1// SPDX-License-Identifier: GPL-2.0
2//
3// max17040_battery.c
4// fuel-gauge systems for lithium-ion (Li+) batteries
5//
6// Copyright (C) 2009 Samsung Electronics
7// Minkyu Kang <mk7.kang@samsung.com>
8
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/platform_device.h>
12#include <linux/mutex.h>
13#include <linux/err.h>
14#include <linux/i2c.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include <linux/power_supply.h>
18#include <linux/of.h>
19#include <linux/regmap.h>
20#include <linux/slab.h>
21#include <linux/iio/consumer.h>
22
23#define MAX17040_VCELL 0x02
24#define MAX17040_SOC 0x04
25#define MAX17040_MODE 0x06
26#define MAX17040_VER 0x08
27#define MAX17040_CONFIG 0x0C
28#define MAX17040_STATUS 0x1A
29#define MAX17040_CMD 0xFE
30
31
32#define MAX17040_DELAY 1000
33#define MAX17040_BATTERY_FULL 95
34#define MAX17040_RCOMP_DEFAULT 0x9700
35
36#define MAX17040_ATHD_MASK 0x3f
37#define MAX17040_ALSC_MASK 0x40
38#define MAX17040_ATHD_DEFAULT_POWER_UP 4
39#define MAX17040_STATUS_HD_MASK 0x1000
40#define MAX17040_STATUS_SC_MASK 0x2000
41#define MAX17040_CFG_RCOMP_MASK 0xff00
42
43enum chip_id {
44 ID_MAX17040,
45 ID_MAX17041,
46 ID_MAX17043,
47 ID_MAX17044,
48 ID_MAX17048,
49 ID_MAX17049,
50 ID_MAX17058,
51 ID_MAX17059,
52};
53
54/* values that differ by chip_id */
55struct chip_data {
56 u16 reset_val;
57 u16 vcell_shift;
58 u16 vcell_mul;
59 u16 vcell_div;
60 u8 has_low_soc_alert;
61 u8 rcomp_bytes;
62 u8 has_soc_alert;
63};
64
65static struct chip_data max17040_family[] = {
66 [ID_MAX17040] = {
67 .reset_val = 0x0054,
68 .vcell_shift = 4,
69 .vcell_mul = 1250,
70 .vcell_div = 1,
71 .has_low_soc_alert = 0,
72 .rcomp_bytes = 2,
73 .has_soc_alert = 0,
74 },
75 [ID_MAX17041] = {
76 .reset_val = 0x0054,
77 .vcell_shift = 4,
78 .vcell_mul = 2500,
79 .vcell_div = 1,
80 .has_low_soc_alert = 0,
81 .rcomp_bytes = 2,
82 .has_soc_alert = 0,
83 },
84 [ID_MAX17043] = {
85 .reset_val = 0x0054,
86 .vcell_shift = 4,
87 .vcell_mul = 1250,
88 .vcell_div = 1,
89 .has_low_soc_alert = 1,
90 .rcomp_bytes = 1,
91 .has_soc_alert = 0,
92 },
93 [ID_MAX17044] = {
94 .reset_val = 0x0054,
95 .vcell_shift = 4,
96 .vcell_mul = 2500,
97 .vcell_div = 1,
98 .has_low_soc_alert = 1,
99 .rcomp_bytes = 1,
100 .has_soc_alert = 0,
101 },
102 [ID_MAX17048] = {
103 .reset_val = 0x5400,
104 .vcell_shift = 0,
105 .vcell_mul = 625,
106 .vcell_div = 8,
107 .has_low_soc_alert = 1,
108 .rcomp_bytes = 1,
109 .has_soc_alert = 1,
110 },
111 [ID_MAX17049] = {
112 .reset_val = 0x5400,
113 .vcell_shift = 0,
114 .vcell_mul = 625,
115 .vcell_div = 4,
116 .has_low_soc_alert = 1,
117 .rcomp_bytes = 1,
118 .has_soc_alert = 1,
119 },
120 [ID_MAX17058] = {
121 .reset_val = 0x5400,
122 .vcell_shift = 0,
123 .vcell_mul = 625,
124 .vcell_div = 8,
125 .has_low_soc_alert = 1,
126 .rcomp_bytes = 1,
127 .has_soc_alert = 0,
128 },
129 [ID_MAX17059] = {
130 .reset_val = 0x5400,
131 .vcell_shift = 0,
132 .vcell_mul = 625,
133 .vcell_div = 4,
134 .has_low_soc_alert = 1,
135 .rcomp_bytes = 1,
136 .has_soc_alert = 0,
137 },
138};
139
140struct max17040_chip {
141 struct i2c_client *client;
142 struct regmap *regmap;
143 struct delayed_work work;
144 struct power_supply *battery;
145 struct chip_data data;
146 struct iio_channel *channel_temp;
147
148 /* battery capacity */
149 int soc;
150 /* Low alert threshold from 32% to 1% of the State of Charge */
151 u32 low_soc_alert;
152 /* some devices return twice the capacity */
153 bool quirk_double_soc;
154 /* higher 8 bits for 17043+, 16 bits for 17040,41 */
155 u16 rcomp;
156};
157
158static int max17040_reset(struct max17040_chip *chip)
159{
160 return regmap_write(map: chip->regmap, MAX17040_CMD, val: chip->data.reset_val);
161}
162
163static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level)
164{
165 level = 32 - level * (chip->quirk_double_soc ? 2 : 1);
166 return regmap_update_bits(map: chip->regmap, MAX17040_CONFIG,
167 MAX17040_ATHD_MASK, val: level);
168}
169
170static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable)
171{
172 return regmap_update_bits(map: chip->regmap, MAX17040_CONFIG,
173 MAX17040_ALSC_MASK, val: enable ? MAX17040_ALSC_MASK : 0);
174}
175
176static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp)
177{
178 u16 mask = chip->data.rcomp_bytes == 2 ?
179 0xffff : MAX17040_CFG_RCOMP_MASK;
180
181 return regmap_update_bits(map: chip->regmap, MAX17040_CONFIG, mask, val: rcomp);
182}
183
184static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell)
185{
186 struct chip_data *d = &chip->data;
187
188 return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div;
189}
190
191
192static int max17040_get_vcell(struct max17040_chip *chip)
193{
194 u32 vcell;
195
196 regmap_read(map: chip->regmap, MAX17040_VCELL, val: &vcell);
197
198 return max17040_raw_vcell_to_uvolts(chip, vcell);
199}
200
201static int max17040_get_soc(struct max17040_chip *chip)
202{
203 u32 soc;
204
205 regmap_read(map: chip->regmap, MAX17040_SOC, val: &soc);
206
207 return soc >> (chip->quirk_double_soc ? 9 : 8);
208}
209
210static int max17040_get_version(struct max17040_chip *chip)
211{
212 int ret;
213 u32 version;
214
215 ret = regmap_read(map: chip->regmap, MAX17040_VER, val: &version);
216
217 return ret ? ret : version;
218}
219
220static int max17040_get_online(struct max17040_chip *chip)
221{
222 return 1;
223}
224
225static int max17040_get_of_data(struct max17040_chip *chip)
226{
227 struct device *dev = &chip->client->dev;
228 struct chip_data *data = &max17040_family[
229 (uintptr_t) of_device_get_match_data(dev)];
230 int rcomp_len;
231 u8 rcomp[2];
232
233 chip->quirk_double_soc = device_property_read_bool(dev,
234 propname: "maxim,double-soc");
235
236 chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
237 device_property_read_u32(dev,
238 propname: "maxim,alert-low-soc-level",
239 val: &chip->low_soc_alert);
240
241 if (chip->low_soc_alert <= 0 ||
242 chip->low_soc_alert > (chip->quirk_double_soc ? 16 : 32)) {
243 dev_err(dev, "maxim,alert-low-soc-level out of bounds\n");
244 return -EINVAL;
245 }
246
247 rcomp_len = device_property_count_u8(dev, propname: "maxim,rcomp");
248 chip->rcomp = MAX17040_RCOMP_DEFAULT;
249 if (rcomp_len == data->rcomp_bytes) {
250 if (!device_property_read_u8_array(dev, propname: "maxim,rcomp",
251 val: rcomp, nval: rcomp_len))
252 chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] :
253 rcomp[0] << 8;
254 } else if (rcomp_len > 0) {
255 dev_err(dev, "maxim,rcomp has incorrect length\n");
256 return -EINVAL;
257 }
258
259 return 0;
260}
261
262static void max17040_check_changes(struct max17040_chip *chip)
263{
264 chip->soc = max17040_get_soc(chip);
265}
266
267static void max17040_queue_work(struct max17040_chip *chip)
268{
269 queue_delayed_work(wq: system_power_efficient_wq, dwork: &chip->work,
270 MAX17040_DELAY);
271}
272
273static void max17040_stop_work(void *data)
274{
275 struct max17040_chip *chip = data;
276
277 cancel_delayed_work_sync(dwork: &chip->work);
278}
279
280static void max17040_work(struct work_struct *work)
281{
282 struct max17040_chip *chip;
283 int last_soc;
284
285 chip = container_of(work, struct max17040_chip, work.work);
286
287 /* store SOC to check changes */
288 last_soc = chip->soc;
289 max17040_check_changes(chip);
290
291 /* check changes and send uevent */
292 if (last_soc != chip->soc)
293 power_supply_changed(psy: chip->battery);
294
295 max17040_queue_work(chip);
296}
297
298/* Returns true if alert cause was SOC change, not low SOC */
299static bool max17040_handle_soc_alert(struct max17040_chip *chip)
300{
301 bool ret = true;
302 u32 data;
303
304 regmap_read(map: chip->regmap, MAX17040_STATUS, val: &data);
305
306 if (data & MAX17040_STATUS_HD_MASK) {
307 // this alert was caused by low soc
308 ret = false;
309 }
310 if (data & MAX17040_STATUS_SC_MASK) {
311 // soc change bit -- deassert to mark as handled
312 regmap_write(map: chip->regmap, MAX17040_STATUS,
313 val: data & ~MAX17040_STATUS_SC_MASK);
314 }
315
316 return ret;
317}
318
319static irqreturn_t max17040_thread_handler(int id, void *dev)
320{
321 struct max17040_chip *chip = dev;
322
323 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip)))
324 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n");
325
326 /* read registers */
327 max17040_check_changes(chip);
328
329 /* send uevent */
330 power_supply_changed(psy: chip->battery);
331
332 /* reset alert bit */
333 max17040_set_low_soc_alert(chip, level: chip->low_soc_alert);
334
335 return IRQ_HANDLED;
336}
337
338static int max17040_enable_alert_irq(struct max17040_chip *chip)
339{
340 struct i2c_client *client = chip->client;
341 int ret;
342
343 ret = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, NULL,
344 thread_fn: max17040_thread_handler, IRQF_ONESHOT,
345 devname: chip->battery->desc->name, dev_id: chip);
346
347 return ret;
348}
349
350static int max17040_prop_writeable(struct power_supply *psy,
351 enum power_supply_property psp)
352{
353 switch (psp) {
354 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
355 return 1;
356 default:
357 return 0;
358 }
359}
360
361static int max17040_set_property(struct power_supply *psy,
362 enum power_supply_property psp,
363 const union power_supply_propval *val)
364{
365 struct max17040_chip *chip = power_supply_get_drvdata(psy);
366 int ret;
367
368 switch (psp) {
369 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
370 /* alert threshold can be programmed from 1% up to 16/32% */
371 if ((val->intval < 1) ||
372 (val->intval > (chip->quirk_double_soc ? 16 : 32))) {
373 ret = -EINVAL;
374 break;
375 }
376 ret = max17040_set_low_soc_alert(chip, level: val->intval);
377 chip->low_soc_alert = val->intval;
378 break;
379 default:
380 ret = -EINVAL;
381 }
382
383 return ret;
384}
385
386static int max17040_get_property(struct power_supply *psy,
387 enum power_supply_property psp,
388 union power_supply_propval *val)
389{
390 struct max17040_chip *chip = power_supply_get_drvdata(psy);
391 int ret;
392
393 switch (psp) {
394 case POWER_SUPPLY_PROP_ONLINE:
395 case POWER_SUPPLY_PROP_PRESENT:
396 val->intval = max17040_get_online(chip);
397 break;
398 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
399 val->intval = max17040_get_vcell(chip);
400 break;
401 case POWER_SUPPLY_PROP_CAPACITY:
402 val->intval = max17040_get_soc(chip);
403 break;
404 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
405 val->intval = chip->low_soc_alert;
406 break;
407 case POWER_SUPPLY_PROP_STATUS:
408 power_supply_get_property_from_supplier(psy, psp, val);
409 break;
410 case POWER_SUPPLY_PROP_TEMP:
411 if (!chip->channel_temp)
412 return -ENODATA;
413
414 ret = iio_read_channel_processed(chan: chip->channel_temp, val: &val->intval);
415 if (ret)
416 return ret;
417
418 val->intval /= 100; /* Convert from milli- to deci-degree */
419
420 break;
421 default:
422 return -EINVAL;
423 }
424 return 0;
425}
426
427static const struct regmap_config max17040_regmap = {
428 .reg_bits = 8,
429 .reg_stride = 2,
430 .val_bits = 16,
431 .val_format_endian = REGMAP_ENDIAN_BIG,
432};
433
434static enum power_supply_property max17040_battery_props[] = {
435 POWER_SUPPLY_PROP_ONLINE,
436 POWER_SUPPLY_PROP_PRESENT,
437 POWER_SUPPLY_PROP_VOLTAGE_NOW,
438 POWER_SUPPLY_PROP_CAPACITY,
439 POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
440 POWER_SUPPLY_PROP_STATUS,
441 POWER_SUPPLY_PROP_TEMP,
442};
443
444static const struct power_supply_desc max17040_battery_desc = {
445 .name = "battery",
446 .type = POWER_SUPPLY_TYPE_BATTERY,
447 .get_property = max17040_get_property,
448 .set_property = max17040_set_property,
449 .property_is_writeable = max17040_prop_writeable,
450 .properties = max17040_battery_props,
451 .num_properties = ARRAY_SIZE(max17040_battery_props),
452};
453
454static int max17040_probe(struct i2c_client *client)
455{
456 const struct i2c_device_id *id = i2c_client_get_device_id(client);
457 struct i2c_adapter *adapter = client->adapter;
458 struct power_supply_config psy_cfg = {};
459 struct max17040_chip *chip;
460 enum chip_id chip_id;
461 bool enable_irq = false;
462 int ret;
463
464 if (!i2c_check_functionality(adap: adapter, I2C_FUNC_SMBUS_BYTE))
465 return -EIO;
466
467 chip = devm_kzalloc(dev: &client->dev, size: sizeof(*chip), GFP_KERNEL);
468 if (!chip)
469 return -ENOMEM;
470
471 chip->client = client;
472 chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap);
473 if (IS_ERR(ptr: chip->regmap))
474 return PTR_ERR(ptr: chip->regmap);
475 chip_id = (enum chip_id) id->driver_data;
476 if (client->dev.of_node) {
477 ret = max17040_get_of_data(chip);
478 if (ret)
479 return ret;
480 chip_id = (uintptr_t)of_device_get_match_data(dev: &client->dev);
481 }
482 chip->data = max17040_family[chip_id];
483
484 i2c_set_clientdata(client, data: chip);
485 psy_cfg.drv_data = chip;
486
487 /* Switch to devm_iio_channel_get_optional when available */
488 chip->channel_temp = devm_iio_channel_get(dev: &client->dev, consumer_channel: "temp");
489 if (IS_ERR(ptr: chip->channel_temp)) {
490 ret = PTR_ERR(ptr: chip->channel_temp);
491 if (ret != -ENODEV)
492 return dev_err_probe(dev: &client->dev, err: PTR_ERR(ptr: chip->channel_temp),
493 fmt: "failed to get temp\n");
494 else
495 chip->channel_temp = NULL;
496 }
497
498 chip->battery = devm_power_supply_register(parent: &client->dev,
499 desc: &max17040_battery_desc, cfg: &psy_cfg);
500 if (IS_ERR(ptr: chip->battery)) {
501 dev_err(&client->dev, "failed: power supply register\n");
502 return PTR_ERR(ptr: chip->battery);
503 }
504
505 ret = max17040_get_version(chip);
506 if (ret < 0)
507 return ret;
508 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);
509
510 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)
511 max17040_reset(chip);
512
513 max17040_set_rcomp(chip, rcomp: chip->rcomp);
514
515 /* check interrupt */
516 if (client->irq && chip->data.has_low_soc_alert) {
517 ret = max17040_set_low_soc_alert(chip, level: chip->low_soc_alert);
518 if (ret) {
519 dev_err(&client->dev,
520 "Failed to set low SOC alert: err %d\n", ret);
521 return ret;
522 }
523
524 enable_irq = true;
525 }
526
527 if (client->irq && chip->data.has_soc_alert) {
528 ret = max17040_set_soc_alert(chip, enable: 1);
529 if (ret) {
530 dev_err(&client->dev,
531 "Failed to set SOC alert: err %d\n", ret);
532 return ret;
533 }
534 enable_irq = true;
535 } else {
536 /* soc alerts negate the need for polling */
537 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
538 ret = devm_add_action(&client->dev, max17040_stop_work, chip);
539 if (ret)
540 return ret;
541 max17040_queue_work(chip);
542 }
543
544 if (enable_irq) {
545 ret = max17040_enable_alert_irq(chip);
546 if (ret) {
547 client->irq = 0;
548 dev_warn(&client->dev,
549 "Failed to get IRQ err %d\n", ret);
550 }
551 }
552
553 return 0;
554}
555
556#ifdef CONFIG_PM_SLEEP
557
558static int max17040_suspend(struct device *dev)
559{
560 struct i2c_client *client = to_i2c_client(dev);
561 struct max17040_chip *chip = i2c_get_clientdata(client);
562
563 if (client->irq && chip->data.has_soc_alert)
564 // disable soc alert to prevent wakeup
565 max17040_set_soc_alert(chip, enable: 0);
566 else
567 cancel_delayed_work(dwork: &chip->work);
568
569 if (client->irq && device_may_wakeup(dev))
570 enable_irq_wake(irq: client->irq);
571
572 return 0;
573}
574
575static int max17040_resume(struct device *dev)
576{
577 struct i2c_client *client = to_i2c_client(dev);
578 struct max17040_chip *chip = i2c_get_clientdata(client);
579
580 if (client->irq && device_may_wakeup(dev))
581 disable_irq_wake(irq: client->irq);
582
583 if (client->irq && chip->data.has_soc_alert)
584 max17040_set_soc_alert(chip, enable: 1);
585 else
586 max17040_queue_work(chip);
587
588 return 0;
589}
590
591static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
592#define MAX17040_PM_OPS (&max17040_pm_ops)
593
594#else
595
596#define MAX17040_PM_OPS NULL
597
598#endif /* CONFIG_PM_SLEEP */
599
600static const struct i2c_device_id max17040_id[] = {
601 { "max17040", ID_MAX17040 },
602 { "max17041", ID_MAX17041 },
603 { "max17043", ID_MAX17043 },
604 { "max77836-battery", ID_MAX17043 },
605 { "max17044", ID_MAX17044 },
606 { "max17048", ID_MAX17048 },
607 { "max17049", ID_MAX17049 },
608 { "max17058", ID_MAX17058 },
609 { "max17059", ID_MAX17059 },
610 { /* sentinel */ }
611};
612MODULE_DEVICE_TABLE(i2c, max17040_id);
613
614static const struct of_device_id max17040_of_match[] = {
615 { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },
616 { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },
617 { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },
618 { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },
619 { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },
620 { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },
621 { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },
622 { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },
623 { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },
624 { /* sentinel */ },
625};
626MODULE_DEVICE_TABLE(of, max17040_of_match);
627
628static struct i2c_driver max17040_i2c_driver = {
629 .driver = {
630 .name = "max17040",
631 .of_match_table = max17040_of_match,
632 .pm = MAX17040_PM_OPS,
633 },
634 .probe = max17040_probe,
635 .id_table = max17040_id,
636};
637module_i2c_driver(max17040_i2c_driver);
638
639MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
640MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
641MODULE_LICENSE("GPL");
642

source code of linux/drivers/power/supply/max17040_battery.c