xref: /linux/drivers/power/supply/ds2781_battery.c (revision 9ffd93852fc66f2bdf61a574db107f106e9fb2ff)
1 /*
2  * 1-wire client/driver for the Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC
3  *
4  * Author: Renata Sayakhova <renata@oktetlabs.ru>
5  *
6  * Based on ds2780_battery drivers
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 
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/param.h>
17 #include <linux/pm.h>
18 #include <linux/platform_device.h>
19 #include <linux/power_supply.h>
20 #include <linux/idr.h>
21 
22 #include <linux/w1.h>
23 #include "../../w1/slaves/w1_ds2781.h"
24 
25 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
26 #define DS2781_CURRENT_UNITS	1563
27 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
28 #define DS2781_CHARGE_UNITS		6250
29 /* Number of bytes in user EEPROM space */
30 #define DS2781_USER_EEPROM_SIZE		(DS2781_EEPROM_BLOCK0_END - \
31 					DS2781_EEPROM_BLOCK0_START + 1)
32 /* Number of bytes in parameter EEPROM space */
33 #define DS2781_PARAM_EEPROM_SIZE	(DS2781_EEPROM_BLOCK1_END - \
34 					DS2781_EEPROM_BLOCK1_START + 1)
35 
36 struct ds2781_device_info {
37 	struct device *dev;
38 	struct power_supply *bat;
39 	struct power_supply_desc bat_desc;
40 	struct device *w1_dev;
41 };
42 
43 enum current_types {
44 	CURRENT_NOW,
45 	CURRENT_AVG,
46 };
47 
48 static const char model[] = "DS2781";
49 static const char manufacturer[] = "Maxim/Dallas";
50 
51 static inline struct ds2781_device_info *
52 to_ds2781_device_info(struct power_supply *psy)
53 {
54 	return power_supply_get_drvdata(psy);
55 }
56 
57 static inline struct power_supply *to_power_supply(struct device *dev)
58 {
59 	return dev_get_drvdata(dev);
60 }
61 
62 static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
63 	char *buf, int addr, size_t count, int io)
64 {
65 	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
66 }
67 
68 static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
69 		int addr, size_t count)
70 {
71 	return ds2781_battery_io(dev_info, buf, addr, count, 0);
72 }
73 
74 static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val,
75 	int addr)
76 {
77 	return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0);
78 }
79 
80 static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val,
81 	int addr)
82 {
83 	int ret;
84 	u8 raw[2];
85 
86 	ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0);
87 	if (ret < 0)
88 		return ret;
89 
90 	*val = (raw[0] << 8) | raw[1];
91 
92 	return 0;
93 }
94 
95 static inline int ds2781_read_block(struct ds2781_device_info *dev_info,
96 	u8 *val, int addr, size_t count)
97 {
98 	return ds2781_battery_io(dev_info, val, addr, count, 0);
99 }
100 
101 static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val,
102 	int addr, size_t count)
103 {
104 	return ds2781_battery_io(dev_info, val, addr, count, 1);
105 }
106 
107 static inline int ds2781_store_eeprom(struct device *dev, int addr)
108 {
109 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA);
110 }
111 
112 static inline int ds2781_recall_eeprom(struct device *dev, int addr)
113 {
114 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA);
115 }
116 
117 static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg)
118 {
119 	int ret;
120 
121 	ret = ds2781_store_eeprom(dev_info->w1_dev, reg);
122 	if (ret < 0)
123 		return ret;
124 
125 	ret = ds2781_recall_eeprom(dev_info->w1_dev, reg);
126 	if (ret < 0)
127 		return ret;
128 
129 	return 0;
130 }
131 
132 /* Set sense resistor value in mhos */
133 static int ds2781_set_sense_register(struct ds2781_device_info *dev_info,
134 	u8 conductance)
135 {
136 	int ret;
137 
138 	ret = ds2781_write(dev_info, &conductance,
139 				DS2781_RSNSP, sizeof(u8));
140 	if (ret < 0)
141 		return ret;
142 
143 	return ds2781_save_eeprom(dev_info, DS2781_RSNSP);
144 }
145 
146 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
147 static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info,
148 	u16 *rsgain)
149 {
150 	return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB);
151 }
152 
153 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
154 static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info,
155 	u16 rsgain)
156 {
157 	int ret;
158 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
159 
160 	ret = ds2781_write(dev_info, raw,
161 				DS2781_RSGAIN_MSB, sizeof(raw));
162 	if (ret < 0)
163 		return ret;
164 
165 	return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB);
166 }
167 
168 static int ds2781_get_voltage(struct ds2781_device_info *dev_info,
169 	int *voltage_uV)
170 {
171 	int ret;
172 	char val[2];
173 	int voltage_raw;
174 
175 	ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8));
176 	if (ret < 0)
177 		return ret;
178 	/*
179 	 * The voltage value is located in 10 bits across the voltage MSB
180 	 * and LSB registers in two's compliment form
181 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
182 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
183 	 * voltage MSB register
184 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
185 	 * voltage LSB register
186 	 */
187 	voltage_raw = (val[0] << 3) |
188 		(val[1] >> 5);
189 
190 	/* DS2781 reports voltage in units of 9.76mV, but the battery class
191 	 * reports in units of uV, so convert by multiplying by 9760. */
192 	*voltage_uV = voltage_raw * 9760;
193 
194 	return 0;
195 }
196 
197 static int ds2781_get_temperature(struct ds2781_device_info *dev_info,
198 	int *temp)
199 {
200 	int ret;
201 	char val[2];
202 	int temp_raw;
203 
204 	ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8));
205 	if (ret < 0)
206 		return ret;
207 	/*
208 	 * The temperature value is located in 10 bits across the temperature
209 	 * MSB and LSB registers in two's compliment form
210 	 * Sign bit of the temperature value is in bit 7 of the temperature
211 	 * MSB register
212 	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
213 	 * temperature MSB register
214 	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
215 	 * temperature LSB register
216 	 */
217 	temp_raw = ((val[0]) << 3) |
218 		(val[1] >> 5);
219 	*temp = temp_raw + (temp_raw / 4);
220 
221 	return 0;
222 }
223 
224 static int ds2781_get_current(struct ds2781_device_info *dev_info,
225 	enum current_types type, int *current_uA)
226 {
227 	int ret, sense_res;
228 	s16 current_raw;
229 	u8 sense_res_raw, reg_msb;
230 
231 	/*
232 	 * The units of measurement for current are dependent on the value of
233 	 * the sense resistor.
234 	 */
235 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
236 	if (ret < 0)
237 		return ret;
238 
239 	if (sense_res_raw == 0) {
240 		dev_err(dev_info->dev, "sense resistor value is 0\n");
241 		return -EINVAL;
242 	}
243 	sense_res = 1000 / sense_res_raw;
244 
245 	if (type == CURRENT_NOW)
246 		reg_msb = DS2781_CURRENT_MSB;
247 	else if (type == CURRENT_AVG)
248 		reg_msb = DS2781_IAVG_MSB;
249 	else
250 		return -EINVAL;
251 
252 	/*
253 	 * The current value is located in 16 bits across the current MSB
254 	 * and LSB registers in two's compliment form
255 	 * Sign bit of the current value is in bit 7 of the current MSB register
256 	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
257 	 * MSB register
258 	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
259 	 * LSB register
260 	 */
261 	ret = ds2781_read16(dev_info, &current_raw, reg_msb);
262 	if (ret < 0)
263 		return ret;
264 
265 	*current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res);
266 	return 0;
267 }
268 
269 static int ds2781_get_accumulated_current(struct ds2781_device_info *dev_info,
270 	int *accumulated_current)
271 {
272 	int ret, sense_res;
273 	s16 current_raw;
274 	u8 sense_res_raw;
275 
276 	/*
277 	 * The units of measurement for accumulated current are dependent on
278 	 * the value of the sense resistor.
279 	 */
280 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
281 	if (ret < 0)
282 		return ret;
283 
284 	if (sense_res_raw == 0) {
285 		dev_err(dev_info->dev, "sense resistor value is 0\n");
286 		return -EINVAL;
287 	}
288 	sense_res = 1000 / sense_res_raw;
289 
290 	/*
291 	 * The ACR value is located in 16 bits across the ACR MSB and
292 	 * LSB registers
293 	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
294 	 * MSB register
295 	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
296 	 * LSB register
297 	 */
298 	ret = ds2781_read16(dev_info, &current_raw, DS2781_ACR_MSB);
299 	if (ret < 0)
300 		return ret;
301 
302 	*accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res);
303 	return 0;
304 }
305 
306 static int ds2781_get_capacity(struct ds2781_device_info *dev_info,
307 	int *capacity)
308 {
309 	int ret;
310 	u8 raw;
311 
312 	ret = ds2781_read8(dev_info, &raw, DS2781_RARC);
313 	if (ret < 0)
314 		return ret;
315 
316 	*capacity = raw;
317 	return 0;
318 }
319 
320 static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status)
321 {
322 	int ret, current_uA, capacity;
323 
324 	ret = ds2781_get_current(dev_info, CURRENT_NOW, &current_uA);
325 	if (ret < 0)
326 		return ret;
327 
328 	ret = ds2781_get_capacity(dev_info, &capacity);
329 	if (ret < 0)
330 		return ret;
331 
332 	if (power_supply_am_i_supplied(dev_info->bat)) {
333 		if (capacity == 100)
334 			*status = POWER_SUPPLY_STATUS_FULL;
335 		else if (current_uA > 50000)
336 			*status = POWER_SUPPLY_STATUS_CHARGING;
337 		else
338 			*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
339 	} else {
340 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
341 	}
342 	return 0;
343 }
344 
345 static int ds2781_get_charge_now(struct ds2781_device_info *dev_info,
346 	int *charge_now)
347 {
348 	int ret;
349 	u16 charge_raw;
350 
351 	/*
352 	 * The RAAC value is located in 16 bits across the RAAC MSB and
353 	 * LSB registers
354 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
355 	 * MSB register
356 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
357 	 * LSB register
358 	 */
359 	ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB);
360 	if (ret < 0)
361 		return ret;
362 
363 	*charge_now = charge_raw * 1600;
364 	return 0;
365 }
366 
367 static int ds2781_get_control_register(struct ds2781_device_info *dev_info,
368 	u8 *control_reg)
369 {
370 	return ds2781_read8(dev_info, control_reg, DS2781_CONTROL);
371 }
372 
373 static int ds2781_set_control_register(struct ds2781_device_info *dev_info,
374 	u8 control_reg)
375 {
376 	int ret;
377 
378 	ret = ds2781_write(dev_info, &control_reg,
379 				DS2781_CONTROL, sizeof(u8));
380 	if (ret < 0)
381 		return ret;
382 
383 	return ds2781_save_eeprom(dev_info, DS2781_CONTROL);
384 }
385 
386 static int ds2781_battery_get_property(struct power_supply *psy,
387 	enum power_supply_property psp,
388 	union power_supply_propval *val)
389 {
390 	int ret = 0;
391 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
392 
393 	switch (psp) {
394 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
395 		ret = ds2781_get_voltage(dev_info, &val->intval);
396 		break;
397 
398 	case POWER_SUPPLY_PROP_TEMP:
399 		ret = ds2781_get_temperature(dev_info, &val->intval);
400 		break;
401 
402 	case POWER_SUPPLY_PROP_MODEL_NAME:
403 		val->strval = model;
404 		break;
405 
406 	case POWER_SUPPLY_PROP_MANUFACTURER:
407 		val->strval = manufacturer;
408 		break;
409 
410 	case POWER_SUPPLY_PROP_CURRENT_NOW:
411 		ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval);
412 		break;
413 
414 	case POWER_SUPPLY_PROP_CURRENT_AVG:
415 		ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval);
416 		break;
417 
418 	case POWER_SUPPLY_PROP_STATUS:
419 		ret = ds2781_get_status(dev_info, &val->intval);
420 		break;
421 
422 	case POWER_SUPPLY_PROP_CAPACITY:
423 		ret = ds2781_get_capacity(dev_info, &val->intval);
424 		break;
425 
426 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
427 		ret = ds2781_get_accumulated_current(dev_info, &val->intval);
428 		break;
429 
430 	case POWER_SUPPLY_PROP_CHARGE_NOW:
431 		ret = ds2781_get_charge_now(dev_info, &val->intval);
432 		break;
433 
434 	default:
435 		ret = -EINVAL;
436 	}
437 
438 	return ret;
439 }
440 
441 static enum power_supply_property ds2781_battery_props[] = {
442 	POWER_SUPPLY_PROP_STATUS,
443 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
444 	POWER_SUPPLY_PROP_TEMP,
445 	POWER_SUPPLY_PROP_MODEL_NAME,
446 	POWER_SUPPLY_PROP_MANUFACTURER,
447 	POWER_SUPPLY_PROP_CURRENT_NOW,
448 	POWER_SUPPLY_PROP_CURRENT_AVG,
449 	POWER_SUPPLY_PROP_CAPACITY,
450 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
451 	POWER_SUPPLY_PROP_CHARGE_NOW,
452 };
453 
454 static ssize_t ds2781_get_pmod_enabled(struct device *dev,
455 	struct device_attribute *attr,
456 	char *buf)
457 {
458 	int ret;
459 	u8 control_reg;
460 	struct power_supply *psy = to_power_supply(dev);
461 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
462 
463 	/* Get power mode */
464 	ret = ds2781_get_control_register(dev_info, &control_reg);
465 	if (ret < 0)
466 		return ret;
467 
468 	return sprintf(buf, "%d\n",
469 		 !!(control_reg & DS2781_CONTROL_PMOD));
470 }
471 
472 static ssize_t ds2781_set_pmod_enabled(struct device *dev,
473 	struct device_attribute *attr,
474 	const char *buf,
475 	size_t count)
476 {
477 	int ret;
478 	u8 control_reg, new_setting;
479 	struct power_supply *psy = to_power_supply(dev);
480 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
481 
482 	/* Set power mode */
483 	ret = ds2781_get_control_register(dev_info, &control_reg);
484 	if (ret < 0)
485 		return ret;
486 
487 	ret = kstrtou8(buf, 0, &new_setting);
488 	if (ret < 0)
489 		return ret;
490 
491 	if ((new_setting != 0) && (new_setting != 1)) {
492 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
493 		return -EINVAL;
494 	}
495 
496 	if (new_setting)
497 		control_reg |= DS2781_CONTROL_PMOD;
498 	else
499 		control_reg &= ~DS2781_CONTROL_PMOD;
500 
501 	ret = ds2781_set_control_register(dev_info, control_reg);
502 	if (ret < 0)
503 		return ret;
504 
505 	return count;
506 }
507 
508 static ssize_t ds2781_get_sense_resistor_value(struct device *dev,
509 	struct device_attribute *attr,
510 	char *buf)
511 {
512 	int ret;
513 	u8 sense_resistor;
514 	struct power_supply *psy = to_power_supply(dev);
515 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
516 
517 	ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP);
518 	if (ret < 0)
519 		return ret;
520 
521 	ret = sprintf(buf, "%d\n", sense_resistor);
522 	return ret;
523 }
524 
525 static ssize_t ds2781_set_sense_resistor_value(struct device *dev,
526 	struct device_attribute *attr,
527 	const char *buf,
528 	size_t count)
529 {
530 	int ret;
531 	u8 new_setting;
532 	struct power_supply *psy = to_power_supply(dev);
533 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
534 
535 	ret = kstrtou8(buf, 0, &new_setting);
536 	if (ret < 0)
537 		return ret;
538 
539 	ret = ds2781_set_sense_register(dev_info, new_setting);
540 	if (ret < 0)
541 		return ret;
542 
543 	return count;
544 }
545 
546 static ssize_t ds2781_get_rsgain_setting(struct device *dev,
547 	struct device_attribute *attr,
548 	char *buf)
549 {
550 	int ret;
551 	u16 rsgain;
552 	struct power_supply *psy = to_power_supply(dev);
553 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
554 
555 	ret = ds2781_get_rsgain_register(dev_info, &rsgain);
556 	if (ret < 0)
557 		return ret;
558 
559 	return sprintf(buf, "%d\n", rsgain);
560 }
561 
562 static ssize_t ds2781_set_rsgain_setting(struct device *dev,
563 	struct device_attribute *attr,
564 	const char *buf,
565 	size_t count)
566 {
567 	int ret;
568 	u16 new_setting;
569 	struct power_supply *psy = to_power_supply(dev);
570 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
571 
572 	ret = kstrtou16(buf, 0, &new_setting);
573 	if (ret < 0)
574 		return ret;
575 
576 	/* Gain can only be from 0 to 1.999 in steps of .001 */
577 	if (new_setting > 1999) {
578 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
579 		return -EINVAL;
580 	}
581 
582 	ret = ds2781_set_rsgain_register(dev_info, new_setting);
583 	if (ret < 0)
584 		return ret;
585 
586 	return count;
587 }
588 
589 static ssize_t ds2781_get_pio_pin(struct device *dev,
590 	struct device_attribute *attr,
591 	char *buf)
592 {
593 	int ret;
594 	u8 sfr;
595 	struct power_supply *psy = to_power_supply(dev);
596 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
597 
598 	ret = ds2781_read8(dev_info, &sfr, DS2781_SFR);
599 	if (ret < 0)
600 		return ret;
601 
602 	ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC);
603 	return ret;
604 }
605 
606 static ssize_t ds2781_set_pio_pin(struct device *dev,
607 	struct device_attribute *attr,
608 	const char *buf,
609 	size_t count)
610 {
611 	int ret;
612 	u8 new_setting;
613 	struct power_supply *psy = to_power_supply(dev);
614 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
615 
616 	ret = kstrtou8(buf, 0, &new_setting);
617 	if (ret < 0)
618 		return ret;
619 
620 	if ((new_setting != 0) && (new_setting != 1)) {
621 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
622 		return -EINVAL;
623 	}
624 
625 	ret = ds2781_write(dev_info, &new_setting,
626 				DS2781_SFR, sizeof(u8));
627 	if (ret < 0)
628 		return ret;
629 
630 	return count;
631 }
632 
633 static ssize_t ds2781_read_param_eeprom_bin(struct file *filp,
634 				struct kobject *kobj,
635 				struct bin_attribute *bin_attr,
636 				char *buf, loff_t off, size_t count)
637 {
638 	struct device *dev = container_of(kobj, struct device, kobj);
639 	struct power_supply *psy = to_power_supply(dev);
640 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
641 
642 	return ds2781_read_block(dev_info, buf,
643 				DS2781_EEPROM_BLOCK1_START + off, count);
644 }
645 
646 static ssize_t ds2781_write_param_eeprom_bin(struct file *filp,
647 				struct kobject *kobj,
648 				struct bin_attribute *bin_attr,
649 				char *buf, loff_t off, size_t count)
650 {
651 	struct device *dev = container_of(kobj, struct device, kobj);
652 	struct power_supply *psy = to_power_supply(dev);
653 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
654 	int ret;
655 
656 	ret = ds2781_write(dev_info, buf,
657 				DS2781_EEPROM_BLOCK1_START + off, count);
658 	if (ret < 0)
659 		return ret;
660 
661 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START);
662 	if (ret < 0)
663 		return ret;
664 
665 	return count;
666 }
667 
668 static struct bin_attribute ds2781_param_eeprom_bin_attr = {
669 	.attr = {
670 		.name = "param_eeprom",
671 		.mode = S_IRUGO | S_IWUSR,
672 	},
673 	.size = DS2781_PARAM_EEPROM_SIZE,
674 	.read = ds2781_read_param_eeprom_bin,
675 	.write = ds2781_write_param_eeprom_bin,
676 };
677 
678 static ssize_t ds2781_read_user_eeprom_bin(struct file *filp,
679 				struct kobject *kobj,
680 				struct bin_attribute *bin_attr,
681 				char *buf, loff_t off, size_t count)
682 {
683 	struct device *dev = container_of(kobj, struct device, kobj);
684 	struct power_supply *psy = to_power_supply(dev);
685 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
686 
687 	return ds2781_read_block(dev_info, buf,
688 				DS2781_EEPROM_BLOCK0_START + off, count);
689 
690 }
691 
692 static ssize_t ds2781_write_user_eeprom_bin(struct file *filp,
693 				struct kobject *kobj,
694 				struct bin_attribute *bin_attr,
695 				char *buf, loff_t off, size_t count)
696 {
697 	struct device *dev = container_of(kobj, struct device, kobj);
698 	struct power_supply *psy = to_power_supply(dev);
699 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
700 	int ret;
701 
702 	ret = ds2781_write(dev_info, buf,
703 				DS2781_EEPROM_BLOCK0_START + off, count);
704 	if (ret < 0)
705 		return ret;
706 
707 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START);
708 	if (ret < 0)
709 		return ret;
710 
711 	return count;
712 }
713 
714 static struct bin_attribute ds2781_user_eeprom_bin_attr = {
715 	.attr = {
716 		.name = "user_eeprom",
717 		.mode = S_IRUGO | S_IWUSR,
718 	},
719 	.size = DS2781_USER_EEPROM_SIZE,
720 	.read = ds2781_read_user_eeprom_bin,
721 	.write = ds2781_write_user_eeprom_bin,
722 };
723 
724 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled,
725 	ds2781_set_pmod_enabled);
726 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
727 	ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value);
728 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting,
729 	ds2781_set_rsgain_setting);
730 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin,
731 	ds2781_set_pio_pin);
732 
733 
734 static struct attribute *ds2781_attributes[] = {
735 	&dev_attr_pmod_enabled.attr,
736 	&dev_attr_sense_resistor_value.attr,
737 	&dev_attr_rsgain_setting.attr,
738 	&dev_attr_pio_pin.attr,
739 	NULL
740 };
741 
742 static const struct attribute_group ds2781_attr_group = {
743 	.attrs = ds2781_attributes,
744 };
745 
746 static int ds2781_battery_probe(struct platform_device *pdev)
747 {
748 	struct power_supply_config psy_cfg = {};
749 	int ret = 0;
750 	struct ds2781_device_info *dev_info;
751 
752 	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
753 	if (!dev_info)
754 		return -ENOMEM;
755 
756 	platform_set_drvdata(pdev, dev_info);
757 
758 	dev_info->dev			= &pdev->dev;
759 	dev_info->w1_dev		= pdev->dev.parent;
760 	dev_info->bat_desc.name		= dev_name(&pdev->dev);
761 	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
762 	dev_info->bat_desc.properties	= ds2781_battery_props;
763 	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2781_battery_props);
764 	dev_info->bat_desc.get_property	= ds2781_battery_get_property;
765 
766 	psy_cfg.drv_data		= dev_info;
767 
768 	dev_info->bat = power_supply_register(&pdev->dev, &dev_info->bat_desc,
769 						&psy_cfg);
770 	if (IS_ERR(dev_info->bat)) {
771 		dev_err(dev_info->dev, "failed to register battery\n");
772 		ret = PTR_ERR(dev_info->bat);
773 		goto fail;
774 	}
775 
776 	ret = sysfs_create_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
777 	if (ret) {
778 		dev_err(dev_info->dev, "failed to create sysfs group\n");
779 		goto fail_unregister;
780 	}
781 
782 	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
783 					&ds2781_param_eeprom_bin_attr);
784 	if (ret) {
785 		dev_err(dev_info->dev,
786 				"failed to create param eeprom bin file");
787 		goto fail_remove_group;
788 	}
789 
790 	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
791 					&ds2781_user_eeprom_bin_attr);
792 	if (ret) {
793 		dev_err(dev_info->dev,
794 				"failed to create user eeprom bin file");
795 		goto fail_remove_bin_file;
796 	}
797 
798 	return 0;
799 
800 fail_remove_bin_file:
801 	sysfs_remove_bin_file(&dev_info->bat->dev.kobj,
802 				&ds2781_param_eeprom_bin_attr);
803 fail_remove_group:
804 	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
805 fail_unregister:
806 	power_supply_unregister(dev_info->bat);
807 fail:
808 	return ret;
809 }
810 
811 static int ds2781_battery_remove(struct platform_device *pdev)
812 {
813 	struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
814 
815 	/*
816 	 * Remove attributes before unregistering power supply
817 	 * because 'bat' will be freed on power_supply_unregister() call.
818 	 */
819 	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
820 
821 	power_supply_unregister(dev_info->bat);
822 
823 	return 0;
824 }
825 
826 static struct platform_driver ds2781_battery_driver = {
827 	.driver = {
828 		.name = "ds2781-battery",
829 	},
830 	.probe	  = ds2781_battery_probe,
831 	.remove   = ds2781_battery_remove,
832 };
833 module_platform_driver(ds2781_battery_driver);
834 
835 MODULE_LICENSE("GPL");
836 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
837 MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauage IC driver");
838 MODULE_ALIAS("platform:ds2781-battery");
839 
840