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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 "../w1/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 device *w1_dev;
40 };
41 
42 enum current_types {
43 	CURRENT_NOW,
44 	CURRENT_AVG,
45 };
46 
47 static const char model[] = "DS2781";
48 static const char manufacturer[] = "Maxim/Dallas";
49 
50 static inline struct ds2781_device_info *
to_ds2781_device_info(struct power_supply * psy)51 to_ds2781_device_info(struct power_supply *psy)
52 {
53 	return container_of(psy, struct ds2781_device_info, bat);
54 }
55 
to_power_supply(struct device * dev)56 static inline struct power_supply *to_power_supply(struct device *dev)
57 {
58 	return dev_get_drvdata(dev);
59 }
60 
ds2781_battery_io(struct ds2781_device_info * dev_info,char * buf,int addr,size_t count,int io)61 static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
62 	char *buf, int addr, size_t count, int io)
63 {
64 	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
65 }
66 
w1_ds2781_read(struct ds2781_device_info * dev_info,char * buf,int addr,size_t count)67 static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
68 		int addr, size_t count)
69 {
70 	return ds2781_battery_io(dev_info, buf, addr, count, 0);
71 }
72 
ds2781_read8(struct ds2781_device_info * dev_info,u8 * val,int addr)73 static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val,
74 	int addr)
75 {
76 	return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0);
77 }
78 
ds2781_read16(struct ds2781_device_info * dev_info,s16 * val,int addr)79 static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val,
80 	int addr)
81 {
82 	int ret;
83 	u8 raw[2];
84 
85 	ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0);
86 	if (ret < 0)
87 		return ret;
88 
89 	*val = (raw[0] << 8) | raw[1];
90 
91 	return 0;
92 }
93 
ds2781_read_block(struct ds2781_device_info * dev_info,u8 * val,int addr,size_t count)94 static inline int ds2781_read_block(struct ds2781_device_info *dev_info,
95 	u8 *val, int addr, size_t count)
96 {
97 	return ds2781_battery_io(dev_info, val, addr, count, 0);
98 }
99 
ds2781_write(struct ds2781_device_info * dev_info,u8 * val,int addr,size_t count)100 static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val,
101 	int addr, size_t count)
102 {
103 	return ds2781_battery_io(dev_info, val, addr, count, 1);
104 }
105 
ds2781_store_eeprom(struct device * dev,int addr)106 static inline int ds2781_store_eeprom(struct device *dev, int addr)
107 {
108 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA);
109 }
110 
ds2781_recall_eeprom(struct device * dev,int addr)111 static inline int ds2781_recall_eeprom(struct device *dev, int addr)
112 {
113 	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA);
114 }
115 
ds2781_save_eeprom(struct ds2781_device_info * dev_info,int reg)116 static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg)
117 {
118 	int ret;
119 
120 	ret = ds2781_store_eeprom(dev_info->w1_dev, reg);
121 	if (ret < 0)
122 		return ret;
123 
124 	ret = ds2781_recall_eeprom(dev_info->w1_dev, reg);
125 	if (ret < 0)
126 		return ret;
127 
128 	return 0;
129 }
130 
131 /* Set sense resistor value in mhos */
ds2781_set_sense_register(struct ds2781_device_info * dev_info,u8 conductance)132 static int ds2781_set_sense_register(struct ds2781_device_info *dev_info,
133 	u8 conductance)
134 {
135 	int ret;
136 
137 	ret = ds2781_write(dev_info, &conductance,
138 				DS2781_RSNSP, sizeof(u8));
139 	if (ret < 0)
140 		return ret;
141 
142 	return ds2781_save_eeprom(dev_info, DS2781_RSNSP);
143 }
144 
145 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
ds2781_get_rsgain_register(struct ds2781_device_info * dev_info,u16 * rsgain)146 static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info,
147 	u16 *rsgain)
148 {
149 	return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB);
150 }
151 
152 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
ds2781_set_rsgain_register(struct ds2781_device_info * dev_info,u16 rsgain)153 static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info,
154 	u16 rsgain)
155 {
156 	int ret;
157 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
158 
159 	ret = ds2781_write(dev_info, raw,
160 				DS2781_RSGAIN_MSB, sizeof(raw));
161 	if (ret < 0)
162 		return ret;
163 
164 	return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB);
165 }
166 
ds2781_get_voltage(struct ds2781_device_info * dev_info,int * voltage_uV)167 static int ds2781_get_voltage(struct ds2781_device_info *dev_info,
168 	int *voltage_uV)
169 {
170 	int ret;
171 	char val[2];
172 	int voltage_raw;
173 
174 	ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8));
175 	if (ret < 0)
176 		return ret;
177 	/*
178 	 * The voltage value is located in 10 bits across the voltage MSB
179 	 * and LSB registers in two's compliment form
180 	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
181 	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
182 	 * voltage MSB register
183 	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
184 	 * voltage LSB register
185 	 */
186 	voltage_raw = (val[0] << 3) |
187 		(val[1] >> 5);
188 
189 	/* DS2781 reports voltage in units of 9.76mV, but the battery class
190 	 * reports in units of uV, so convert by multiplying by 9760. */
191 	*voltage_uV = voltage_raw * 9760;
192 
193 	return 0;
194 }
195 
ds2781_get_temperature(struct ds2781_device_info * dev_info,int * temp)196 static int ds2781_get_temperature(struct ds2781_device_info *dev_info,
197 	int *temp)
198 {
199 	int ret;
200 	char val[2];
201 	int temp_raw;
202 
203 	ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8));
204 	if (ret < 0)
205 		return ret;
206 	/*
207 	 * The temperature value is located in 10 bits across the temperature
208 	 * MSB and LSB registers in two's compliment form
209 	 * Sign bit of the temperature value is in bit 7 of the temperature
210 	 * MSB register
211 	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
212 	 * temperature MSB register
213 	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
214 	 * temperature LSB register
215 	 */
216 	temp_raw = ((val[0]) << 3) |
217 		(val[1] >> 5);
218 	*temp = temp_raw + (temp_raw / 4);
219 
220 	return 0;
221 }
222 
ds2781_get_current(struct ds2781_device_info * dev_info,enum current_types type,int * current_uA)223 static int ds2781_get_current(struct ds2781_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 = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
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 = DS2781_CURRENT_MSB;
246 	else if (type == CURRENT_AVG)
247 		reg_msb = DS2781_IAVG_MSB;
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 = ds2781_read16(dev_info, &current_raw, reg_msb);
261 	if (ret < 0)
262 		return ret;
263 
264 	*current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res);
265 	return 0;
266 }
267 
ds2781_get_accumulated_current(struct ds2781_device_info * dev_info,int * accumulated_current)268 static int ds2781_get_accumulated_current(struct ds2781_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 = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
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 -EINVAL;
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 = ds2781_read16(dev_info, &current_raw, DS2781_ACR_MSB);
298 	if (ret < 0)
299 		return ret;
300 
301 	*accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res);
302 	return 0;
303 }
304 
ds2781_get_capacity(struct ds2781_device_info * dev_info,int * capacity)305 static int ds2781_get_capacity(struct ds2781_device_info *dev_info,
306 	int *capacity)
307 {
308 	int ret;
309 	u8 raw;
310 
311 	ret = ds2781_read8(dev_info, &raw, DS2781_RARC);
312 	if (ret < 0)
313 		return ret;
314 
315 	*capacity = raw;
316 	return 0;
317 }
318 
ds2781_get_status(struct ds2781_device_info * dev_info,int * status)319 static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status)
320 {
321 	int ret, current_uA, capacity;
322 
323 	ret = ds2781_get_current(dev_info, CURRENT_NOW, &current_uA);
324 	if (ret < 0)
325 		return ret;
326 
327 	ret = ds2781_get_capacity(dev_info, &capacity);
328 	if (ret < 0)
329 		return ret;
330 
331 	if (power_supply_am_i_supplied(&dev_info->bat)) {
332 		if (capacity == 100)
333 			*status = POWER_SUPPLY_STATUS_FULL;
334 		else if (current_uA > 50000)
335 			*status = POWER_SUPPLY_STATUS_CHARGING;
336 		else
337 			*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
338 	} else {
339 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
340 	}
341 	return 0;
342 }
343 
ds2781_get_charge_now(struct ds2781_device_info * dev_info,int * charge_now)344 static int ds2781_get_charge_now(struct ds2781_device_info *dev_info,
345 	int *charge_now)
346 {
347 	int ret;
348 	u16 charge_raw;
349 
350 	/*
351 	 * The RAAC value is located in 16 bits across the RAAC MSB and
352 	 * LSB registers
353 	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
354 	 * MSB register
355 	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
356 	 * LSB register
357 	 */
358 	ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB);
359 	if (ret < 0)
360 		return ret;
361 
362 	*charge_now = charge_raw * 1600;
363 	return 0;
364 }
365 
ds2781_get_control_register(struct ds2781_device_info * dev_info,u8 * control_reg)366 static int ds2781_get_control_register(struct ds2781_device_info *dev_info,
367 	u8 *control_reg)
368 {
369 	return ds2781_read8(dev_info, control_reg, DS2781_CONTROL);
370 }
371 
ds2781_set_control_register(struct ds2781_device_info * dev_info,u8 control_reg)372 static int ds2781_set_control_register(struct ds2781_device_info *dev_info,
373 	u8 control_reg)
374 {
375 	int ret;
376 
377 	ret = ds2781_write(dev_info, &control_reg,
378 				DS2781_CONTROL, sizeof(u8));
379 	if (ret < 0)
380 		return ret;
381 
382 	return ds2781_save_eeprom(dev_info, DS2781_CONTROL);
383 }
384 
ds2781_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)385 static int ds2781_battery_get_property(struct power_supply *psy,
386 	enum power_supply_property psp,
387 	union power_supply_propval *val)
388 {
389 	int ret = 0;
390 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
391 
392 	switch (psp) {
393 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
394 		ret = ds2781_get_voltage(dev_info, &val->intval);
395 		break;
396 
397 	case POWER_SUPPLY_PROP_TEMP:
398 		ret = ds2781_get_temperature(dev_info, &val->intval);
399 		break;
400 
401 	case POWER_SUPPLY_PROP_MODEL_NAME:
402 		val->strval = model;
403 		break;
404 
405 	case POWER_SUPPLY_PROP_MANUFACTURER:
406 		val->strval = manufacturer;
407 		break;
408 
409 	case POWER_SUPPLY_PROP_CURRENT_NOW:
410 		ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval);
411 		break;
412 
413 	case POWER_SUPPLY_PROP_CURRENT_AVG:
414 		ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval);
415 		break;
416 
417 	case POWER_SUPPLY_PROP_STATUS:
418 		ret = ds2781_get_status(dev_info, &val->intval);
419 		break;
420 
421 	case POWER_SUPPLY_PROP_CAPACITY:
422 		ret = ds2781_get_capacity(dev_info, &val->intval);
423 		break;
424 
425 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
426 		ret = ds2781_get_accumulated_current(dev_info, &val->intval);
427 		break;
428 
429 	case POWER_SUPPLY_PROP_CHARGE_NOW:
430 		ret = ds2781_get_charge_now(dev_info, &val->intval);
431 		break;
432 
433 	default:
434 		ret = -EINVAL;
435 	}
436 
437 	return ret;
438 }
439 
440 static enum power_supply_property ds2781_battery_props[] = {
441 	POWER_SUPPLY_PROP_STATUS,
442 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
443 	POWER_SUPPLY_PROP_TEMP,
444 	POWER_SUPPLY_PROP_MODEL_NAME,
445 	POWER_SUPPLY_PROP_MANUFACTURER,
446 	POWER_SUPPLY_PROP_CURRENT_NOW,
447 	POWER_SUPPLY_PROP_CURRENT_AVG,
448 	POWER_SUPPLY_PROP_CAPACITY,
449 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
450 	POWER_SUPPLY_PROP_CHARGE_NOW,
451 };
452 
ds2781_get_pmod_enabled(struct device * dev,struct device_attribute * attr,char * buf)453 static ssize_t ds2781_get_pmod_enabled(struct device *dev,
454 	struct device_attribute *attr,
455 	char *buf)
456 {
457 	int ret;
458 	u8 control_reg;
459 	struct power_supply *psy = to_power_supply(dev);
460 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
461 
462 	/* Get power mode */
463 	ret = ds2781_get_control_register(dev_info, &control_reg);
464 	if (ret < 0)
465 		return ret;
466 
467 	return sprintf(buf, "%d\n",
468 		 !!(control_reg & DS2781_CONTROL_PMOD));
469 }
470 
ds2781_set_pmod_enabled(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)471 static ssize_t ds2781_set_pmod_enabled(struct device *dev,
472 	struct device_attribute *attr,
473 	const char *buf,
474 	size_t count)
475 {
476 	int ret;
477 	u8 control_reg, new_setting;
478 	struct power_supply *psy = to_power_supply(dev);
479 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
480 
481 	/* Set power mode */
482 	ret = ds2781_get_control_register(dev_info, &control_reg);
483 	if (ret < 0)
484 		return ret;
485 
486 	ret = kstrtou8(buf, 0, &new_setting);
487 	if (ret < 0)
488 		return ret;
489 
490 	if ((new_setting != 0) && (new_setting != 1)) {
491 		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
492 		return -EINVAL;
493 	}
494 
495 	if (new_setting)
496 		control_reg |= DS2781_CONTROL_PMOD;
497 	else
498 		control_reg &= ~DS2781_CONTROL_PMOD;
499 
500 	ret = ds2781_set_control_register(dev_info, control_reg);
501 	if (ret < 0)
502 		return ret;
503 
504 	return count;
505 }
506 
ds2781_get_sense_resistor_value(struct device * dev,struct device_attribute * attr,char * buf)507 static ssize_t ds2781_get_sense_resistor_value(struct device *dev,
508 	struct device_attribute *attr,
509 	char *buf)
510 {
511 	int ret;
512 	u8 sense_resistor;
513 	struct power_supply *psy = to_power_supply(dev);
514 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
515 
516 	ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP);
517 	if (ret < 0)
518 		return ret;
519 
520 	ret = sprintf(buf, "%d\n", sense_resistor);
521 	return ret;
522 }
523 
ds2781_set_sense_resistor_value(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)524 static ssize_t ds2781_set_sense_resistor_value(struct device *dev,
525 	struct device_attribute *attr,
526 	const char *buf,
527 	size_t count)
528 {
529 	int ret;
530 	u8 new_setting;
531 	struct power_supply *psy = to_power_supply(dev);
532 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
533 
534 	ret = kstrtou8(buf, 0, &new_setting);
535 	if (ret < 0)
536 		return ret;
537 
538 	ret = ds2781_set_sense_register(dev_info, new_setting);
539 	if (ret < 0)
540 		return ret;
541 
542 	return count;
543 }
544 
ds2781_get_rsgain_setting(struct device * dev,struct device_attribute * attr,char * buf)545 static ssize_t ds2781_get_rsgain_setting(struct device *dev,
546 	struct device_attribute *attr,
547 	char *buf)
548 {
549 	int ret;
550 	u16 rsgain;
551 	struct power_supply *psy = to_power_supply(dev);
552 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
553 
554 	ret = ds2781_get_rsgain_register(dev_info, &rsgain);
555 	if (ret < 0)
556 		return ret;
557 
558 	return sprintf(buf, "%d\n", rsgain);
559 }
560 
ds2781_set_rsgain_setting(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)561 static ssize_t ds2781_set_rsgain_setting(struct device *dev,
562 	struct device_attribute *attr,
563 	const char *buf,
564 	size_t count)
565 {
566 	int ret;
567 	u16 new_setting;
568 	struct power_supply *psy = to_power_supply(dev);
569 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
570 
571 	ret = kstrtou16(buf, 0, &new_setting);
572 	if (ret < 0)
573 		return ret;
574 
575 	/* Gain can only be from 0 to 1.999 in steps of .001 */
576 	if (new_setting > 1999) {
577 		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
578 		return -EINVAL;
579 	}
580 
581 	ret = ds2781_set_rsgain_register(dev_info, new_setting);
582 	if (ret < 0)
583 		return ret;
584 
585 	return count;
586 }
587 
ds2781_get_pio_pin(struct device * dev,struct device_attribute * attr,char * buf)588 static ssize_t ds2781_get_pio_pin(struct device *dev,
589 	struct device_attribute *attr,
590 	char *buf)
591 {
592 	int ret;
593 	u8 sfr;
594 	struct power_supply *psy = to_power_supply(dev);
595 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
596 
597 	ret = ds2781_read8(dev_info, &sfr, DS2781_SFR);
598 	if (ret < 0)
599 		return ret;
600 
601 	ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC);
602 	return ret;
603 }
604 
ds2781_set_pio_pin(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)605 static ssize_t ds2781_set_pio_pin(struct device *dev,
606 	struct device_attribute *attr,
607 	const char *buf,
608 	size_t count)
609 {
610 	int ret;
611 	u8 new_setting;
612 	struct power_supply *psy = to_power_supply(dev);
613 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
614 
615 	ret = kstrtou8(buf, 0, &new_setting);
616 	if (ret < 0)
617 		return ret;
618 
619 	if ((new_setting != 0) && (new_setting != 1)) {
620 		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
621 		return -EINVAL;
622 	}
623 
624 	ret = ds2781_write(dev_info, &new_setting,
625 				DS2781_SFR, sizeof(u8));
626 	if (ret < 0)
627 		return ret;
628 
629 	return count;
630 }
631 
ds2781_read_param_eeprom_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)632 static ssize_t ds2781_read_param_eeprom_bin(struct file *filp,
633 				struct kobject *kobj,
634 				struct bin_attribute *bin_attr,
635 				char *buf, loff_t off, size_t count)
636 {
637 	struct device *dev = container_of(kobj, struct device, kobj);
638 	struct power_supply *psy = to_power_supply(dev);
639 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
640 
641 	count = min_t(loff_t, count, DS2781_PARAM_EEPROM_SIZE - off);
642 
643 	return ds2781_read_block(dev_info, buf,
644 				DS2781_EEPROM_BLOCK1_START + off, count);
645 }
646 
ds2781_write_param_eeprom_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)647 static ssize_t ds2781_write_param_eeprom_bin(struct file *filp,
648 				struct kobject *kobj,
649 				struct bin_attribute *bin_attr,
650 				char *buf, loff_t off, size_t count)
651 {
652 	struct device *dev = container_of(kobj, struct device, kobj);
653 	struct power_supply *psy = to_power_supply(dev);
654 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
655 	int ret;
656 
657 	count = min_t(loff_t, count, DS2781_PARAM_EEPROM_SIZE - off);
658 
659 	ret = ds2781_write(dev_info, buf,
660 				DS2781_EEPROM_BLOCK1_START + off, count);
661 	if (ret < 0)
662 		return ret;
663 
664 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START);
665 	if (ret < 0)
666 		return ret;
667 
668 	return count;
669 }
670 
671 static struct bin_attribute ds2781_param_eeprom_bin_attr = {
672 	.attr = {
673 		.name = "param_eeprom",
674 		.mode = S_IRUGO | S_IWUSR,
675 	},
676 	.size = DS2781_PARAM_EEPROM_SIZE,
677 	.read = ds2781_read_param_eeprom_bin,
678 	.write = ds2781_write_param_eeprom_bin,
679 };
680 
ds2781_read_user_eeprom_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)681 static ssize_t ds2781_read_user_eeprom_bin(struct file *filp,
682 				struct kobject *kobj,
683 				struct bin_attribute *bin_attr,
684 				char *buf, loff_t off, size_t count)
685 {
686 	struct device *dev = container_of(kobj, struct device, kobj);
687 	struct power_supply *psy = to_power_supply(dev);
688 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
689 
690 	count = min_t(loff_t, count, DS2781_USER_EEPROM_SIZE - off);
691 
692 	return ds2781_read_block(dev_info, buf,
693 				DS2781_EEPROM_BLOCK0_START + off, count);
694 
695 }
696 
ds2781_write_user_eeprom_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)697 static ssize_t ds2781_write_user_eeprom_bin(struct file *filp,
698 				struct kobject *kobj,
699 				struct bin_attribute *bin_attr,
700 				char *buf, loff_t off, size_t count)
701 {
702 	struct device *dev = container_of(kobj, struct device, kobj);
703 	struct power_supply *psy = to_power_supply(dev);
704 	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
705 	int ret;
706 
707 	count = min_t(loff_t, count, DS2781_USER_EEPROM_SIZE - off);
708 
709 	ret = ds2781_write(dev_info, buf,
710 				DS2781_EEPROM_BLOCK0_START + off, count);
711 	if (ret < 0)
712 		return ret;
713 
714 	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START);
715 	if (ret < 0)
716 		return ret;
717 
718 	return count;
719 }
720 
721 static struct bin_attribute ds2781_user_eeprom_bin_attr = {
722 	.attr = {
723 		.name = "user_eeprom",
724 		.mode = S_IRUGO | S_IWUSR,
725 	},
726 	.size = DS2781_USER_EEPROM_SIZE,
727 	.read = ds2781_read_user_eeprom_bin,
728 	.write = ds2781_write_user_eeprom_bin,
729 };
730 
731 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled,
732 	ds2781_set_pmod_enabled);
733 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
734 	ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value);
735 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting,
736 	ds2781_set_rsgain_setting);
737 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin,
738 	ds2781_set_pio_pin);
739 
740 
741 static struct attribute *ds2781_attributes[] = {
742 	&dev_attr_pmod_enabled.attr,
743 	&dev_attr_sense_resistor_value.attr,
744 	&dev_attr_rsgain_setting.attr,
745 	&dev_attr_pio_pin.attr,
746 	NULL
747 };
748 
749 static const struct attribute_group ds2781_attr_group = {
750 	.attrs = ds2781_attributes,
751 };
752 
ds2781_battery_probe(struct platform_device * pdev)753 static int ds2781_battery_probe(struct platform_device *pdev)
754 {
755 	int ret = 0;
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.name		= dev_name(&pdev->dev);
767 	dev_info->bat.type		= POWER_SUPPLY_TYPE_BATTERY;
768 	dev_info->bat.properties	= ds2781_battery_props;
769 	dev_info->bat.num_properties	= ARRAY_SIZE(ds2781_battery_props);
770 	dev_info->bat.get_property	= ds2781_battery_get_property;
771 
772 	ret = power_supply_register(&pdev->dev, &dev_info->bat);
773 	if (ret) {
774 		dev_err(dev_info->dev, "failed to register battery\n");
775 		goto fail;
776 	}
777 
778 	ret = sysfs_create_group(&dev_info->bat.dev->kobj, &ds2781_attr_group);
779 	if (ret) {
780 		dev_err(dev_info->dev, "failed to create sysfs group\n");
781 		goto fail_unregister;
782 	}
783 
784 	ret = sysfs_create_bin_file(&dev_info->bat.dev->kobj,
785 					&ds2781_param_eeprom_bin_attr);
786 	if (ret) {
787 		dev_err(dev_info->dev,
788 				"failed to create param eeprom bin file");
789 		goto fail_remove_group;
790 	}
791 
792 	ret = sysfs_create_bin_file(&dev_info->bat.dev->kobj,
793 					&ds2781_user_eeprom_bin_attr);
794 	if (ret) {
795 		dev_err(dev_info->dev,
796 				"failed to create user eeprom bin file");
797 		goto fail_remove_bin_file;
798 	}
799 
800 	return 0;
801 
802 fail_remove_bin_file:
803 	sysfs_remove_bin_file(&dev_info->bat.dev->kobj,
804 				&ds2781_param_eeprom_bin_attr);
805 fail_remove_group:
806 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2781_attr_group);
807 fail_unregister:
808 	power_supply_unregister(&dev_info->bat);
809 fail:
810 	return ret;
811 }
812 
ds2781_battery_remove(struct platform_device * pdev)813 static int ds2781_battery_remove(struct platform_device *pdev)
814 {
815 	struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
816 
817 	/* remove attributes */
818 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2781_attr_group);
819 
820 	power_supply_unregister(&dev_info->bat);
821 
822 	return 0;
823 }
824 
825 static struct platform_driver ds2781_battery_driver = {
826 	.driver = {
827 		.name = "ds2781-battery",
828 	},
829 	.probe	  = ds2781_battery_probe,
830 	.remove   = ds2781_battery_remove,
831 };
832 module_platform_driver(ds2781_battery_driver);
833 
834 MODULE_LICENSE("GPL");
835 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
836 MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauage IC driver");
837 MODULE_ALIAS("platform:ds2781-battery");
838 
839