1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Gas Gauge driver for SBS Compliant Batteries
4  *
5  * Copyright (c) 2010, NVIDIA Corporation.
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/err.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/power/sbs-battery.h>
19 #include <linux/power_supply.h>
20 #include <linux/slab.h>
21 #include <linux/stat.h>
22 
23 enum {
24 	REG_MANUFACTURER_DATA,
25 	REG_TEMPERATURE,
26 	REG_VOLTAGE,
27 	REG_CURRENT,
28 	REG_CAPACITY,
29 	REG_TIME_TO_EMPTY,
30 	REG_TIME_TO_FULL,
31 	REG_STATUS,
32 	REG_CAPACITY_LEVEL,
33 	REG_CYCLE_COUNT,
34 	REG_SERIAL_NUMBER,
35 	REG_REMAINING_CAPACITY,
36 	REG_REMAINING_CAPACITY_CHARGE,
37 	REG_FULL_CHARGE_CAPACITY,
38 	REG_FULL_CHARGE_CAPACITY_CHARGE,
39 	REG_DESIGN_CAPACITY,
40 	REG_DESIGN_CAPACITY_CHARGE,
41 	REG_DESIGN_VOLTAGE_MIN,
42 	REG_DESIGN_VOLTAGE_MAX,
43 	REG_MANUFACTURER,
44 	REG_MODEL_NAME,
45 };
46 
47 /* Battery Mode defines */
48 #define BATTERY_MODE_OFFSET		0x03
49 #define BATTERY_MODE_MASK		0x8000
50 enum sbs_battery_mode {
51 	BATTERY_MODE_AMPS = 0,
52 	BATTERY_MODE_WATTS = 0x8000
53 };
54 
55 /* manufacturer access defines */
56 #define MANUFACTURER_ACCESS_STATUS	0x0006
57 #define MANUFACTURER_ACCESS_SLEEP	0x0011
58 
59 /* battery status value bits */
60 #define BATTERY_INITIALIZED		0x80
61 #define BATTERY_DISCHARGING		0x40
62 #define BATTERY_FULL_CHARGED		0x20
63 #define BATTERY_FULL_DISCHARGED		0x10
64 
65 /* min_value and max_value are only valid for numerical data */
66 #define SBS_DATA(_psp, _addr, _min_value, _max_value) { \
67 	.psp = _psp, \
68 	.addr = _addr, \
69 	.min_value = _min_value, \
70 	.max_value = _max_value, \
71 }
72 
73 static const struct chip_data {
74 	enum power_supply_property psp;
75 	u8 addr;
76 	int min_value;
77 	int max_value;
78 } sbs_data[] = {
79 	[REG_MANUFACTURER_DATA] =
80 		SBS_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
81 	[REG_TEMPERATURE] =
82 		SBS_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
83 	[REG_VOLTAGE] =
84 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
85 	[REG_CURRENT] =
86 		SBS_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, 32767),
87 	[REG_CAPACITY] =
88 		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0D, 0, 100),
89 	[REG_REMAINING_CAPACITY] =
90 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
91 	[REG_REMAINING_CAPACITY_CHARGE] =
92 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
93 	[REG_FULL_CHARGE_CAPACITY] =
94 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
95 	[REG_FULL_CHARGE_CAPACITY_CHARGE] =
96 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
97 	[REG_TIME_TO_EMPTY] =
98 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, 65535),
99 	[REG_TIME_TO_FULL] =
100 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, 65535),
101 	[REG_STATUS] =
102 		SBS_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
103 	[REG_CAPACITY_LEVEL] =
104 		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY_LEVEL, 0x16, 0, 65535),
105 	[REG_CYCLE_COUNT] =
106 		SBS_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
107 	[REG_DESIGN_CAPACITY] =
108 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0, 65535),
109 	[REG_DESIGN_CAPACITY_CHARGE] =
110 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0, 65535),
111 	[REG_DESIGN_VOLTAGE_MIN] =
112 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN, 0x19, 0, 65535),
113 	[REG_DESIGN_VOLTAGE_MAX] =
114 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0, 65535),
115 	[REG_SERIAL_NUMBER] =
116 		SBS_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
117 	/* Properties of type `const char *' */
118 	[REG_MANUFACTURER] =
119 		SBS_DATA(POWER_SUPPLY_PROP_MANUFACTURER, 0x20, 0, 65535),
120 	[REG_MODEL_NAME] =
121 		SBS_DATA(POWER_SUPPLY_PROP_MODEL_NAME, 0x21, 0, 65535)
122 };
123 
124 static enum power_supply_property sbs_properties[] = {
125 	POWER_SUPPLY_PROP_STATUS,
126 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
127 	POWER_SUPPLY_PROP_HEALTH,
128 	POWER_SUPPLY_PROP_PRESENT,
129 	POWER_SUPPLY_PROP_TECHNOLOGY,
130 	POWER_SUPPLY_PROP_CYCLE_COUNT,
131 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
132 	POWER_SUPPLY_PROP_CURRENT_NOW,
133 	POWER_SUPPLY_PROP_CAPACITY,
134 	POWER_SUPPLY_PROP_TEMP,
135 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
136 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
137 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
138 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
139 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
140 	POWER_SUPPLY_PROP_ENERGY_NOW,
141 	POWER_SUPPLY_PROP_ENERGY_FULL,
142 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
143 	POWER_SUPPLY_PROP_CHARGE_NOW,
144 	POWER_SUPPLY_PROP_CHARGE_FULL,
145 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
146 	/* Properties of type `const char *' */
147 	POWER_SUPPLY_PROP_MANUFACTURER,
148 	POWER_SUPPLY_PROP_MODEL_NAME
149 };
150 
151 /* Supports special manufacturer commands from TI BQ20Z75 IC. */
152 #define SBS_FLAGS_TI_BQ20Z75		BIT(0)
153 
154 struct sbs_info {
155 	struct i2c_client		*client;
156 	struct power_supply		*power_supply;
157 	bool				is_present;
158 	struct gpio_desc		*gpio_detect;
159 	bool				enable_detection;
160 	int				last_state;
161 	int				poll_time;
162 	u32				i2c_retry_count;
163 	u32				poll_retry_count;
164 	struct delayed_work		work;
165 	struct mutex			mode_lock;
166 	u32				flags;
167 };
168 
169 static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
170 static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1];
171 static bool force_load;
172 
173 static int sbs_read_word_data(struct i2c_client *client, u8 address)
174 {
175 	struct sbs_info *chip = i2c_get_clientdata(client);
176 	int retries = chip->i2c_retry_count;
177 	s32 ret = 0;
178 
179 	while (retries > 0) {
180 		ret = i2c_smbus_read_word_data(client, address);
181 		if (ret >= 0)
182 			break;
183 		retries--;
184 	}
185 
186 	if (ret < 0) {
187 		dev_dbg(&client->dev,
188 			"%s: i2c read at address 0x%x failed\n",
189 			__func__, address);
190 		return ret;
191 	}
192 
193 	return ret;
194 }
195 
196 static int sbs_read_string_data(struct i2c_client *client, u8 address,
197 				char *values)
198 {
199 	struct sbs_info *chip = i2c_get_clientdata(client);
200 	s32 ret = 0, block_length = 0;
201 	int retries_length, retries_block;
202 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
203 
204 	retries_length = chip->i2c_retry_count;
205 	retries_block = chip->i2c_retry_count;
206 
207 	/* Adapter needs to support these two functions */
208 	if (!i2c_check_functionality(client->adapter,
209 				     I2C_FUNC_SMBUS_BYTE_DATA |
210 				     I2C_FUNC_SMBUS_I2C_BLOCK)){
211 		return -ENODEV;
212 	}
213 
214 	/* Get the length of block data */
215 	while (retries_length > 0) {
216 		ret = i2c_smbus_read_byte_data(client, address);
217 		if (ret >= 0)
218 			break;
219 		retries_length--;
220 	}
221 
222 	if (ret < 0) {
223 		dev_dbg(&client->dev,
224 			"%s: i2c read at address 0x%x failed\n",
225 			__func__, address);
226 		return ret;
227 	}
228 
229 	/* block_length does not include NULL terminator */
230 	block_length = ret;
231 	if (block_length > I2C_SMBUS_BLOCK_MAX) {
232 		dev_err(&client->dev,
233 			"%s: Returned block_length is longer than 0x%x\n",
234 			__func__, I2C_SMBUS_BLOCK_MAX);
235 		return -EINVAL;
236 	}
237 
238 	/* Get the block data */
239 	while (retries_block > 0) {
240 		ret = i2c_smbus_read_i2c_block_data(
241 				client, address,
242 				block_length + 1, block_buffer);
243 		if (ret >= 0)
244 			break;
245 		retries_block--;
246 	}
247 
248 	if (ret < 0) {
249 		dev_dbg(&client->dev,
250 			"%s: i2c read at address 0x%x failed\n",
251 			__func__, address);
252 		return ret;
253 	}
254 
255 	/* block_buffer[0] == block_length */
256 	memcpy(values, block_buffer + 1, block_length);
257 	values[block_length] = '\0';
258 
259 	return ret;
260 }
261 
262 static int sbs_write_word_data(struct i2c_client *client, u8 address,
263 	u16 value)
264 {
265 	struct sbs_info *chip = i2c_get_clientdata(client);
266 	int retries = chip->i2c_retry_count;
267 	s32 ret = 0;
268 
269 	while (retries > 0) {
270 		ret = i2c_smbus_write_word_data(client, address, value);
271 		if (ret >= 0)
272 			break;
273 		retries--;
274 	}
275 
276 	if (ret < 0) {
277 		dev_dbg(&client->dev,
278 			"%s: i2c write to address 0x%x failed\n",
279 			__func__, address);
280 		return ret;
281 	}
282 
283 	return 0;
284 }
285 
286 static int sbs_status_correct(struct i2c_client *client, int *intval)
287 {
288 	int ret;
289 
290 	ret = sbs_read_word_data(client, sbs_data[REG_CURRENT].addr);
291 	if (ret < 0)
292 		return ret;
293 
294 	ret = (s16)ret;
295 
296 	/* Not drawing current means full (cannot be not charging) */
297 	if (ret == 0)
298 		*intval = POWER_SUPPLY_STATUS_FULL;
299 
300 	if (*intval == POWER_SUPPLY_STATUS_FULL) {
301 		/* Drawing or providing current when full */
302 		if (ret > 0)
303 			*intval = POWER_SUPPLY_STATUS_CHARGING;
304 		else if (ret < 0)
305 			*intval = POWER_SUPPLY_STATUS_DISCHARGING;
306 	}
307 
308 	return 0;
309 }
310 
311 static int sbs_get_battery_presence_and_health(
312 	struct i2c_client *client, enum power_supply_property psp,
313 	union power_supply_propval *val)
314 {
315 	int ret;
316 
317 	if (psp == POWER_SUPPLY_PROP_PRESENT) {
318 		/* Dummy command; if it succeeds, battery is present. */
319 		ret = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
320 		if (ret < 0)
321 			val->intval = 0; /* battery disconnected */
322 		else
323 			val->intval = 1; /* battery present */
324 	} else { /* POWER_SUPPLY_PROP_HEALTH */
325 		/* SBS spec doesn't have a general health command. */
326 		val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
327 	}
328 
329 	return 0;
330 }
331 
332 static int sbs_get_ti_battery_presence_and_health(
333 	struct i2c_client *client, enum power_supply_property psp,
334 	union power_supply_propval *val)
335 {
336 	s32 ret;
337 
338 	/*
339 	 * Write to ManufacturerAccess with ManufacturerAccess command
340 	 * and then read the status.
341 	 */
342 	ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
343 				  MANUFACTURER_ACCESS_STATUS);
344 	if (ret < 0) {
345 		if (psp == POWER_SUPPLY_PROP_PRESENT)
346 			val->intval = 0; /* battery removed */
347 		return ret;
348 	}
349 
350 	ret = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr);
351 	if (ret < 0) {
352 		if (psp == POWER_SUPPLY_PROP_PRESENT)
353 			val->intval = 0; /* battery removed */
354 		return ret;
355 	}
356 
357 	if (ret < sbs_data[REG_MANUFACTURER_DATA].min_value ||
358 	    ret > sbs_data[REG_MANUFACTURER_DATA].max_value) {
359 		val->intval = 0;
360 		return 0;
361 	}
362 
363 	/* Mask the upper nibble of 2nd byte and
364 	 * lower byte of response then
365 	 * shift the result by 8 to get status*/
366 	ret &= 0x0F00;
367 	ret >>= 8;
368 	if (psp == POWER_SUPPLY_PROP_PRESENT) {
369 		if (ret == 0x0F)
370 			/* battery removed */
371 			val->intval = 0;
372 		else
373 			val->intval = 1;
374 	} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
375 		if (ret == 0x09)
376 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
377 		else if (ret == 0x0B)
378 			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
379 		else if (ret == 0x0C)
380 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
381 		else
382 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
383 	}
384 
385 	return 0;
386 }
387 
388 static int sbs_get_battery_property(struct i2c_client *client,
389 	int reg_offset, enum power_supply_property psp,
390 	union power_supply_propval *val)
391 {
392 	struct sbs_info *chip = i2c_get_clientdata(client);
393 	s32 ret;
394 
395 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
396 	if (ret < 0)
397 		return ret;
398 
399 	/* returned values are 16 bit */
400 	if (sbs_data[reg_offset].min_value < 0)
401 		ret = (s16)ret;
402 
403 	if (ret >= sbs_data[reg_offset].min_value &&
404 	    ret <= sbs_data[reg_offset].max_value) {
405 		val->intval = ret;
406 		if (psp == POWER_SUPPLY_PROP_CAPACITY_LEVEL) {
407 			if (!(ret & BATTERY_INITIALIZED))
408 				val->intval =
409 					POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
410 			else if (ret & BATTERY_FULL_CHARGED)
411 				val->intval =
412 					POWER_SUPPLY_CAPACITY_LEVEL_FULL;
413 			else if (ret & BATTERY_FULL_DISCHARGED)
414 				val->intval =
415 					POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
416 			else
417 				val->intval =
418 					POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
419 			return 0;
420 		} else if (psp != POWER_SUPPLY_PROP_STATUS) {
421 			return 0;
422 		}
423 
424 		if (ret & BATTERY_FULL_CHARGED)
425 			val->intval = POWER_SUPPLY_STATUS_FULL;
426 		else if (ret & BATTERY_DISCHARGING)
427 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
428 		else
429 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
430 
431 		sbs_status_correct(client, &val->intval);
432 
433 		if (chip->poll_time == 0)
434 			chip->last_state = val->intval;
435 		else if (chip->last_state != val->intval) {
436 			cancel_delayed_work_sync(&chip->work);
437 			power_supply_changed(chip->power_supply);
438 			chip->poll_time = 0;
439 		}
440 	} else {
441 		if (psp == POWER_SUPPLY_PROP_STATUS)
442 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
443 		else if (psp == POWER_SUPPLY_PROP_CAPACITY)
444 			/* sbs spec says that this can be >100 %
445 			 * even if max value is 100 %
446 			 */
447 			val->intval = min(ret, 100);
448 		else
449 			val->intval = 0;
450 	}
451 
452 	return 0;
453 }
454 
455 static int sbs_get_battery_string_property(struct i2c_client *client,
456 	int reg_offset, enum power_supply_property psp, char *val)
457 {
458 	s32 ret;
459 
460 	ret = sbs_read_string_data(client, sbs_data[reg_offset].addr, val);
461 
462 	if (ret < 0)
463 		return ret;
464 
465 	return 0;
466 }
467 
468 static void  sbs_unit_adjustment(struct i2c_client *client,
469 	enum power_supply_property psp, union power_supply_propval *val)
470 {
471 #define BASE_UNIT_CONVERSION		1000
472 #define BATTERY_MODE_CAP_MULT_WATT	(10 * BASE_UNIT_CONVERSION)
473 #define TIME_UNIT_CONVERSION		60
474 #define TEMP_KELVIN_TO_CELSIUS		2731
475 	switch (psp) {
476 	case POWER_SUPPLY_PROP_ENERGY_NOW:
477 	case POWER_SUPPLY_PROP_ENERGY_FULL:
478 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
479 		/* sbs provides energy in units of 10mWh.
480 		 * Convert to µWh
481 		 */
482 		val->intval *= BATTERY_MODE_CAP_MULT_WATT;
483 		break;
484 
485 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
486 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
487 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
488 	case POWER_SUPPLY_PROP_CURRENT_NOW:
489 	case POWER_SUPPLY_PROP_CHARGE_NOW:
490 	case POWER_SUPPLY_PROP_CHARGE_FULL:
491 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
492 		val->intval *= BASE_UNIT_CONVERSION;
493 		break;
494 
495 	case POWER_SUPPLY_PROP_TEMP:
496 		/* sbs provides battery temperature in 0.1K
497 		 * so convert it to 0.1°C
498 		 */
499 		val->intval -= TEMP_KELVIN_TO_CELSIUS;
500 		break;
501 
502 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
503 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
504 		/* sbs provides time to empty and time to full in minutes.
505 		 * Convert to seconds
506 		 */
507 		val->intval *= TIME_UNIT_CONVERSION;
508 		break;
509 
510 	default:
511 		dev_dbg(&client->dev,
512 			"%s: no need for unit conversion %d\n", __func__, psp);
513 	}
514 }
515 
516 static enum sbs_battery_mode sbs_set_battery_mode(struct i2c_client *client,
517 	enum sbs_battery_mode mode)
518 {
519 	int ret, original_val;
520 
521 	original_val = sbs_read_word_data(client, BATTERY_MODE_OFFSET);
522 	if (original_val < 0)
523 		return original_val;
524 
525 	if ((original_val & BATTERY_MODE_MASK) == mode)
526 		return mode;
527 
528 	if (mode == BATTERY_MODE_AMPS)
529 		ret = original_val & ~BATTERY_MODE_MASK;
530 	else
531 		ret = original_val | BATTERY_MODE_MASK;
532 
533 	ret = sbs_write_word_data(client, BATTERY_MODE_OFFSET, ret);
534 	if (ret < 0)
535 		return ret;
536 
537 	usleep_range(1000, 2000);
538 
539 	return original_val & BATTERY_MODE_MASK;
540 }
541 
542 static int sbs_get_battery_capacity(struct i2c_client *client,
543 	int reg_offset, enum power_supply_property psp,
544 	union power_supply_propval *val)
545 {
546 	s32 ret;
547 	enum sbs_battery_mode mode = BATTERY_MODE_WATTS;
548 
549 	if (power_supply_is_amp_property(psp))
550 		mode = BATTERY_MODE_AMPS;
551 
552 	mode = sbs_set_battery_mode(client, mode);
553 	if (mode < 0)
554 		return mode;
555 
556 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
557 	if (ret < 0)
558 		return ret;
559 
560 	val->intval = ret;
561 
562 	ret = sbs_set_battery_mode(client, mode);
563 	if (ret < 0)
564 		return ret;
565 
566 	return 0;
567 }
568 
569 static char sbs_serial[5];
570 static int sbs_get_battery_serial_number(struct i2c_client *client,
571 	union power_supply_propval *val)
572 {
573 	int ret;
574 
575 	ret = sbs_read_word_data(client, sbs_data[REG_SERIAL_NUMBER].addr);
576 	if (ret < 0)
577 		return ret;
578 
579 	sprintf(sbs_serial, "%04x", ret);
580 	val->strval = sbs_serial;
581 
582 	return 0;
583 }
584 
585 static int sbs_get_property_index(struct i2c_client *client,
586 	enum power_supply_property psp)
587 {
588 	int count;
589 	for (count = 0; count < ARRAY_SIZE(sbs_data); count++)
590 		if (psp == sbs_data[count].psp)
591 			return count;
592 
593 	dev_warn(&client->dev,
594 		"%s: Invalid Property - %d\n", __func__, psp);
595 
596 	return -EINVAL;
597 }
598 
599 static int sbs_get_property(struct power_supply *psy,
600 	enum power_supply_property psp,
601 	union power_supply_propval *val)
602 {
603 	int ret = 0;
604 	struct sbs_info *chip = power_supply_get_drvdata(psy);
605 	struct i2c_client *client = chip->client;
606 
607 	if (chip->gpio_detect) {
608 		ret = gpiod_get_value_cansleep(chip->gpio_detect);
609 		if (ret < 0)
610 			return ret;
611 		if (psp == POWER_SUPPLY_PROP_PRESENT) {
612 			val->intval = ret;
613 			chip->is_present = val->intval;
614 			return 0;
615 		}
616 		if (ret == 0)
617 			return -ENODATA;
618 	}
619 
620 	switch (psp) {
621 	case POWER_SUPPLY_PROP_PRESENT:
622 	case POWER_SUPPLY_PROP_HEALTH:
623 		if (client->flags & SBS_FLAGS_TI_BQ20Z75)
624 			ret = sbs_get_ti_battery_presence_and_health(client,
625 								     psp, val);
626 		else
627 			ret = sbs_get_battery_presence_and_health(client, psp,
628 								  val);
629 		if (psp == POWER_SUPPLY_PROP_PRESENT)
630 			return 0;
631 		break;
632 
633 	case POWER_SUPPLY_PROP_TECHNOLOGY:
634 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
635 		goto done; /* don't trigger power_supply_changed()! */
636 
637 	case POWER_SUPPLY_PROP_ENERGY_NOW:
638 	case POWER_SUPPLY_PROP_ENERGY_FULL:
639 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
640 	case POWER_SUPPLY_PROP_CHARGE_NOW:
641 	case POWER_SUPPLY_PROP_CHARGE_FULL:
642 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
643 		ret = sbs_get_property_index(client, psp);
644 		if (ret < 0)
645 			break;
646 
647 		/* sbs_get_battery_capacity() will change the battery mode
648 		 * temporarily to read the requested attribute. Ensure we stay
649 		 * in the desired mode for the duration of the attribute read.
650 		 */
651 		mutex_lock(&chip->mode_lock);
652 		ret = sbs_get_battery_capacity(client, ret, psp, val);
653 		mutex_unlock(&chip->mode_lock);
654 		break;
655 
656 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
657 		ret = sbs_get_battery_serial_number(client, val);
658 		break;
659 
660 	case POWER_SUPPLY_PROP_STATUS:
661 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
662 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
663 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
664 	case POWER_SUPPLY_PROP_CURRENT_NOW:
665 	case POWER_SUPPLY_PROP_TEMP:
666 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
667 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
668 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
669 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
670 	case POWER_SUPPLY_PROP_CAPACITY:
671 		ret = sbs_get_property_index(client, psp);
672 		if (ret < 0)
673 			break;
674 
675 		ret = sbs_get_battery_property(client, ret, psp, val);
676 		break;
677 
678 	case POWER_SUPPLY_PROP_MODEL_NAME:
679 		ret = sbs_get_property_index(client, psp);
680 		if (ret < 0)
681 			break;
682 
683 		ret = sbs_get_battery_string_property(client, ret, psp,
684 						      model_name);
685 		val->strval = model_name;
686 		break;
687 
688 	case POWER_SUPPLY_PROP_MANUFACTURER:
689 		ret = sbs_get_property_index(client, psp);
690 		if (ret < 0)
691 			break;
692 
693 		ret = sbs_get_battery_string_property(client, ret, psp,
694 						      manufacturer);
695 		val->strval = manufacturer;
696 		break;
697 
698 	default:
699 		dev_err(&client->dev,
700 			"%s: INVALID property\n", __func__);
701 		return -EINVAL;
702 	}
703 
704 	if (!chip->enable_detection)
705 		goto done;
706 
707 	if (!chip->gpio_detect &&
708 		chip->is_present != (ret >= 0)) {
709 		chip->is_present = (ret >= 0);
710 		power_supply_changed(chip->power_supply);
711 	}
712 
713 done:
714 	if (!ret) {
715 		/* Convert units to match requirements for power supply class */
716 		sbs_unit_adjustment(client, psp, val);
717 	}
718 
719 	dev_dbg(&client->dev,
720 		"%s: property = %d, value = %x\n", __func__, psp, val->intval);
721 
722 	if (ret && chip->is_present)
723 		return ret;
724 
725 	/* battery not present, so return NODATA for properties */
726 	if (ret)
727 		return -ENODATA;
728 
729 	return 0;
730 }
731 
732 static void sbs_supply_changed(struct sbs_info *chip)
733 {
734 	struct power_supply *battery = chip->power_supply;
735 	int ret;
736 
737 	ret = gpiod_get_value_cansleep(chip->gpio_detect);
738 	if (ret < 0)
739 		return;
740 	chip->is_present = ret;
741 	power_supply_changed(battery);
742 }
743 
744 static irqreturn_t sbs_irq(int irq, void *devid)
745 {
746 	sbs_supply_changed(devid);
747 	return IRQ_HANDLED;
748 }
749 
750 static void sbs_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
751 	unsigned int data)
752 {
753 	sbs_supply_changed(i2c_get_clientdata(client));
754 }
755 
756 static void sbs_external_power_changed(struct power_supply *psy)
757 {
758 	struct sbs_info *chip = power_supply_get_drvdata(psy);
759 
760 	/* cancel outstanding work */
761 	cancel_delayed_work_sync(&chip->work);
762 
763 	schedule_delayed_work(&chip->work, HZ);
764 	chip->poll_time = chip->poll_retry_count;
765 }
766 
767 static void sbs_delayed_work(struct work_struct *work)
768 {
769 	struct sbs_info *chip;
770 	s32 ret;
771 
772 	chip = container_of(work, struct sbs_info, work.work);
773 
774 	ret = sbs_read_word_data(chip->client, sbs_data[REG_STATUS].addr);
775 	/* if the read failed, give up on this work */
776 	if (ret < 0) {
777 		chip->poll_time = 0;
778 		return;
779 	}
780 
781 	if (ret & BATTERY_FULL_CHARGED)
782 		ret = POWER_SUPPLY_STATUS_FULL;
783 	else if (ret & BATTERY_DISCHARGING)
784 		ret = POWER_SUPPLY_STATUS_DISCHARGING;
785 	else
786 		ret = POWER_SUPPLY_STATUS_CHARGING;
787 
788 	sbs_status_correct(chip->client, &ret);
789 
790 	if (chip->last_state != ret) {
791 		chip->poll_time = 0;
792 		power_supply_changed(chip->power_supply);
793 		return;
794 	}
795 	if (chip->poll_time > 0) {
796 		schedule_delayed_work(&chip->work, HZ);
797 		chip->poll_time--;
798 		return;
799 	}
800 }
801 
802 static const struct power_supply_desc sbs_default_desc = {
803 	.type = POWER_SUPPLY_TYPE_BATTERY,
804 	.properties = sbs_properties,
805 	.num_properties = ARRAY_SIZE(sbs_properties),
806 	.get_property = sbs_get_property,
807 	.external_power_changed = sbs_external_power_changed,
808 };
809 
810 static int sbs_probe(struct i2c_client *client,
811 	const struct i2c_device_id *id)
812 {
813 	struct sbs_info *chip;
814 	struct power_supply_desc *sbs_desc;
815 	struct sbs_platform_data *pdata = client->dev.platform_data;
816 	struct power_supply_config psy_cfg = {};
817 	int rc;
818 	int irq;
819 
820 	sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc,
821 			sizeof(*sbs_desc), GFP_KERNEL);
822 	if (!sbs_desc)
823 		return -ENOMEM;
824 
825 	sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s",
826 			dev_name(&client->dev));
827 	if (!sbs_desc->name)
828 		return -ENOMEM;
829 
830 	chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
831 	if (!chip)
832 		return -ENOMEM;
833 
834 	chip->flags = (u32)(uintptr_t)of_device_get_match_data(&client->dev);
835 	chip->client = client;
836 	chip->enable_detection = false;
837 	psy_cfg.of_node = client->dev.of_node;
838 	psy_cfg.drv_data = chip;
839 	chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
840 	mutex_init(&chip->mode_lock);
841 
842 	/* use pdata if available, fall back to DT properties,
843 	 * or hardcoded defaults if not
844 	 */
845 	rc = of_property_read_u32(client->dev.of_node, "sbs,i2c-retry-count",
846 				  &chip->i2c_retry_count);
847 	if (rc)
848 		chip->i2c_retry_count = 0;
849 
850 	rc = of_property_read_u32(client->dev.of_node, "sbs,poll-retry-count",
851 				  &chip->poll_retry_count);
852 	if (rc)
853 		chip->poll_retry_count = 0;
854 
855 	if (pdata) {
856 		chip->poll_retry_count = pdata->poll_retry_count;
857 		chip->i2c_retry_count  = pdata->i2c_retry_count;
858 	}
859 	chip->i2c_retry_count = chip->i2c_retry_count + 1;
860 
861 	chip->gpio_detect = devm_gpiod_get_optional(&client->dev,
862 			"sbs,battery-detect", GPIOD_IN);
863 	if (IS_ERR(chip->gpio_detect)) {
864 		dev_err(&client->dev, "Failed to get gpio: %ld\n",
865 			PTR_ERR(chip->gpio_detect));
866 		return PTR_ERR(chip->gpio_detect);
867 	}
868 
869 	i2c_set_clientdata(client, chip);
870 
871 	if (!chip->gpio_detect)
872 		goto skip_gpio;
873 
874 	irq = gpiod_to_irq(chip->gpio_detect);
875 	if (irq <= 0) {
876 		dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
877 		goto skip_gpio;
878 	}
879 
880 	rc = devm_request_threaded_irq(&client->dev, irq, NULL, sbs_irq,
881 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
882 		dev_name(&client->dev), chip);
883 	if (rc) {
884 		dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
885 		goto skip_gpio;
886 	}
887 
888 skip_gpio:
889 	/*
890 	 * Before we register, we might need to make sure we can actually talk
891 	 * to the battery.
892 	 */
893 	if (!(force_load || chip->gpio_detect)) {
894 		rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
895 
896 		if (rc < 0) {
897 			dev_err(&client->dev, "%s: Failed to get device status\n",
898 				__func__);
899 			goto exit_psupply;
900 		}
901 	}
902 
903 	chip->power_supply = devm_power_supply_register(&client->dev, sbs_desc,
904 						   &psy_cfg);
905 	if (IS_ERR(chip->power_supply)) {
906 		dev_err(&client->dev,
907 			"%s: Failed to register power supply\n", __func__);
908 		rc = PTR_ERR(chip->power_supply);
909 		goto exit_psupply;
910 	}
911 
912 	dev_info(&client->dev,
913 		"%s: battery gas gauge device registered\n", client->name);
914 
915 	INIT_DELAYED_WORK(&chip->work, sbs_delayed_work);
916 
917 	chip->enable_detection = true;
918 
919 	return 0;
920 
921 exit_psupply:
922 	return rc;
923 }
924 
925 static int sbs_remove(struct i2c_client *client)
926 {
927 	struct sbs_info *chip = i2c_get_clientdata(client);
928 
929 	cancel_delayed_work_sync(&chip->work);
930 
931 	return 0;
932 }
933 
934 #if defined CONFIG_PM_SLEEP
935 
936 static int sbs_suspend(struct device *dev)
937 {
938 	struct i2c_client *client = to_i2c_client(dev);
939 	struct sbs_info *chip = i2c_get_clientdata(client);
940 	int ret;
941 
942 	if (chip->poll_time > 0)
943 		cancel_delayed_work_sync(&chip->work);
944 
945 	if (chip->flags & SBS_FLAGS_TI_BQ20Z75) {
946 		/* Write to manufacturer access with sleep command. */
947 		ret = sbs_write_word_data(client,
948 					  sbs_data[REG_MANUFACTURER_DATA].addr,
949 					  MANUFACTURER_ACCESS_SLEEP);
950 		if (chip->is_present && ret < 0)
951 			return ret;
952 	}
953 
954 	return 0;
955 }
956 
957 static SIMPLE_DEV_PM_OPS(sbs_pm_ops, sbs_suspend, NULL);
958 #define SBS_PM_OPS (&sbs_pm_ops)
959 
960 #else
961 #define SBS_PM_OPS NULL
962 #endif
963 
964 static const struct i2c_device_id sbs_id[] = {
965 	{ "bq20z75", 0 },
966 	{ "sbs-battery", 1 },
967 	{}
968 };
969 MODULE_DEVICE_TABLE(i2c, sbs_id);
970 
971 static const struct of_device_id sbs_dt_ids[] = {
972 	{ .compatible = "sbs,sbs-battery" },
973 	{
974 		.compatible = "ti,bq20z75",
975 		.data = (void *)SBS_FLAGS_TI_BQ20Z75,
976 	},
977 	{ }
978 };
979 MODULE_DEVICE_TABLE(of, sbs_dt_ids);
980 
981 static struct i2c_driver sbs_battery_driver = {
982 	.probe		= sbs_probe,
983 	.remove		= sbs_remove,
984 	.alert		= sbs_alert,
985 	.id_table	= sbs_id,
986 	.driver = {
987 		.name	= "sbs-battery",
988 		.of_match_table = sbs_dt_ids,
989 		.pm	= SBS_PM_OPS,
990 	},
991 };
992 module_i2c_driver(sbs_battery_driver);
993 
994 MODULE_DESCRIPTION("SBS battery monitor driver");
995 MODULE_LICENSE("GPL");
996 
997 module_param(force_load, bool, S_IRUSR | S_IRGRP | S_IROTH);
998 MODULE_PARM_DESC(force_load,
999 		 "Attempt to load the driver even if no battery is connected");
1000