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