1 /*
2  * Gas Gauge driver for SBS Compliant Batteries
3  *
4  * Copyright (c) 2010, NVIDIA Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
19  */
20 
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/err.h>
25 #include <linux/power_supply.h>
26 #include <linux/i2c.h>
27 #include <linux/slab.h>
28 #include <linux/interrupt.h>
29 #include <linux/gpio/consumer.h>
30 #include <linux/of.h>
31 #include <linux/stat.h>
32 
33 #include <linux/power/sbs-battery.h>
34 
35 enum {
36 	REG_MANUFACTURER_DATA,
37 	REG_TEMPERATURE,
38 	REG_VOLTAGE,
39 	REG_CURRENT,
40 	REG_CAPACITY,
41 	REG_TIME_TO_EMPTY,
42 	REG_TIME_TO_FULL,
43 	REG_STATUS,
44 	REG_CAPACITY_LEVEL,
45 	REG_CYCLE_COUNT,
46 	REG_SERIAL_NUMBER,
47 	REG_REMAINING_CAPACITY,
48 	REG_REMAINING_CAPACITY_CHARGE,
49 	REG_FULL_CHARGE_CAPACITY,
50 	REG_FULL_CHARGE_CAPACITY_CHARGE,
51 	REG_DESIGN_CAPACITY,
52 	REG_DESIGN_CAPACITY_CHARGE,
53 	REG_DESIGN_VOLTAGE_MIN,
54 	REG_DESIGN_VOLTAGE_MAX,
55 	REG_MANUFACTURER,
56 	REG_MODEL_NAME,
57 };
58 
59 /* Battery Mode defines */
60 #define BATTERY_MODE_OFFSET		0x03
61 #define BATTERY_MODE_MASK		0x8000
62 enum sbs_battery_mode {
63 	BATTERY_MODE_AMPS,
64 	BATTERY_MODE_WATTS
65 };
66 
67 /* manufacturer access defines */
68 #define MANUFACTURER_ACCESS_STATUS	0x0006
69 #define MANUFACTURER_ACCESS_SLEEP	0x0011
70 
71 /* battery status value bits */
72 #define BATTERY_INITIALIZED		0x80
73 #define BATTERY_DISCHARGING		0x40
74 #define BATTERY_FULL_CHARGED		0x20
75 #define BATTERY_FULL_DISCHARGED		0x10
76 
77 /* min_value and max_value are only valid for numerical data */
78 #define SBS_DATA(_psp, _addr, _min_value, _max_value) { \
79 	.psp = _psp, \
80 	.addr = _addr, \
81 	.min_value = _min_value, \
82 	.max_value = _max_value, \
83 }
84 
85 static const struct chip_data {
86 	enum power_supply_property psp;
87 	u8 addr;
88 	int min_value;
89 	int max_value;
90 } sbs_data[] = {
91 	[REG_MANUFACTURER_DATA] =
92 		SBS_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
93 	[REG_TEMPERATURE] =
94 		SBS_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
95 	[REG_VOLTAGE] =
96 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
97 	[REG_CURRENT] =
98 		SBS_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, 32767),
99 	[REG_CAPACITY] =
100 		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0D, 0, 100),
101 	[REG_REMAINING_CAPACITY] =
102 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
103 	[REG_REMAINING_CAPACITY_CHARGE] =
104 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
105 	[REG_FULL_CHARGE_CAPACITY] =
106 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
107 	[REG_FULL_CHARGE_CAPACITY_CHARGE] =
108 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
109 	[REG_TIME_TO_EMPTY] =
110 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, 65535),
111 	[REG_TIME_TO_FULL] =
112 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, 65535),
113 	[REG_STATUS] =
114 		SBS_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
115 	[REG_CAPACITY_LEVEL] =
116 		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY_LEVEL, 0x16, 0, 65535),
117 	[REG_CYCLE_COUNT] =
118 		SBS_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
119 	[REG_DESIGN_CAPACITY] =
120 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0, 65535),
121 	[REG_DESIGN_CAPACITY_CHARGE] =
122 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0, 65535),
123 	[REG_DESIGN_VOLTAGE_MIN] =
124 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN, 0x19, 0, 65535),
125 	[REG_DESIGN_VOLTAGE_MAX] =
126 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0, 65535),
127 	[REG_SERIAL_NUMBER] =
128 		SBS_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
129 	/* Properties of type `const char *' */
130 	[REG_MANUFACTURER] =
131 		SBS_DATA(POWER_SUPPLY_PROP_MANUFACTURER, 0x20, 0, 65535),
132 	[REG_MODEL_NAME] =
133 		SBS_DATA(POWER_SUPPLY_PROP_MODEL_NAME, 0x21, 0, 65535)
134 };
135 
136 static enum power_supply_property sbs_properties[] = {
137 	POWER_SUPPLY_PROP_STATUS,
138 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
139 	POWER_SUPPLY_PROP_HEALTH,
140 	POWER_SUPPLY_PROP_PRESENT,
141 	POWER_SUPPLY_PROP_TECHNOLOGY,
142 	POWER_SUPPLY_PROP_CYCLE_COUNT,
143 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
144 	POWER_SUPPLY_PROP_CURRENT_NOW,
145 	POWER_SUPPLY_PROP_CAPACITY,
146 	POWER_SUPPLY_PROP_TEMP,
147 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
148 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
149 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
150 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
151 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
152 	POWER_SUPPLY_PROP_ENERGY_NOW,
153 	POWER_SUPPLY_PROP_ENERGY_FULL,
154 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
155 	POWER_SUPPLY_PROP_CHARGE_NOW,
156 	POWER_SUPPLY_PROP_CHARGE_FULL,
157 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
158 	/* Properties of type `const char *' */
159 	POWER_SUPPLY_PROP_MANUFACTURER,
160 	POWER_SUPPLY_PROP_MODEL_NAME
161 };
162 
163 struct sbs_info {
164 	struct i2c_client		*client;
165 	struct power_supply		*power_supply;
166 	bool				is_present;
167 	struct gpio_desc		*gpio_detect;
168 	bool				enable_detection;
169 	int				last_state;
170 	int				poll_time;
171 	u32				i2c_retry_count;
172 	u32				poll_retry_count;
173 	struct delayed_work		work;
174 };
175 
176 static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
177 static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1];
178 static bool force_load;
179 
180 static int sbs_read_word_data(struct i2c_client *client, u8 address)
181 {
182 	struct sbs_info *chip = i2c_get_clientdata(client);
183 	s32 ret = 0;
184 	int retries = 1;
185 
186 	retries = chip->i2c_retry_count;
187 
188 	while (retries > 0) {
189 		ret = i2c_smbus_read_word_data(client, address);
190 		if (ret >= 0)
191 			break;
192 		retries--;
193 	}
194 
195 	if (ret < 0) {
196 		dev_dbg(&client->dev,
197 			"%s: i2c read at address 0x%x failed\n",
198 			__func__, address);
199 		return ret;
200 	}
201 
202 	return le16_to_cpu(ret);
203 }
204 
205 static int sbs_read_string_data(struct i2c_client *client, u8 address,
206 				char *values)
207 {
208 	struct sbs_info *chip = i2c_get_clientdata(client);
209 	s32 ret = 0, block_length = 0;
210 	int retries_length = 1, retries_block = 1;
211 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
212 
213 	retries_length = chip->i2c_retry_count;
214 	retries_block = chip->i2c_retry_count;
215 
216 	/* Adapter needs to support these two functions */
217 	if (!i2c_check_functionality(client->adapter,
218 				     I2C_FUNC_SMBUS_BYTE_DATA |
219 				     I2C_FUNC_SMBUS_I2C_BLOCK)){
220 		return -ENODEV;
221 	}
222 
223 	/* Get the length of block data */
224 	while (retries_length > 0) {
225 		ret = i2c_smbus_read_byte_data(client, address);
226 		if (ret >= 0)
227 			break;
228 		retries_length--;
229 	}
230 
231 	if (ret < 0) {
232 		dev_dbg(&client->dev,
233 			"%s: i2c read at address 0x%x failed\n",
234 			__func__, address);
235 		return ret;
236 	}
237 
238 	/* block_length does not include NULL terminator */
239 	block_length = ret;
240 	if (block_length > I2C_SMBUS_BLOCK_MAX) {
241 		dev_err(&client->dev,
242 			"%s: Returned block_length is longer than 0x%x\n",
243 			__func__, I2C_SMBUS_BLOCK_MAX);
244 		return -EINVAL;
245 	}
246 
247 	/* Get the block data */
248 	while (retries_block > 0) {
249 		ret = i2c_smbus_read_i2c_block_data(
250 				client, address,
251 				block_length + 1, block_buffer);
252 		if (ret >= 0)
253 			break;
254 		retries_block--;
255 	}
256 
257 	if (ret < 0) {
258 		dev_dbg(&client->dev,
259 			"%s: i2c read at address 0x%x failed\n",
260 			__func__, address);
261 		return ret;
262 	}
263 
264 	/* block_buffer[0] == block_length */
265 	memcpy(values, block_buffer + 1, block_length);
266 	values[block_length] = '\0';
267 
268 	return le16_to_cpu(ret);
269 }
270 
271 static int sbs_write_word_data(struct i2c_client *client, u8 address,
272 	u16 value)
273 {
274 	struct sbs_info *chip = i2c_get_clientdata(client);
275 	s32 ret = 0;
276 	int retries = 1;
277 
278 	retries = chip->i2c_retry_count;
279 
280 	while (retries > 0) {
281 		ret = i2c_smbus_write_word_data(client, address,
282 			le16_to_cpu(value));
283 		if (ret >= 0)
284 			break;
285 		retries--;
286 	}
287 
288 	if (ret < 0) {
289 		dev_dbg(&client->dev,
290 			"%s: i2c write to address 0x%x failed\n",
291 			__func__, address);
292 		return ret;
293 	}
294 
295 	return 0;
296 }
297 
298 static int sbs_status_correct(struct i2c_client *client, int *intval)
299 {
300 	int ret;
301 
302 	ret = sbs_read_word_data(client, sbs_data[REG_CURRENT].addr);
303 	if (ret < 0)
304 		return ret;
305 
306 	ret = (s16)ret;
307 
308 	/* Not drawing current means full (cannot be not charging) */
309 	if (ret == 0)
310 		*intval = POWER_SUPPLY_STATUS_FULL;
311 
312 	if (*intval == POWER_SUPPLY_STATUS_FULL) {
313 		/* Drawing or providing current when full */
314 		if (ret > 0)
315 			*intval = POWER_SUPPLY_STATUS_CHARGING;
316 		else if (ret < 0)
317 			*intval = POWER_SUPPLY_STATUS_DISCHARGING;
318 	}
319 
320 	return 0;
321 }
322 
323 static int sbs_get_battery_presence_and_health(
324 	struct i2c_client *client, enum power_supply_property psp,
325 	union power_supply_propval *val)
326 {
327 	s32 ret;
328 	struct sbs_info *chip = i2c_get_clientdata(client);
329 
330 	if (psp == POWER_SUPPLY_PROP_PRESENT && chip->gpio_detect) {
331 		ret = gpiod_get_value_cansleep(chip->gpio_detect);
332 		if (ret < 0)
333 			return ret;
334 		val->intval = ret;
335 		chip->is_present = val->intval;
336 		return ret;
337 	}
338 
339 	/*
340 	 * Write to ManufacturerAccess with ManufacturerAccess command
341 	 * and then read the status. Do not check for error on the write
342 	 * since not all batteries implement write access to this command,
343 	 * while others mandate it.
344 	 */
345 	sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
346 			    MANUFACTURER_ACCESS_STATUS);
347 
348 	ret = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr);
349 	if (ret < 0) {
350 		if (psp == POWER_SUPPLY_PROP_PRESENT)
351 			val->intval = 0; /* battery removed */
352 		return ret;
353 	}
354 
355 	if (ret < sbs_data[REG_MANUFACTURER_DATA].min_value ||
356 	    ret > sbs_data[REG_MANUFACTURER_DATA].max_value) {
357 		val->intval = 0;
358 		return 0;
359 	}
360 
361 	/* Mask the upper nibble of 2nd byte and
362 	 * lower byte of response then
363 	 * shift the result by 8 to get status*/
364 	ret &= 0x0F00;
365 	ret >>= 8;
366 	if (psp == POWER_SUPPLY_PROP_PRESENT) {
367 		if (ret == 0x0F)
368 			/* battery removed */
369 			val->intval = 0;
370 		else
371 			val->intval = 1;
372 	} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
373 		if (ret == 0x09)
374 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
375 		else if (ret == 0x0B)
376 			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
377 		else if (ret == 0x0C)
378 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
379 		else
380 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
381 	}
382 
383 	return 0;
384 }
385 
386 static int sbs_get_battery_property(struct i2c_client *client,
387 	int reg_offset, enum power_supply_property psp,
388 	union power_supply_propval *val)
389 {
390 	struct sbs_info *chip = i2c_get_clientdata(client);
391 	s32 ret;
392 
393 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
394 	if (ret < 0)
395 		return ret;
396 
397 	/* returned values are 16 bit */
398 	if (sbs_data[reg_offset].min_value < 0)
399 		ret = (s16)ret;
400 
401 	if (ret >= sbs_data[reg_offset].min_value &&
402 	    ret <= sbs_data[reg_offset].max_value) {
403 		val->intval = ret;
404 		if (psp == POWER_SUPPLY_PROP_CAPACITY_LEVEL) {
405 			if (!(ret & BATTERY_INITIALIZED))
406 				val->intval =
407 					POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
408 			else if (ret & BATTERY_FULL_CHARGED)
409 				val->intval =
410 					POWER_SUPPLY_CAPACITY_LEVEL_FULL;
411 			else if (ret & BATTERY_FULL_DISCHARGED)
412 				val->intval =
413 					POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
414 			else
415 				val->intval =
416 					POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
417 			return 0;
418 		} else if (psp != POWER_SUPPLY_PROP_STATUS) {
419 			return 0;
420 		}
421 
422 		if (ret & BATTERY_FULL_CHARGED)
423 			val->intval = POWER_SUPPLY_STATUS_FULL;
424 		else if (ret & BATTERY_DISCHARGING)
425 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
426 		else
427 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
428 
429 		sbs_status_correct(client, &val->intval);
430 
431 		if (chip->poll_time == 0)
432 			chip->last_state = val->intval;
433 		else if (chip->last_state != val->intval) {
434 			cancel_delayed_work_sync(&chip->work);
435 			power_supply_changed(chip->power_supply);
436 			chip->poll_time = 0;
437 		}
438 	} else {
439 		if (psp == POWER_SUPPLY_PROP_STATUS)
440 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
441 		else
442 			val->intval = 0;
443 	}
444 
445 	return 0;
446 }
447 
448 static int sbs_get_battery_string_property(struct i2c_client *client,
449 	int reg_offset, enum power_supply_property psp, char *val)
450 {
451 	s32 ret;
452 
453 	ret = sbs_read_string_data(client, sbs_data[reg_offset].addr, val);
454 
455 	if (ret < 0)
456 		return ret;
457 
458 	return 0;
459 }
460 
461 static void  sbs_unit_adjustment(struct i2c_client *client,
462 	enum power_supply_property psp, union power_supply_propval *val)
463 {
464 #define BASE_UNIT_CONVERSION		1000
465 #define BATTERY_MODE_CAP_MULT_WATT	(10 * BASE_UNIT_CONVERSION)
466 #define TIME_UNIT_CONVERSION		60
467 #define TEMP_KELVIN_TO_CELSIUS		2731
468 	switch (psp) {
469 	case POWER_SUPPLY_PROP_ENERGY_NOW:
470 	case POWER_SUPPLY_PROP_ENERGY_FULL:
471 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
472 		/* sbs provides energy in units of 10mWh.
473 		 * Convert to µWh
474 		 */
475 		val->intval *= BATTERY_MODE_CAP_MULT_WATT;
476 		break;
477 
478 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
479 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
480 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
481 	case POWER_SUPPLY_PROP_CURRENT_NOW:
482 	case POWER_SUPPLY_PROP_CHARGE_NOW:
483 	case POWER_SUPPLY_PROP_CHARGE_FULL:
484 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
485 		val->intval *= BASE_UNIT_CONVERSION;
486 		break;
487 
488 	case POWER_SUPPLY_PROP_TEMP:
489 		/* sbs provides battery temperature in 0.1K
490 		 * so convert it to 0.1°C
491 		 */
492 		val->intval -= TEMP_KELVIN_TO_CELSIUS;
493 		break;
494 
495 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
496 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
497 		/* sbs provides time to empty and time to full in minutes.
498 		 * Convert to seconds
499 		 */
500 		val->intval *= TIME_UNIT_CONVERSION;
501 		break;
502 
503 	default:
504 		dev_dbg(&client->dev,
505 			"%s: no need for unit conversion %d\n", __func__, psp);
506 	}
507 }
508 
509 static enum sbs_battery_mode sbs_set_battery_mode(struct i2c_client *client,
510 	enum sbs_battery_mode mode)
511 {
512 	int ret, original_val;
513 
514 	original_val = sbs_read_word_data(client, BATTERY_MODE_OFFSET);
515 	if (original_val < 0)
516 		return original_val;
517 
518 	if ((original_val & BATTERY_MODE_MASK) == mode)
519 		return mode;
520 
521 	if (mode == BATTERY_MODE_AMPS)
522 		ret = original_val & ~BATTERY_MODE_MASK;
523 	else
524 		ret = original_val | BATTERY_MODE_MASK;
525 
526 	ret = sbs_write_word_data(client, BATTERY_MODE_OFFSET, ret);
527 	if (ret < 0)
528 		return ret;
529 
530 	return original_val & BATTERY_MODE_MASK;
531 }
532 
533 static int sbs_get_battery_capacity(struct i2c_client *client,
534 	int reg_offset, enum power_supply_property psp,
535 	union power_supply_propval *val)
536 {
537 	s32 ret;
538 	enum sbs_battery_mode mode = BATTERY_MODE_WATTS;
539 
540 	if (power_supply_is_amp_property(psp))
541 		mode = BATTERY_MODE_AMPS;
542 
543 	mode = sbs_set_battery_mode(client, mode);
544 	if (mode < 0)
545 		return mode;
546 
547 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
548 	if (ret < 0)
549 		return ret;
550 
551 	if (psp == POWER_SUPPLY_PROP_CAPACITY) {
552 		/* sbs spec says that this can be >100 %
553 		* even if max value is 100 % */
554 		val->intval = min(ret, 100);
555 	} else
556 		val->intval = ret;
557 
558 	ret = sbs_set_battery_mode(client, mode);
559 	if (ret < 0)
560 		return ret;
561 
562 	return 0;
563 }
564 
565 static char sbs_serial[5];
566 static int sbs_get_battery_serial_number(struct i2c_client *client,
567 	union power_supply_propval *val)
568 {
569 	int ret;
570 
571 	ret = sbs_read_word_data(client, sbs_data[REG_SERIAL_NUMBER].addr);
572 	if (ret < 0)
573 		return ret;
574 
575 	ret = sprintf(sbs_serial, "%04x", ret);
576 	val->strval = sbs_serial;
577 
578 	return 0;
579 }
580 
581 static int sbs_get_property_index(struct i2c_client *client,
582 	enum power_supply_property psp)
583 {
584 	int count;
585 	for (count = 0; count < ARRAY_SIZE(sbs_data); count++)
586 		if (psp == sbs_data[count].psp)
587 			return count;
588 
589 	dev_warn(&client->dev,
590 		"%s: Invalid Property - %d\n", __func__, psp);
591 
592 	return -EINVAL;
593 }
594 
595 static int sbs_get_property(struct power_supply *psy,
596 	enum power_supply_property psp,
597 	union power_supply_propval *val)
598 {
599 	int ret = 0;
600 	struct sbs_info *chip = power_supply_get_drvdata(psy);
601 	struct i2c_client *client = chip->client;
602 
603 	switch (psp) {
604 	case POWER_SUPPLY_PROP_PRESENT:
605 	case POWER_SUPPLY_PROP_HEALTH:
606 		ret = sbs_get_battery_presence_and_health(client, psp, val);
607 		if (psp == POWER_SUPPLY_PROP_PRESENT)
608 			return 0;
609 		break;
610 
611 	case POWER_SUPPLY_PROP_TECHNOLOGY:
612 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
613 		goto done; /* don't trigger power_supply_changed()! */
614 
615 	case POWER_SUPPLY_PROP_ENERGY_NOW:
616 	case POWER_SUPPLY_PROP_ENERGY_FULL:
617 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
618 	case POWER_SUPPLY_PROP_CHARGE_NOW:
619 	case POWER_SUPPLY_PROP_CHARGE_FULL:
620 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
621 	case POWER_SUPPLY_PROP_CAPACITY:
622 		ret = sbs_get_property_index(client, psp);
623 		if (ret < 0)
624 			break;
625 
626 		ret = sbs_get_battery_capacity(client, ret, psp, val);
627 		break;
628 
629 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
630 		ret = sbs_get_battery_serial_number(client, val);
631 		break;
632 
633 	case POWER_SUPPLY_PROP_STATUS:
634 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
635 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
636 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
637 	case POWER_SUPPLY_PROP_CURRENT_NOW:
638 	case POWER_SUPPLY_PROP_TEMP:
639 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
640 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
641 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
642 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
643 		ret = sbs_get_property_index(client, psp);
644 		if (ret < 0)
645 			break;
646 
647 		ret = sbs_get_battery_property(client, ret, psp, val);
648 		break;
649 
650 	case POWER_SUPPLY_PROP_MODEL_NAME:
651 		ret = sbs_get_property_index(client, psp);
652 		if (ret < 0)
653 			break;
654 
655 		ret = sbs_get_battery_string_property(client, ret, psp,
656 						      model_name);
657 		val->strval = model_name;
658 		break;
659 
660 	case POWER_SUPPLY_PROP_MANUFACTURER:
661 		ret = sbs_get_property_index(client, psp);
662 		if (ret < 0)
663 			break;
664 
665 		ret = sbs_get_battery_string_property(client, ret, psp,
666 						      manufacturer);
667 		val->strval = manufacturer;
668 		break;
669 
670 	default:
671 		dev_err(&client->dev,
672 			"%s: INVALID property\n", __func__);
673 		return -EINVAL;
674 	}
675 
676 	if (!chip->enable_detection)
677 		goto done;
678 
679 	if (!chip->gpio_detect &&
680 		chip->is_present != (ret >= 0)) {
681 		chip->is_present = (ret >= 0);
682 		power_supply_changed(chip->power_supply);
683 	}
684 
685 done:
686 	if (!ret) {
687 		/* Convert units to match requirements for power supply class */
688 		sbs_unit_adjustment(client, psp, val);
689 	}
690 
691 	dev_dbg(&client->dev,
692 		"%s: property = %d, value = %x\n", __func__, psp, val->intval);
693 
694 	if (ret && chip->is_present)
695 		return ret;
696 
697 	/* battery not present, so return NODATA for properties */
698 	if (ret)
699 		return -ENODATA;
700 
701 	return 0;
702 }
703 
704 static void sbs_supply_changed(struct sbs_info *chip)
705 {
706 	struct power_supply *battery = chip->power_supply;
707 	int ret;
708 
709 	ret = gpiod_get_value_cansleep(chip->gpio_detect);
710 	if (ret < 0)
711 		return;
712 	chip->is_present = ret;
713 	power_supply_changed(battery);
714 }
715 
716 static irqreturn_t sbs_irq(int irq, void *devid)
717 {
718 	sbs_supply_changed(devid);
719 	return IRQ_HANDLED;
720 }
721 
722 static void sbs_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
723 	unsigned int data)
724 {
725 	sbs_supply_changed(i2c_get_clientdata(client));
726 }
727 
728 static void sbs_external_power_changed(struct power_supply *psy)
729 {
730 	struct sbs_info *chip = power_supply_get_drvdata(psy);
731 
732 	/* cancel outstanding work */
733 	cancel_delayed_work_sync(&chip->work);
734 
735 	schedule_delayed_work(&chip->work, HZ);
736 	chip->poll_time = chip->poll_retry_count;
737 }
738 
739 static void sbs_delayed_work(struct work_struct *work)
740 {
741 	struct sbs_info *chip;
742 	s32 ret;
743 
744 	chip = container_of(work, struct sbs_info, work.work);
745 
746 	ret = sbs_read_word_data(chip->client, sbs_data[REG_STATUS].addr);
747 	/* if the read failed, give up on this work */
748 	if (ret < 0) {
749 		chip->poll_time = 0;
750 		return;
751 	}
752 
753 	if (ret & BATTERY_FULL_CHARGED)
754 		ret = POWER_SUPPLY_STATUS_FULL;
755 	else if (ret & BATTERY_DISCHARGING)
756 		ret = POWER_SUPPLY_STATUS_DISCHARGING;
757 	else
758 		ret = POWER_SUPPLY_STATUS_CHARGING;
759 
760 	sbs_status_correct(chip->client, &ret);
761 
762 	if (chip->last_state != ret) {
763 		chip->poll_time = 0;
764 		power_supply_changed(chip->power_supply);
765 		return;
766 	}
767 	if (chip->poll_time > 0) {
768 		schedule_delayed_work(&chip->work, HZ);
769 		chip->poll_time--;
770 		return;
771 	}
772 }
773 
774 static const struct power_supply_desc sbs_default_desc = {
775 	.type = POWER_SUPPLY_TYPE_BATTERY,
776 	.properties = sbs_properties,
777 	.num_properties = ARRAY_SIZE(sbs_properties),
778 	.get_property = sbs_get_property,
779 	.external_power_changed = sbs_external_power_changed,
780 };
781 
782 static int sbs_probe(struct i2c_client *client,
783 	const struct i2c_device_id *id)
784 {
785 	struct sbs_info *chip;
786 	struct power_supply_desc *sbs_desc;
787 	struct sbs_platform_data *pdata = client->dev.platform_data;
788 	struct power_supply_config psy_cfg = {};
789 	int rc;
790 	int irq;
791 
792 	sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc,
793 			sizeof(*sbs_desc), GFP_KERNEL);
794 	if (!sbs_desc)
795 		return -ENOMEM;
796 
797 	sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s",
798 			dev_name(&client->dev));
799 	if (!sbs_desc->name)
800 		return -ENOMEM;
801 
802 	chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
803 	if (!chip)
804 		return -ENOMEM;
805 
806 	chip->client = client;
807 	chip->enable_detection = false;
808 	psy_cfg.of_node = client->dev.of_node;
809 	psy_cfg.drv_data = chip;
810 	chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
811 
812 	/* use pdata if available, fall back to DT properties,
813 	 * or hardcoded defaults if not
814 	 */
815 	rc = of_property_read_u32(client->dev.of_node, "sbs,i2c-retry-count",
816 				  &chip->i2c_retry_count);
817 	if (rc)
818 		chip->i2c_retry_count = 0;
819 
820 	rc = of_property_read_u32(client->dev.of_node, "sbs,poll-retry-count",
821 				  &chip->poll_retry_count);
822 	if (rc)
823 		chip->poll_retry_count = 0;
824 
825 	if (pdata) {
826 		chip->poll_retry_count = pdata->poll_retry_count;
827 		chip->i2c_retry_count  = pdata->i2c_retry_count;
828 	}
829 	chip->i2c_retry_count = chip->i2c_retry_count + 1;
830 
831 	chip->gpio_detect = devm_gpiod_get_optional(&client->dev,
832 			"sbs,battery-detect", GPIOD_IN);
833 	if (IS_ERR(chip->gpio_detect)) {
834 		dev_err(&client->dev, "Failed to get gpio: %ld\n",
835 			PTR_ERR(chip->gpio_detect));
836 		return PTR_ERR(chip->gpio_detect);
837 	}
838 
839 	i2c_set_clientdata(client, chip);
840 
841 	if (!chip->gpio_detect)
842 		goto skip_gpio;
843 
844 	irq = gpiod_to_irq(chip->gpio_detect);
845 	if (irq <= 0) {
846 		dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
847 		goto skip_gpio;
848 	}
849 
850 	rc = devm_request_threaded_irq(&client->dev, irq, NULL, sbs_irq,
851 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
852 		dev_name(&client->dev), chip);
853 	if (rc) {
854 		dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
855 		goto skip_gpio;
856 	}
857 
858 skip_gpio:
859 	/*
860 	 * Before we register, we might need to make sure we can actually talk
861 	 * to the battery.
862 	 */
863 	if (!(force_load || chip->gpio_detect)) {
864 		rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
865 
866 		if (rc < 0) {
867 			dev_err(&client->dev, "%s: Failed to get device status\n",
868 				__func__);
869 			goto exit_psupply;
870 		}
871 	}
872 
873 	chip->power_supply = devm_power_supply_register(&client->dev, sbs_desc,
874 						   &psy_cfg);
875 	if (IS_ERR(chip->power_supply)) {
876 		dev_err(&client->dev,
877 			"%s: Failed to register power supply\n", __func__);
878 		rc = PTR_ERR(chip->power_supply);
879 		goto exit_psupply;
880 	}
881 
882 	dev_info(&client->dev,
883 		"%s: battery gas gauge device registered\n", client->name);
884 
885 	INIT_DELAYED_WORK(&chip->work, sbs_delayed_work);
886 
887 	chip->enable_detection = true;
888 
889 	return 0;
890 
891 exit_psupply:
892 	return rc;
893 }
894 
895 static int sbs_remove(struct i2c_client *client)
896 {
897 	struct sbs_info *chip = i2c_get_clientdata(client);
898 
899 	cancel_delayed_work_sync(&chip->work);
900 
901 	return 0;
902 }
903 
904 #if defined CONFIG_PM_SLEEP
905 
906 static int sbs_suspend(struct device *dev)
907 {
908 	struct i2c_client *client = to_i2c_client(dev);
909 	struct sbs_info *chip = i2c_get_clientdata(client);
910 
911 	if (chip->poll_time > 0)
912 		cancel_delayed_work_sync(&chip->work);
913 
914 	/*
915 	 * Write to manufacturer access with sleep command.
916 	 * Support is manufacturer dependend, so ignore errors.
917 	 */
918 	sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
919 		MANUFACTURER_ACCESS_SLEEP);
920 
921 	return 0;
922 }
923 
924 static SIMPLE_DEV_PM_OPS(sbs_pm_ops, sbs_suspend, NULL);
925 #define SBS_PM_OPS (&sbs_pm_ops)
926 
927 #else
928 #define SBS_PM_OPS NULL
929 #endif
930 
931 static const struct i2c_device_id sbs_id[] = {
932 	{ "bq20z75", 0 },
933 	{ "sbs-battery", 1 },
934 	{}
935 };
936 MODULE_DEVICE_TABLE(i2c, sbs_id);
937 
938 static const struct of_device_id sbs_dt_ids[] = {
939 	{ .compatible = "sbs,sbs-battery" },
940 	{ .compatible = "ti,bq20z75" },
941 	{ }
942 };
943 MODULE_DEVICE_TABLE(of, sbs_dt_ids);
944 
945 static struct i2c_driver sbs_battery_driver = {
946 	.probe		= sbs_probe,
947 	.remove		= sbs_remove,
948 	.alert		= sbs_alert,
949 	.id_table	= sbs_id,
950 	.driver = {
951 		.name	= "sbs-battery",
952 		.of_match_table = sbs_dt_ids,
953 		.pm	= SBS_PM_OPS,
954 	},
955 };
956 module_i2c_driver(sbs_battery_driver);
957 
958 MODULE_DESCRIPTION("SBS battery monitor driver");
959 MODULE_LICENSE("GPL");
960 
961 module_param(force_load, bool, S_IRUSR | S_IRGRP | S_IROTH);
962 MODULE_PARM_DESC(force_load,
963 		 "Attempt to load the driver even if no battery is connected");
964