1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Battery driver for 7th-generation Microsoft Surface devices via Surface
4 * System Aggregator Module (SSAM).
5 *
6 * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
7 */
8
9#include <linux/unaligned.h>
10#include <linux/jiffies.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/power_supply.h>
15#include <linux/sysfs.h>
16#include <linux/types.h>
17#include <linux/workqueue.h>
18
19#include <linux/surface_aggregator/device.h>
20
21
22/* -- SAM interface. -------------------------------------------------------- */
23
24enum sam_event_cid_bat {
25 SAM_EVENT_CID_BAT_BIX = 0x15,
26 SAM_EVENT_CID_BAT_BST = 0x16,
27 SAM_EVENT_CID_BAT_ADP = 0x17,
28 SAM_EVENT_CID_BAT_PROT = 0x18,
29 SAM_EVENT_CID_BAT_DPTF = 0x53,
30};
31
32enum sam_battery_sta {
33 SAM_BATTERY_STA_OK = 0x0f,
34 SAM_BATTERY_STA_PRESENT = 0x10,
35};
36
37enum sam_battery_state {
38 SAM_BATTERY_STATE_DISCHARGING = BIT(0),
39 SAM_BATTERY_STATE_CHARGING = BIT(1),
40 SAM_BATTERY_STATE_CRITICAL = BIT(2),
41};
42
43enum sam_battery_power_unit {
44 SAM_BATTERY_POWER_UNIT_mW = 0,
45 SAM_BATTERY_POWER_UNIT_mA = 1,
46};
47
48/* Equivalent to data returned in ACPI _BIX method, revision 0. */
49struct spwr_bix {
50 u8 revision;
51 __le32 power_unit;
52 __le32 design_cap;
53 __le32 last_full_charge_cap;
54 __le32 technology;
55 __le32 design_voltage;
56 __le32 design_cap_warn;
57 __le32 design_cap_low;
58 __le32 cycle_count;
59 __le32 measurement_accuracy;
60 __le32 max_sampling_time;
61 __le32 min_sampling_time;
62 __le32 max_avg_interval;
63 __le32 min_avg_interval;
64 __le32 bat_cap_granularity_1;
65 __le32 bat_cap_granularity_2;
66 __u8 model[21];
67 __u8 serial[11];
68 __u8 type[5];
69 __u8 oem_info[21];
70} __packed;
71
72static_assert(sizeof(struct spwr_bix) == 119);
73
74/* Equivalent to data returned in ACPI _BST method. */
75struct spwr_bst {
76 __le32 state;
77 __le32 present_rate;
78 __le32 remaining_cap;
79 __le32 present_voltage;
80} __packed;
81
82static_assert(sizeof(struct spwr_bst) == 16);
83
84#define SPWR_BIX_REVISION 0
85#define SPWR_BATTERY_VALUE_UNKNOWN 0xffffffff
86
87/* Get battery status (_STA) */
88SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_sta, __le32, {
89 .target_category = SSAM_SSH_TC_BAT,
90 .command_id = 0x01,
91});
92
93/* Get battery static information (_BIX). */
94SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_bix, struct spwr_bix, {
95 .target_category = SSAM_SSH_TC_BAT,
96 .command_id = 0x02,
97});
98
99/* Get battery dynamic information (_BST). */
100SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_bst, struct spwr_bst, {
101 .target_category = SSAM_SSH_TC_BAT,
102 .command_id = 0x03,
103});
104
105/* Set battery trip point (_BTP). */
106SSAM_DEFINE_SYNC_REQUEST_CL_W(ssam_bat_set_btp, __le32, {
107 .target_category = SSAM_SSH_TC_BAT,
108 .command_id = 0x04,
109});
110
111
112/* -- Device structures. ---------------------------------------------------- */
113
114struct spwr_psy_properties {
115 const char *name;
116 struct ssam_event_registry registry;
117};
118
119struct spwr_battery_device {
120 struct ssam_device *sdev;
121
122 char name[32];
123 struct power_supply *psy;
124 struct power_supply_desc psy_desc;
125
126 struct delayed_work update_work;
127
128 struct ssam_event_notifier notif;
129
130 struct mutex lock; /* Guards access to state data below. */
131 unsigned long timestamp;
132
133 __le32 sta;
134 struct spwr_bix bix;
135 struct spwr_bst bst;
136 u32 alarm;
137};
138
139
140/* -- Module parameters. ---------------------------------------------------- */
141
142static unsigned int cache_time = 1000;
143module_param(cache_time, uint, 0644);
144MODULE_PARM_DESC(cache_time, "battery state caching time in milliseconds [default: 1000]");
145
146
147/* -- State management. ----------------------------------------------------- */
148
149/*
150 * Delay for battery update quirk. See spwr_external_power_changed() below
151 * for more details.
152 */
153#define SPWR_AC_BAT_UPDATE_DELAY msecs_to_jiffies(5000)
154
155static bool spwr_battery_present(struct spwr_battery_device *bat)
156{
157 lockdep_assert_held(&bat->lock);
158
159 return le32_to_cpu(bat->sta) & SAM_BATTERY_STA_PRESENT;
160}
161
162static int spwr_battery_load_sta(struct spwr_battery_device *bat)
163{
164 lockdep_assert_held(&bat->lock);
165
166 return ssam_retry(ssam_bat_get_sta, bat->sdev, &bat->sta);
167}
168
169static int spwr_battery_load_bix(struct spwr_battery_device *bat)
170{
171 int status;
172
173 lockdep_assert_held(&bat->lock);
174
175 if (!spwr_battery_present(bat))
176 return 0;
177
178 status = ssam_retry(ssam_bat_get_bix, bat->sdev, &bat->bix);
179
180 /* Enforce NULL terminated strings in case anything goes wrong... */
181 bat->bix.model[ARRAY_SIZE(bat->bix.model) - 1] = 0;
182 bat->bix.serial[ARRAY_SIZE(bat->bix.serial) - 1] = 0;
183 bat->bix.type[ARRAY_SIZE(bat->bix.type) - 1] = 0;
184 bat->bix.oem_info[ARRAY_SIZE(bat->bix.oem_info) - 1] = 0;
185
186 return status;
187}
188
189static int spwr_battery_load_bst(struct spwr_battery_device *bat)
190{
191 lockdep_assert_held(&bat->lock);
192
193 if (!spwr_battery_present(bat))
194 return 0;
195
196 return ssam_retry(ssam_bat_get_bst, bat->sdev, &bat->bst);
197}
198
199static int spwr_battery_set_alarm_unlocked(struct spwr_battery_device *bat, u32 value)
200{
201 __le32 value_le = cpu_to_le32(value);
202
203 lockdep_assert_held(&bat->lock);
204
205 bat->alarm = value;
206 return ssam_retry(ssam_bat_set_btp, bat->sdev, &value_le);
207}
208
209static int spwr_battery_update_bst_unlocked(struct spwr_battery_device *bat, bool cached)
210{
211 unsigned long cache_deadline = bat->timestamp + msecs_to_jiffies(m: cache_time);
212 int status;
213
214 lockdep_assert_held(&bat->lock);
215
216 if (cached && bat->timestamp && time_is_after_jiffies(cache_deadline))
217 return 0;
218
219 status = spwr_battery_load_sta(bat);
220 if (status)
221 return status;
222
223 status = spwr_battery_load_bst(bat);
224 if (status)
225 return status;
226
227 bat->timestamp = jiffies;
228 return 0;
229}
230
231static int spwr_battery_update_bst(struct spwr_battery_device *bat, bool cached)
232{
233 int status;
234
235 mutex_lock(&bat->lock);
236 status = spwr_battery_update_bst_unlocked(bat, cached);
237 mutex_unlock(lock: &bat->lock);
238
239 return status;
240}
241
242static int spwr_battery_update_bix_unlocked(struct spwr_battery_device *bat)
243{
244 int status;
245
246 lockdep_assert_held(&bat->lock);
247
248 status = spwr_battery_load_sta(bat);
249 if (status)
250 return status;
251
252 status = spwr_battery_load_bix(bat);
253 if (status)
254 return status;
255
256 status = spwr_battery_load_bst(bat);
257 if (status)
258 return status;
259
260 if (bat->bix.revision != SPWR_BIX_REVISION)
261 dev_warn(&bat->sdev->dev, "unsupported battery revision: %u\n", bat->bix.revision);
262
263 bat->timestamp = jiffies;
264 return 0;
265}
266
267static u32 sprw_battery_get_full_cap_safe(struct spwr_battery_device *bat)
268{
269 u32 full_cap = get_unaligned_le32(p: &bat->bix.last_full_charge_cap);
270
271 lockdep_assert_held(&bat->lock);
272
273 if (full_cap == 0 || full_cap == SPWR_BATTERY_VALUE_UNKNOWN)
274 full_cap = get_unaligned_le32(p: &bat->bix.design_cap);
275
276 return full_cap;
277}
278
279static bool spwr_battery_is_full(struct spwr_battery_device *bat)
280{
281 u32 state = get_unaligned_le32(p: &bat->bst.state);
282 u32 full_cap = sprw_battery_get_full_cap_safe(bat);
283 u32 remaining_cap = get_unaligned_le32(p: &bat->bst.remaining_cap);
284
285 lockdep_assert_held(&bat->lock);
286
287 return full_cap != SPWR_BATTERY_VALUE_UNKNOWN && full_cap != 0 &&
288 remaining_cap != SPWR_BATTERY_VALUE_UNKNOWN &&
289 remaining_cap >= full_cap &&
290 state == 0;
291}
292
293static int spwr_battery_recheck_full(struct spwr_battery_device *bat)
294{
295 bool present;
296 u32 unit;
297 int status;
298
299 mutex_lock(&bat->lock);
300 unit = get_unaligned_le32(p: &bat->bix.power_unit);
301 present = spwr_battery_present(bat);
302
303 status = spwr_battery_update_bix_unlocked(bat);
304 if (status)
305 goto out;
306
307 /* If battery has been attached, (re-)initialize alarm. */
308 if (!present && spwr_battery_present(bat)) {
309 u32 cap_warn = get_unaligned_le32(p: &bat->bix.design_cap_warn);
310
311 status = spwr_battery_set_alarm_unlocked(bat, value: cap_warn);
312 if (status)
313 goto out;
314 }
315
316 /*
317 * Warn if the unit has changed. This is something we genuinely don't
318 * expect to happen, so make this a big warning. If it does, we'll
319 * need to add support for it.
320 */
321 WARN_ON(unit != get_unaligned_le32(&bat->bix.power_unit));
322
323out:
324 mutex_unlock(lock: &bat->lock);
325
326 if (!status)
327 power_supply_changed(psy: bat->psy);
328
329 return status;
330}
331
332static int spwr_battery_recheck_status(struct spwr_battery_device *bat)
333{
334 int status;
335
336 status = spwr_battery_update_bst(bat, cached: false);
337 if (!status)
338 power_supply_changed(psy: bat->psy);
339
340 return status;
341}
342
343static u32 spwr_notify_bat(struct ssam_event_notifier *nf, const struct ssam_event *event)
344{
345 struct spwr_battery_device *bat = container_of(nf, struct spwr_battery_device, notif);
346 int status;
347
348 /*
349 * We cannot use strict matching when registering the notifier as the
350 * EC expects us to register it against instance ID 0. Strict matching
351 * would thus drop events, as those may have non-zero instance IDs in
352 * this subsystem. So we need to check the instance ID of the event
353 * here manually.
354 */
355 if (event->instance_id != bat->sdev->uid.instance)
356 return 0;
357
358 dev_dbg(&bat->sdev->dev, "power event (cid = %#04x, iid = %#04x, tid = %#04x)\n",
359 event->command_id, event->instance_id, event->target_id);
360
361 switch (event->command_id) {
362 case SAM_EVENT_CID_BAT_BIX:
363 status = spwr_battery_recheck_full(bat);
364 break;
365
366 case SAM_EVENT_CID_BAT_BST:
367 status = spwr_battery_recheck_status(bat);
368 break;
369
370 case SAM_EVENT_CID_BAT_PROT:
371 /*
372 * TODO: Implement support for battery protection status change
373 * event.
374 */
375 status = 0;
376 break;
377
378 case SAM_EVENT_CID_BAT_DPTF:
379 /*
380 * TODO: Implement support for DPTF event.
381 */
382 status = 0;
383 break;
384
385 default:
386 return 0;
387 }
388
389 return ssam_notifier_from_errno(err: status) | SSAM_NOTIF_HANDLED;
390}
391
392static void spwr_battery_update_bst_workfn(struct work_struct *work)
393{
394 struct delayed_work *dwork = to_delayed_work(work);
395 struct spwr_battery_device *bat;
396 int status;
397
398 bat = container_of(dwork, struct spwr_battery_device, update_work);
399
400 status = spwr_battery_update_bst(bat, cached: false);
401 if (status) {
402 dev_err(&bat->sdev->dev, "failed to update battery state: %d\n", status);
403 return;
404 }
405
406 power_supply_changed(psy: bat->psy);
407}
408
409static void spwr_external_power_changed(struct power_supply *psy)
410{
411 struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
412
413 /*
414 * Handle battery update quirk: When the battery is fully charged (or
415 * charged up to the limit imposed by the UEFI battery limit) and the
416 * adapter is plugged in or removed, the EC does not send a separate
417 * event for the state (charging/discharging) change. Furthermore it
418 * may take some time until the state is updated on the battery.
419 * Schedule an update to solve this.
420 */
421
422 schedule_delayed_work(dwork: &bat->update_work, SPWR_AC_BAT_UPDATE_DELAY);
423}
424
425
426/* -- Properties. ----------------------------------------------------------- */
427
428static const enum power_supply_property spwr_battery_props_chg[] = {
429 POWER_SUPPLY_PROP_STATUS,
430 POWER_SUPPLY_PROP_PRESENT,
431 POWER_SUPPLY_PROP_TECHNOLOGY,
432 POWER_SUPPLY_PROP_CYCLE_COUNT,
433 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
434 POWER_SUPPLY_PROP_VOLTAGE_NOW,
435 POWER_SUPPLY_PROP_CURRENT_NOW,
436 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
437 POWER_SUPPLY_PROP_CHARGE_FULL,
438 POWER_SUPPLY_PROP_CHARGE_NOW,
439 POWER_SUPPLY_PROP_CAPACITY,
440 POWER_SUPPLY_PROP_CAPACITY_LEVEL,
441 POWER_SUPPLY_PROP_MODEL_NAME,
442 POWER_SUPPLY_PROP_MANUFACTURER,
443 POWER_SUPPLY_PROP_SERIAL_NUMBER,
444};
445
446static const enum power_supply_property spwr_battery_props_eng[] = {
447 POWER_SUPPLY_PROP_STATUS,
448 POWER_SUPPLY_PROP_PRESENT,
449 POWER_SUPPLY_PROP_TECHNOLOGY,
450 POWER_SUPPLY_PROP_CYCLE_COUNT,
451 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
452 POWER_SUPPLY_PROP_VOLTAGE_NOW,
453 POWER_SUPPLY_PROP_POWER_NOW,
454 POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
455 POWER_SUPPLY_PROP_ENERGY_FULL,
456 POWER_SUPPLY_PROP_ENERGY_NOW,
457 POWER_SUPPLY_PROP_CAPACITY,
458 POWER_SUPPLY_PROP_CAPACITY_LEVEL,
459 POWER_SUPPLY_PROP_MODEL_NAME,
460 POWER_SUPPLY_PROP_MANUFACTURER,
461 POWER_SUPPLY_PROP_SERIAL_NUMBER,
462};
463
464static int spwr_battery_prop_status(struct spwr_battery_device *bat)
465{
466 u32 state = get_unaligned_le32(p: &bat->bst.state);
467 u32 present_rate = get_unaligned_le32(p: &bat->bst.present_rate);
468
469 lockdep_assert_held(&bat->lock);
470
471 if (state & SAM_BATTERY_STATE_DISCHARGING)
472 return POWER_SUPPLY_STATUS_DISCHARGING;
473
474 if (state & SAM_BATTERY_STATE_CHARGING)
475 return POWER_SUPPLY_STATUS_CHARGING;
476
477 if (spwr_battery_is_full(bat))
478 return POWER_SUPPLY_STATUS_FULL;
479
480 if (present_rate == 0)
481 return POWER_SUPPLY_STATUS_NOT_CHARGING;
482
483 return POWER_SUPPLY_STATUS_UNKNOWN;
484}
485
486static int spwr_battery_prop_technology(struct spwr_battery_device *bat)
487{
488 lockdep_assert_held(&bat->lock);
489
490 if (!strcasecmp(s1: "NiCd", s2: bat->bix.type))
491 return POWER_SUPPLY_TECHNOLOGY_NiCd;
492
493 if (!strcasecmp(s1: "NiMH", s2: bat->bix.type))
494 return POWER_SUPPLY_TECHNOLOGY_NiMH;
495
496 if (!strcasecmp(s1: "LION", s2: bat->bix.type))
497 return POWER_SUPPLY_TECHNOLOGY_LION;
498
499 if (!strncasecmp(s1: "LI-ION", s2: bat->bix.type, n: 6))
500 return POWER_SUPPLY_TECHNOLOGY_LION;
501
502 if (!strcasecmp(s1: "LiP", s2: bat->bix.type))
503 return POWER_SUPPLY_TECHNOLOGY_LIPO;
504
505 return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
506}
507
508static int spwr_battery_prop_capacity(struct spwr_battery_device *bat)
509{
510 u32 full_cap = sprw_battery_get_full_cap_safe(bat);
511 u32 remaining_cap = get_unaligned_le32(p: &bat->bst.remaining_cap);
512
513 lockdep_assert_held(&bat->lock);
514
515 if (full_cap == 0 || full_cap == SPWR_BATTERY_VALUE_UNKNOWN)
516 return -ENODATA;
517
518 if (remaining_cap == SPWR_BATTERY_VALUE_UNKNOWN)
519 return -ENODATA;
520
521 return remaining_cap * 100 / full_cap;
522}
523
524static int spwr_battery_prop_capacity_level(struct spwr_battery_device *bat)
525{
526 u32 state = get_unaligned_le32(p: &bat->bst.state);
527 u32 remaining_cap = get_unaligned_le32(p: &bat->bst.remaining_cap);
528
529 lockdep_assert_held(&bat->lock);
530
531 if (state & SAM_BATTERY_STATE_CRITICAL)
532 return POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
533
534 if (spwr_battery_is_full(bat))
535 return POWER_SUPPLY_CAPACITY_LEVEL_FULL;
536
537 if (remaining_cap <= bat->alarm)
538 return POWER_SUPPLY_CAPACITY_LEVEL_LOW;
539
540 return POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
541}
542
543static int spwr_battery_get_property(struct power_supply *psy, enum power_supply_property psp,
544 union power_supply_propval *val)
545{
546 struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
547 u32 value;
548 int status;
549
550 mutex_lock(&bat->lock);
551
552 status = spwr_battery_update_bst_unlocked(bat, cached: true);
553 if (status)
554 goto out;
555
556 /* Abort if battery is not present. */
557 if (!spwr_battery_present(bat) && psp != POWER_SUPPLY_PROP_PRESENT) {
558 status = -ENODEV;
559 goto out;
560 }
561
562 switch (psp) {
563 case POWER_SUPPLY_PROP_STATUS:
564 val->intval = spwr_battery_prop_status(bat);
565 break;
566
567 case POWER_SUPPLY_PROP_PRESENT:
568 val->intval = spwr_battery_present(bat);
569 break;
570
571 case POWER_SUPPLY_PROP_TECHNOLOGY:
572 val->intval = spwr_battery_prop_technology(bat);
573 break;
574
575 case POWER_SUPPLY_PROP_CYCLE_COUNT:
576 value = get_unaligned_le32(p: &bat->bix.cycle_count);
577 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
578 val->intval = value;
579 else
580 status = -ENODATA;
581 break;
582
583 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
584 value = get_unaligned_le32(p: &bat->bix.design_voltage);
585 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
586 val->intval = value * 1000;
587 else
588 status = -ENODATA;
589 break;
590
591 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
592 value = get_unaligned_le32(p: &bat->bst.present_voltage);
593 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
594 val->intval = value * 1000;
595 else
596 status = -ENODATA;
597 break;
598
599 case POWER_SUPPLY_PROP_CURRENT_NOW:
600 case POWER_SUPPLY_PROP_POWER_NOW:
601 value = get_unaligned_le32(p: &bat->bst.present_rate);
602 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
603 val->intval = value * 1000;
604 else
605 status = -ENODATA;
606 break;
607
608 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
609 case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
610 value = get_unaligned_le32(p: &bat->bix.design_cap);
611 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
612 val->intval = value * 1000;
613 else
614 status = -ENODATA;
615 break;
616
617 case POWER_SUPPLY_PROP_CHARGE_FULL:
618 case POWER_SUPPLY_PROP_ENERGY_FULL:
619 value = get_unaligned_le32(p: &bat->bix.last_full_charge_cap);
620 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
621 val->intval = value * 1000;
622 else
623 status = -ENODATA;
624 break;
625
626 case POWER_SUPPLY_PROP_CHARGE_NOW:
627 case POWER_SUPPLY_PROP_ENERGY_NOW:
628 value = get_unaligned_le32(p: &bat->bst.remaining_cap);
629 if (value != SPWR_BATTERY_VALUE_UNKNOWN)
630 val->intval = value * 1000;
631 else
632 status = -ENODATA;
633 break;
634
635 case POWER_SUPPLY_PROP_CAPACITY:
636 val->intval = spwr_battery_prop_capacity(bat);
637 break;
638
639 case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
640 val->intval = spwr_battery_prop_capacity_level(bat);
641 break;
642
643 case POWER_SUPPLY_PROP_MODEL_NAME:
644 val->strval = bat->bix.model;
645 break;
646
647 case POWER_SUPPLY_PROP_MANUFACTURER:
648 val->strval = bat->bix.oem_info;
649 break;
650
651 case POWER_SUPPLY_PROP_SERIAL_NUMBER:
652 val->strval = bat->bix.serial;
653 break;
654
655 default:
656 status = -EINVAL;
657 break;
658 }
659
660out:
661 mutex_unlock(lock: &bat->lock);
662 return status;
663}
664
665
666/* -- Alarm attribute. ------------------------------------------------------ */
667
668static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, char *buf)
669{
670 struct power_supply *psy = dev_to_psy(dev);
671 struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
672 int status;
673
674 mutex_lock(&bat->lock);
675 status = sysfs_emit(buf, fmt: "%d\n", bat->alarm * 1000);
676 mutex_unlock(lock: &bat->lock);
677
678 return status;
679}
680
681static ssize_t alarm_store(struct device *dev, struct device_attribute *attr, const char *buf,
682 size_t count)
683{
684 struct power_supply *psy = dev_to_psy(dev);
685 struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
686 unsigned long value;
687 int status;
688
689 status = kstrtoul(s: buf, base: 0, res: &value);
690 if (status)
691 return status;
692
693 mutex_lock(&bat->lock);
694
695 if (!spwr_battery_present(bat)) {
696 mutex_unlock(lock: &bat->lock);
697 return -ENODEV;
698 }
699
700 status = spwr_battery_set_alarm_unlocked(bat, value: value / 1000);
701 if (status) {
702 mutex_unlock(lock: &bat->lock);
703 return status;
704 }
705
706 mutex_unlock(lock: &bat->lock);
707 return count;
708}
709
710static DEVICE_ATTR_RW(alarm);
711
712static struct attribute *spwr_battery_attrs[] = {
713 &dev_attr_alarm.attr,
714 NULL,
715};
716ATTRIBUTE_GROUPS(spwr_battery);
717
718
719/* -- Device setup. --------------------------------------------------------- */
720
721static void spwr_battery_init(struct spwr_battery_device *bat, struct ssam_device *sdev,
722 struct ssam_event_registry registry, const char *name)
723{
724 mutex_init(&bat->lock);
725 strscpy(bat->name, name, sizeof(bat->name));
726
727 bat->sdev = sdev;
728
729 bat->notif.base.priority = 1;
730 bat->notif.base.fn = spwr_notify_bat;
731 bat->notif.event.reg = registry;
732 bat->notif.event.id.target_category = sdev->uid.category;
733 bat->notif.event.id.instance = 0; /* need to register with instance 0 */
734 bat->notif.event.mask = SSAM_EVENT_MASK_TARGET;
735 bat->notif.event.flags = SSAM_EVENT_SEQUENCED;
736
737 bat->psy_desc.name = bat->name;
738 bat->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
739 bat->psy_desc.get_property = spwr_battery_get_property;
740
741 INIT_DELAYED_WORK(&bat->update_work, spwr_battery_update_bst_workfn);
742}
743
744static int spwr_battery_register(struct spwr_battery_device *bat)
745{
746 struct power_supply_config psy_cfg = {};
747 __le32 sta;
748 int status;
749
750 /* Make sure the device is there and functioning properly. */
751 status = ssam_retry(ssam_bat_get_sta, bat->sdev, &sta);
752 if (status)
753 return status;
754
755 if ((le32_to_cpu(sta) & SAM_BATTERY_STA_OK) != SAM_BATTERY_STA_OK)
756 return -ENODEV;
757
758 /* Satisfy lockdep although we are in an exclusive context here. */
759 mutex_lock(&bat->lock);
760
761 status = spwr_battery_update_bix_unlocked(bat);
762 if (status) {
763 mutex_unlock(lock: &bat->lock);
764 return status;
765 }
766
767 if (spwr_battery_present(bat)) {
768 u32 cap_warn = get_unaligned_le32(p: &bat->bix.design_cap_warn);
769
770 status = spwr_battery_set_alarm_unlocked(bat, value: cap_warn);
771 if (status) {
772 mutex_unlock(lock: &bat->lock);
773 return status;
774 }
775 }
776
777 mutex_unlock(lock: &bat->lock);
778
779 bat->psy_desc.external_power_changed = spwr_external_power_changed;
780
781 switch (get_unaligned_le32(p: &bat->bix.power_unit)) {
782 case SAM_BATTERY_POWER_UNIT_mW:
783 bat->psy_desc.properties = spwr_battery_props_eng;
784 bat->psy_desc.num_properties = ARRAY_SIZE(spwr_battery_props_eng);
785 break;
786
787 case SAM_BATTERY_POWER_UNIT_mA:
788 bat->psy_desc.properties = spwr_battery_props_chg;
789 bat->psy_desc.num_properties = ARRAY_SIZE(spwr_battery_props_chg);
790 break;
791
792 default:
793 dev_err(&bat->sdev->dev, "unsupported battery power unit: %u\n",
794 get_unaligned_le32(&bat->bix.power_unit));
795 return -EINVAL;
796 }
797
798 psy_cfg.drv_data = bat;
799 psy_cfg.attr_grp = spwr_battery_groups;
800
801 bat->psy = devm_power_supply_register(parent: &bat->sdev->dev, desc: &bat->psy_desc, cfg: &psy_cfg);
802 if (IS_ERR(ptr: bat->psy))
803 return PTR_ERR(ptr: bat->psy);
804
805 return ssam_device_notifier_register(sdev: bat->sdev, n: &bat->notif);
806}
807
808
809/* -- Driver setup. --------------------------------------------------------- */
810
811static int __maybe_unused surface_battery_resume(struct device *dev)
812{
813 return spwr_battery_recheck_full(bat: dev_get_drvdata(dev));
814}
815static SIMPLE_DEV_PM_OPS(surface_battery_pm_ops, NULL, surface_battery_resume);
816
817static int surface_battery_probe(struct ssam_device *sdev)
818{
819 const struct spwr_psy_properties *p;
820 struct spwr_battery_device *bat;
821
822 p = ssam_device_get_match_data(dev: sdev);
823 if (!p)
824 return -ENODEV;
825
826 bat = devm_kzalloc(dev: &sdev->dev, size: sizeof(*bat), GFP_KERNEL);
827 if (!bat)
828 return -ENOMEM;
829
830 spwr_battery_init(bat, sdev, registry: p->registry, name: p->name);
831 ssam_device_set_drvdata(sdev, data: bat);
832
833 return spwr_battery_register(bat);
834}
835
836static void surface_battery_remove(struct ssam_device *sdev)
837{
838 struct spwr_battery_device *bat = ssam_device_get_drvdata(sdev);
839
840 ssam_device_notifier_unregister(sdev, n: &bat->notif);
841 cancel_delayed_work_sync(dwork: &bat->update_work);
842}
843
844static const struct spwr_psy_properties spwr_psy_props_bat1 = {
845 .name = "BAT1",
846 .registry = SSAM_EVENT_REGISTRY_SAM,
847};
848
849static const struct spwr_psy_properties spwr_psy_props_bat2_sb3 = {
850 .name = "BAT2",
851 .registry = SSAM_EVENT_REGISTRY_KIP,
852};
853
854static const struct ssam_device_id surface_battery_match[] = {
855 { SSAM_SDEV(BAT, SAM, 0x01, 0x00), (unsigned long)&spwr_psy_props_bat1 },
856 { SSAM_SDEV(BAT, KIP, 0x01, 0x00), (unsigned long)&spwr_psy_props_bat2_sb3 },
857 { },
858};
859MODULE_DEVICE_TABLE(ssam, surface_battery_match);
860
861static struct ssam_device_driver surface_battery_driver = {
862 .probe = surface_battery_probe,
863 .remove = surface_battery_remove,
864 .match_table = surface_battery_match,
865 .driver = {
866 .name = "surface_battery",
867 .pm = &surface_battery_pm_ops,
868 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
869 },
870};
871module_ssam_device_driver(surface_battery_driver);
872
873MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
874MODULE_DESCRIPTION("Battery driver for Surface System Aggregator Module");
875MODULE_LICENSE("GPL");
876

source code of linux/drivers/power/supply/surface_battery.c