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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.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_CYCLE_COUNT,
45 	REG_SERIAL_NUMBER,
46 	REG_REMAINING_CAPACITY,
47 	REG_REMAINING_CAPACITY_CHARGE,
48 	REG_FULL_CHARGE_CAPACITY,
49 	REG_FULL_CHARGE_CAPACITY_CHARGE,
50 	REG_DESIGN_CAPACITY,
51 	REG_DESIGN_CAPACITY_CHARGE,
52 	REG_DESIGN_VOLTAGE_MIN,
53 	REG_DESIGN_VOLTAGE_MAX,
54 	REG_MANUFACTURER,
55 	REG_MODEL_NAME,
56 };
57 
58 /* Battery Mode defines */
59 #define BATTERY_MODE_OFFSET		0x03
60 #define BATTERY_MODE_MASK		0x8000
61 enum sbs_battery_mode {
62 	BATTERY_MODE_AMPS,
63 	BATTERY_MODE_WATTS
64 };
65 
66 /* manufacturer access defines */
67 #define MANUFACTURER_ACCESS_STATUS	0x0006
68 #define MANUFACTURER_ACCESS_SLEEP	0x0011
69 
70 /* battery status value bits */
71 #define BATTERY_DISCHARGING		0x40
72 #define BATTERY_FULL_CHARGED		0x20
73 #define BATTERY_FULL_DISCHARGED		0x10
74 
75 /* min_value and max_value are only valid for numerical data */
76 #define SBS_DATA(_psp, _addr, _min_value, _max_value) { \
77 	.psp = _psp, \
78 	.addr = _addr, \
79 	.min_value = _min_value, \
80 	.max_value = _max_value, \
81 }
82 
83 static const struct chip_data {
84 	enum power_supply_property psp;
85 	u8 addr;
86 	int min_value;
87 	int max_value;
88 } sbs_data[] = {
89 	[REG_MANUFACTURER_DATA] =
90 		SBS_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
91 	[REG_TEMPERATURE] =
92 		SBS_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
93 	[REG_VOLTAGE] =
94 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
95 	[REG_CURRENT] =
96 		SBS_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, 32767),
97 	[REG_CAPACITY] =
98 		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0D, 0, 100),
99 	[REG_REMAINING_CAPACITY] =
100 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
101 	[REG_REMAINING_CAPACITY_CHARGE] =
102 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
103 	[REG_FULL_CHARGE_CAPACITY] =
104 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
105 	[REG_FULL_CHARGE_CAPACITY_CHARGE] =
106 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
107 	[REG_TIME_TO_EMPTY] =
108 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, 65535),
109 	[REG_TIME_TO_FULL] =
110 		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, 65535),
111 	[REG_STATUS] =
112 		SBS_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
113 	[REG_CYCLE_COUNT] =
114 		SBS_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
115 	[REG_DESIGN_CAPACITY] =
116 		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0, 65535),
117 	[REG_DESIGN_CAPACITY_CHARGE] =
118 		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0, 65535),
119 	[REG_DESIGN_VOLTAGE_MIN] =
120 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN, 0x19, 0, 65535),
121 	[REG_DESIGN_VOLTAGE_MAX] =
122 		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0, 65535),
123 	[REG_SERIAL_NUMBER] =
124 		SBS_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
125 	/* Properties of type `const char *' */
126 	[REG_MANUFACTURER] =
127 		SBS_DATA(POWER_SUPPLY_PROP_MANUFACTURER, 0x20, 0, 65535),
128 	[REG_MODEL_NAME] =
129 		SBS_DATA(POWER_SUPPLY_PROP_MODEL_NAME, 0x21, 0, 65535)
130 };
131 
132 static enum power_supply_property sbs_properties[] = {
133 	POWER_SUPPLY_PROP_STATUS,
134 	POWER_SUPPLY_PROP_HEALTH,
135 	POWER_SUPPLY_PROP_PRESENT,
136 	POWER_SUPPLY_PROP_TECHNOLOGY,
137 	POWER_SUPPLY_PROP_CYCLE_COUNT,
138 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
139 	POWER_SUPPLY_PROP_CURRENT_NOW,
140 	POWER_SUPPLY_PROP_CAPACITY,
141 	POWER_SUPPLY_PROP_TEMP,
142 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
143 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
144 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
145 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
146 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
147 	POWER_SUPPLY_PROP_ENERGY_NOW,
148 	POWER_SUPPLY_PROP_ENERGY_FULL,
149 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
150 	POWER_SUPPLY_PROP_CHARGE_NOW,
151 	POWER_SUPPLY_PROP_CHARGE_FULL,
152 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
153 	/* Properties of type `const char *' */
154 	POWER_SUPPLY_PROP_MANUFACTURER,
155 	POWER_SUPPLY_PROP_MODEL_NAME
156 };
157 
158 struct sbs_info {
159 	struct i2c_client		*client;
160 	struct power_supply		*power_supply;
161 	struct sbs_platform_data	*pdata;
162 	bool				is_present;
163 	bool				gpio_detect;
164 	bool				enable_detection;
165 	int				irq;
166 	int				last_state;
167 	int				poll_time;
168 	struct delayed_work		work;
169 	int				ignore_changes;
170 };
171 
172 static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
173 static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1];
174 static bool force_load;
175 
sbs_read_word_data(struct i2c_client * client,u8 address)176 static int sbs_read_word_data(struct i2c_client *client, u8 address)
177 {
178 	struct sbs_info *chip = i2c_get_clientdata(client);
179 	s32 ret = 0;
180 	int retries = 1;
181 
182 	if (chip->pdata)
183 		retries = max(chip->pdata->i2c_retry_count + 1, 1);
184 
185 	while (retries > 0) {
186 		ret = i2c_smbus_read_word_data(client, address);
187 		if (ret >= 0)
188 			break;
189 		retries--;
190 	}
191 
192 	if (ret < 0) {
193 		dev_dbg(&client->dev,
194 			"%s: i2c read at address 0x%x failed\n",
195 			__func__, address);
196 		return ret;
197 	}
198 
199 	return le16_to_cpu(ret);
200 }
201 
sbs_read_string_data(struct i2c_client * client,u8 address,char * values)202 static int sbs_read_string_data(struct i2c_client *client, u8 address,
203 				char *values)
204 {
205 	struct sbs_info *chip = i2c_get_clientdata(client);
206 	s32 ret = 0, block_length = 0;
207 	int retries_length = 1, retries_block = 1;
208 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
209 
210 	if (chip->pdata) {
211 		retries_length = max(chip->pdata->i2c_retry_count + 1, 1);
212 		retries_block = max(chip->pdata->i2c_retry_count + 1, 1);
213 	}
214 
215 	/* Adapter needs to support these two functions */
216 	if (!i2c_check_functionality(client->adapter,
217 				     I2C_FUNC_SMBUS_BYTE_DATA |
218 				     I2C_FUNC_SMBUS_I2C_BLOCK)){
219 		return -ENODEV;
220 	}
221 
222 	/* Get the length of block data */
223 	while (retries_length > 0) {
224 		ret = i2c_smbus_read_byte_data(client, address);
225 		if (ret >= 0)
226 			break;
227 		retries_length--;
228 	}
229 
230 	if (ret < 0) {
231 		dev_dbg(&client->dev,
232 			"%s: i2c read at address 0x%x failed\n",
233 			__func__, address);
234 		return ret;
235 	}
236 
237 	/* block_length does not include NULL terminator */
238 	block_length = ret;
239 	if (block_length > I2C_SMBUS_BLOCK_MAX) {
240 		dev_err(&client->dev,
241 			"%s: Returned block_length is longer than 0x%x\n",
242 			__func__, I2C_SMBUS_BLOCK_MAX);
243 		return -EINVAL;
244 	}
245 
246 	/* Get the block data */
247 	while (retries_block > 0) {
248 		ret = i2c_smbus_read_i2c_block_data(
249 				client, address,
250 				block_length + 1, block_buffer);
251 		if (ret >= 0)
252 			break;
253 		retries_block--;
254 	}
255 
256 	if (ret < 0) {
257 		dev_dbg(&client->dev,
258 			"%s: i2c read at address 0x%x failed\n",
259 			__func__, address);
260 		return ret;
261 	}
262 
263 	/* block_buffer[0] == block_length */
264 	memcpy(values, block_buffer + 1, block_length);
265 	values[block_length] = '\0';
266 
267 	return le16_to_cpu(ret);
268 }
269 
sbs_write_word_data(struct i2c_client * client,u8 address,u16 value)270 static int sbs_write_word_data(struct i2c_client *client, u8 address,
271 	u16 value)
272 {
273 	struct sbs_info *chip = i2c_get_clientdata(client);
274 	s32 ret = 0;
275 	int retries = 1;
276 
277 	if (chip->pdata)
278 		retries = max(chip->pdata->i2c_retry_count + 1, 1);
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 
sbs_get_battery_presence_and_health(struct i2c_client * client,enum power_supply_property psp,union power_supply_propval * val)298 static int sbs_get_battery_presence_and_health(
299 	struct i2c_client *client, enum power_supply_property psp,
300 	union power_supply_propval *val)
301 {
302 	s32 ret;
303 	struct sbs_info *chip = i2c_get_clientdata(client);
304 
305 	if (psp == POWER_SUPPLY_PROP_PRESENT &&
306 		chip->gpio_detect) {
307 		ret = gpio_get_value(chip->pdata->battery_detect);
308 		if (ret == chip->pdata->battery_detect_present)
309 			val->intval = 1;
310 		else
311 			val->intval = 0;
312 		chip->is_present = val->intval;
313 		return ret;
314 	}
315 
316 	/* Write to ManufacturerAccess with
317 	 * ManufacturerAccess command and then
318 	 * read the status */
319 	ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
320 					MANUFACTURER_ACCESS_STATUS);
321 	if (ret < 0) {
322 		if (psp == POWER_SUPPLY_PROP_PRESENT)
323 			val->intval = 0; /* battery removed */
324 		return ret;
325 	}
326 
327 	ret = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr);
328 	if (ret < 0)
329 		return ret;
330 
331 	if (ret < sbs_data[REG_MANUFACTURER_DATA].min_value ||
332 	    ret > sbs_data[REG_MANUFACTURER_DATA].max_value) {
333 		val->intval = 0;
334 		return 0;
335 	}
336 
337 	/* Mask the upper nibble of 2nd byte and
338 	 * lower byte of response then
339 	 * shift the result by 8 to get status*/
340 	ret &= 0x0F00;
341 	ret >>= 8;
342 	if (psp == POWER_SUPPLY_PROP_PRESENT) {
343 		if (ret == 0x0F)
344 			/* battery removed */
345 			val->intval = 0;
346 		else
347 			val->intval = 1;
348 	} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
349 		if (ret == 0x09)
350 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
351 		else if (ret == 0x0B)
352 			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
353 		else if (ret == 0x0C)
354 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
355 		else
356 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
357 	}
358 
359 	return 0;
360 }
361 
sbs_get_battery_property(struct i2c_client * client,int reg_offset,enum power_supply_property psp,union power_supply_propval * val)362 static int sbs_get_battery_property(struct i2c_client *client,
363 	int reg_offset, enum power_supply_property psp,
364 	union power_supply_propval *val)
365 {
366 	struct sbs_info *chip = i2c_get_clientdata(client);
367 	s32 ret;
368 
369 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
370 	if (ret < 0)
371 		return ret;
372 
373 	/* returned values are 16 bit */
374 	if (sbs_data[reg_offset].min_value < 0)
375 		ret = (s16)ret;
376 
377 	if (ret >= sbs_data[reg_offset].min_value &&
378 	    ret <= sbs_data[reg_offset].max_value) {
379 		val->intval = ret;
380 		if (psp != POWER_SUPPLY_PROP_STATUS)
381 			return 0;
382 
383 		if (ret & BATTERY_FULL_CHARGED)
384 			val->intval = POWER_SUPPLY_STATUS_FULL;
385 		else if (ret & BATTERY_FULL_DISCHARGED)
386 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
387 		else if (ret & BATTERY_DISCHARGING)
388 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
389 		else
390 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
391 
392 		if (chip->poll_time == 0)
393 			chip->last_state = val->intval;
394 		else if (chip->last_state != val->intval) {
395 			cancel_delayed_work_sync(&chip->work);
396 			power_supply_changed(chip->power_supply);
397 			chip->poll_time = 0;
398 		}
399 	} else {
400 		if (psp == POWER_SUPPLY_PROP_STATUS)
401 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
402 		else
403 			val->intval = 0;
404 	}
405 
406 	return 0;
407 }
408 
sbs_get_battery_string_property(struct i2c_client * client,int reg_offset,enum power_supply_property psp,char * val)409 static int sbs_get_battery_string_property(struct i2c_client *client,
410 	int reg_offset, enum power_supply_property psp, char *val)
411 {
412 	s32 ret;
413 
414 	ret = sbs_read_string_data(client, sbs_data[reg_offset].addr, val);
415 
416 	if (ret < 0)
417 		return ret;
418 
419 	return 0;
420 }
421 
sbs_unit_adjustment(struct i2c_client * client,enum power_supply_property psp,union power_supply_propval * val)422 static void  sbs_unit_adjustment(struct i2c_client *client,
423 	enum power_supply_property psp, union power_supply_propval *val)
424 {
425 #define BASE_UNIT_CONVERSION		1000
426 #define BATTERY_MODE_CAP_MULT_WATT	(10 * BASE_UNIT_CONVERSION)
427 #define TIME_UNIT_CONVERSION		60
428 #define TEMP_KELVIN_TO_CELSIUS		2731
429 	switch (psp) {
430 	case POWER_SUPPLY_PROP_ENERGY_NOW:
431 	case POWER_SUPPLY_PROP_ENERGY_FULL:
432 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
433 		/* sbs provides energy in units of 10mWh.
434 		 * Convert to µWh
435 		 */
436 		val->intval *= BATTERY_MODE_CAP_MULT_WATT;
437 		break;
438 
439 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
440 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
441 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
442 	case POWER_SUPPLY_PROP_CURRENT_NOW:
443 	case POWER_SUPPLY_PROP_CHARGE_NOW:
444 	case POWER_SUPPLY_PROP_CHARGE_FULL:
445 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
446 		val->intval *= BASE_UNIT_CONVERSION;
447 		break;
448 
449 	case POWER_SUPPLY_PROP_TEMP:
450 		/* sbs provides battery temperature in 0.1K
451 		 * so convert it to 0.1°C
452 		 */
453 		val->intval -= TEMP_KELVIN_TO_CELSIUS;
454 		break;
455 
456 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
457 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
458 		/* sbs provides time to empty and time to full in minutes.
459 		 * Convert to seconds
460 		 */
461 		val->intval *= TIME_UNIT_CONVERSION;
462 		break;
463 
464 	default:
465 		dev_dbg(&client->dev,
466 			"%s: no need for unit conversion %d\n", __func__, psp);
467 	}
468 }
469 
sbs_set_battery_mode(struct i2c_client * client,enum sbs_battery_mode mode)470 static enum sbs_battery_mode sbs_set_battery_mode(struct i2c_client *client,
471 	enum sbs_battery_mode mode)
472 {
473 	int ret, original_val;
474 
475 	original_val = sbs_read_word_data(client, BATTERY_MODE_OFFSET);
476 	if (original_val < 0)
477 		return original_val;
478 
479 	if ((original_val & BATTERY_MODE_MASK) == mode)
480 		return mode;
481 
482 	if (mode == BATTERY_MODE_AMPS)
483 		ret = original_val & ~BATTERY_MODE_MASK;
484 	else
485 		ret = original_val | BATTERY_MODE_MASK;
486 
487 	ret = sbs_write_word_data(client, BATTERY_MODE_OFFSET, ret);
488 	if (ret < 0)
489 		return ret;
490 
491 	return original_val & BATTERY_MODE_MASK;
492 }
493 
sbs_get_battery_capacity(struct i2c_client * client,int reg_offset,enum power_supply_property psp,union power_supply_propval * val)494 static int sbs_get_battery_capacity(struct i2c_client *client,
495 	int reg_offset, enum power_supply_property psp,
496 	union power_supply_propval *val)
497 {
498 	s32 ret;
499 	enum sbs_battery_mode mode = BATTERY_MODE_WATTS;
500 
501 	if (power_supply_is_amp_property(psp))
502 		mode = BATTERY_MODE_AMPS;
503 
504 	mode = sbs_set_battery_mode(client, mode);
505 	if (mode < 0)
506 		return mode;
507 
508 	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
509 	if (ret < 0)
510 		return ret;
511 
512 	if (psp == POWER_SUPPLY_PROP_CAPACITY) {
513 		/* sbs spec says that this can be >100 %
514 		* even if max value is 100 % */
515 		val->intval = min(ret, 100);
516 	} else
517 		val->intval = ret;
518 
519 	ret = sbs_set_battery_mode(client, mode);
520 	if (ret < 0)
521 		return ret;
522 
523 	return 0;
524 }
525 
526 static char sbs_serial[5];
sbs_get_battery_serial_number(struct i2c_client * client,union power_supply_propval * val)527 static int sbs_get_battery_serial_number(struct i2c_client *client,
528 	union power_supply_propval *val)
529 {
530 	int ret;
531 
532 	ret = sbs_read_word_data(client, sbs_data[REG_SERIAL_NUMBER].addr);
533 	if (ret < 0)
534 		return ret;
535 
536 	ret = sprintf(sbs_serial, "%04x", ret);
537 	val->strval = sbs_serial;
538 
539 	return 0;
540 }
541 
sbs_get_property_index(struct i2c_client * client,enum power_supply_property psp)542 static int sbs_get_property_index(struct i2c_client *client,
543 	enum power_supply_property psp)
544 {
545 	int count;
546 	for (count = 0; count < ARRAY_SIZE(sbs_data); count++)
547 		if (psp == sbs_data[count].psp)
548 			return count;
549 
550 	dev_warn(&client->dev,
551 		"%s: Invalid Property - %d\n", __func__, psp);
552 
553 	return -EINVAL;
554 }
555 
sbs_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)556 static int sbs_get_property(struct power_supply *psy,
557 	enum power_supply_property psp,
558 	union power_supply_propval *val)
559 {
560 	int ret = 0;
561 	struct sbs_info *chip = power_supply_get_drvdata(psy);
562 	struct i2c_client *client = chip->client;
563 
564 	switch (psp) {
565 	case POWER_SUPPLY_PROP_PRESENT:
566 	case POWER_SUPPLY_PROP_HEALTH:
567 		ret = sbs_get_battery_presence_and_health(client, psp, val);
568 		if (psp == POWER_SUPPLY_PROP_PRESENT)
569 			return 0;
570 		break;
571 
572 	case POWER_SUPPLY_PROP_TECHNOLOGY:
573 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
574 		goto done; /* don't trigger power_supply_changed()! */
575 
576 	case POWER_SUPPLY_PROP_ENERGY_NOW:
577 	case POWER_SUPPLY_PROP_ENERGY_FULL:
578 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
579 	case POWER_SUPPLY_PROP_CHARGE_NOW:
580 	case POWER_SUPPLY_PROP_CHARGE_FULL:
581 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
582 	case POWER_SUPPLY_PROP_CAPACITY:
583 		ret = sbs_get_property_index(client, psp);
584 		if (ret < 0)
585 			break;
586 
587 		ret = sbs_get_battery_capacity(client, ret, psp, val);
588 		break;
589 
590 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
591 		ret = sbs_get_battery_serial_number(client, val);
592 		break;
593 
594 	case POWER_SUPPLY_PROP_STATUS:
595 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
596 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
597 	case POWER_SUPPLY_PROP_CURRENT_NOW:
598 	case POWER_SUPPLY_PROP_TEMP:
599 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
600 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
601 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
602 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
603 		ret = sbs_get_property_index(client, psp);
604 		if (ret < 0)
605 			break;
606 
607 		ret = sbs_get_battery_property(client, ret, psp, val);
608 		break;
609 
610 	case POWER_SUPPLY_PROP_MODEL_NAME:
611 		ret = sbs_get_property_index(client, psp);
612 		if (ret < 0)
613 			break;
614 
615 		ret = sbs_get_battery_string_property(client, ret, psp,
616 						      model_name);
617 		val->strval = model_name;
618 		break;
619 
620 	case POWER_SUPPLY_PROP_MANUFACTURER:
621 		ret = sbs_get_property_index(client, psp);
622 		if (ret < 0)
623 			break;
624 
625 		ret = sbs_get_battery_string_property(client, ret, psp,
626 						      manufacturer);
627 		val->strval = manufacturer;
628 		break;
629 
630 	default:
631 		dev_err(&client->dev,
632 			"%s: INVALID property\n", __func__);
633 		return -EINVAL;
634 	}
635 
636 	if (!chip->enable_detection)
637 		goto done;
638 
639 	if (!chip->gpio_detect &&
640 		chip->is_present != (ret >= 0)) {
641 		chip->is_present = (ret >= 0);
642 		power_supply_changed(chip->power_supply);
643 	}
644 
645 done:
646 	if (!ret) {
647 		/* Convert units to match requirements for power supply class */
648 		sbs_unit_adjustment(client, psp, val);
649 	}
650 
651 	dev_dbg(&client->dev,
652 		"%s: property = %d, value = %x\n", __func__, psp, val->intval);
653 
654 	if (ret && chip->is_present)
655 		return ret;
656 
657 	/* battery not present, so return NODATA for properties */
658 	if (ret)
659 		return -ENODATA;
660 
661 	return 0;
662 }
663 
sbs_irq(int irq,void * devid)664 static irqreturn_t sbs_irq(int irq, void *devid)
665 {
666 	struct power_supply *battery = devid;
667 
668 	power_supply_changed(battery);
669 
670 	return IRQ_HANDLED;
671 }
672 
sbs_external_power_changed(struct power_supply * psy)673 static void sbs_external_power_changed(struct power_supply *psy)
674 {
675 	struct sbs_info *chip = power_supply_get_drvdata(psy);
676 
677 	if (chip->ignore_changes > 0) {
678 		chip->ignore_changes--;
679 		return;
680 	}
681 
682 	/* cancel outstanding work */
683 	cancel_delayed_work_sync(&chip->work);
684 
685 	schedule_delayed_work(&chip->work, HZ);
686 	chip->poll_time = chip->pdata->poll_retry_count;
687 }
688 
sbs_delayed_work(struct work_struct * work)689 static void sbs_delayed_work(struct work_struct *work)
690 {
691 	struct sbs_info *chip;
692 	s32 ret;
693 
694 	chip = container_of(work, struct sbs_info, work.work);
695 
696 	ret = sbs_read_word_data(chip->client, sbs_data[REG_STATUS].addr);
697 	/* if the read failed, give up on this work */
698 	if (ret < 0) {
699 		chip->poll_time = 0;
700 		return;
701 	}
702 
703 	if (ret & BATTERY_FULL_CHARGED)
704 		ret = POWER_SUPPLY_STATUS_FULL;
705 	else if (ret & BATTERY_FULL_DISCHARGED)
706 		ret = POWER_SUPPLY_STATUS_NOT_CHARGING;
707 	else if (ret & BATTERY_DISCHARGING)
708 		ret = POWER_SUPPLY_STATUS_DISCHARGING;
709 	else
710 		ret = POWER_SUPPLY_STATUS_CHARGING;
711 
712 	if (chip->last_state != ret) {
713 		chip->poll_time = 0;
714 		power_supply_changed(chip->power_supply);
715 		return;
716 	}
717 	if (chip->poll_time > 0) {
718 		schedule_delayed_work(&chip->work, HZ);
719 		chip->poll_time--;
720 		return;
721 	}
722 }
723 
724 #if defined(CONFIG_OF)
725 
726 #include <linux/of_device.h>
727 #include <linux/of_gpio.h>
728 
729 static const struct of_device_id sbs_dt_ids[] = {
730 	{ .compatible = "sbs,sbs-battery" },
731 	{ .compatible = "ti,bq20z75" },
732 	{ }
733 };
734 MODULE_DEVICE_TABLE(of, sbs_dt_ids);
735 
sbs_of_populate_pdata(struct i2c_client * client)736 static struct sbs_platform_data *sbs_of_populate_pdata(
737 		struct i2c_client *client)
738 {
739 	struct device_node *of_node = client->dev.of_node;
740 	struct sbs_platform_data *pdata = client->dev.platform_data;
741 	enum of_gpio_flags gpio_flags;
742 	int rc;
743 	u32 prop;
744 
745 	/* verify this driver matches this device */
746 	if (!of_node)
747 		return NULL;
748 
749 	/* if platform data is set, honor it */
750 	if (pdata)
751 		return pdata;
752 
753 	/* first make sure at least one property is set, otherwise
754 	 * it won't change behavior from running without pdata.
755 	 */
756 	if (!of_get_property(of_node, "sbs,i2c-retry-count", NULL) &&
757 		!of_get_property(of_node, "sbs,poll-retry-count", NULL) &&
758 		!of_get_property(of_node, "sbs,battery-detect-gpios", NULL))
759 		goto of_out;
760 
761 	pdata = devm_kzalloc(&client->dev, sizeof(struct sbs_platform_data),
762 				GFP_KERNEL);
763 	if (!pdata)
764 		goto of_out;
765 
766 	rc = of_property_read_u32(of_node, "sbs,i2c-retry-count", &prop);
767 	if (!rc)
768 		pdata->i2c_retry_count = prop;
769 
770 	rc = of_property_read_u32(of_node, "sbs,poll-retry-count", &prop);
771 	if (!rc)
772 		pdata->poll_retry_count = prop;
773 
774 	if (!of_get_property(of_node, "sbs,battery-detect-gpios", NULL)) {
775 		pdata->battery_detect = -1;
776 		goto of_out;
777 	}
778 
779 	pdata->battery_detect = of_get_named_gpio_flags(of_node,
780 			"sbs,battery-detect-gpios", 0, &gpio_flags);
781 
782 	if (gpio_flags & OF_GPIO_ACTIVE_LOW)
783 		pdata->battery_detect_present = 0;
784 	else
785 		pdata->battery_detect_present = 1;
786 
787 of_out:
788 	return pdata;
789 }
790 #else
sbs_of_populate_pdata(struct i2c_client * client)791 static struct sbs_platform_data *sbs_of_populate_pdata(
792 	struct i2c_client *client)
793 {
794 	return client->dev.platform_data;
795 }
796 #endif
797 
798 static const struct power_supply_desc sbs_default_desc = {
799 	.type = POWER_SUPPLY_TYPE_BATTERY,
800 	.properties = sbs_properties,
801 	.num_properties = ARRAY_SIZE(sbs_properties),
802 	.get_property = sbs_get_property,
803 	.external_power_changed = sbs_external_power_changed,
804 };
805 
sbs_probe(struct i2c_client * client,const struct i2c_device_id * id)806 static int sbs_probe(struct i2c_client *client,
807 	const struct i2c_device_id *id)
808 {
809 	struct sbs_info *chip;
810 	struct power_supply_desc *sbs_desc;
811 	struct sbs_platform_data *pdata = client->dev.platform_data;
812 	struct power_supply_config psy_cfg = {};
813 	int rc;
814 	int irq;
815 
816 	sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc,
817 			sizeof(*sbs_desc), GFP_KERNEL);
818 	if (!sbs_desc)
819 		return -ENOMEM;
820 
821 	sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s",
822 			dev_name(&client->dev));
823 	if (!sbs_desc->name)
824 		return -ENOMEM;
825 
826 	chip = kzalloc(sizeof(struct sbs_info), GFP_KERNEL);
827 	if (!chip)
828 		return -ENOMEM;
829 
830 	chip->client = client;
831 	chip->enable_detection = false;
832 	chip->gpio_detect = false;
833 	psy_cfg.of_node = client->dev.of_node;
834 	psy_cfg.drv_data = chip;
835 	/* ignore first notification of external change, it is generated
836 	 * from the power_supply_register call back
837 	 */
838 	chip->ignore_changes = 1;
839 	chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
840 
841 	pdata = sbs_of_populate_pdata(client);
842 
843 	if (pdata) {
844 		chip->gpio_detect = gpio_is_valid(pdata->battery_detect);
845 		chip->pdata = pdata;
846 	}
847 
848 	i2c_set_clientdata(client, chip);
849 
850 	if (!chip->gpio_detect)
851 		goto skip_gpio;
852 
853 	rc = gpio_request(pdata->battery_detect, dev_name(&client->dev));
854 	if (rc) {
855 		dev_warn(&client->dev, "Failed to request gpio: %d\n", rc);
856 		chip->gpio_detect = false;
857 		goto skip_gpio;
858 	}
859 
860 	rc = gpio_direction_input(pdata->battery_detect);
861 	if (rc) {
862 		dev_warn(&client->dev, "Failed to get gpio as input: %d\n", rc);
863 		gpio_free(pdata->battery_detect);
864 		chip->gpio_detect = false;
865 		goto skip_gpio;
866 	}
867 
868 	irq = gpio_to_irq(pdata->battery_detect);
869 	if (irq <= 0) {
870 		dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
871 		gpio_free(pdata->battery_detect);
872 		chip->gpio_detect = false;
873 		goto skip_gpio;
874 	}
875 
876 	rc = request_irq(irq, sbs_irq,
877 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
878 		dev_name(&client->dev), chip->power_supply);
879 	if (rc) {
880 		dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
881 		gpio_free(pdata->battery_detect);
882 		chip->gpio_detect = false;
883 		goto skip_gpio;
884 	}
885 
886 	chip->irq = irq;
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) {
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 = 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 	if (chip->irq)
923 		free_irq(chip->irq, chip->power_supply);
924 	if (chip->gpio_detect)
925 		gpio_free(pdata->battery_detect);
926 
927 	kfree(chip);
928 
929 	return rc;
930 }
931 
sbs_remove(struct i2c_client * client)932 static int sbs_remove(struct i2c_client *client)
933 {
934 	struct sbs_info *chip = i2c_get_clientdata(client);
935 
936 	if (chip->irq)
937 		free_irq(chip->irq, chip->power_supply);
938 	if (chip->gpio_detect)
939 		gpio_free(chip->pdata->battery_detect);
940 
941 	power_supply_unregister(chip->power_supply);
942 
943 	cancel_delayed_work_sync(&chip->work);
944 
945 	kfree(chip);
946 	chip = NULL;
947 
948 	return 0;
949 }
950 
951 #if defined CONFIG_PM_SLEEP
952 
sbs_suspend(struct device * dev)953 static int sbs_suspend(struct device *dev)
954 {
955 	struct i2c_client *client = to_i2c_client(dev);
956 	struct sbs_info *chip = i2c_get_clientdata(client);
957 	s32 ret;
958 
959 	if (chip->poll_time > 0)
960 		cancel_delayed_work_sync(&chip->work);
961 
962 	/* write to manufacturer access with sleep command */
963 	ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
964 		MANUFACTURER_ACCESS_SLEEP);
965 	if (chip->is_present && ret < 0)
966 		return ret;
967 
968 	return 0;
969 }
970 
971 static SIMPLE_DEV_PM_OPS(sbs_pm_ops, sbs_suspend, NULL);
972 #define SBS_PM_OPS (&sbs_pm_ops)
973 
974 #else
975 #define SBS_PM_OPS NULL
976 #endif
977 
978 static const struct i2c_device_id sbs_id[] = {
979 	{ "bq20z75", 0 },
980 	{ "sbs-battery", 1 },
981 	{}
982 };
983 MODULE_DEVICE_TABLE(i2c, sbs_id);
984 
985 static struct i2c_driver sbs_battery_driver = {
986 	.probe		= sbs_probe,
987 	.remove		= sbs_remove,
988 	.id_table	= sbs_id,
989 	.driver = {
990 		.name	= "sbs-battery",
991 		.of_match_table = of_match_ptr(sbs_dt_ids),
992 		.pm	= SBS_PM_OPS,
993 	},
994 };
995 module_i2c_driver(sbs_battery_driver);
996 
997 MODULE_DESCRIPTION("SBS battery monitor driver");
998 MODULE_LICENSE("GPL");
999 
1000 module_param(force_load, bool, S_IRUSR | S_IRGRP | S_IROTH);
1001 MODULE_PARM_DESC(force_load,
1002 		 "Attempt to load the driver even if no battery is connected");
1003