
278
279 psy = devm_power_supply_register(dev, &mm8013_desc, &psy_cfg);
280 if (IS_ERR(psy))
281 return PTR_ERR(psy);
282
283 return 0;
284 }
285
286 static const struct i2c_device_id mm8013_id_table[] = {
287 { "mm8013" },
288 {}
289 };
290 MODULE_DEVICE_TABLE(i2c, mm8013_id_table);
291
292 static const struct of_device_id mm8013_match_table[] = {
293 { .compatible = "mitsumi,mm8013" },
294 {}
295 };
296
297 static struct i2c_driver mm8013_i2c_driver = {
298 .probe = mm8013_probe,
299 .id_table = mm8013_id_table,
300 .driver = {
301 .name = "mm8013",
302 .of_match_table = mm8013_match_table,
303 },
304 };
305 module_i2c_driver(mm8013_i2c_driver);
306
307 MODULE_DESCRIPTION("MM8013 fuel gauge driver");
308 MODULE_LICENSE("GPL");
309