1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
4  *
5  * Copyright (C) 2010 Indesign, LLC
6  *
7  * Author: Clifton Barnes <cabarnes@indesign-llc.com>
8  *
9  * Based on ds2760_battery and ds2782_battery drivers
10  */
11 
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/param.h>
15 #include <linux/pm.h>
16 #include <linux/platform_device.h>
17 #include <linux/power_supply.h>
18 #include <linux/idr.h>
19 
20 #include <linux/w1.h>
21 #include "../../w1/slaves/w1_ds2780.h"
22 
23 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
24 #define DS2780_CURRENT_UNITS	1563
25 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
26 #define DS2780_CHARGE_UNITS		6250
27 /* Number of bytes in user EEPROM space */
28 #define DS2780_USER_EEPROM_SIZE		(DS2780_EEPROM_BLOCK0_END - \
29 					DS2780_EEPROM_BLOCK0_START + 1)
30 /* Number of bytes in parameter EEPROM space */
31 #define DS2780_PARAM_EEPROM_SIZE	(DS2780_EEPROM_BLOCK1_END - \
32 					DS2780_EEPROM_BLOCK1_START + 1)
33 
34 struct ds2780_device_info {
35 	struct device *dev;
36 	struct power_supply *bat;
37 	struct power_supply_desc bat_desc;
38 	struct device *w1_dev;
39 };
40 
41 enum current_types {
42 	CURRENT_NOW,
43 	CURRENT_AVG,
44 };
45 
46 static const char model[] = "DS2780";
47 static const char manufacturer[] = "Maxim/Dallas";
48 
49 static inline struct ds2780_device_info *
50 to_ds2780_device_info(struct power_supply *psy)
51 {
52 	return power_supply_get_drvdata(psy);
53 }
54 
55 static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
56 	char *buf, int addr, size_t count, int io)
57 {
58 	return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
59 }
60 
61 static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
62 	int addr)
63 {
64 	return ds2780_battery_io(dev_info, val, addr, sizeof(u8), 0);
65 }
66 
67 static int ds2780_read16(struct ds2780_device_info *dev_info, s16 *val,
68 	int addr)
69 {
70 	int ret;
71 	u8 raw[2];
72 
73 	ret = ds2780_battery_io(dev_info, raw, addr, sizeof(raw), 0);
74 	if (ret < 0)
75 		return ret;
76 
77 	*val = (raw[0] << 8) | raw[1];
78 
79 	return 0;
80 }
81 
82 static inline int ds2780_read_block(struct ds2780_device_info *dev_info,
83 	u8 *val, int addr, size_t count)
84 {
85 	return ds2780_battery_io(dev_info, val, addr, count, 0);
86 }
87 
88 static inline int ds2780_write(struct ds2780_device_info *dev_info, u8 *val,
89 	int addr, size_t count)
90 {
91 	return ds2780_battery_io(dev_info, val, addr, count, 1);
92 }
93 
94 static inline int ds2780_store_eeprom(struct device *dev, int addr)
95 {
96 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_COPY_DATA);
97 }
98 
99 static inline int ds2780_recall_eeprom(struct device *dev, int addr)
100 {
101 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_RECALL_DATA);
102 }
103 
104 static int ds2780_save_eeprom(struct ds2780_device_info *dev_info, int reg)
105 {
106 	int ret;
107 
108 	ret = ds2780_store_eeprom(dev_info->w1_dev, reg);
109 	if (ret < 0)
110 		return ret;
111 
112 	ret = ds2780_recall_eeprom(dev_info->w1_dev, reg);
113 	if (ret < 0)
114 		return ret;
115 
116 	return 0;
117 }
118 
119 /* Set sense resistor value in mhos */
120 static int ds2780_set_sense_register(struct ds2780_device_info *dev_info,
121 	u8 conductance)
122 {
123 	int ret;
124 
125 	ret = ds2780_write(dev_info, &conductance,
126 				DS2780_RSNSP_REG, sizeof(u8));
127 	if (ret < 0)
128 		return ret;
129 
130 	return ds2780_save_eeprom(dev_info, DS2780_RSNSP_REG);
131 }
132 
133 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
134 static int ds2780_get_rsgain_register(struct ds2780_device_info *dev_info,
135 	u16 *rsgain)
136 {
137 	return ds2780_read16(dev_info, rsgain, DS2780_RSGAIN_MSB_REG);
138 }
139 
140 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
141 static int ds2780_set_rsgain_register(struct ds2780_device_info *dev_info,
142 	u16 rsgain)
143 {
144 	int ret;
145 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
146 
147 	ret = ds2780_write(dev_info, raw,
148 				DS2780_RSGAIN_MSB_REG, sizeof(raw));
149 	if (ret < 0)
150 		return ret;
151 
152 	return ds2780_save_eeprom(dev_info, DS2780_RSGAIN_MSB_REG);
153 }
154 
155 static int ds2780_get_voltage(struct ds2780_device_info *dev_info,
156 	int *voltage_uV)
157 {
158 	int ret;
159 	s16 voltage_raw;
160 
161 	/*
162 	 * The voltage value is located in 10 bits across the voltage MSB
163 	 * and LSB registers in two's complement form
164 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
165 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
166 	 * voltage MSB register
167 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
168 	 * voltage LSB register
169 	 */
170 	ret = ds2780_read16(dev_info, &voltage_raw,
171 				DS2780_VOLT_MSB_REG);
172 	if (ret < 0)
173 		return ret;
174 
175 	/*
176 	 * DS2780 reports voltage in units of 4.88mV, but the battery class
177 	 * reports in units of uV, so convert by multiplying by 4880.
178 	 */
179 	*voltage_uV = (voltage_raw / 32) * 4880;
180 	return 0;
181 }
182 
183 static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
184 	int *temperature)
185 {
186 	int ret;
187 	s16 temperature_raw;
188 
189 	/*
190 	 * The temperature value is located in 10 bits across the temperature
191 	 * MSB and LSB registers in two's complement form
192 	 * Sign bit of the temperature value is in bit 7 of the temperature
193 	 * MSB register
194 	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
195 	 * temperature MSB register
196 	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
197 	 * temperature LSB register
198 	 */
199 	ret = ds2780_read16(dev_info, &temperature_raw,
200 				DS2780_TEMP_MSB_REG);
201 	if (ret < 0)
202 		return ret;
203 
204 	/*
205 	 * Temperature is measured in units of 0.125 degrees celcius, the
206 	 * power_supply class measures temperature in tenths of degrees
207 	 * celsius. The temperature value is stored as a 10 bit number, plus
208 	 * sign in the upper bits of a 16 bit register.
209 	 */
210 	*temperature = ((temperature_raw / 32) * 125) / 100;
211 	return 0;
212 }
213 
214 static int ds2780_get_current(struct ds2780_device_info *dev_info,
215 	enum current_types type, int *current_uA)
216 {
217 	int ret, sense_res;
218 	s16 current_raw;
219 	u8 sense_res_raw, reg_msb;
220 
221 	/*
222 	 * The units of measurement for current are dependent on the value of
223 	 * the sense resistor.
224 	 */
225 	ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
226 	if (ret < 0)
227 		return ret;
228 
229 	if (sense_res_raw == 0) {
230 		dev_err(dev_info->dev, "sense resistor value is 0\n");
231 		return -EINVAL;
232 	}
233 	sense_res = 1000 / sense_res_raw;
234 
235 	if (type == CURRENT_NOW)
236 		reg_msb = DS2780_CURRENT_MSB_REG;
237 	else if (type == CURRENT_AVG)
238 		reg_msb = DS2780_IAVG_MSB_REG;
239 	else
240 		return -EINVAL;
241 
242 	/*
243 	 * The current value is located in 16 bits across the current MSB
244 	 * and LSB registers in two's complement form
245 	 * Sign bit of the current value is in bit 7 of the current MSB register
246 	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
247 	 * MSB register
248 	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
249 	 * LSB register
250 	 */
251 	ret = ds2780_read16(dev_info, &current_raw, reg_msb);
252 	if (ret < 0)
253 		return ret;
254 
255 	*current_uA = current_raw * (DS2780_CURRENT_UNITS / sense_res);
256 	return 0;
257 }
258 
259 static int ds2780_get_accumulated_current(struct ds2780_device_info *dev_info,
260 	int *accumulated_current)
261 {
262 	int ret, sense_res;
263 	s16 current_raw;
264 	u8 sense_res_raw;
265 
266 	/*
267 	 * The units of measurement for accumulated current are dependent on
268 	 * the value of the sense resistor.
269 	 */
270 	ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
271 	if (ret < 0)
272 		return ret;
273 
274 	if (sense_res_raw == 0) {
275 		dev_err(dev_info->dev, "sense resistor value is 0\n");
276 		return -ENXIO;
277 	}
278 	sense_res = 1000 / sense_res_raw;
279 
280 	/*
281 	 * The ACR value is located in 16 bits across the ACR MSB and
282 	 * LSB registers
283 	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
284 	 * MSB register
285 	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
286 	 * LSB register
287 	 */
288 	ret = ds2780_read16(dev_info, &current_raw, DS2780_ACR_MSB_REG);
289 	if (ret < 0)
290 		return ret;
291 
292 	*accumulated_current = current_raw * (DS2780_CHARGE_UNITS / sense_res);
293 	return 0;
294 }
295 
296 static int ds2780_get_capacity(struct ds2780_device_info *dev_info,
297 	int *capacity)
298 {
299 	int ret;
300 	u8 raw;
301 
302 	ret = ds2780_read8(dev_info, &raw, DS2780_RARC_REG);
303 	if (ret < 0)
304 		return ret;
305 
306 	*capacity = raw;
307 	return raw;
308 }
309 
310 static int ds2780_get_status(struct ds2780_device_info *dev_info, int *status)
311 {
312 	int ret, current_uA, capacity;
313 
314 	ret = ds2780_get_current(dev_info, CURRENT_NOW, &current_uA);
315 	if (ret < 0)
316 		return ret;
317 
318 	ret = ds2780_get_capacity(dev_info, &capacity);
319 	if (ret < 0)
320 		return ret;
321 
322 	if (capacity == 100)
323 		*status = POWER_SUPPLY_STATUS_FULL;
324 	else if (current_uA == 0)
325 		*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
326 	else if (current_uA < 0)
327 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
328 	else
329 		*status = POWER_SUPPLY_STATUS_CHARGING;
330 
331 	return 0;
332 }
333 
334 static int ds2780_get_charge_now(struct ds2780_device_info *dev_info,
335 	int *charge_now)
336 {
337 	int ret;
338 	u16 charge_raw;
339 
340 	/*
341 	 * The RAAC value is located in 16 bits across the RAAC MSB and
342 	 * LSB registers
343 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
344 	 * MSB register
345 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
346 	 * LSB register
347 	 */
348 	ret = ds2780_read16(dev_info, &charge_raw, DS2780_RAAC_MSB_REG);
349 	if (ret < 0)
350 		return ret;
351 
352 	*charge_now = charge_raw * 1600;
353 	return 0;
354 }
355 
356 static int ds2780_get_control_register(struct ds2780_device_info *dev_info,
357 	u8 *control_reg)
358 {
359 	return ds2780_read8(dev_info, control_reg, DS2780_CONTROL_REG);
360 }
361 
362 static int ds2780_set_control_register(struct ds2780_device_info *dev_info,
363 	u8 control_reg)
364 {
365 	int ret;
366 
367 	ret = ds2780_write(dev_info, &control_reg,
368 				DS2780_CONTROL_REG, sizeof(u8));
369 	if (ret < 0)
370 		return ret;
371 
372 	return ds2780_save_eeprom(dev_info, DS2780_CONTROL_REG);
373 }
374 
375 static int ds2780_battery_get_property(struct power_supply *psy,
376 	enum power_supply_property psp,
377 	union power_supply_propval *val)
378 {
379 	int ret = 0;
380 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
381 
382 	switch (psp) {
383 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
384 		ret = ds2780_get_voltage(dev_info, &val->intval);
385 		break;
386 
387 	case POWER_SUPPLY_PROP_TEMP:
388 		ret = ds2780_get_temperature(dev_info, &val->intval);
389 		break;
390 
391 	case POWER_SUPPLY_PROP_MODEL_NAME:
392 		val->strval = model;
393 		break;
394 
395 	case POWER_SUPPLY_PROP_MANUFACTURER:
396 		val->strval = manufacturer;
397 		break;
398 
399 	case POWER_SUPPLY_PROP_CURRENT_NOW:
400 		ret = ds2780_get_current(dev_info, CURRENT_NOW, &val->intval);
401 		break;
402 
403 	case POWER_SUPPLY_PROP_CURRENT_AVG:
404 		ret = ds2780_get_current(dev_info, CURRENT_AVG, &val->intval);
405 		break;
406 
407 	case POWER_SUPPLY_PROP_STATUS:
408 		ret = ds2780_get_status(dev_info, &val->intval);
409 		break;
410 
411 	case POWER_SUPPLY_PROP_CAPACITY:
412 		ret = ds2780_get_capacity(dev_info, &val->intval);
413 		break;
414 
415 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
416 		ret = ds2780_get_accumulated_current(dev_info, &val->intval);
417 		break;
418 
419 	case POWER_SUPPLY_PROP_CHARGE_NOW:
420 		ret = ds2780_get_charge_now(dev_info, &val->intval);
421 		break;
422 
423 	default:
424 		ret = -EINVAL;
425 	}
426 
427 	return ret;
428 }
429 
430 static enum power_supply_property ds2780_battery_props[] = {
431 	POWER_SUPPLY_PROP_STATUS,
432 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
433 	POWER_SUPPLY_PROP_TEMP,
434 	POWER_SUPPLY_PROP_MODEL_NAME,
435 	POWER_SUPPLY_PROP_MANUFACTURER,
436 	POWER_SUPPLY_PROP_CURRENT_NOW,
437 	POWER_SUPPLY_PROP_CURRENT_AVG,
438 	POWER_SUPPLY_PROP_CAPACITY,
439 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
440 	POWER_SUPPLY_PROP_CHARGE_NOW,
441 };
442 
443 static ssize_t ds2780_get_pmod_enabled(struct device *dev,
444 	struct device_attribute *attr,
445 	char *buf)
446 {
447 	int ret;
448 	u8 control_reg;
449 	struct power_supply *psy = to_power_supply(dev);
450 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
451 
452 	/* Get power mode */
453 	ret = ds2780_get_control_register(dev_info, &control_reg);
454 	if (ret < 0)
455 		return ret;
456 
457 	return sysfs_emit(buf, "%d\n",
458 		 !!(control_reg & DS2780_CONTROL_REG_PMOD));
459 }
460 
461 static ssize_t ds2780_set_pmod_enabled(struct device *dev,
462 	struct device_attribute *attr,
463 	const char *buf,
464 	size_t count)
465 {
466 	int ret;
467 	u8 control_reg, new_setting;
468 	struct power_supply *psy = to_power_supply(dev);
469 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
470 
471 	/* Set power mode */
472 	ret = ds2780_get_control_register(dev_info, &control_reg);
473 	if (ret < 0)
474 		return ret;
475 
476 	ret = kstrtou8(buf, 0, &new_setting);
477 	if (ret < 0)
478 		return ret;
479 
480 	if ((new_setting != 0) && (new_setting != 1)) {
481 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
482 		return -EINVAL;
483 	}
484 
485 	if (new_setting)
486 		control_reg |= DS2780_CONTROL_REG_PMOD;
487 	else
488 		control_reg &= ~DS2780_CONTROL_REG_PMOD;
489 
490 	ret = ds2780_set_control_register(dev_info, control_reg);
491 	if (ret < 0)
492 		return ret;
493 
494 	return count;
495 }
496 
497 static ssize_t ds2780_get_sense_resistor_value(struct device *dev,
498 	struct device_attribute *attr,
499 	char *buf)
500 {
501 	int ret;
502 	u8 sense_resistor;
503 	struct power_supply *psy = to_power_supply(dev);
504 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
505 
506 	ret = ds2780_read8(dev_info, &sense_resistor, DS2780_RSNSP_REG);
507 	if (ret < 0)
508 		return ret;
509 
510 	ret = sysfs_emit(buf, "%d\n", sense_resistor);
511 	return ret;
512 }
513 
514 static ssize_t ds2780_set_sense_resistor_value(struct device *dev,
515 	struct device_attribute *attr,
516 	const char *buf,
517 	size_t count)
518 {
519 	int ret;
520 	u8 new_setting;
521 	struct power_supply *psy = to_power_supply(dev);
522 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
523 
524 	ret = kstrtou8(buf, 0, &new_setting);
525 	if (ret < 0)
526 		return ret;
527 
528 	ret = ds2780_set_sense_register(dev_info, new_setting);
529 	if (ret < 0)
530 		return ret;
531 
532 	return count;
533 }
534 
535 static ssize_t ds2780_get_rsgain_setting(struct device *dev,
536 	struct device_attribute *attr,
537 	char *buf)
538 {
539 	int ret;
540 	u16 rsgain;
541 	struct power_supply *psy = to_power_supply(dev);
542 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
543 
544 	ret = ds2780_get_rsgain_register(dev_info, &rsgain);
545 	if (ret < 0)
546 		return ret;
547 
548 	return sysfs_emit(buf, "%d\n", rsgain);
549 }
550 
551 static ssize_t ds2780_set_rsgain_setting(struct device *dev,
552 	struct device_attribute *attr,
553 	const char *buf,
554 	size_t count)
555 {
556 	int ret;
557 	u16 new_setting;
558 	struct power_supply *psy = to_power_supply(dev);
559 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
560 
561 	ret = kstrtou16(buf, 0, &new_setting);
562 	if (ret < 0)
563 		return ret;
564 
565 	/* Gain can only be from 0 to 1.999 in steps of .001 */
566 	if (new_setting > 1999) {
567 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
568 		return -EINVAL;
569 	}
570 
571 	ret = ds2780_set_rsgain_register(dev_info, new_setting);
572 	if (ret < 0)
573 		return ret;
574 
575 	return count;
576 }
577 
578 static ssize_t ds2780_get_pio_pin(struct device *dev,
579 	struct device_attribute *attr,
580 	char *buf)
581 {
582 	int ret;
583 	u8 sfr;
584 	struct power_supply *psy = to_power_supply(dev);
585 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
586 
587 	ret = ds2780_read8(dev_info, &sfr, DS2780_SFR_REG);
588 	if (ret < 0)
589 		return ret;
590 
591 	ret = sysfs_emit(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
592 	return ret;
593 }
594 
595 static ssize_t ds2780_set_pio_pin(struct device *dev,
596 	struct device_attribute *attr,
597 	const char *buf,
598 	size_t count)
599 {
600 	int ret;
601 	u8 new_setting;
602 	struct power_supply *psy = to_power_supply(dev);
603 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
604 
605 	ret = kstrtou8(buf, 0, &new_setting);
606 	if (ret < 0)
607 		return ret;
608 
609 	if ((new_setting != 0) && (new_setting != 1)) {
610 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
611 		return -EINVAL;
612 	}
613 
614 	ret = ds2780_write(dev_info, &new_setting,
615 				DS2780_SFR_REG, sizeof(u8));
616 	if (ret < 0)
617 		return ret;
618 
619 	return count;
620 }
621 
622 static ssize_t ds2780_read_param_eeprom_bin(struct file *filp,
623 				struct kobject *kobj,
624 				struct bin_attribute *bin_attr,
625 				char *buf, loff_t off, size_t count)
626 {
627 	struct device *dev = kobj_to_dev(kobj);
628 	struct power_supply *psy = to_power_supply(dev);
629 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
630 
631 	return ds2780_read_block(dev_info, buf,
632 				DS2780_EEPROM_BLOCK1_START + off, count);
633 }
634 
635 static ssize_t ds2780_write_param_eeprom_bin(struct file *filp,
636 				struct kobject *kobj,
637 				struct bin_attribute *bin_attr,
638 				char *buf, loff_t off, size_t count)
639 {
640 	struct device *dev = kobj_to_dev(kobj);
641 	struct power_supply *psy = to_power_supply(dev);
642 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
643 	int ret;
644 
645 	ret = ds2780_write(dev_info, buf,
646 				DS2780_EEPROM_BLOCK1_START + off, count);
647 	if (ret < 0)
648 		return ret;
649 
650 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
651 	if (ret < 0)
652 		return ret;
653 
654 	return count;
655 }
656 
657 static struct bin_attribute ds2780_param_eeprom_bin_attr = {
658 	.attr = {
659 		.name = "param_eeprom",
660 		.mode = S_IRUGO | S_IWUSR,
661 	},
662 	.size = DS2780_PARAM_EEPROM_SIZE,
663 	.read = ds2780_read_param_eeprom_bin,
664 	.write = ds2780_write_param_eeprom_bin,
665 };
666 
667 static ssize_t ds2780_read_user_eeprom_bin(struct file *filp,
668 				struct kobject *kobj,
669 				struct bin_attribute *bin_attr,
670 				char *buf, loff_t off, size_t count)
671 {
672 	struct device *dev = kobj_to_dev(kobj);
673 	struct power_supply *psy = to_power_supply(dev);
674 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
675 
676 	return ds2780_read_block(dev_info, buf,
677 				DS2780_EEPROM_BLOCK0_START + off, count);
678 }
679 
680 static ssize_t ds2780_write_user_eeprom_bin(struct file *filp,
681 				struct kobject *kobj,
682 				struct bin_attribute *bin_attr,
683 				char *buf, loff_t off, size_t count)
684 {
685 	struct device *dev = kobj_to_dev(kobj);
686 	struct power_supply *psy = to_power_supply(dev);
687 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
688 	int ret;
689 
690 	ret = ds2780_write(dev_info, buf,
691 				DS2780_EEPROM_BLOCK0_START + off, count);
692 	if (ret < 0)
693 		return ret;
694 
695 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
696 	if (ret < 0)
697 		return ret;
698 
699 	return count;
700 }
701 
702 static struct bin_attribute ds2780_user_eeprom_bin_attr = {
703 	.attr = {
704 		.name = "user_eeprom",
705 		.mode = S_IRUGO | S_IWUSR,
706 	},
707 	.size = DS2780_USER_EEPROM_SIZE,
708 	.read = ds2780_read_user_eeprom_bin,
709 	.write = ds2780_write_user_eeprom_bin,
710 };
711 
712 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
713 	ds2780_set_pmod_enabled);
714 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
715 	ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
716 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
717 	ds2780_set_rsgain_setting);
718 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
719 	ds2780_set_pio_pin);
720 
721 static struct attribute *ds2780_sysfs_attrs[] = {
722 	&dev_attr_pmod_enabled.attr,
723 	&dev_attr_sense_resistor_value.attr,
724 	&dev_attr_rsgain_setting.attr,
725 	&dev_attr_pio_pin.attr,
726 	NULL
727 };
728 
729 static struct bin_attribute *ds2780_sysfs_bin_attrs[] = {
730 	&ds2780_param_eeprom_bin_attr,
731 	&ds2780_user_eeprom_bin_attr,
732 	NULL
733 };
734 
735 static const struct attribute_group ds2780_sysfs_group = {
736 	.attrs = ds2780_sysfs_attrs,
737 	.bin_attrs = ds2780_sysfs_bin_attrs,
738 };
739 
740 static const struct attribute_group *ds2780_sysfs_groups[] = {
741 	&ds2780_sysfs_group,
742 	NULL,
743 };
744 
745 static int ds2780_battery_probe(struct platform_device *pdev)
746 {
747 	struct power_supply_config psy_cfg = {};
748 	struct ds2780_device_info *dev_info;
749 
750 	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
751 	if (!dev_info)
752 		return -ENOMEM;
753 
754 	platform_set_drvdata(pdev, dev_info);
755 
756 	dev_info->dev			= &pdev->dev;
757 	dev_info->w1_dev		= pdev->dev.parent;
758 	dev_info->bat_desc.name		= dev_name(&pdev->dev);
759 	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
760 	dev_info->bat_desc.properties	= ds2780_battery_props;
761 	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2780_battery_props);
762 	dev_info->bat_desc.get_property	= ds2780_battery_get_property;
763 
764 	psy_cfg.drv_data		= dev_info;
765 	psy_cfg.attr_grp		= ds2780_sysfs_groups;
766 
767 	dev_info->bat = devm_power_supply_register(&pdev->dev,
768 						   &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 		return PTR_ERR(dev_info->bat);
773 	}
774 
775 	return 0;
776 }
777 
778 static struct platform_driver ds2780_battery_driver = {
779 	.driver = {
780 		.name = "ds2780-battery",
781 	},
782 	.probe	  = ds2780_battery_probe,
783 };
784 
785 module_platform_driver(ds2780_battery_driver);
786 
787 MODULE_LICENSE("GPL");
788 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
789 MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC driver");
790 MODULE_ALIAS("platform:ds2780-battery");
791