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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
24#define DS2780_CURRENT_UNITS 1563
25
26#define DS2780_CHARGE_UNITS 6250
27
28#define DS2780_USER_EEPROM_SIZE (DS2780_EEPROM_BLOCK0_END - \
29 DS2780_EEPROM_BLOCK0_START + 1)
30
31#define DS2780_PARAM_EEPROM_SIZE (DS2780_EEPROM_BLOCK1_END - \
32 DS2780_EEPROM_BLOCK1_START + 1)
33
34struct 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
41enum current_types {
42 CURRENT_NOW,
43 CURRENT_AVG,
44};
45
46static const char model[] = "DS2780";
47static const char manufacturer[] = "Maxim/Dallas";
48
49static inline struct ds2780_device_info *
50to_ds2780_device_info(struct power_supply *psy)
51{
52 return power_supply_get_drvdata(psy);
53}
54
55static 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
61static 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
67static 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
82static 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
88static 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
94static 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
99static 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
104static 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
120static 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
134static 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
141static 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
155static 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
163
164
165
166
167
168
169
170 ret = ds2780_read16(dev_info, &voltage_raw,
171 DS2780_VOLT_MSB_REG);
172 if (ret < 0)
173 return ret;
174
175
176
177
178
179 *voltage_uV = (voltage_raw / 32) * 4880;
180 return 0;
181}
182
183static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
184 int *temperature)
185{
186 int ret;
187 s16 temperature_raw;
188
189
190
191
192
193
194
195
196
197
198
199 ret = ds2780_read16(dev_info, &temperature_raw,
200 DS2780_TEMP_MSB_REG);
201 if (ret < 0)
202 return ret;
203
204
205
206
207
208
209
210 *temperature = ((temperature_raw / 32) * 125) / 100;
211 return 0;
212}
213
214static 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
223
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
244
245
246
247
248
249
250
251 ret = ds2780_read16(dev_info, ¤t_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
259static 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
268
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
282
283
284
285
286
287
288 ret = ds2780_read16(dev_info, ¤t_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
296static 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
310static 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, ¤t_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
334static 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
342
343
344
345
346
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
356static 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
362static 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
375static 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
430static 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
443static 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
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
461static 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
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
497static 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 = sprintf(buf, "%d\n", sense_resistor);
511 return ret;
512}
513
514static 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
535static 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
551static 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
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
578static 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 = sprintf(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
592 return ret;
593}
594
595static 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
622static 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
635static 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
657static 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
667static 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
680static 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
702static 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
712static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
713 ds2780_set_pmod_enabled);
714static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
715 ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
716static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
717 ds2780_set_rsgain_setting);
718static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
719 ds2780_set_pio_pin);
720
721static 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
729static struct bin_attribute *ds2780_sysfs_bin_attrs[] = {
730 &ds2780_param_eeprom_bin_attr,
731 &ds2780_user_eeprom_bin_attr,
732 NULL
733};
734
735static const struct attribute_group ds2780_sysfs_group = {
736 .attrs = ds2780_sysfs_attrs,
737 .bin_attrs = ds2780_sysfs_bin_attrs,
738};
739
740static const struct attribute_group *ds2780_sysfs_groups[] = {
741 &ds2780_sysfs_group,
742 NULL,
743};
744
745static 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
778static struct platform_driver ds2780_battery_driver = {
779 .driver = {
780 .name = "ds2780-battery",
781 },
782 .probe = ds2780_battery_probe,
783};
784
785module_platform_driver(ds2780_battery_driver);
786
787MODULE_LICENSE("GPL");
788MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
789MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC driver");
790MODULE_ALIAS("platform:ds2780-battery");
791