1 /*
2  * 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
3  *
4  * Copyright (C) 2010 Indesign, LLC
5  *
6  * Author: Clifton Barnes <cabarnes@indesign-llc.com>
7  *
8  * Based on ds2760_battery and ds2782_battery drivers
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  */
15 
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/param.h>
19 #include <linux/pm.h>
20 #include <linux/platform_device.h>
21 #include <linux/power_supply.h>
22 #include <linux/idr.h>
23 
24 #include <linux/w1.h>
25 #include "../../w1/slaves/w1_ds2780.h"
26 
27 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
28 #define DS2780_CURRENT_UNITS	1563
29 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
30 #define DS2780_CHARGE_UNITS		6250
31 /* Number of bytes in user EEPROM space */
32 #define DS2780_USER_EEPROM_SIZE		(DS2780_EEPROM_BLOCK0_END - \
33 					DS2780_EEPROM_BLOCK0_START + 1)
34 /* Number of bytes in parameter EEPROM space */
35 #define DS2780_PARAM_EEPROM_SIZE	(DS2780_EEPROM_BLOCK1_END - \
36 					DS2780_EEPROM_BLOCK1_START + 1)
37 
38 struct ds2780_device_info {
39 	struct device *dev;
40 	struct power_supply *bat;
41 	struct power_supply_desc bat_desc;
42 	struct device *w1_dev;
43 };
44 
45 enum current_types {
46 	CURRENT_NOW,
47 	CURRENT_AVG,
48 };
49 
50 static const char model[] = "DS2780";
51 static const char manufacturer[] = "Maxim/Dallas";
52 
53 static inline struct ds2780_device_info *
54 to_ds2780_device_info(struct power_supply *psy)
55 {
56 	return power_supply_get_drvdata(psy);
57 }
58 
59 static inline struct power_supply *to_power_supply(struct device *dev)
60 {
61 	return dev_get_drvdata(dev);
62 }
63 
64 static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
65 	char *buf, int addr, size_t count, int io)
66 {
67 	return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
68 }
69 
70 static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
71 	int addr)
72 {
73 	return ds2780_battery_io(dev_info, val, addr, sizeof(u8), 0);
74 }
75 
76 static int ds2780_read16(struct ds2780_device_info *dev_info, s16 *val,
77 	int addr)
78 {
79 	int ret;
80 	u8 raw[2];
81 
82 	ret = ds2780_battery_io(dev_info, raw, addr, sizeof(raw), 0);
83 	if (ret < 0)
84 		return ret;
85 
86 	*val = (raw[0] << 8) | raw[1];
87 
88 	return 0;
89 }
90 
91 static inline int ds2780_read_block(struct ds2780_device_info *dev_info,
92 	u8 *val, int addr, size_t count)
93 {
94 	return ds2780_battery_io(dev_info, val, addr, count, 0);
95 }
96 
97 static inline int ds2780_write(struct ds2780_device_info *dev_info, u8 *val,
98 	int addr, size_t count)
99 {
100 	return ds2780_battery_io(dev_info, val, addr, count, 1);
101 }
102 
103 static inline int ds2780_store_eeprom(struct device *dev, int addr)
104 {
105 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_COPY_DATA);
106 }
107 
108 static inline int ds2780_recall_eeprom(struct device *dev, int addr)
109 {
110 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_RECALL_DATA);
111 }
112 
113 static int ds2780_save_eeprom(struct ds2780_device_info *dev_info, int reg)
114 {
115 	int ret;
116 
117 	ret = ds2780_store_eeprom(dev_info->w1_dev, reg);
118 	if (ret < 0)
119 		return ret;
120 
121 	ret = ds2780_recall_eeprom(dev_info->w1_dev, reg);
122 	if (ret < 0)
123 		return ret;
124 
125 	return 0;
126 }
127 
128 /* Set sense resistor value in mhos */
129 static int ds2780_set_sense_register(struct ds2780_device_info *dev_info,
130 	u8 conductance)
131 {
132 	int ret;
133 
134 	ret = ds2780_write(dev_info, &conductance,
135 				DS2780_RSNSP_REG, sizeof(u8));
136 	if (ret < 0)
137 		return ret;
138 
139 	return ds2780_save_eeprom(dev_info, DS2780_RSNSP_REG);
140 }
141 
142 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
143 static int ds2780_get_rsgain_register(struct ds2780_device_info *dev_info,
144 	u16 *rsgain)
145 {
146 	return ds2780_read16(dev_info, rsgain, DS2780_RSGAIN_MSB_REG);
147 }
148 
149 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
150 static int ds2780_set_rsgain_register(struct ds2780_device_info *dev_info,
151 	u16 rsgain)
152 {
153 	int ret;
154 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
155 
156 	ret = ds2780_write(dev_info, raw,
157 				DS2780_RSGAIN_MSB_REG, sizeof(raw));
158 	if (ret < 0)
159 		return ret;
160 
161 	return ds2780_save_eeprom(dev_info, DS2780_RSGAIN_MSB_REG);
162 }
163 
164 static int ds2780_get_voltage(struct ds2780_device_info *dev_info,
165 	int *voltage_uV)
166 {
167 	int ret;
168 	s16 voltage_raw;
169 
170 	/*
171 	 * The voltage value is located in 10 bits across the voltage MSB
172 	 * and LSB registers in two's compliment form
173 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
174 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
175 	 * voltage MSB register
176 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
177 	 * voltage LSB register
178 	 */
179 	ret = ds2780_read16(dev_info, &voltage_raw,
180 				DS2780_VOLT_MSB_REG);
181 	if (ret < 0)
182 		return ret;
183 
184 	/*
185 	 * DS2780 reports voltage in units of 4.88mV, but the battery class
186 	 * reports in units of uV, so convert by multiplying by 4880.
187 	 */
188 	*voltage_uV = (voltage_raw / 32) * 4880;
189 	return 0;
190 }
191 
192 static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
193 	int *temperature)
194 {
195 	int ret;
196 	s16 temperature_raw;
197 
198 	/*
199 	 * The temperature value is located in 10 bits across the temperature
200 	 * MSB and LSB registers in two's compliment 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 	ret = ds2780_read16(dev_info, &temperature_raw,
209 				DS2780_TEMP_MSB_REG);
210 	if (ret < 0)
211 		return ret;
212 
213 	/*
214 	 * Temperature is measured in units of 0.125 degrees celcius, the
215 	 * power_supply class measures temperature in tenths of degrees
216 	 * celsius. The temperature value is stored as a 10 bit number, plus
217 	 * sign in the upper bits of a 16 bit register.
218 	 */
219 	*temperature = ((temperature_raw / 32) * 125) / 100;
220 	return 0;
221 }
222 
223 static int ds2780_get_current(struct ds2780_device_info *dev_info,
224 	enum current_types type, int *current_uA)
225 {
226 	int ret, sense_res;
227 	s16 current_raw;
228 	u8 sense_res_raw, reg_msb;
229 
230 	/*
231 	 * The units of measurement for current are dependent on the value of
232 	 * the sense resistor.
233 	 */
234 	ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
235 	if (ret < 0)
236 		return ret;
237 
238 	if (sense_res_raw == 0) {
239 		dev_err(dev_info->dev, "sense resistor value is 0\n");
240 		return -EINVAL;
241 	}
242 	sense_res = 1000 / sense_res_raw;
243 
244 	if (type == CURRENT_NOW)
245 		reg_msb = DS2780_CURRENT_MSB_REG;
246 	else if (type == CURRENT_AVG)
247 		reg_msb = DS2780_IAVG_MSB_REG;
248 	else
249 		return -EINVAL;
250 
251 	/*
252 	 * The current value is located in 16 bits across the current MSB
253 	 * and LSB registers in two's compliment form
254 	 * Sign bit of the current value is in bit 7 of the current MSB register
255 	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
256 	 * MSB register
257 	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
258 	 * LSB register
259 	 */
260 	ret = ds2780_read16(dev_info, &current_raw, reg_msb);
261 	if (ret < 0)
262 		return ret;
263 
264 	*current_uA = current_raw * (DS2780_CURRENT_UNITS / sense_res);
265 	return 0;
266 }
267 
268 static int ds2780_get_accumulated_current(struct ds2780_device_info *dev_info,
269 	int *accumulated_current)
270 {
271 	int ret, sense_res;
272 	s16 current_raw;
273 	u8 sense_res_raw;
274 
275 	/*
276 	 * The units of measurement for accumulated current are dependent on
277 	 * the value of the sense resistor.
278 	 */
279 	ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
280 	if (ret < 0)
281 		return ret;
282 
283 	if (sense_res_raw == 0) {
284 		dev_err(dev_info->dev, "sense resistor value is 0\n");
285 		return -ENXIO;
286 	}
287 	sense_res = 1000 / sense_res_raw;
288 
289 	/*
290 	 * The ACR value is located in 16 bits across the ACR MSB and
291 	 * LSB registers
292 	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
293 	 * MSB register
294 	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
295 	 * LSB register
296 	 */
297 	ret = ds2780_read16(dev_info, &current_raw, DS2780_ACR_MSB_REG);
298 	if (ret < 0)
299 		return ret;
300 
301 	*accumulated_current = current_raw * (DS2780_CHARGE_UNITS / sense_res);
302 	return 0;
303 }
304 
305 static int ds2780_get_capacity(struct ds2780_device_info *dev_info,
306 	int *capacity)
307 {
308 	int ret;
309 	u8 raw;
310 
311 	ret = ds2780_read8(dev_info, &raw, DS2780_RARC_REG);
312 	if (ret < 0)
313 		return ret;
314 
315 	*capacity = raw;
316 	return raw;
317 }
318 
319 static int ds2780_get_status(struct ds2780_device_info *dev_info, int *status)
320 {
321 	int ret, current_uA, capacity;
322 
323 	ret = ds2780_get_current(dev_info, CURRENT_NOW, &current_uA);
324 	if (ret < 0)
325 		return ret;
326 
327 	ret = ds2780_get_capacity(dev_info, &capacity);
328 	if (ret < 0)
329 		return ret;
330 
331 	if (capacity == 100)
332 		*status = POWER_SUPPLY_STATUS_FULL;
333 	else if (current_uA == 0)
334 		*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
335 	else if (current_uA < 0)
336 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
337 	else
338 		*status = POWER_SUPPLY_STATUS_CHARGING;
339 
340 	return 0;
341 }
342 
343 static int ds2780_get_charge_now(struct ds2780_device_info *dev_info,
344 	int *charge_now)
345 {
346 	int ret;
347 	u16 charge_raw;
348 
349 	/*
350 	 * The RAAC value is located in 16 bits across the RAAC MSB and
351 	 * LSB registers
352 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
353 	 * MSB register
354 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
355 	 * LSB register
356 	 */
357 	ret = ds2780_read16(dev_info, &charge_raw, DS2780_RAAC_MSB_REG);
358 	if (ret < 0)
359 		return ret;
360 
361 	*charge_now = charge_raw * 1600;
362 	return 0;
363 }
364 
365 static int ds2780_get_control_register(struct ds2780_device_info *dev_info,
366 	u8 *control_reg)
367 {
368 	return ds2780_read8(dev_info, control_reg, DS2780_CONTROL_REG);
369 }
370 
371 static int ds2780_set_control_register(struct ds2780_device_info *dev_info,
372 	u8 control_reg)
373 {
374 	int ret;
375 
376 	ret = ds2780_write(dev_info, &control_reg,
377 				DS2780_CONTROL_REG, sizeof(u8));
378 	if (ret < 0)
379 		return ret;
380 
381 	return ds2780_save_eeprom(dev_info, DS2780_CONTROL_REG);
382 }
383 
384 static int ds2780_battery_get_property(struct power_supply *psy,
385 	enum power_supply_property psp,
386 	union power_supply_propval *val)
387 {
388 	int ret = 0;
389 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
390 
391 	switch (psp) {
392 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
393 		ret = ds2780_get_voltage(dev_info, &val->intval);
394 		break;
395 
396 	case POWER_SUPPLY_PROP_TEMP:
397 		ret = ds2780_get_temperature(dev_info, &val->intval);
398 		break;
399 
400 	case POWER_SUPPLY_PROP_MODEL_NAME:
401 		val->strval = model;
402 		break;
403 
404 	case POWER_SUPPLY_PROP_MANUFACTURER:
405 		val->strval = manufacturer;
406 		break;
407 
408 	case POWER_SUPPLY_PROP_CURRENT_NOW:
409 		ret = ds2780_get_current(dev_info, CURRENT_NOW, &val->intval);
410 		break;
411 
412 	case POWER_SUPPLY_PROP_CURRENT_AVG:
413 		ret = ds2780_get_current(dev_info, CURRENT_AVG, &val->intval);
414 		break;
415 
416 	case POWER_SUPPLY_PROP_STATUS:
417 		ret = ds2780_get_status(dev_info, &val->intval);
418 		break;
419 
420 	case POWER_SUPPLY_PROP_CAPACITY:
421 		ret = ds2780_get_capacity(dev_info, &val->intval);
422 		break;
423 
424 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
425 		ret = ds2780_get_accumulated_current(dev_info, &val->intval);
426 		break;
427 
428 	case POWER_SUPPLY_PROP_CHARGE_NOW:
429 		ret = ds2780_get_charge_now(dev_info, &val->intval);
430 		break;
431 
432 	default:
433 		ret = -EINVAL;
434 	}
435 
436 	return ret;
437 }
438 
439 static enum power_supply_property ds2780_battery_props[] = {
440 	POWER_SUPPLY_PROP_STATUS,
441 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
442 	POWER_SUPPLY_PROP_TEMP,
443 	POWER_SUPPLY_PROP_MODEL_NAME,
444 	POWER_SUPPLY_PROP_MANUFACTURER,
445 	POWER_SUPPLY_PROP_CURRENT_NOW,
446 	POWER_SUPPLY_PROP_CURRENT_AVG,
447 	POWER_SUPPLY_PROP_CAPACITY,
448 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
449 	POWER_SUPPLY_PROP_CHARGE_NOW,
450 };
451 
452 static ssize_t ds2780_get_pmod_enabled(struct device *dev,
453 	struct device_attribute *attr,
454 	char *buf)
455 {
456 	int ret;
457 	u8 control_reg;
458 	struct power_supply *psy = to_power_supply(dev);
459 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
460 
461 	/* Get power mode */
462 	ret = ds2780_get_control_register(dev_info, &control_reg);
463 	if (ret < 0)
464 		return ret;
465 
466 	return sprintf(buf, "%d\n",
467 		 !!(control_reg & DS2780_CONTROL_REG_PMOD));
468 }
469 
470 static ssize_t ds2780_set_pmod_enabled(struct device *dev,
471 	struct device_attribute *attr,
472 	const char *buf,
473 	size_t count)
474 {
475 	int ret;
476 	u8 control_reg, new_setting;
477 	struct power_supply *psy = to_power_supply(dev);
478 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
479 
480 	/* Set power mode */
481 	ret = ds2780_get_control_register(dev_info, &control_reg);
482 	if (ret < 0)
483 		return ret;
484 
485 	ret = kstrtou8(buf, 0, &new_setting);
486 	if (ret < 0)
487 		return ret;
488 
489 	if ((new_setting != 0) && (new_setting != 1)) {
490 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
491 		return -EINVAL;
492 	}
493 
494 	if (new_setting)
495 		control_reg |= DS2780_CONTROL_REG_PMOD;
496 	else
497 		control_reg &= ~DS2780_CONTROL_REG_PMOD;
498 
499 	ret = ds2780_set_control_register(dev_info, control_reg);
500 	if (ret < 0)
501 		return ret;
502 
503 	return count;
504 }
505 
506 static ssize_t ds2780_get_sense_resistor_value(struct device *dev,
507 	struct device_attribute *attr,
508 	char *buf)
509 {
510 	int ret;
511 	u8 sense_resistor;
512 	struct power_supply *psy = to_power_supply(dev);
513 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
514 
515 	ret = ds2780_read8(dev_info, &sense_resistor, DS2780_RSNSP_REG);
516 	if (ret < 0)
517 		return ret;
518 
519 	ret = sprintf(buf, "%d\n", sense_resistor);
520 	return ret;
521 }
522 
523 static ssize_t ds2780_set_sense_resistor_value(struct device *dev,
524 	struct device_attribute *attr,
525 	const char *buf,
526 	size_t count)
527 {
528 	int ret;
529 	u8 new_setting;
530 	struct power_supply *psy = to_power_supply(dev);
531 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
532 
533 	ret = kstrtou8(buf, 0, &new_setting);
534 	if (ret < 0)
535 		return ret;
536 
537 	ret = ds2780_set_sense_register(dev_info, new_setting);
538 	if (ret < 0)
539 		return ret;
540 
541 	return count;
542 }
543 
544 static ssize_t ds2780_get_rsgain_setting(struct device *dev,
545 	struct device_attribute *attr,
546 	char *buf)
547 {
548 	int ret;
549 	u16 rsgain;
550 	struct power_supply *psy = to_power_supply(dev);
551 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
552 
553 	ret = ds2780_get_rsgain_register(dev_info, &rsgain);
554 	if (ret < 0)
555 		return ret;
556 
557 	return sprintf(buf, "%d\n", rsgain);
558 }
559 
560 static ssize_t ds2780_set_rsgain_setting(struct device *dev,
561 	struct device_attribute *attr,
562 	const char *buf,
563 	size_t count)
564 {
565 	int ret;
566 	u16 new_setting;
567 	struct power_supply *psy = to_power_supply(dev);
568 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
569 
570 	ret = kstrtou16(buf, 0, &new_setting);
571 	if (ret < 0)
572 		return ret;
573 
574 	/* Gain can only be from 0 to 1.999 in steps of .001 */
575 	if (new_setting > 1999) {
576 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
577 		return -EINVAL;
578 	}
579 
580 	ret = ds2780_set_rsgain_register(dev_info, new_setting);
581 	if (ret < 0)
582 		return ret;
583 
584 	return count;
585 }
586 
587 static ssize_t ds2780_get_pio_pin(struct device *dev,
588 	struct device_attribute *attr,
589 	char *buf)
590 {
591 	int ret;
592 	u8 sfr;
593 	struct power_supply *psy = to_power_supply(dev);
594 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
595 
596 	ret = ds2780_read8(dev_info, &sfr, DS2780_SFR_REG);
597 	if (ret < 0)
598 		return ret;
599 
600 	ret = sprintf(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
601 	return ret;
602 }
603 
604 static ssize_t ds2780_set_pio_pin(struct device *dev,
605 	struct device_attribute *attr,
606 	const char *buf,
607 	size_t count)
608 {
609 	int ret;
610 	u8 new_setting;
611 	struct power_supply *psy = to_power_supply(dev);
612 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
613 
614 	ret = kstrtou8(buf, 0, &new_setting);
615 	if (ret < 0)
616 		return ret;
617 
618 	if ((new_setting != 0) && (new_setting != 1)) {
619 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
620 		return -EINVAL;
621 	}
622 
623 	ret = ds2780_write(dev_info, &new_setting,
624 				DS2780_SFR_REG, sizeof(u8));
625 	if (ret < 0)
626 		return ret;
627 
628 	return count;
629 }
630 
631 static ssize_t ds2780_read_param_eeprom_bin(struct file *filp,
632 				struct kobject *kobj,
633 				struct bin_attribute *bin_attr,
634 				char *buf, loff_t off, size_t count)
635 {
636 	struct device *dev = container_of(kobj, struct device, kobj);
637 	struct power_supply *psy = to_power_supply(dev);
638 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
639 
640 	return ds2780_read_block(dev_info, buf,
641 				DS2780_EEPROM_BLOCK1_START + off, count);
642 }
643 
644 static ssize_t ds2780_write_param_eeprom_bin(struct file *filp,
645 				struct kobject *kobj,
646 				struct bin_attribute *bin_attr,
647 				char *buf, loff_t off, size_t count)
648 {
649 	struct device *dev = container_of(kobj, struct device, kobj);
650 	struct power_supply *psy = to_power_supply(dev);
651 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
652 	int ret;
653 
654 	ret = ds2780_write(dev_info, buf,
655 				DS2780_EEPROM_BLOCK1_START + off, count);
656 	if (ret < 0)
657 		return ret;
658 
659 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
660 	if (ret < 0)
661 		return ret;
662 
663 	return count;
664 }
665 
666 static const struct bin_attribute ds2780_param_eeprom_bin_attr = {
667 	.attr = {
668 		.name = "param_eeprom",
669 		.mode = S_IRUGO | S_IWUSR,
670 	},
671 	.size = DS2780_PARAM_EEPROM_SIZE,
672 	.read = ds2780_read_param_eeprom_bin,
673 	.write = ds2780_write_param_eeprom_bin,
674 };
675 
676 static ssize_t ds2780_read_user_eeprom_bin(struct file *filp,
677 				struct kobject *kobj,
678 				struct bin_attribute *bin_attr,
679 				char *buf, loff_t off, size_t count)
680 {
681 	struct device *dev = container_of(kobj, struct device, kobj);
682 	struct power_supply *psy = to_power_supply(dev);
683 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
684 
685 	return ds2780_read_block(dev_info, buf,
686 				DS2780_EEPROM_BLOCK0_START + off, count);
687 }
688 
689 static ssize_t ds2780_write_user_eeprom_bin(struct file *filp,
690 				struct kobject *kobj,
691 				struct bin_attribute *bin_attr,
692 				char *buf, loff_t off, size_t count)
693 {
694 	struct device *dev = container_of(kobj, struct device, kobj);
695 	struct power_supply *psy = to_power_supply(dev);
696 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
697 	int ret;
698 
699 	ret = ds2780_write(dev_info, buf,
700 				DS2780_EEPROM_BLOCK0_START + off, count);
701 	if (ret < 0)
702 		return ret;
703 
704 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
705 	if (ret < 0)
706 		return ret;
707 
708 	return count;
709 }
710 
711 static const struct bin_attribute ds2780_user_eeprom_bin_attr = {
712 	.attr = {
713 		.name = "user_eeprom",
714 		.mode = S_IRUGO | S_IWUSR,
715 	},
716 	.size = DS2780_USER_EEPROM_SIZE,
717 	.read = ds2780_read_user_eeprom_bin,
718 	.write = ds2780_write_user_eeprom_bin,
719 };
720 
721 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
722 	ds2780_set_pmod_enabled);
723 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
724 	ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
725 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
726 	ds2780_set_rsgain_setting);
727 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
728 	ds2780_set_pio_pin);
729 
730 
731 static struct attribute *ds2780_attributes[] = {
732 	&dev_attr_pmod_enabled.attr,
733 	&dev_attr_sense_resistor_value.attr,
734 	&dev_attr_rsgain_setting.attr,
735 	&dev_attr_pio_pin.attr,
736 	NULL
737 };
738 
739 static const struct attribute_group ds2780_attr_group = {
740 	.attrs = ds2780_attributes,
741 };
742 
743 static int ds2780_battery_probe(struct platform_device *pdev)
744 {
745 	struct power_supply_config psy_cfg = {};
746 	int ret = 0;
747 	struct ds2780_device_info *dev_info;
748 
749 	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
750 	if (!dev_info) {
751 		ret = -ENOMEM;
752 		goto fail;
753 	}
754 
755 	platform_set_drvdata(pdev, dev_info);
756 
757 	dev_info->dev			= &pdev->dev;
758 	dev_info->w1_dev		= pdev->dev.parent;
759 	dev_info->bat_desc.name		= dev_name(&pdev->dev);
760 	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
761 	dev_info->bat_desc.properties	= ds2780_battery_props;
762 	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2780_battery_props);
763 	dev_info->bat_desc.get_property	= ds2780_battery_get_property;
764 
765 	psy_cfg.drv_data		= dev_info;
766 
767 	dev_info->bat = power_supply_register(&pdev->dev, &dev_info->bat_desc,
768 					      &psy_cfg);
769 	if (IS_ERR(dev_info->bat)) {
770 		dev_err(dev_info->dev, "failed to register battery\n");
771 		ret = PTR_ERR(dev_info->bat);
772 		goto fail;
773 	}
774 
775 	ret = sysfs_create_group(&dev_info->bat->dev.kobj, &ds2780_attr_group);
776 	if (ret) {
777 		dev_err(dev_info->dev, "failed to create sysfs group\n");
778 		goto fail_unregister;
779 	}
780 
781 	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
782 					&ds2780_param_eeprom_bin_attr);
783 	if (ret) {
784 		dev_err(dev_info->dev,
785 				"failed to create param eeprom bin file");
786 		goto fail_remove_group;
787 	}
788 
789 	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
790 					&ds2780_user_eeprom_bin_attr);
791 	if (ret) {
792 		dev_err(dev_info->dev,
793 				"failed to create user eeprom bin file");
794 		goto fail_remove_bin_file;
795 	}
796 
797 	return 0;
798 
799 fail_remove_bin_file:
800 	sysfs_remove_bin_file(&dev_info->bat->dev.kobj,
801 				&ds2780_param_eeprom_bin_attr);
802 fail_remove_group:
803 	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2780_attr_group);
804 fail_unregister:
805 	power_supply_unregister(dev_info->bat);
806 fail:
807 	return ret;
808 }
809 
810 static int ds2780_battery_remove(struct platform_device *pdev)
811 {
812 	struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);
813 
814 	/*
815 	 * Remove attributes before unregistering power supply
816 	 * because 'bat' will be freed on power_supply_unregister() call.
817 	 */
818 	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2780_attr_group);
819 
820 	power_supply_unregister(dev_info->bat);
821 
822 	return 0;
823 }
824 
825 static struct platform_driver ds2780_battery_driver = {
826 	.driver = {
827 		.name = "ds2780-battery",
828 	},
829 	.probe	  = ds2780_battery_probe,
830 	.remove   = ds2780_battery_remove,
831 };
832 
833 module_platform_driver(ds2780_battery_driver);
834 
835 MODULE_LICENSE("GPL");
836 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
837 MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauage IC driver");
838 MODULE_ALIAS("platform:ds2780-battery");
839