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 int ds2781_battery_io(struct ds2781_device_info *dev_info,
58 	char *buf, int addr, size_t count, int io)
59 {
60 	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
61 }
62 
63 static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
64 		int addr, size_t count)
65 {
66 	return ds2781_battery_io(dev_info, buf, addr, count, 0);
67 }
68 
69 static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val,
70 	int addr)
71 {
72 	return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0);
73 }
74 
75 static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val,
76 	int addr)
77 {
78 	int ret;
79 	u8 raw[2];
80 
81 	ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0);
82 	if (ret < 0)
83 		return ret;
84 
85 	*val = (raw[0] << 8) | raw[1];
86 
87 	return 0;
88 }
89 
90 static inline int ds2781_read_block(struct ds2781_device_info *dev_info,
91 	u8 *val, int addr, size_t count)
92 {
93 	return ds2781_battery_io(dev_info, val, addr, count, 0);
94 }
95 
96 static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val,
97 	int addr, size_t count)
98 {
99 	return ds2781_battery_io(dev_info, val, addr, count, 1);
100 }
101 
102 static inline int ds2781_store_eeprom(struct device *dev, int addr)
103 {
104 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA);
105 }
106 
107 static inline int ds2781_recall_eeprom(struct device *dev, int addr)
108 {
109 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA);
110 }
111 
112 static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg)
113 {
114 	int ret;
115 
116 	ret = ds2781_store_eeprom(dev_info->w1_dev, reg);
117 	if (ret < 0)
118 		return ret;
119 
120 	ret = ds2781_recall_eeprom(dev_info->w1_dev, reg);
121 	if (ret < 0)
122 		return ret;
123 
124 	return 0;
125 }
126 
127 /* Set sense resistor value in mhos */
128 static int ds2781_set_sense_register(struct ds2781_device_info *dev_info,
129 	u8 conductance)
130 {
131 	int ret;
132 
133 	ret = ds2781_write(dev_info, &conductance,
134 				DS2781_RSNSP, sizeof(u8));
135 	if (ret < 0)
136 		return ret;
137 
138 	return ds2781_save_eeprom(dev_info, DS2781_RSNSP);
139 }
140 
141 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
142 static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info,
143 	u16 *rsgain)
144 {
145 	return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB);
146 }
147 
148 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
149 static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info,
150 	u16 rsgain)
151 {
152 	int ret;
153 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
154 
155 	ret = ds2781_write(dev_info, raw,
156 				DS2781_RSGAIN_MSB, sizeof(raw));
157 	if (ret < 0)
158 		return ret;
159 
160 	return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB);
161 }
162 
163 static int ds2781_get_voltage(struct ds2781_device_info *dev_info,
164 	int *voltage_uV)
165 {
166 	int ret;
167 	char val[2];
168 	int voltage_raw;
169 
170 	ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8));
171 	if (ret < 0)
172 		return ret;
173 	/*
174 	 * The voltage value is located in 10 bits across the voltage MSB
175 	 * and LSB registers in two's compliment form
176 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
177 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
178 	 * voltage MSB register
179 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
180 	 * voltage LSB register
181 	 */
182 	voltage_raw = (val[0] << 3) |
183 		(val[1] >> 5);
184 
185 	/* DS2781 reports voltage in units of 9.76mV, but the battery class
186 	 * reports in units of uV, so convert by multiplying by 9760. */
187 	*voltage_uV = voltage_raw * 9760;
188 
189 	return 0;
190 }
191 
192 static int ds2781_get_temperature(struct ds2781_device_info *dev_info,
193 	int *temp)
194 {
195 	int ret;
196 	char val[2];
197 	int temp_raw;
198 
199 	ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8));
200 	if (ret < 0)
201 		return ret;
202 	/*
203 	 * The temperature value is located in 10 bits across the temperature
204 	 * MSB and LSB registers in two's compliment form
205 	 * Sign bit of the temperature value is in bit 7 of the temperature
206 	 * MSB register
207 	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
208 	 * temperature MSB register
209 	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
210 	 * temperature LSB register
211 	 */
212 	temp_raw = ((val[0]) << 3) |
213 		(val[1] >> 5);
214 	*temp = temp_raw + (temp_raw / 4);
215 
216 	return 0;
217 }
218 
219 static int ds2781_get_current(struct ds2781_device_info *dev_info,
220 	enum current_types type, int *current_uA)
221 {
222 	int ret, sense_res;
223 	s16 current_raw;
224 	u8 sense_res_raw, reg_msb;
225 
226 	/*
227 	 * The units of measurement for current are dependent on the value of
228 	 * the sense resistor.
229 	 */
230 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
231 	if (ret < 0)
232 		return ret;
233 
234 	if (sense_res_raw == 0) {
235 		dev_err(dev_info->dev, "sense resistor value is 0\n");
236 		return -EINVAL;
237 	}
238 	sense_res = 1000 / sense_res_raw;
239 
240 	if (type == CURRENT_NOW)
241 		reg_msb = DS2781_CURRENT_MSB;
242 	else if (type == CURRENT_AVG)
243 		reg_msb = DS2781_IAVG_MSB;
244 	else
245 		return -EINVAL;
246 
247 	/*
248 	 * The current value is located in 16 bits across the current MSB
249 	 * and LSB registers in two's compliment form
250 	 * Sign bit of the current value is in bit 7 of the current MSB register
251 	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
252 	 * MSB register
253 	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
254 	 * LSB register
255 	 */
256 	ret = ds2781_read16(dev_info, &current_raw, reg_msb);
257 	if (ret < 0)
258 		return ret;
259 
260 	*current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res);
261 	return 0;
262 }
263 
264 static int ds2781_get_accumulated_current(struct ds2781_device_info *dev_info,
265 	int *accumulated_current)
266 {
267 	int ret, sense_res;
268 	s16 current_raw;
269 	u8 sense_res_raw;
270 
271 	/*
272 	 * The units of measurement for accumulated current are dependent on
273 	 * the value of the sense resistor.
274 	 */
275 	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
276 	if (ret < 0)
277 		return ret;
278 
279 	if (sense_res_raw == 0) {
280 		dev_err(dev_info->dev, "sense resistor value is 0\n");
281 		return -EINVAL;
282 	}
283 	sense_res = 1000 / sense_res_raw;
284 
285 	/*
286 	 * The ACR value is located in 16 bits across the ACR MSB and
287 	 * LSB registers
288 	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
289 	 * MSB register
290 	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
291 	 * LSB register
292 	 */
293 	ret = ds2781_read16(dev_info, &current_raw, DS2781_ACR_MSB);
294 	if (ret < 0)
295 		return ret;
296 
297 	*accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res);
298 	return 0;
299 }
300 
301 static int ds2781_get_capacity(struct ds2781_device_info *dev_info,
302 	int *capacity)
303 {
304 	int ret;
305 	u8 raw;
306 
307 	ret = ds2781_read8(dev_info, &raw, DS2781_RARC);
308 	if (ret < 0)
309 		return ret;
310 
311 	*capacity = raw;
312 	return 0;
313 }
314 
315 static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status)
316 {
317 	int ret, current_uA, capacity;
318 
319 	ret = ds2781_get_current(dev_info, CURRENT_NOW, &current_uA);
320 	if (ret < 0)
321 		return ret;
322 
323 	ret = ds2781_get_capacity(dev_info, &capacity);
324 	if (ret < 0)
325 		return ret;
326 
327 	if (power_supply_am_i_supplied(dev_info->bat)) {
328 		if (capacity == 100)
329 			*status = POWER_SUPPLY_STATUS_FULL;
330 		else if (current_uA > 50000)
331 			*status = POWER_SUPPLY_STATUS_CHARGING;
332 		else
333 			*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
334 	} else {
335 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
336 	}
337 	return 0;
338 }
339 
340 static int ds2781_get_charge_now(struct ds2781_device_info *dev_info,
341 	int *charge_now)
342 {
343 	int ret;
344 	u16 charge_raw;
345 
346 	/*
347 	 * The RAAC value is located in 16 bits across the RAAC MSB and
348 	 * LSB registers
349 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
350 	 * MSB register
351 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
352 	 * LSB register
353 	 */
354 	ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB);
355 	if (ret < 0)
356 		return ret;
357 
358 	*charge_now = charge_raw * 1600;
359 	return 0;
360 }
361 
362 static int ds2781_get_control_register(struct ds2781_device_info *dev_info,
363 	u8 *control_reg)
364 {
365 	return ds2781_read8(dev_info, control_reg, DS2781_CONTROL);
366 }
367 
368 static int ds2781_set_control_register(struct ds2781_device_info *dev_info,
369 	u8 control_reg)
370 {
371 	int ret;
372 
373 	ret = ds2781_write(dev_info, &control_reg,
374 				DS2781_CONTROL, sizeof(u8));
375 	if (ret < 0)
376 		return ret;
377 
378 	return ds2781_save_eeprom(dev_info, DS2781_CONTROL);
379 }
380 
381 static int ds2781_battery_get_property(struct power_supply *psy,
382 	enum power_supply_property psp,
383 	union power_supply_propval *val)
384 {
385 	int ret = 0;
386 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
387 
388 	switch (psp) {
389 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
390 		ret = ds2781_get_voltage(dev_info, &val->intval);
391 		break;
392 
393 	case POWER_SUPPLY_PROP_TEMP:
394 		ret = ds2781_get_temperature(dev_info, &val->intval);
395 		break;
396 
397 	case POWER_SUPPLY_PROP_MODEL_NAME:
398 		val->strval = model;
399 		break;
400 
401 	case POWER_SUPPLY_PROP_MANUFACTURER:
402 		val->strval = manufacturer;
403 		break;
404 
405 	case POWER_SUPPLY_PROP_CURRENT_NOW:
406 		ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval);
407 		break;
408 
409 	case POWER_SUPPLY_PROP_CURRENT_AVG:
410 		ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval);
411 		break;
412 
413 	case POWER_SUPPLY_PROP_STATUS:
414 		ret = ds2781_get_status(dev_info, &val->intval);
415 		break;
416 
417 	case POWER_SUPPLY_PROP_CAPACITY:
418 		ret = ds2781_get_capacity(dev_info, &val->intval);
419 		break;
420 
421 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
422 		ret = ds2781_get_accumulated_current(dev_info, &val->intval);
423 		break;
424 
425 	case POWER_SUPPLY_PROP_CHARGE_NOW:
426 		ret = ds2781_get_charge_now(dev_info, &val->intval);
427 		break;
428 
429 	default:
430 		ret = -EINVAL;
431 	}
432 
433 	return ret;
434 }
435 
436 static enum power_supply_property ds2781_battery_props[] = {
437 	POWER_SUPPLY_PROP_STATUS,
438 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
439 	POWER_SUPPLY_PROP_TEMP,
440 	POWER_SUPPLY_PROP_MODEL_NAME,
441 	POWER_SUPPLY_PROP_MANUFACTURER,
442 	POWER_SUPPLY_PROP_CURRENT_NOW,
443 	POWER_SUPPLY_PROP_CURRENT_AVG,
444 	POWER_SUPPLY_PROP_CAPACITY,
445 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
446 	POWER_SUPPLY_PROP_CHARGE_NOW,
447 };
448 
449 static ssize_t ds2781_get_pmod_enabled(struct device *dev,
450 	struct device_attribute *attr,
451 	char *buf)
452 {
453 	int ret;
454 	u8 control_reg;
455 	struct power_supply *psy = to_power_supply(dev);
456 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
457 
458 	/* Get power mode */
459 	ret = ds2781_get_control_register(dev_info, &control_reg);
460 	if (ret < 0)
461 		return ret;
462 
463 	return sprintf(buf, "%d\n",
464 		 !!(control_reg & DS2781_CONTROL_PMOD));
465 }
466 
467 static ssize_t ds2781_set_pmod_enabled(struct device *dev,
468 	struct device_attribute *attr,
469 	const char *buf,
470 	size_t count)
471 {
472 	int ret;
473 	u8 control_reg, new_setting;
474 	struct power_supply *psy = to_power_supply(dev);
475 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
476 
477 	/* Set power mode */
478 	ret = ds2781_get_control_register(dev_info, &control_reg);
479 	if (ret < 0)
480 		return ret;
481 
482 	ret = kstrtou8(buf, 0, &new_setting);
483 	if (ret < 0)
484 		return ret;
485 
486 	if ((new_setting != 0) && (new_setting != 1)) {
487 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
488 		return -EINVAL;
489 	}
490 
491 	if (new_setting)
492 		control_reg |= DS2781_CONTROL_PMOD;
493 	else
494 		control_reg &= ~DS2781_CONTROL_PMOD;
495 
496 	ret = ds2781_set_control_register(dev_info, control_reg);
497 	if (ret < 0)
498 		return ret;
499 
500 	return count;
501 }
502 
503 static ssize_t ds2781_get_sense_resistor_value(struct device *dev,
504 	struct device_attribute *attr,
505 	char *buf)
506 {
507 	int ret;
508 	u8 sense_resistor;
509 	struct power_supply *psy = to_power_supply(dev);
510 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
511 
512 	ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP);
513 	if (ret < 0)
514 		return ret;
515 
516 	ret = sprintf(buf, "%d\n", sense_resistor);
517 	return ret;
518 }
519 
520 static ssize_t ds2781_set_sense_resistor_value(struct device *dev,
521 	struct device_attribute *attr,
522 	const char *buf,
523 	size_t count)
524 {
525 	int ret;
526 	u8 new_setting;
527 	struct power_supply *psy = to_power_supply(dev);
528 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
529 
530 	ret = kstrtou8(buf, 0, &new_setting);
531 	if (ret < 0)
532 		return ret;
533 
534 	ret = ds2781_set_sense_register(dev_info, new_setting);
535 	if (ret < 0)
536 		return ret;
537 
538 	return count;
539 }
540 
541 static ssize_t ds2781_get_rsgain_setting(struct device *dev,
542 	struct device_attribute *attr,
543 	char *buf)
544 {
545 	int ret;
546 	u16 rsgain;
547 	struct power_supply *psy = to_power_supply(dev);
548 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
549 
550 	ret = ds2781_get_rsgain_register(dev_info, &rsgain);
551 	if (ret < 0)
552 		return ret;
553 
554 	return sprintf(buf, "%d\n", rsgain);
555 }
556 
557 static ssize_t ds2781_set_rsgain_setting(struct device *dev,
558 	struct device_attribute *attr,
559 	const char *buf,
560 	size_t count)
561 {
562 	int ret;
563 	u16 new_setting;
564 	struct power_supply *psy = to_power_supply(dev);
565 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
566 
567 	ret = kstrtou16(buf, 0, &new_setting);
568 	if (ret < 0)
569 		return ret;
570 
571 	/* Gain can only be from 0 to 1.999 in steps of .001 */
572 	if (new_setting > 1999) {
573 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
574 		return -EINVAL;
575 	}
576 
577 	ret = ds2781_set_rsgain_register(dev_info, new_setting);
578 	if (ret < 0)
579 		return ret;
580 
581 	return count;
582 }
583 
584 static ssize_t ds2781_get_pio_pin(struct device *dev,
585 	struct device_attribute *attr,
586 	char *buf)
587 {
588 	int ret;
589 	u8 sfr;
590 	struct power_supply *psy = to_power_supply(dev);
591 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
592 
593 	ret = ds2781_read8(dev_info, &sfr, DS2781_SFR);
594 	if (ret < 0)
595 		return ret;
596 
597 	ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC);
598 	return ret;
599 }
600 
601 static ssize_t ds2781_set_pio_pin(struct device *dev,
602 	struct device_attribute *attr,
603 	const char *buf,
604 	size_t count)
605 {
606 	int ret;
607 	u8 new_setting;
608 	struct power_supply *psy = to_power_supply(dev);
609 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
610 
611 	ret = kstrtou8(buf, 0, &new_setting);
612 	if (ret < 0)
613 		return ret;
614 
615 	if ((new_setting != 0) && (new_setting != 1)) {
616 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
617 		return -EINVAL;
618 	}
619 
620 	ret = ds2781_write(dev_info, &new_setting,
621 				DS2781_SFR, sizeof(u8));
622 	if (ret < 0)
623 		return ret;
624 
625 	return count;
626 }
627 
628 static ssize_t ds2781_read_param_eeprom_bin(struct file *filp,
629 				struct kobject *kobj,
630 				struct bin_attribute *bin_attr,
631 				char *buf, loff_t off, size_t count)
632 {
633 	struct device *dev = container_of(kobj, struct device, kobj);
634 	struct power_supply *psy = to_power_supply(dev);
635 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
636 
637 	return ds2781_read_block(dev_info, buf,
638 				DS2781_EEPROM_BLOCK1_START + off, count);
639 }
640 
641 static ssize_t ds2781_write_param_eeprom_bin(struct file *filp,
642 				struct kobject *kobj,
643 				struct bin_attribute *bin_attr,
644 				char *buf, loff_t off, size_t count)
645 {
646 	struct device *dev = container_of(kobj, struct device, kobj);
647 	struct power_supply *psy = to_power_supply(dev);
648 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
649 	int ret;
650 
651 	ret = ds2781_write(dev_info, buf,
652 				DS2781_EEPROM_BLOCK1_START + off, count);
653 	if (ret < 0)
654 		return ret;
655 
656 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START);
657 	if (ret < 0)
658 		return ret;
659 
660 	return count;
661 }
662 
663 static struct bin_attribute ds2781_param_eeprom_bin_attr = {
664 	.attr = {
665 		.name = "param_eeprom",
666 		.mode = S_IRUGO | S_IWUSR,
667 	},
668 	.size = DS2781_PARAM_EEPROM_SIZE,
669 	.read = ds2781_read_param_eeprom_bin,
670 	.write = ds2781_write_param_eeprom_bin,
671 };
672 
673 static ssize_t ds2781_read_user_eeprom_bin(struct file *filp,
674 				struct kobject *kobj,
675 				struct bin_attribute *bin_attr,
676 				char *buf, loff_t off, size_t count)
677 {
678 	struct device *dev = container_of(kobj, struct device, kobj);
679 	struct power_supply *psy = to_power_supply(dev);
680 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
681 
682 	return ds2781_read_block(dev_info, buf,
683 				DS2781_EEPROM_BLOCK0_START + off, count);
684 
685 }
686 
687 static ssize_t ds2781_write_user_eeprom_bin(struct file *filp,
688 				struct kobject *kobj,
689 				struct bin_attribute *bin_attr,
690 				char *buf, loff_t off, size_t count)
691 {
692 	struct device *dev = container_of(kobj, struct device, kobj);
693 	struct power_supply *psy = to_power_supply(dev);
694 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
695 	int ret;
696 
697 	ret = ds2781_write(dev_info, buf,
698 				DS2781_EEPROM_BLOCK0_START + off, count);
699 	if (ret < 0)
700 		return ret;
701 
702 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START);
703 	if (ret < 0)
704 		return ret;
705 
706 	return count;
707 }
708 
709 static struct bin_attribute ds2781_user_eeprom_bin_attr = {
710 	.attr = {
711 		.name = "user_eeprom",
712 		.mode = S_IRUGO | S_IWUSR,
713 	},
714 	.size = DS2781_USER_EEPROM_SIZE,
715 	.read = ds2781_read_user_eeprom_bin,
716 	.write = ds2781_write_user_eeprom_bin,
717 };
718 
719 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled,
720 	ds2781_set_pmod_enabled);
721 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
722 	ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value);
723 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting,
724 	ds2781_set_rsgain_setting);
725 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin,
726 	ds2781_set_pio_pin);
727 
728 static struct attribute *ds2781_sysfs_attrs[] = {
729 	&dev_attr_pmod_enabled.attr,
730 	&dev_attr_sense_resistor_value.attr,
731 	&dev_attr_rsgain_setting.attr,
732 	&dev_attr_pio_pin.attr,
733 	NULL
734 };
735 
736 static struct bin_attribute *ds2781_sysfs_bin_attrs[] = {
737 	&ds2781_param_eeprom_bin_attr,
738 	&ds2781_user_eeprom_bin_attr,
739 	NULL,
740 };
741 
742 static const struct attribute_group ds2781_sysfs_group = {
743 	.attrs = ds2781_sysfs_attrs,
744 	.bin_attrs = ds2781_sysfs_bin_attrs,
745 
746 };
747 
748 static const struct attribute_group *ds2781_sysfs_groups[] = {
749 	&ds2781_sysfs_group,
750 	NULL,
751 };
752 
753 static int ds2781_battery_probe(struct platform_device *pdev)
754 {
755 	struct power_supply_config psy_cfg = {};
756 	struct ds2781_device_info *dev_info;
757 
758 	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
759 	if (!dev_info)
760 		return -ENOMEM;
761 
762 	platform_set_drvdata(pdev, dev_info);
763 
764 	dev_info->dev			= &pdev->dev;
765 	dev_info->w1_dev		= pdev->dev.parent;
766 	dev_info->bat_desc.name		= dev_name(&pdev->dev);
767 	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
768 	dev_info->bat_desc.properties	= ds2781_battery_props;
769 	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2781_battery_props);
770 	dev_info->bat_desc.get_property	= ds2781_battery_get_property;
771 
772 	psy_cfg.drv_data		= dev_info;
773 	psy_cfg.attr_grp		= ds2781_sysfs_groups;
774 
775 	dev_info->bat = power_supply_register(&pdev->dev, &dev_info->bat_desc,
776 						&psy_cfg);
777 	if (IS_ERR(dev_info->bat)) {
778 		dev_err(dev_info->dev, "failed to register battery\n");
779 		return PTR_ERR(dev_info->bat);
780 	}
781 
782 	return 0;
783 }
784 
785 static int ds2781_battery_remove(struct platform_device *pdev)
786 {
787 	struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
788 
789 	power_supply_unregister(dev_info->bat);
790 
791 	return 0;
792 }
793 
794 static struct platform_driver ds2781_battery_driver = {
795 	.driver = {
796 		.name = "ds2781-battery",
797 	},
798 	.probe	  = ds2781_battery_probe,
799 	.remove   = ds2781_battery_remove,
800 };
801 module_platform_driver(ds2781_battery_driver);
802 
803 MODULE_LICENSE("GPL");
804 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
805 MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC driver");
806 MODULE_ALIAS("platform:ds2781-battery");
807 
808