Commit | Line | Data |
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bfdb46ce RM |
1 | /* |
2 | * I2C client/driver for the Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC | |
3 | * | |
4 | * Copyright (C) 2009 Bluewater Systems Ltd | |
5 | * | |
1c5454ee | 6 | * Author: Ryan Mallon |
bfdb46ce | 7 | * |
9b9ade6b YV |
8 | * DS2786 added by Yulia Vilensky <vilensky@compulab.co.il> |
9 | * | |
7cee9aef ER |
10 | * UEvent sending added by Evgeny Romanov <romanov@neurosoft.ru> |
11 | * | |
bfdb46ce RM |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/swab.h> | |
23 | #include <linux/i2c.h> | |
7cee9aef | 24 | #include <linux/delay.h> |
bfdb46ce RM |
25 | #include <linux/idr.h> |
26 | #include <linux/power_supply.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
9b9ade6b | 28 | #include <linux/ds2782_battery.h> |
bfdb46ce RM |
29 | |
30 | #define DS2782_REG_RARC 0x06 /* Remaining active relative capacity */ | |
31 | ||
9b9ade6b YV |
32 | #define DS278x_REG_VOLT_MSB 0x0c |
33 | #define DS278x_REG_TEMP_MSB 0x0a | |
34 | #define DS278x_REG_CURRENT_MSB 0x0e | |
bfdb46ce RM |
35 | |
36 | /* EEPROM Block */ | |
37 | #define DS2782_REG_RSNSP 0x69 /* Sense resistor value */ | |
38 | ||
39 | /* Current unit measurement in uA for a 1 milli-ohm sense resistor */ | |
40 | #define DS2782_CURRENT_UNITS 1563 | |
41 | ||
9b9ade6b YV |
42 | #define DS2786_REG_RARC 0x02 /* Remaining active relative capacity */ |
43 | ||
44 | #define DS2786_CURRENT_UNITS 25 | |
45 | ||
7cee9aef ER |
46 | #define DS278x_DELAY 1000 |
47 | ||
9b9ade6b YV |
48 | struct ds278x_info; |
49 | ||
50 | struct ds278x_battery_ops { | |
eb9650d6 | 51 | int (*get_battery_current)(struct ds278x_info *info, int *current_uA); |
353f867b RM |
52 | int (*get_battery_voltage)(struct ds278x_info *info, int *voltage_uV); |
53 | int (*get_battery_capacity)(struct ds278x_info *info, int *capacity); | |
9b9ade6b YV |
54 | }; |
55 | ||
297d716f | 56 | #define to_ds278x_info(x) power_supply_get_drvdata(x) |
bfdb46ce | 57 | |
9b9ade6b | 58 | struct ds278x_info { |
bfdb46ce | 59 | struct i2c_client *client; |
297d716f KK |
60 | struct power_supply *battery; |
61 | struct power_supply_desc battery_desc; | |
9b9ade6b | 62 | struct ds278x_battery_ops *ops; |
7cee9aef | 63 | struct delayed_work bat_work; |
bfdb46ce | 64 | int id; |
9b9ade6b | 65 | int rsns; |
7cee9aef ER |
66 | int capacity; |
67 | int status; /* State Of Charge */ | |
bfdb46ce RM |
68 | }; |
69 | ||
70 | static DEFINE_IDR(battery_id); | |
71 | static DEFINE_MUTEX(battery_lock); | |
72 | ||
9b9ade6b | 73 | static inline int ds278x_read_reg(struct ds278x_info *info, int reg, u8 *val) |
bfdb46ce RM |
74 | { |
75 | int ret; | |
76 | ||
77 | ret = i2c_smbus_read_byte_data(info->client, reg); | |
78 | if (ret < 0) { | |
79 | dev_err(&info->client->dev, "register read failed\n"); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | *val = ret; | |
84 | return 0; | |
85 | } | |
86 | ||
9b9ade6b | 87 | static inline int ds278x_read_reg16(struct ds278x_info *info, int reg_msb, |
bfdb46ce RM |
88 | s16 *val) |
89 | { | |
90 | int ret; | |
91 | ||
8511748b | 92 | ret = i2c_smbus_read_word_data(info->client, reg_msb); |
bfdb46ce RM |
93 | if (ret < 0) { |
94 | dev_err(&info->client->dev, "register read failed\n"); | |
95 | return ret; | |
96 | } | |
97 | ||
8511748b | 98 | *val = swab16(ret); |
bfdb46ce RM |
99 | return 0; |
100 | } | |
101 | ||
9b9ade6b | 102 | static int ds278x_get_temp(struct ds278x_info *info, int *temp) |
bfdb46ce RM |
103 | { |
104 | s16 raw; | |
105 | int err; | |
106 | ||
107 | /* | |
108 | * Temperature is measured in units of 0.125 degrees celcius, the | |
109 | * power_supply class measures temperature in tenths of degrees | |
110 | * celsius. The temperature value is stored as a 10 bit number, plus | |
111 | * sign in the upper bits of a 16 bit register. | |
112 | */ | |
9b9ade6b | 113 | err = ds278x_read_reg16(info, DS278x_REG_TEMP_MSB, &raw); |
bfdb46ce RM |
114 | if (err) |
115 | return err; | |
116 | *temp = ((raw / 32) * 125) / 100; | |
117 | return 0; | |
118 | } | |
119 | ||
9b9ade6b | 120 | static int ds2782_get_current(struct ds278x_info *info, int *current_uA) |
bfdb46ce RM |
121 | { |
122 | int sense_res; | |
123 | int err; | |
124 | u8 sense_res_raw; | |
125 | s16 raw; | |
126 | ||
127 | /* | |
128 | * The units of measurement for current are dependent on the value of | |
129 | * the sense resistor. | |
130 | */ | |
9b9ade6b | 131 | err = ds278x_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw); |
bfdb46ce RM |
132 | if (err) |
133 | return err; | |
134 | if (sense_res_raw == 0) { | |
135 | dev_err(&info->client->dev, "sense resistor value is 0\n"); | |
136 | return -ENXIO; | |
137 | } | |
138 | sense_res = 1000 / sense_res_raw; | |
139 | ||
140 | dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n", | |
141 | sense_res); | |
9b9ade6b | 142 | err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); |
bfdb46ce RM |
143 | if (err) |
144 | return err; | |
145 | *current_uA = raw * (DS2782_CURRENT_UNITS / sense_res); | |
146 | return 0; | |
147 | } | |
148 | ||
353f867b | 149 | static int ds2782_get_voltage(struct ds278x_info *info, int *voltage_uV) |
bfdb46ce RM |
150 | { |
151 | s16 raw; | |
152 | int err; | |
153 | ||
154 | /* | |
155 | * Voltage is measured in units of 4.88mV. The voltage is stored as | |
156 | * a 10-bit number plus sign, in the upper bits of a 16-bit register | |
157 | */ | |
9b9ade6b | 158 | err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); |
bfdb46ce RM |
159 | if (err) |
160 | return err; | |
353f867b | 161 | *voltage_uV = (raw / 32) * 4800; |
bfdb46ce RM |
162 | return 0; |
163 | } | |
164 | ||
9b9ade6b | 165 | static int ds2782_get_capacity(struct ds278x_info *info, int *capacity) |
bfdb46ce RM |
166 | { |
167 | int err; | |
168 | u8 raw; | |
169 | ||
9b9ade6b | 170 | err = ds278x_read_reg(info, DS2782_REG_RARC, &raw); |
bfdb46ce RM |
171 | if (err) |
172 | return err; | |
173 | *capacity = raw; | |
2d31757c | 174 | return 0; |
bfdb46ce RM |
175 | } |
176 | ||
9b9ade6b YV |
177 | static int ds2786_get_current(struct ds278x_info *info, int *current_uA) |
178 | { | |
179 | int err; | |
180 | s16 raw; | |
181 | ||
182 | err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); | |
183 | if (err) | |
184 | return err; | |
185 | *current_uA = (raw / 16) * (DS2786_CURRENT_UNITS / info->rsns); | |
186 | return 0; | |
187 | } | |
188 | ||
353f867b | 189 | static int ds2786_get_voltage(struct ds278x_info *info, int *voltage_uV) |
9b9ade6b YV |
190 | { |
191 | s16 raw; | |
192 | int err; | |
193 | ||
194 | /* | |
195 | * Voltage is measured in units of 1.22mV. The voltage is stored as | |
1b5e1c6e | 196 | * a 12-bit number plus sign, in the upper bits of a 16-bit register |
9b9ade6b YV |
197 | */ |
198 | err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); | |
199 | if (err) | |
200 | return err; | |
353f867b | 201 | *voltage_uV = (raw / 8) * 1220; |
9b9ade6b YV |
202 | return 0; |
203 | } | |
204 | ||
205 | static int ds2786_get_capacity(struct ds278x_info *info, int *capacity) | |
206 | { | |
207 | int err; | |
208 | u8 raw; | |
209 | ||
210 | err = ds278x_read_reg(info, DS2786_REG_RARC, &raw); | |
211 | if (err) | |
212 | return err; | |
213 | /* Relative capacity is displayed with resolution 0.5 % */ | |
214 | *capacity = raw/2 ; | |
215 | return 0; | |
216 | } | |
217 | ||
218 | static int ds278x_get_status(struct ds278x_info *info, int *status) | |
bfdb46ce RM |
219 | { |
220 | int err; | |
221 | int current_uA; | |
222 | int capacity; | |
223 | ||
eb9650d6 | 224 | err = info->ops->get_battery_current(info, ¤t_uA); |
bfdb46ce RM |
225 | if (err) |
226 | return err; | |
227 | ||
eb9650d6 | 228 | err = info->ops->get_battery_capacity(info, &capacity); |
bfdb46ce RM |
229 | if (err) |
230 | return err; | |
231 | ||
7cee9aef ER |
232 | info->capacity = capacity; |
233 | ||
bfdb46ce RM |
234 | if (capacity == 100) |
235 | *status = POWER_SUPPLY_STATUS_FULL; | |
236 | else if (current_uA == 0) | |
237 | *status = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
238 | else if (current_uA < 0) | |
239 | *status = POWER_SUPPLY_STATUS_DISCHARGING; | |
240 | else | |
241 | *status = POWER_SUPPLY_STATUS_CHARGING; | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
9b9ade6b | 246 | static int ds278x_battery_get_property(struct power_supply *psy, |
bfdb46ce RM |
247 | enum power_supply_property prop, |
248 | union power_supply_propval *val) | |
249 | { | |
9b9ade6b | 250 | struct ds278x_info *info = to_ds278x_info(psy); |
bfdb46ce RM |
251 | int ret; |
252 | ||
253 | switch (prop) { | |
254 | case POWER_SUPPLY_PROP_STATUS: | |
9b9ade6b | 255 | ret = ds278x_get_status(info, &val->intval); |
bfdb46ce RM |
256 | break; |
257 | ||
258 | case POWER_SUPPLY_PROP_CAPACITY: | |
eb9650d6 | 259 | ret = info->ops->get_battery_capacity(info, &val->intval); |
bfdb46ce RM |
260 | break; |
261 | ||
262 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
eb9650d6 | 263 | ret = info->ops->get_battery_voltage(info, &val->intval); |
bfdb46ce RM |
264 | break; |
265 | ||
266 | case POWER_SUPPLY_PROP_CURRENT_NOW: | |
eb9650d6 | 267 | ret = info->ops->get_battery_current(info, &val->intval); |
bfdb46ce RM |
268 | break; |
269 | ||
270 | case POWER_SUPPLY_PROP_TEMP: | |
9b9ade6b | 271 | ret = ds278x_get_temp(info, &val->intval); |
bfdb46ce RM |
272 | break; |
273 | ||
274 | default: | |
275 | ret = -EINVAL; | |
276 | } | |
277 | ||
278 | return ret; | |
279 | } | |
280 | ||
7cee9aef ER |
281 | static void ds278x_bat_update(struct ds278x_info *info) |
282 | { | |
283 | int old_status = info->status; | |
284 | int old_capacity = info->capacity; | |
285 | ||
286 | ds278x_get_status(info, &info->status); | |
287 | ||
288 | if ((old_status != info->status) || (old_capacity != info->capacity)) | |
297d716f | 289 | power_supply_changed(info->battery); |
7cee9aef ER |
290 | } |
291 | ||
292 | static void ds278x_bat_work(struct work_struct *work) | |
293 | { | |
294 | struct ds278x_info *info; | |
295 | ||
296 | info = container_of(work, struct ds278x_info, bat_work.work); | |
297 | ds278x_bat_update(info); | |
298 | ||
299 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
300 | } | |
301 | ||
9b9ade6b | 302 | static enum power_supply_property ds278x_battery_props[] = { |
bfdb46ce RM |
303 | POWER_SUPPLY_PROP_STATUS, |
304 | POWER_SUPPLY_PROP_CAPACITY, | |
305 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
306 | POWER_SUPPLY_PROP_CURRENT_NOW, | |
307 | POWER_SUPPLY_PROP_TEMP, | |
308 | }; | |
309 | ||
297d716f | 310 | static void ds278x_power_supply_init(struct power_supply_desc *battery) |
bfdb46ce RM |
311 | { |
312 | battery->type = POWER_SUPPLY_TYPE_BATTERY; | |
9b9ade6b YV |
313 | battery->properties = ds278x_battery_props; |
314 | battery->num_properties = ARRAY_SIZE(ds278x_battery_props); | |
315 | battery->get_property = ds278x_battery_get_property; | |
bfdb46ce RM |
316 | battery->external_power_changed = NULL; |
317 | } | |
318 | ||
9b9ade6b | 319 | static int ds278x_battery_remove(struct i2c_client *client) |
bfdb46ce | 320 | { |
9b9ade6b | 321 | struct ds278x_info *info = i2c_get_clientdata(client); |
bfdb46ce | 322 | |
297d716f KK |
323 | power_supply_unregister(info->battery); |
324 | kfree(info->battery_desc.name); | |
bfdb46ce RM |
325 | |
326 | mutex_lock(&battery_lock); | |
327 | idr_remove(&battery_id, info->id); | |
328 | mutex_unlock(&battery_lock); | |
329 | ||
7cee9aef ER |
330 | cancel_delayed_work(&info->bat_work); |
331 | ||
bfdb46ce RM |
332 | kfree(info); |
333 | return 0; | |
334 | } | |
335 | ||
cc6616f6 | 336 | #ifdef CONFIG_PM_SLEEP |
7cee9aef | 337 | |
cc6616f6 | 338 | static int ds278x_suspend(struct device *dev) |
7cee9aef | 339 | { |
cc6616f6 | 340 | struct i2c_client *client = to_i2c_client(dev); |
7cee9aef ER |
341 | struct ds278x_info *info = i2c_get_clientdata(client); |
342 | ||
343 | cancel_delayed_work(&info->bat_work); | |
344 | return 0; | |
345 | } | |
346 | ||
cc6616f6 | 347 | static int ds278x_resume(struct device *dev) |
7cee9aef | 348 | { |
cc6616f6 | 349 | struct i2c_client *client = to_i2c_client(dev); |
7cee9aef ER |
350 | struct ds278x_info *info = i2c_get_clientdata(client); |
351 | ||
352 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
353 | return 0; | |
354 | } | |
99a79565 | 355 | #endif /* CONFIG_PM_SLEEP */ |
7cee9aef | 356 | |
cc6616f6 | 357 | static SIMPLE_DEV_PM_OPS(ds278x_battery_pm_ops, ds278x_suspend, ds278x_resume); |
7cee9aef | 358 | |
ab6cc8f9 AV |
359 | enum ds278x_num_id { |
360 | DS2782 = 0, | |
361 | DS2786, | |
362 | }; | |
363 | ||
9b9ade6b | 364 | static struct ds278x_battery_ops ds278x_ops[] = { |
ab6cc8f9 | 365 | [DS2782] = { |
eb9650d6 PH |
366 | .get_battery_current = ds2782_get_current, |
367 | .get_battery_voltage = ds2782_get_voltage, | |
368 | .get_battery_capacity = ds2782_get_capacity, | |
9b9ade6b | 369 | }, |
ab6cc8f9 | 370 | [DS2786] = { |
eb9650d6 PH |
371 | .get_battery_current = ds2786_get_current, |
372 | .get_battery_voltage = ds2786_get_voltage, | |
373 | .get_battery_capacity = ds2786_get_capacity, | |
9b9ade6b YV |
374 | } |
375 | }; | |
376 | ||
377 | static int ds278x_battery_probe(struct i2c_client *client, | |
bfdb46ce RM |
378 | const struct i2c_device_id *id) |
379 | { | |
9b9ade6b | 380 | struct ds278x_platform_data *pdata = client->dev.platform_data; |
297d716f | 381 | struct power_supply_config psy_cfg = {}; |
9b9ade6b | 382 | struct ds278x_info *info; |
bfdb46ce RM |
383 | int ret; |
384 | int num; | |
385 | ||
9b9ade6b YV |
386 | /* |
387 | * ds2786 should have the sense resistor value set | |
388 | * in the platform data | |
389 | */ | |
ab6cc8f9 | 390 | if (id->driver_data == DS2786 && !pdata) { |
9b9ade6b YV |
391 | dev_err(&client->dev, "missing platform data for ds2786\n"); |
392 | return -EINVAL; | |
393 | } | |
394 | ||
bfdb46ce | 395 | /* Get an ID for this battery */ |
bfdb46ce | 396 | mutex_lock(&battery_lock); |
05e2cefa | 397 | ret = idr_alloc(&battery_id, client, 0, 0, GFP_KERNEL); |
bfdb46ce RM |
398 | mutex_unlock(&battery_lock); |
399 | if (ret < 0) | |
400 | goto fail_id; | |
05e2cefa | 401 | num = ret; |
bfdb46ce RM |
402 | |
403 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
404 | if (!info) { | |
405 | ret = -ENOMEM; | |
406 | goto fail_info; | |
407 | } | |
408 | ||
297d716f KK |
409 | info->battery_desc.name = kasprintf(GFP_KERNEL, "%s-%d", |
410 | client->name, num); | |
411 | if (!info->battery_desc.name) { | |
bfdb46ce RM |
412 | ret = -ENOMEM; |
413 | goto fail_name; | |
414 | } | |
415 | ||
ab6cc8f9 | 416 | if (id->driver_data == DS2786) |
9b9ade6b YV |
417 | info->rsns = pdata->rsns; |
418 | ||
bfdb46ce RM |
419 | i2c_set_clientdata(client, info); |
420 | info->client = client; | |
9b9ade6b YV |
421 | info->id = num; |
422 | info->ops = &ds278x_ops[id->driver_data]; | |
297d716f KK |
423 | ds278x_power_supply_init(&info->battery_desc); |
424 | psy_cfg.drv_data = info; | |
bfdb46ce | 425 | |
7cee9aef ER |
426 | info->capacity = 100; |
427 | info->status = POWER_SUPPLY_STATUS_FULL; | |
428 | ||
429 | INIT_DELAYED_WORK(&info->bat_work, ds278x_bat_work); | |
430 | ||
297d716f KK |
431 | info->battery = power_supply_register(&client->dev, |
432 | &info->battery_desc, &psy_cfg); | |
433 | if (IS_ERR(info->battery)) { | |
bfdb46ce | 434 | dev_err(&client->dev, "failed to register battery\n"); |
297d716f | 435 | ret = PTR_ERR(info->battery); |
bfdb46ce | 436 | goto fail_register; |
7cee9aef ER |
437 | } else { |
438 | schedule_delayed_work(&info->bat_work, DS278x_DELAY); | |
bfdb46ce RM |
439 | } |
440 | ||
441 | return 0; | |
442 | ||
443 | fail_register: | |
297d716f | 444 | kfree(info->battery_desc.name); |
bfdb46ce | 445 | fail_name: |
bfdb46ce RM |
446 | kfree(info); |
447 | fail_info: | |
448 | mutex_lock(&battery_lock); | |
449 | idr_remove(&battery_id, num); | |
450 | mutex_unlock(&battery_lock); | |
451 | fail_id: | |
452 | return ret; | |
453 | } | |
454 | ||
9b9ade6b | 455 | static const struct i2c_device_id ds278x_id[] = { |
ab6cc8f9 AV |
456 | {"ds2782", DS2782}, |
457 | {"ds2786", DS2786}, | |
bfdb46ce RM |
458 | {}, |
459 | }; | |
84ab16f5 | 460 | MODULE_DEVICE_TABLE(i2c, ds278x_id); |
bfdb46ce | 461 | |
9b9ade6b | 462 | static struct i2c_driver ds278x_battery_driver = { |
bfdb46ce RM |
463 | .driver = { |
464 | .name = "ds2782-battery", | |
99a79565 | 465 | .pm = &ds278x_battery_pm_ops, |
bfdb46ce | 466 | }, |
9b9ade6b YV |
467 | .probe = ds278x_battery_probe, |
468 | .remove = ds278x_battery_remove, | |
469 | .id_table = ds278x_id, | |
bfdb46ce | 470 | }; |
5ff92e7a | 471 | module_i2c_driver(ds278x_battery_driver); |
bfdb46ce | 472 | |
1c5454ee | 473 | MODULE_AUTHOR("Ryan Mallon"); |
bfdb46ce RM |
474 | MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver"); |
475 | MODULE_LICENSE("GPL"); |