Merge git://git.infradead.org/battery-2.6
[pandora-kernel.git] / drivers / power / ds2780_battery.c
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 "../w1/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 device *w1_dev;
42 };
43
44 enum current_types {
45         CURRENT_NOW,
46         CURRENT_AVG,
47 };
48
49 static const char model[] = "DS2780";
50 static const char manufacturer[] = "Maxim/Dallas";
51
52 static inline struct ds2780_device_info *to_ds2780_device_info(
53         struct power_supply *psy)
54 {
55         return container_of(psy, struct ds2780_device_info, bat);
56 }
57
58 static inline struct power_supply *to_power_supply(struct device *dev)
59 {
60         return dev_get_drvdata(dev);
61 }
62
63 static inline int ds2780_read8(struct device *dev, u8 *val, int addr)
64 {
65         return w1_ds2780_io(dev, val, addr, sizeof(u8), 0);
66 }
67
68 static int ds2780_read16(struct device *dev, s16 *val, int addr)
69 {
70         int ret;
71         u8 raw[2];
72
73         ret = w1_ds2780_io(dev, raw, addr, sizeof(u8) * 2, 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 device *dev, u8 *val, int addr,
83         size_t count)
84 {
85         return w1_ds2780_io(dev, val, addr, count, 0);
86 }
87
88 static inline int ds2780_write(struct device *dev, u8 *val, int addr,
89         size_t count)
90 {
91         return w1_ds2780_io(dev, 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->w1_dev, &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->w1_dev, 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->w1_dev, raw,
148                                 DS2780_RSGAIN_MSB_REG, sizeof(u8) * 2);
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 compliment 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->w1_dev, &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 compliment 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->w1_dev, &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->w1_dev, &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 -ENXIO;
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 compliment 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->w1_dev, &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->w1_dev, &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->w1_dev, &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->w1_dev, &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->w1_dev, &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->w1_dev, 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->w1_dev, &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 sprintf(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->w1_dev, &sense_resistor, DS2780_RSNSP_REG);
507         if (ret < 0)
508                 return ret;
509
510         ret = sprintf(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 sprintf(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->w1_dev, &sfr, DS2780_SFR_REG);
588         if (ret < 0)
589                 return ret;
590
591         ret = sprintf(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->w1_dev, &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 = container_of(kobj, struct device, kobj);
628         struct power_supply *psy = to_power_supply(dev);
629         struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
630
631         count = min_t(loff_t, count,
632                 DS2780_EEPROM_BLOCK1_END -
633                 DS2780_EEPROM_BLOCK1_START + 1 - off);
634
635         return ds2780_read_block(dev_info->w1_dev, buf,
636                                 DS2780_EEPROM_BLOCK1_START + off, count);
637 }
638
639 static ssize_t ds2780_write_param_eeprom_bin(struct file *filp,
640                                 struct kobject *kobj,
641                                 struct bin_attribute *bin_attr,
642                                 char *buf, loff_t off, size_t count)
643 {
644         struct device *dev = container_of(kobj, struct device, kobj);
645         struct power_supply *psy = to_power_supply(dev);
646         struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
647         int ret;
648
649         count = min_t(loff_t, count,
650                 DS2780_EEPROM_BLOCK1_END -
651                 DS2780_EEPROM_BLOCK1_START + 1 - off);
652
653         ret = ds2780_write(dev_info->w1_dev, buf,
654                                 DS2780_EEPROM_BLOCK1_START + off, count);
655         if (ret < 0)
656                 return ret;
657
658         ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
659         if (ret < 0)
660                 return ret;
661
662         return count;
663 }
664
665 static struct bin_attribute ds2780_param_eeprom_bin_attr = {
666         .attr = {
667                 .name = "param_eeprom",
668                 .mode = S_IRUGO | S_IWUSR,
669         },
670         .size = DS2780_EEPROM_BLOCK1_END - DS2780_EEPROM_BLOCK1_START + 1,
671         .read = ds2780_read_param_eeprom_bin,
672         .write = ds2780_write_param_eeprom_bin,
673 };
674
675 static ssize_t ds2780_read_user_eeprom_bin(struct file *filp,
676                                 struct kobject *kobj,
677                                 struct bin_attribute *bin_attr,
678                                 char *buf, loff_t off, size_t count)
679 {
680         struct device *dev = container_of(kobj, struct device, kobj);
681         struct power_supply *psy = to_power_supply(dev);
682         struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
683
684         count = min_t(loff_t, count,
685                 DS2780_EEPROM_BLOCK0_END -
686                 DS2780_EEPROM_BLOCK0_START + 1 - off);
687
688         return ds2780_read_block(dev_info->w1_dev, buf,
689                                 DS2780_EEPROM_BLOCK0_START + off, count);
690
691 }
692
693 static ssize_t ds2780_write_user_eeprom_bin(struct file *filp,
694                                 struct kobject *kobj,
695                                 struct bin_attribute *bin_attr,
696                                 char *buf, loff_t off, size_t count)
697 {
698         struct device *dev = container_of(kobj, struct device, kobj);
699         struct power_supply *psy = to_power_supply(dev);
700         struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
701         int ret;
702
703         count = min_t(loff_t, count,
704                 DS2780_EEPROM_BLOCK0_END -
705                 DS2780_EEPROM_BLOCK0_START + 1 - off);
706
707         ret = ds2780_write(dev_info->w1_dev, buf,
708                                 DS2780_EEPROM_BLOCK0_START + off, count);
709         if (ret < 0)
710                 return ret;
711
712         ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
713         if (ret < 0)
714                 return ret;
715
716         return count;
717 }
718
719 static struct bin_attribute ds2780_user_eeprom_bin_attr = {
720         .attr = {
721                 .name = "user_eeprom",
722                 .mode = S_IRUGO | S_IWUSR,
723         },
724         .size = DS2780_EEPROM_BLOCK0_END - DS2780_EEPROM_BLOCK0_START + 1,
725         .read = ds2780_read_user_eeprom_bin,
726         .write = ds2780_write_user_eeprom_bin,
727 };
728
729 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
730         ds2780_set_pmod_enabled);
731 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
732         ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
733 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
734         ds2780_set_rsgain_setting);
735 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
736         ds2780_set_pio_pin);
737
738
739 static struct attribute *ds2780_attributes[] = {
740         &dev_attr_pmod_enabled.attr,
741         &dev_attr_sense_resistor_value.attr,
742         &dev_attr_rsgain_setting.attr,
743         &dev_attr_pio_pin.attr,
744         NULL
745 };
746
747 static const struct attribute_group ds2780_attr_group = {
748         .attrs = ds2780_attributes,
749 };
750
751 static int __devinit ds2780_battery_probe(struct platform_device *pdev)
752 {
753         int ret = 0;
754         struct ds2780_device_info *dev_info;
755
756         dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL);
757         if (!dev_info) {
758                 ret = -ENOMEM;
759                 goto fail;
760         }
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        = ds2780_battery_props;
769         dev_info->bat.num_properties    = ARRAY_SIZE(ds2780_battery_props);
770         dev_info->bat.get_property      = ds2780_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_free_info;
776         }
777
778         ret = sysfs_create_group(&dev_info->bat.dev->kobj, &ds2780_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                                         &ds2780_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                                         &ds2780_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                                 &ds2780_param_eeprom_bin_attr);
805 fail_remove_group:
806         sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
807 fail_unregister:
808         power_supply_unregister(&dev_info->bat);
809 fail_free_info:
810         kfree(dev_info);
811 fail:
812         return ret;
813 }
814
815 static int __devexit ds2780_battery_remove(struct platform_device *pdev)
816 {
817         struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);
818
819         /* remove attributes */
820         sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
821
822         power_supply_unregister(&dev_info->bat);
823
824         kfree(dev_info);
825         return 0;
826 }
827
828 MODULE_ALIAS("platform:ds2780-battery");
829
830 static struct platform_driver ds2780_battery_driver = {
831         .driver = {
832                 .name = "ds2780-battery",
833         },
834         .probe    = ds2780_battery_probe,
835         .remove   = ds2780_battery_remove,
836 };
837
838 static int __init ds2780_battery_init(void)
839 {
840         return platform_driver_register(&ds2780_battery_driver);
841 }
842
843 static void __exit ds2780_battery_exit(void)
844 {
845         platform_driver_unregister(&ds2780_battery_driver);
846 }
847
848 module_init(ds2780_battery_init);
849 module_exit(ds2780_battery_exit);
850
851 MODULE_LICENSE("GPL");
852 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
853 MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauage IC driver");