1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * 1-wire client/driver for the Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC
4  *
5  * Author: Renata Sayakhova <renata@oktetlabs.ru>
6  *
7  * Based on ds2780_battery drivers
8  */
9 
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/param.h>
13 #include <linux/pm.h>
14 #include <linux/platform_device.h>
15 #include <linux/power_supply.h>
16 #include <linux/idr.h>
17 
18 #include <linux/w1.h>
19 #include "../../w1/slaves/w1_ds2781.h"
20 
21 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
22 #define DS2781_CURRENT_UNITS	1563
23 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
24 #define DS2781_CHARGE_UNITS		6250
25 /* Number of bytes in user EEPROM space */
26 #define DS2781_USER_EEPROM_SIZE		(DS2781_EEPROM_BLOCK0_END - \
27 					DS2781_EEPROM_BLOCK0_START + 1)
28 /* Number of bytes in parameter EEPROM space */
29 #define DS2781_PARAM_EEPROM_SIZE	(DS2781_EEPROM_BLOCK1_END - \
30 					DS2781_EEPROM_BLOCK1_START + 1)
31 
32 struct ds2781_device_info {
33 	struct device *dev;
34 	struct power_supply *bat;
35 	struct power_supply_desc bat_desc;
36 	struct device *w1_dev;
37 };
38 
39 enum current_types {
40 	CURRENT_NOW,
41 	CURRENT_AVG,
42 };
43 
44 static const char model[] = "DS2781";
45 static const char manufacturer[] = "Maxim/Dallas";
46 
47 static inline struct ds2781_device_info *
48 to_ds2781_device_info(struct power_supply *psy)
49 {
50 	return power_supply_get_drvdata(psy);
51 }
52 
53 static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
54 	char *buf, int addr, size_t count, int io)
55 {
56 	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
57 }
58 
59 static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
60 		int addr, size_t count)
61 {
62 	return ds2781_battery_io(dev_info, buf, addr, count, 0);
63 }
64 
65 static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val,
66 	int addr)
67 {
68 	return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0);
69 }
70 
71 static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val,
72 	int addr)
73 {
74 	int ret;
75 	u8 raw[2];
76 
77 	ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0);
78 	if (ret < 0)
79 		return ret;
80 
81 	*val = (raw[0] << 8) | raw[1];
82 
83 	return 0;
84 }
85 
86 static inline int ds2781_read_block(struct ds2781_device_info *dev_info,
87 	u8 *val, int addr, size_t count)
88 {
89 	return ds2781_battery_io(dev_info, val, addr, count, 0);
90 }
91 
92 static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val,
93 	int addr, size_t count)
94 {
95 	return ds2781_battery_io(dev_info, val, addr, count, 1);
96 }
97 
98 static inline int ds2781_store_eeprom(struct device *dev, int addr)
99 {
100 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA);
101 }
102 
103 static inline int ds2781_recall_eeprom(struct device *dev, int addr)
104 {
105 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA);
106 }
107 
108 static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg)
109 {
110 	int ret;
111 
112 	ret = ds2781_store_eeprom(dev_info->w1_dev, reg);
113 	if (ret < 0)
114 		return ret;
115 
116 	ret = ds2781_recall_eeprom(dev_info->w1_dev, reg);
117 	if (ret < 0)
118 		return ret;
119 
120 	return 0;
121 }
122 
123 /* Set sense resistor value in mhos */
124 static int ds2781_set_sense_register(struct ds2781_device_info *dev_info,
125 	u8 conductance)
126 {
127 	int ret;
128 
129 	ret = ds2781_write(dev_info, &conductance,
130 				DS2781_RSNSP, sizeof(u8));
131 	if (ret < 0)
132 		return ret;
133 
134 	return ds2781_save_eeprom(dev_info, DS2781_RSNSP);
135 }
136 
137 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
138 static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info,
139 	u16 *rsgain)
140 {
141 	return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB);
142 }
143 
144 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
145 static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info,
146 	u16 rsgain)
147 {
148 	int ret;
149 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
150 
151 	ret = ds2781_write(dev_info, raw,
152 				DS2781_RSGAIN_MSB, sizeof(raw));
153 	if (ret < 0)
154 		return ret;
155 
156 	return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB);
157 }
158 
159 static int ds2781_get_voltage(struct ds2781_device_info *dev_info,
160 	int *voltage_uV)
161 {
162 	int ret;
163 	char val[2];
164 	int voltage_raw;
165 
166 	ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8));
167 	if (ret < 0)
168 		return ret;
169 	/*
170 	 * The voltage value is located in 10 bits across the voltage MSB
171 	 * and LSB registers in two's complement form
172 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
173 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
174 	 * voltage MSB register
175 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
176 	 * voltage LSB register
177 	 */
178 	voltage_raw = (val[0] << 3) |
179 		(val[1] >> 5);
180 
181 	/* DS2781 reports voltage in units of 9.76mV, but the battery class
182 	 * reports in units of uV, so convert by multiplying by 9760. */
183 	*voltage_uV = voltage_raw * 9760;
184 
185 	return 0;
186 }
187 
188 static int ds2781_get_temperature(struct ds2781_device_info *dev_info,
189 	int *temp)
190 {
191 	int ret;
192 	char val[2];
193 	int temp_raw;
194 
195 	ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8));
196 	if (ret < 0)
197 		return ret;
198 	/*
199 	 * The temperature value is located in 10 bits across the temperature
200 	 * MSB and LSB registers in two's complement form
201 	 * Sign bit of the temperature value is in bit 7 of the temperature
202 	 * MSB register
203 	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
204 	 * temperature MSB register
205 	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
206 	 * temperature LSB register
207 	 */
208 	temp_raw = ((val[0]) << 3) |
209 		(val[1] >> 5);
210 	*temp = temp_raw + (temp_raw / 4);
211 
212 	return 0;
213 }
214 
215 static int ds2781_get_current(struct ds2781_device_info *dev_info,
216 	enum current_types type, int *current_uA)
217 {
218 	int ret, sense_res;
219 	s16 current_raw;
220 	u8 sense_res_raw, reg_msb;
221 
222 	/*
223 	 * The units of measurement for current are dependent on the value of
224 	 * the sense resistor.
225 	 */
226 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
227 	if (ret < 0)
228 		return ret;
229 
230 	if (sense_res_raw == 0) {
231 		dev_err(dev_info->dev, "sense resistor value is 0\n");
232 		return -EINVAL;
233 	}
234 	sense_res = 1000 / sense_res_raw;
235 
236 	if (type == CURRENT_NOW)
237 		reg_msb = DS2781_CURRENT_MSB;
238 	else if (type == CURRENT_AVG)
239 		reg_msb = DS2781_IAVG_MSB;
240 	else
241 		return -EINVAL;
242 
243 	/*
244 	 * The current value is located in 16 bits across the current MSB
245 	 * and LSB registers in two's complement form
246 	 * Sign bit of the current value is in bit 7 of the current MSB register
247 	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
248 	 * MSB register
249 	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
250 	 * LSB register
251 	 */
252 	ret = ds2781_read16(dev_info, &current_raw, reg_msb);
253 	if (ret < 0)
254 		return ret;
255 
256 	*current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res);
257 	return 0;
258 }
259 
260 static int ds2781_get_accumulated_current(struct ds2781_device_info *dev_info,
261 	int *accumulated_current)
262 {
263 	int ret, sense_res;
264 	s16 current_raw;
265 	u8 sense_res_raw;
266 
267 	/*
268 	 * The units of measurement for accumulated current are dependent on
269 	 * the value of the sense resistor.
270 	 */
271 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
272 	if (ret < 0)
273 		return ret;
274 
275 	if (sense_res_raw == 0) {
276 		dev_err(dev_info->dev, "sense resistor value is 0\n");
277 		return -EINVAL;
278 	}
279 	sense_res = 1000 / sense_res_raw;
280 
281 	/*
282 	 * The ACR value is located in 16 bits across the ACR MSB and
283 	 * LSB registers
284 	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
285 	 * MSB register
286 	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
287 	 * LSB register
288 	 */
289 	ret = ds2781_read16(dev_info, &current_raw, DS2781_ACR_MSB);
290 	if (ret < 0)
291 		return ret;
292 
293 	*accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res);
294 	return 0;
295 }
296 
297 static int ds2781_get_capacity(struct ds2781_device_info *dev_info,
298 	int *capacity)
299 {
300 	int ret;
301 	u8 raw;
302 
303 	ret = ds2781_read8(dev_info, &raw, DS2781_RARC);
304 	if (ret < 0)
305 		return ret;
306 
307 	*capacity = raw;
308 	return 0;
309 }
310 
311 static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status)
312 {
313 	int ret, current_uA, capacity;
314 
315 	ret = ds2781_get_current(dev_info, CURRENT_NOW, &current_uA);
316 	if (ret < 0)
317 		return ret;
318 
319 	ret = ds2781_get_capacity(dev_info, &capacity);
320 	if (ret < 0)
321 		return ret;
322 
323 	if (power_supply_am_i_supplied(dev_info->bat)) {
324 		if (capacity == 100)
325 			*status = POWER_SUPPLY_STATUS_FULL;
326 		else if (current_uA > 50000)
327 			*status = POWER_SUPPLY_STATUS_CHARGING;
328 		else
329 			*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
330 	} else {
331 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
332 	}
333 	return 0;
334 }
335 
336 static int ds2781_get_charge_now(struct ds2781_device_info *dev_info,
337 	int *charge_now)
338 {
339 	int ret;
340 	u16 charge_raw;
341 
342 	/*
343 	 * The RAAC value is located in 16 bits across the RAAC MSB and
344 	 * LSB registers
345 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
346 	 * MSB register
347 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
348 	 * LSB register
349 	 */
350 	ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB);
351 	if (ret < 0)
352 		return ret;
353 
354 	*charge_now = charge_raw * 1600;
355 	return 0;
356 }
357 
358 static int ds2781_get_control_register(struct ds2781_device_info *dev_info,
359 	u8 *control_reg)
360 {
361 	return ds2781_read8(dev_info, control_reg, DS2781_CONTROL);
362 }
363 
364 static int ds2781_set_control_register(struct ds2781_device_info *dev_info,
365 	u8 control_reg)
366 {
367 	int ret;
368 
369 	ret = ds2781_write(dev_info, &control_reg,
370 				DS2781_CONTROL, sizeof(u8));
371 	if (ret < 0)
372 		return ret;
373 
374 	return ds2781_save_eeprom(dev_info, DS2781_CONTROL);
375 }
376 
377 static int ds2781_battery_get_property(struct power_supply *psy,
378 	enum power_supply_property psp,
379 	union power_supply_propval *val)
380 {
381 	int ret = 0;
382 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
383 
384 	switch (psp) {
385 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
386 		ret = ds2781_get_voltage(dev_info, &val->intval);
387 		break;
388 
389 	case POWER_SUPPLY_PROP_TEMP:
390 		ret = ds2781_get_temperature(dev_info, &val->intval);
391 		break;
392 
393 	case POWER_SUPPLY_PROP_MODEL_NAME:
394 		val->strval = model;
395 		break;
396 
397 	case POWER_SUPPLY_PROP_MANUFACTURER:
398 		val->strval = manufacturer;
399 		break;
400 
401 	case POWER_SUPPLY_PROP_CURRENT_NOW:
402 		ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval);
403 		break;
404 
405 	case POWER_SUPPLY_PROP_CURRENT_AVG:
406 		ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval);
407 		break;
408 
409 	case POWER_SUPPLY_PROP_STATUS:
410 		ret = ds2781_get_status(dev_info, &val->intval);
411 		break;
412 
413 	case POWER_SUPPLY_PROP_CAPACITY:
414 		ret = ds2781_get_capacity(dev_info, &val->intval);
415 		break;
416 
417 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
418 		ret = ds2781_get_accumulated_current(dev_info, &val->intval);
419 		break;
420 
421 	case POWER_SUPPLY_PROP_CHARGE_NOW:
422 		ret = ds2781_get_charge_now(dev_info, &val->intval);
423 		break;
424 
425 	default:
426 		ret = -EINVAL;
427 	}
428 
429 	return ret;
430 }
431 
432 static enum power_supply_property ds2781_battery_props[] = {
433 	POWER_SUPPLY_PROP_STATUS,
434 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
435 	POWER_SUPPLY_PROP_TEMP,
436 	POWER_SUPPLY_PROP_MODEL_NAME,
437 	POWER_SUPPLY_PROP_MANUFACTURER,
438 	POWER_SUPPLY_PROP_CURRENT_NOW,
439 	POWER_SUPPLY_PROP_CURRENT_AVG,
440 	POWER_SUPPLY_PROP_CAPACITY,
441 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
442 	POWER_SUPPLY_PROP_CHARGE_NOW,
443 };
444 
445 static ssize_t ds2781_get_pmod_enabled(struct device *dev,
446 	struct device_attribute *attr,
447 	char *buf)
448 {
449 	int ret;
450 	u8 control_reg;
451 	struct power_supply *psy = to_power_supply(dev);
452 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
453 
454 	/* Get power mode */
455 	ret = ds2781_get_control_register(dev_info, &control_reg);
456 	if (ret < 0)
457 		return ret;
458 
459 	return sprintf(buf, "%d\n",
460 		 !!(control_reg & DS2781_CONTROL_PMOD));
461 }
462 
463 static ssize_t ds2781_set_pmod_enabled(struct device *dev,
464 	struct device_attribute *attr,
465 	const char *buf,
466 	size_t count)
467 {
468 	int ret;
469 	u8 control_reg, new_setting;
470 	struct power_supply *psy = to_power_supply(dev);
471 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
472 
473 	/* Set power mode */
474 	ret = ds2781_get_control_register(dev_info, &control_reg);
475 	if (ret < 0)
476 		return ret;
477 
478 	ret = kstrtou8(buf, 0, &new_setting);
479 	if (ret < 0)
480 		return ret;
481 
482 	if ((new_setting != 0) && (new_setting != 1)) {
483 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
484 		return -EINVAL;
485 	}
486 
487 	if (new_setting)
488 		control_reg |= DS2781_CONTROL_PMOD;
489 	else
490 		control_reg &= ~DS2781_CONTROL_PMOD;
491 
492 	ret = ds2781_set_control_register(dev_info, control_reg);
493 	if (ret < 0)
494 		return ret;
495 
496 	return count;
497 }
498 
499 static ssize_t ds2781_get_sense_resistor_value(struct device *dev,
500 	struct device_attribute *attr,
501 	char *buf)
502 {
503 	int ret;
504 	u8 sense_resistor;
505 	struct power_supply *psy = to_power_supply(dev);
506 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
507 
508 	ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP);
509 	if (ret < 0)
510 		return ret;
511 
512 	ret = sprintf(buf, "%d\n", sense_resistor);
513 	return ret;
514 }
515 
516 static ssize_t ds2781_set_sense_resistor_value(struct device *dev,
517 	struct device_attribute *attr,
518 	const char *buf,
519 	size_t count)
520 {
521 	int ret;
522 	u8 new_setting;
523 	struct power_supply *psy = to_power_supply(dev);
524 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
525 
526 	ret = kstrtou8(buf, 0, &new_setting);
527 	if (ret < 0)
528 		return ret;
529 
530 	ret = ds2781_set_sense_register(dev_info, new_setting);
531 	if (ret < 0)
532 		return ret;
533 
534 	return count;
535 }
536 
537 static ssize_t ds2781_get_rsgain_setting(struct device *dev,
538 	struct device_attribute *attr,
539 	char *buf)
540 {
541 	int ret;
542 	u16 rsgain;
543 	struct power_supply *psy = to_power_supply(dev);
544 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
545 
546 	ret = ds2781_get_rsgain_register(dev_info, &rsgain);
547 	if (ret < 0)
548 		return ret;
549 
550 	return sprintf(buf, "%d\n", rsgain);
551 }
552 
553 static ssize_t ds2781_set_rsgain_setting(struct device *dev,
554 	struct device_attribute *attr,
555 	const char *buf,
556 	size_t count)
557 {
558 	int ret;
559 	u16 new_setting;
560 	struct power_supply *psy = to_power_supply(dev);
561 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
562 
563 	ret = kstrtou16(buf, 0, &new_setting);
564 	if (ret < 0)
565 		return ret;
566 
567 	/* Gain can only be from 0 to 1.999 in steps of .001 */
568 	if (new_setting > 1999) {
569 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
570 		return -EINVAL;
571 	}
572 
573 	ret = ds2781_set_rsgain_register(dev_info, new_setting);
574 	if (ret < 0)
575 		return ret;
576 
577 	return count;
578 }
579 
580 static ssize_t ds2781_get_pio_pin(struct device *dev,
581 	struct device_attribute *attr,
582 	char *buf)
583 {
584 	int ret;
585 	u8 sfr;
586 	struct power_supply *psy = to_power_supply(dev);
587 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
588 
589 	ret = ds2781_read8(dev_info, &sfr, DS2781_SFR);
590 	if (ret < 0)
591 		return ret;
592 
593 	ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC);
594 	return ret;
595 }
596 
597 static ssize_t ds2781_set_pio_pin(struct device *dev,
598 	struct device_attribute *attr,
599 	const char *buf,
600 	size_t count)
601 {
602 	int ret;
603 	u8 new_setting;
604 	struct power_supply *psy = to_power_supply(dev);
605 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
606 
607 	ret = kstrtou8(buf, 0, &new_setting);
608 	if (ret < 0)
609 		return ret;
610 
611 	if ((new_setting != 0) && (new_setting != 1)) {
612 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
613 		return -EINVAL;
614 	}
615 
616 	ret = ds2781_write(dev_info, &new_setting,
617 				DS2781_SFR, sizeof(u8));
618 	if (ret < 0)
619 		return ret;
620 
621 	return count;
622 }
623 
624 static ssize_t ds2781_read_param_eeprom_bin(struct file *filp,
625 				struct kobject *kobj,
626 				struct bin_attribute *bin_attr,
627 				char *buf, loff_t off, size_t count)
628 {
629 	struct device *dev = container_of(kobj, struct device, kobj);
630 	struct power_supply *psy = to_power_supply(dev);
631 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
632 
633 	return ds2781_read_block(dev_info, buf,
634 				DS2781_EEPROM_BLOCK1_START + off, count);
635 }
636 
637 static ssize_t ds2781_write_param_eeprom_bin(struct file *filp,
638 				struct kobject *kobj,
639 				struct bin_attribute *bin_attr,
640 				char *buf, loff_t off, size_t count)
641 {
642 	struct device *dev = container_of(kobj, struct device, kobj);
643 	struct power_supply *psy = to_power_supply(dev);
644 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
645 	int ret;
646 
647 	ret = ds2781_write(dev_info, buf,
648 				DS2781_EEPROM_BLOCK1_START + off, count);
649 	if (ret < 0)
650 		return ret;
651 
652 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START);
653 	if (ret < 0)
654 		return ret;
655 
656 	return count;
657 }
658 
659 static struct bin_attribute ds2781_param_eeprom_bin_attr = {
660 	.attr = {
661 		.name = "param_eeprom",
662 		.mode = S_IRUGO | S_IWUSR,
663 	},
664 	.size = DS2781_PARAM_EEPROM_SIZE,
665 	.read = ds2781_read_param_eeprom_bin,
666 	.write = ds2781_write_param_eeprom_bin,
667 };
668 
669 static ssize_t ds2781_read_user_eeprom_bin(struct file *filp,
670 				struct kobject *kobj,
671 				struct bin_attribute *bin_attr,
672 				char *buf, loff_t off, size_t count)
673 {
674 	struct device *dev = container_of(kobj, struct device, kobj);
675 	struct power_supply *psy = to_power_supply(dev);
676 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
677 
678 	return ds2781_read_block(dev_info, buf,
679 				DS2781_EEPROM_BLOCK0_START + off, count);
680 
681 }
682 
683 static ssize_t ds2781_write_user_eeprom_bin(struct file *filp,
684 				struct kobject *kobj,
685 				struct bin_attribute *bin_attr,
686 				char *buf, loff_t off, size_t count)
687 {
688 	struct device *dev = container_of(kobj, struct device, kobj);
689 	struct power_supply *psy = to_power_supply(dev);
690 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
691 	int ret;
692 
693 	ret = ds2781_write(dev_info, buf,
694 				DS2781_EEPROM_BLOCK0_START + off, count);
695 	if (ret < 0)
696 		return ret;
697 
698 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START);
699 	if (ret < 0)
700 		return ret;
701 
702 	return count;
703 }
704 
705 static struct bin_attribute ds2781_user_eeprom_bin_attr = {
706 	.attr = {
707 		.name = "user_eeprom",
708 		.mode = S_IRUGO | S_IWUSR,
709 	},
710 	.size = DS2781_USER_EEPROM_SIZE,
711 	.read = ds2781_read_user_eeprom_bin,
712 	.write = ds2781_write_user_eeprom_bin,
713 };
714 
715 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled,
716 	ds2781_set_pmod_enabled);
717 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
718 	ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value);
719 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting,
720 	ds2781_set_rsgain_setting);
721 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin,
722 	ds2781_set_pio_pin);
723 
724 static struct attribute *ds2781_sysfs_attrs[] = {
725 	&dev_attr_pmod_enabled.attr,
726 	&dev_attr_sense_resistor_value.attr,
727 	&dev_attr_rsgain_setting.attr,
728 	&dev_attr_pio_pin.attr,
729 	NULL
730 };
731 
732 static struct bin_attribute *ds2781_sysfs_bin_attrs[] = {
733 	&ds2781_param_eeprom_bin_attr,
734 	&ds2781_user_eeprom_bin_attr,
735 	NULL,
736 };
737 
738 static const struct attribute_group ds2781_sysfs_group = {
739 	.attrs = ds2781_sysfs_attrs,
740 	.bin_attrs = ds2781_sysfs_bin_attrs,
741 
742 };
743 
744 static const struct attribute_group *ds2781_sysfs_groups[] = {
745 	&ds2781_sysfs_group,
746 	NULL,
747 };
748 
749 static int ds2781_battery_probe(struct platform_device *pdev)
750 {
751 	struct power_supply_config psy_cfg = {};
752 	struct ds2781_device_info *dev_info;
753 
754 	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
755 	if (!dev_info)
756 		return -ENOMEM;
757 
758 	platform_set_drvdata(pdev, dev_info);
759 
760 	dev_info->dev			= &pdev->dev;
761 	dev_info->w1_dev		= pdev->dev.parent;
762 	dev_info->bat_desc.name		= dev_name(&pdev->dev);
763 	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
764 	dev_info->bat_desc.properties	= ds2781_battery_props;
765 	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2781_battery_props);
766 	dev_info->bat_desc.get_property	= ds2781_battery_get_property;
767 
768 	psy_cfg.drv_data		= dev_info;
769 	psy_cfg.attr_grp		= ds2781_sysfs_groups;
770 
771 	dev_info->bat = devm_power_supply_register(&pdev->dev,
772 						   &dev_info->bat_desc,
773 						   &psy_cfg);
774 	if (IS_ERR(dev_info->bat)) {
775 		dev_err(dev_info->dev, "failed to register battery\n");
776 		return PTR_ERR(dev_info->bat);
777 	}
778 
779 	return 0;
780 }
781 
782 static struct platform_driver ds2781_battery_driver = {
783 	.driver = {
784 		.name = "ds2781-battery",
785 	},
786 	.probe	  = ds2781_battery_probe,
787 };
788 module_platform_driver(ds2781_battery_driver);
789 
790 MODULE_LICENSE("GPL");
791 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
792 MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC driver");
793 MODULE_ALIAS("platform:ds2781-battery");
794 
795