1 /*
2  * Battery driver for CPCAP PMIC
3  *
4  * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
5  *
6  * Some parts of the code based on earlie Motorola mapphone Linux kernel
7  * drivers:
8  *
9  * Copyright (C) 2009-2010 Motorola, Inc.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14 
15  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
16  * kind, whether express or implied; without even the implied warranty
17  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/err.h>
23 #include <linux/interrupt.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/of_device.h>
27 #include <linux/platform_device.h>
28 #include <linux/power_supply.h>
29 #include <linux/reboot.h>
30 #include <linux/regmap.h>
31 
32 #include <linux/iio/consumer.h>
33 #include <linux/iio/types.h>
34 #include <linux/mfd/motorola-cpcap.h>
35 
36 #include <asm/div64.h>
37 
38 /*
39  * Register bit defines for CPCAP_REG_BPEOL. Some of these seem to
40  * map to MC13783UG.pdf "Table 5-19. Register 13, Power Control 0"
41  * to enable BATTDETEN, LOBAT and EOL features. We currently use
42  * LOBAT interrupts instead of EOL.
43  */
44 #define CPCAP_REG_BPEOL_BIT_EOL9	BIT(9)	/* Set for EOL irq */
45 #define CPCAP_REG_BPEOL_BIT_EOL8	BIT(8)	/* Set for EOL irq */
46 #define CPCAP_REG_BPEOL_BIT_UNKNOWN7	BIT(7)
47 #define CPCAP_REG_BPEOL_BIT_UNKNOWN6	BIT(6)
48 #define CPCAP_REG_BPEOL_BIT_UNKNOWN5	BIT(5)
49 #define CPCAP_REG_BPEOL_BIT_EOL_MULTI	BIT(4)	/* Set for multiple EOL irqs */
50 #define CPCAP_REG_BPEOL_BIT_UNKNOWN3	BIT(3)
51 #define CPCAP_REG_BPEOL_BIT_UNKNOWN2	BIT(2)
52 #define CPCAP_REG_BPEOL_BIT_BATTDETEN	BIT(1)	/* Enable battery detect */
53 #define CPCAP_REG_BPEOL_BIT_EOLSEL	BIT(0)	/* BPDET = 0, EOL = 1 */
54 
55 #define CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS	250
56 
57 enum {
58 	CPCAP_BATTERY_IIO_BATTDET,
59 	CPCAP_BATTERY_IIO_VOLTAGE,
60 	CPCAP_BATTERY_IIO_CHRG_CURRENT,
61 	CPCAP_BATTERY_IIO_BATT_CURRENT,
62 	CPCAP_BATTERY_IIO_NR,
63 };
64 
65 enum cpcap_battery_irq_action {
66 	CPCAP_BATTERY_IRQ_ACTION_NONE,
67 	CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW,
68 	CPCAP_BATTERY_IRQ_ACTION_POWEROFF,
69 };
70 
71 struct cpcap_interrupt_desc {
72 	const char *name;
73 	struct list_head node;
74 	int irq;
75 	enum cpcap_battery_irq_action action;
76 };
77 
78 struct cpcap_battery_config {
79 	int ccm;
80 	int cd_factor;
81 	struct power_supply_info info;
82 };
83 
84 struct cpcap_coulomb_counter_data {
85 	s32 sample;		/* 24-bits */
86 	s32 accumulator;
87 	s16 offset;		/* 10-bits */
88 };
89 
90 enum cpcap_battery_state {
91 	CPCAP_BATTERY_STATE_PREVIOUS,
92 	CPCAP_BATTERY_STATE_LATEST,
93 	CPCAP_BATTERY_STATE_NR,
94 };
95 
96 struct cpcap_battery_state_data {
97 	int voltage;
98 	int current_ua;
99 	int counter_uah;
100 	int temperature;
101 	ktime_t time;
102 	struct cpcap_coulomb_counter_data cc;
103 };
104 
105 struct cpcap_battery_ddata {
106 	struct device *dev;
107 	struct regmap *reg;
108 	struct list_head irq_list;
109 	struct iio_channel *channels[CPCAP_BATTERY_IIO_NR];
110 	struct power_supply *psy;
111 	struct cpcap_battery_config config;
112 	struct cpcap_battery_state_data state[CPCAP_BATTERY_STATE_NR];
113 	atomic_t active;
114 	int status;
115 	u16 vendor;
116 };
117 
118 #define CPCAP_NO_BATTERY	-400
119 
120 static struct cpcap_battery_state_data *
121 cpcap_battery_get_state(struct cpcap_battery_ddata *ddata,
122 			enum cpcap_battery_state state)
123 {
124 	if (state >= CPCAP_BATTERY_STATE_NR)
125 		return NULL;
126 
127 	return &ddata->state[state];
128 }
129 
130 static struct cpcap_battery_state_data *
131 cpcap_battery_latest(struct cpcap_battery_ddata *ddata)
132 {
133 	return cpcap_battery_get_state(ddata, CPCAP_BATTERY_STATE_LATEST);
134 }
135 
136 static struct cpcap_battery_state_data *
137 cpcap_battery_previous(struct cpcap_battery_ddata *ddata)
138 {
139 	return cpcap_battery_get_state(ddata, CPCAP_BATTERY_STATE_PREVIOUS);
140 }
141 
142 static int cpcap_charger_battery_temperature(struct cpcap_battery_ddata *ddata,
143 					     int *value)
144 {
145 	struct iio_channel *channel;
146 	int error;
147 
148 	channel = ddata->channels[CPCAP_BATTERY_IIO_BATTDET];
149 	error = iio_read_channel_processed(channel, value);
150 	if (error < 0) {
151 		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
152 		*value = CPCAP_NO_BATTERY;
153 
154 		return error;
155 	}
156 
157 	*value /= 100;
158 
159 	return 0;
160 }
161 
162 static int cpcap_battery_get_voltage(struct cpcap_battery_ddata *ddata)
163 {
164 	struct iio_channel *channel;
165 	int error, value = 0;
166 
167 	channel = ddata->channels[CPCAP_BATTERY_IIO_VOLTAGE];
168 	error = iio_read_channel_processed(channel, &value);
169 	if (error < 0) {
170 		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
171 
172 		return 0;
173 	}
174 
175 	return value * 1000;
176 }
177 
178 static int cpcap_battery_get_current(struct cpcap_battery_ddata *ddata)
179 {
180 	struct iio_channel *channel;
181 	int error, value = 0;
182 
183 	channel = ddata->channels[CPCAP_BATTERY_IIO_BATT_CURRENT];
184 	error = iio_read_channel_processed(channel, &value);
185 	if (error < 0) {
186 		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
187 
188 		return 0;
189 	}
190 
191 	return value * 1000;
192 }
193 
194 /**
195  * cpcap_battery_cc_raw_div - calculate and divide coulomb counter μAms values
196  * @ddata: device driver data
197  * @sample: coulomb counter sample value
198  * @accumulator: coulomb counter integrator value
199  * @offset: coulomb counter offset value
200  * @divider: conversion divider
201  *
202  * Note that cc_lsb and cc_dur values are from Motorola Linux kernel
203  * function data_get_avg_curr_ua() and seem to be based on measured test
204  * results. It also has the following comment:
205  *
206  * Adjustment factors are applied here as a temp solution per the test
207  * results. Need to work out a formal solution for this adjustment.
208  *
209  * A coulomb counter for similar hardware seems to be documented in
210  * "TWL6030 Gas Gauging Basics (Rev. A)" swca095a.pdf in chapter
211  * "10 Calculating Accumulated Current". We however follow what the
212  * Motorola mapphone Linux kernel is doing as there may be either a
213  * TI or ST coulomb counter in the PMIC.
214  */
215 static int cpcap_battery_cc_raw_div(struct cpcap_battery_ddata *ddata,
216 				    u32 sample, s32 accumulator,
217 				    s16 offset, u32 divider)
218 {
219 	s64 acc;
220 	u64 tmp;
221 	int avg_current;
222 	u32 cc_lsb;
223 
224 	sample &= 0xffffff;		/* 24-bits, unsigned */
225 	offset &= 0x7ff;		/* 10-bits, signed */
226 
227 	switch (ddata->vendor) {
228 	case CPCAP_VENDOR_ST:
229 		cc_lsb = 95374;		/* μAms per LSB */
230 		break;
231 	case CPCAP_VENDOR_TI:
232 		cc_lsb = 91501;		/* μAms per LSB */
233 		break;
234 	default:
235 		return -EINVAL;
236 	}
237 
238 	acc = accumulator;
239 	acc = acc - ((s64)sample * offset);
240 	cc_lsb = (cc_lsb * ddata->config.cd_factor) / 1000;
241 
242 	if (acc >=  0)
243 		tmp = acc;
244 	else
245 		tmp = acc * -1;
246 
247 	tmp = tmp * cc_lsb;
248 	do_div(tmp, divider);
249 	avg_current = tmp;
250 
251 	if (acc >= 0)
252 		return -avg_current;
253 	else
254 		return avg_current;
255 }
256 
257 /* 3600000μAms = 1μAh */
258 static int cpcap_battery_cc_to_uah(struct cpcap_battery_ddata *ddata,
259 				   u32 sample, s32 accumulator,
260 				   s16 offset)
261 {
262 	return cpcap_battery_cc_raw_div(ddata, sample,
263 					accumulator, offset,
264 					3600000);
265 }
266 
267 static int cpcap_battery_cc_to_ua(struct cpcap_battery_ddata *ddata,
268 				  u32 sample, s32 accumulator,
269 				  s16 offset)
270 {
271 	return cpcap_battery_cc_raw_div(ddata, sample,
272 					accumulator, offset,
273 					sample *
274 					CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS);
275 }
276 
277 /**
278  * cpcap_battery_read_accumulated - reads cpcap coulomb counter
279  * @ddata: device driver data
280  * @regs: coulomb counter values
281  *
282  * Based on Motorola mapphone kernel function data_read_regs().
283  * Looking at the registers, the coulomb counter seems similar to
284  * the coulomb counter in TWL6030. See "TWL6030 Gas Gauging Basics
285  * (Rev. A) swca095a.pdf for "10 Calculating Accumulated Current".
286  *
287  * Note that swca095a.pdf instructs to stop the coulomb counter
288  * before reading to avoid values changing. Motorola mapphone
289  * Linux kernel does not do it, so let's assume they've verified
290  * the data produced is correct.
291  */
292 static int
293 cpcap_battery_read_accumulated(struct cpcap_battery_ddata *ddata,
294 			       struct cpcap_coulomb_counter_data *ccd)
295 {
296 	u16 buf[7];	/* CPCAP_REG_CC1 to CCI */
297 	int error;
298 
299 	ccd->sample = 0;
300 	ccd->accumulator = 0;
301 	ccd->offset = 0;
302 
303 	/* Read coulomb counter register range */
304 	error = regmap_bulk_read(ddata->reg, CPCAP_REG_CCS1,
305 				 buf, ARRAY_SIZE(buf));
306 	if (error)
307 		return 0;
308 
309 	/* Sample value CPCAP_REG_CCS1 & 2 */
310 	ccd->sample = (buf[1] & 0x0fff) << 16;
311 	ccd->sample |= buf[0];
312 
313 	/* Accumulator value CPCAP_REG_CCA1 & 2 */
314 	ccd->accumulator = ((s16)buf[3]) << 16;
315 	ccd->accumulator |= buf[2];
316 
317 	/* Offset value CPCAP_REG_CCO */
318 	ccd->offset = buf[5];
319 
320 	/* Adjust offset based on mode value CPCAP_REG_CCM? */
321 	if (buf[4] >= 0x200)
322 		ccd->offset |= 0xfc00;
323 
324 	return cpcap_battery_cc_to_uah(ddata,
325 				       ccd->sample,
326 				       ccd->accumulator,
327 				       ccd->offset);
328 }
329 
330 /**
331  * cpcap_battery_cc_get_avg_current - read cpcap coulumb counter
332  * @ddata: cpcap battery driver device data
333  */
334 static int cpcap_battery_cc_get_avg_current(struct cpcap_battery_ddata *ddata)
335 {
336 	int value, acc, error;
337 	s32 sample = 1;
338 	s16 offset;
339 
340 	if (ddata->vendor == CPCAP_VENDOR_ST)
341 		sample = 4;
342 
343 	/* Coulomb counter integrator */
344 	error = regmap_read(ddata->reg, CPCAP_REG_CCI, &value);
345 	if (error)
346 		return error;
347 
348 	if ((ddata->vendor == CPCAP_VENDOR_TI) && (value > 0x2000))
349 		value = value | 0xc000;
350 
351 	acc = (s16)value;
352 
353 	/* Coulomb counter sample time */
354 	error = regmap_read(ddata->reg, CPCAP_REG_CCM, &value);
355 	if (error)
356 		return error;
357 
358 	if (value < 0x200)
359 		offset = value;
360 	else
361 		offset = value | 0xfc00;
362 
363 	return cpcap_battery_cc_to_ua(ddata, sample, acc, offset);
364 }
365 
366 static bool cpcap_battery_full(struct cpcap_battery_ddata *ddata)
367 {
368 	struct cpcap_battery_state_data *state = cpcap_battery_latest(ddata);
369 
370 	/* Basically anything that measures above 4347000 is full */
371 	if (state->voltage >= (ddata->config.info.voltage_max_design - 4000))
372 		return true;
373 
374 	return false;
375 }
376 
377 static int cpcap_battery_update_status(struct cpcap_battery_ddata *ddata)
378 {
379 	struct cpcap_battery_state_data state, *latest, *previous;
380 	ktime_t now;
381 	int error;
382 
383 	memset(&state, 0, sizeof(state));
384 	now = ktime_get();
385 
386 	latest = cpcap_battery_latest(ddata);
387 	if (latest) {
388 		s64 delta_ms = ktime_to_ms(ktime_sub(now, latest->time));
389 
390 		if (delta_ms < CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS)
391 			return delta_ms;
392 	}
393 
394 	state.time = now;
395 	state.voltage = cpcap_battery_get_voltage(ddata);
396 	state.current_ua = cpcap_battery_get_current(ddata);
397 	state.counter_uah = cpcap_battery_read_accumulated(ddata, &state.cc);
398 
399 	error = cpcap_charger_battery_temperature(ddata,
400 						  &state.temperature);
401 	if (error)
402 		return error;
403 
404 	previous = cpcap_battery_previous(ddata);
405 	memcpy(previous, latest, sizeof(*previous));
406 	memcpy(latest, &state, sizeof(*latest));
407 
408 	return 0;
409 }
410 
411 static enum power_supply_property cpcap_battery_props[] = {
412 	POWER_SUPPLY_PROP_STATUS,
413 	POWER_SUPPLY_PROP_PRESENT,
414 	POWER_SUPPLY_PROP_TECHNOLOGY,
415 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
416 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
417 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
418 	POWER_SUPPLY_PROP_CURRENT_AVG,
419 	POWER_SUPPLY_PROP_CURRENT_NOW,
420 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
421 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
422 	POWER_SUPPLY_PROP_POWER_NOW,
423 	POWER_SUPPLY_PROP_POWER_AVG,
424 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
425 	POWER_SUPPLY_PROP_SCOPE,
426 	POWER_SUPPLY_PROP_TEMP,
427 };
428 
429 static int cpcap_battery_get_property(struct power_supply *psy,
430 				      enum power_supply_property psp,
431 				      union power_supply_propval *val)
432 {
433 	struct cpcap_battery_ddata *ddata = power_supply_get_drvdata(psy);
434 	struct cpcap_battery_state_data *latest, *previous;
435 	u32 sample;
436 	s32 accumulator;
437 	int cached;
438 	s64 tmp;
439 
440 	cached = cpcap_battery_update_status(ddata);
441 	if (cached < 0)
442 		return cached;
443 
444 	latest = cpcap_battery_latest(ddata);
445 	previous = cpcap_battery_previous(ddata);
446 
447 	switch (psp) {
448 	case POWER_SUPPLY_PROP_PRESENT:
449 		if (latest->temperature > CPCAP_NO_BATTERY)
450 			val->intval = 1;
451 		else
452 			val->intval = 0;
453 		break;
454 	case POWER_SUPPLY_PROP_STATUS:
455 		if (cpcap_battery_full(ddata)) {
456 			val->intval = POWER_SUPPLY_STATUS_FULL;
457 			break;
458 		}
459 		if (cpcap_battery_cc_get_avg_current(ddata) < 0)
460 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
461 		else
462 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
463 		break;
464 	case POWER_SUPPLY_PROP_TECHNOLOGY:
465 		val->intval = ddata->config.info.technology;
466 		break;
467 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
468 		val->intval = cpcap_battery_get_voltage(ddata);
469 		break;
470 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
471 		val->intval = ddata->config.info.voltage_max_design;
472 		break;
473 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
474 		val->intval = ddata->config.info.voltage_min_design;
475 		break;
476 	case POWER_SUPPLY_PROP_CURRENT_AVG:
477 		if (cached) {
478 			val->intval = cpcap_battery_cc_get_avg_current(ddata);
479 			break;
480 		}
481 		sample = latest->cc.sample - previous->cc.sample;
482 		accumulator = latest->cc.accumulator - previous->cc.accumulator;
483 		val->intval = cpcap_battery_cc_to_ua(ddata, sample,
484 						     accumulator,
485 						     latest->cc.offset);
486 		break;
487 	case POWER_SUPPLY_PROP_CURRENT_NOW:
488 		val->intval = latest->current_ua;
489 		break;
490 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
491 		val->intval = latest->counter_uah;
492 		break;
493 	case POWER_SUPPLY_PROP_POWER_NOW:
494 		tmp = (latest->voltage / 10000) * latest->current_ua;
495 		val->intval = div64_s64(tmp, 100);
496 		break;
497 	case POWER_SUPPLY_PROP_POWER_AVG:
498 		if (cached) {
499 			tmp = cpcap_battery_cc_get_avg_current(ddata);
500 			tmp *= (latest->voltage / 10000);
501 			val->intval = div64_s64(tmp, 100);
502 			break;
503 		}
504 		sample = latest->cc.sample - previous->cc.sample;
505 		accumulator = latest->cc.accumulator - previous->cc.accumulator;
506 		tmp = cpcap_battery_cc_to_ua(ddata, sample, accumulator,
507 					     latest->cc.offset);
508 		tmp *= ((latest->voltage + previous->voltage) / 20000);
509 		val->intval = div64_s64(tmp, 100);
510 		break;
511 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
512 		if (cpcap_battery_full(ddata))
513 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
514 		else if (latest->voltage >= 3750000)
515 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_HIGH;
516 		else if (latest->voltage >= 3300000)
517 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
518 		else if (latest->voltage > 3100000)
519 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
520 		else if (latest->voltage <= 3100000)
521 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
522 		else
523 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
524 		break;
525 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
526 		val->intval = ddata->config.info.charge_full_design;
527 		break;
528 	case POWER_SUPPLY_PROP_SCOPE:
529 		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
530 		break;
531 	case POWER_SUPPLY_PROP_TEMP:
532 		val->intval = latest->temperature;
533 		break;
534 	default:
535 		return -EINVAL;
536 	}
537 
538 	return 0;
539 }
540 
541 static irqreturn_t cpcap_battery_irq_thread(int irq, void *data)
542 {
543 	struct cpcap_battery_ddata *ddata = data;
544 	struct cpcap_battery_state_data *latest;
545 	struct cpcap_interrupt_desc *d;
546 
547 	if (!atomic_read(&ddata->active))
548 		return IRQ_NONE;
549 
550 	list_for_each_entry(d, &ddata->irq_list, node) {
551 		if (irq == d->irq)
552 			break;
553 	}
554 
555 	if (!d)
556 		return IRQ_NONE;
557 
558 	latest = cpcap_battery_latest(ddata);
559 
560 	switch (d->action) {
561 	case CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW:
562 		if (latest->counter_uah >= 0)
563 			dev_warn(ddata->dev, "Battery low at 3.3V!\n");
564 		break;
565 	case CPCAP_BATTERY_IRQ_ACTION_POWEROFF:
566 		if (latest->counter_uah >= 0) {
567 			dev_emerg(ddata->dev,
568 				  "Battery empty at 3.1V, powering off\n");
569 			orderly_poweroff(true);
570 		}
571 		break;
572 	default:
573 		break;
574 	}
575 
576 	power_supply_changed(ddata->psy);
577 
578 	return IRQ_HANDLED;
579 }
580 
581 static int cpcap_battery_init_irq(struct platform_device *pdev,
582 				  struct cpcap_battery_ddata *ddata,
583 				  const char *name)
584 {
585 	struct cpcap_interrupt_desc *d;
586 	int irq, error;
587 
588 	irq = platform_get_irq_byname(pdev, name);
589 	if (irq < 0)
590 		return irq;
591 
592 	error = devm_request_threaded_irq(ddata->dev, irq, NULL,
593 					  cpcap_battery_irq_thread,
594 					  IRQF_SHARED,
595 					  name, ddata);
596 	if (error) {
597 		dev_err(ddata->dev, "could not get irq %s: %i\n",
598 			name, error);
599 
600 		return error;
601 	}
602 
603 	d = devm_kzalloc(ddata->dev, sizeof(*d), GFP_KERNEL);
604 	if (!d)
605 		return -ENOMEM;
606 
607 	d->name = name;
608 	d->irq = irq;
609 
610 	if (!strncmp(name, "lowbph", 6))
611 		d->action = CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW;
612 	else if (!strncmp(name, "lowbpl", 6))
613 		d->action = CPCAP_BATTERY_IRQ_ACTION_POWEROFF;
614 
615 	list_add(&d->node, &ddata->irq_list);
616 
617 	return 0;
618 }
619 
620 static int cpcap_battery_init_interrupts(struct platform_device *pdev,
621 					 struct cpcap_battery_ddata *ddata)
622 {
623 	static const char * const cpcap_battery_irqs[] = {
624 		"eol", "lowbph", "lowbpl",
625 		"chrgcurr1", "battdetb"
626 	};
627 	int i, error;
628 
629 	for (i = 0; i < ARRAY_SIZE(cpcap_battery_irqs); i++) {
630 		error = cpcap_battery_init_irq(pdev, ddata,
631 					       cpcap_battery_irqs[i]);
632 		if (error)
633 			return error;
634 	}
635 
636 	/* Enable low battery interrupts for 3.3V high and 3.1V low */
637 	error = regmap_update_bits(ddata->reg, CPCAP_REG_BPEOL,
638 				   0xffff,
639 				   CPCAP_REG_BPEOL_BIT_BATTDETEN);
640 	if (error)
641 		return error;
642 
643 	return 0;
644 }
645 
646 static int cpcap_battery_init_iio(struct cpcap_battery_ddata *ddata)
647 {
648 	const char * const names[CPCAP_BATTERY_IIO_NR] = {
649 		"battdetb", "battp", "chg_isense", "batti",
650 	};
651 	int error, i;
652 
653 	for (i = 0; i < CPCAP_BATTERY_IIO_NR; i++) {
654 		ddata->channels[i] = devm_iio_channel_get(ddata->dev,
655 							  names[i]);
656 		if (IS_ERR(ddata->channels[i])) {
657 			error = PTR_ERR(ddata->channels[i]);
658 			goto out_err;
659 		}
660 
661 		if (!ddata->channels[i]->indio_dev) {
662 			error = -ENXIO;
663 			goto out_err;
664 		}
665 	}
666 
667 	return 0;
668 
669 out_err:
670 	dev_err(ddata->dev, "could not initialize VBUS or ID IIO: %i\n",
671 		error);
672 
673 	return error;
674 }
675 
676 /*
677  * Based on the values from Motorola mapphone Linux kernel. In the
678  * the Motorola mapphone Linux kernel tree the value for pm_cd_factor
679  * is passed to the kernel via device tree. If it turns out to be
680  * something device specific we can consider that too later.
681  *
682  * And looking at the battery full and shutdown values for the stock
683  * kernel on droid 4, full is 4351000 and software initiates shutdown
684  * at 3078000. The device will die around 2743000.
685  */
686 static const struct cpcap_battery_config cpcap_battery_default_data = {
687 	.ccm = 0x3ff,
688 	.cd_factor = 0x3cc,
689 	.info.technology = POWER_SUPPLY_TECHNOLOGY_LION,
690 	.info.voltage_max_design = 4351000,
691 	.info.voltage_min_design = 3100000,
692 	.info.charge_full_design = 1740000,
693 };
694 
695 #ifdef CONFIG_OF
696 static const struct of_device_id cpcap_battery_id_table[] = {
697 	{
698 		.compatible = "motorola,cpcap-battery",
699 		.data = &cpcap_battery_default_data,
700 	},
701 	{},
702 };
703 MODULE_DEVICE_TABLE(of, cpcap_battery_id_table);
704 #endif
705 
706 static int cpcap_battery_probe(struct platform_device *pdev)
707 {
708 	struct power_supply_desc *psy_desc;
709 	struct cpcap_battery_ddata *ddata;
710 	const struct of_device_id *match;
711 	struct power_supply_config psy_cfg = {};
712 	int error;
713 
714 	match = of_match_device(of_match_ptr(cpcap_battery_id_table),
715 				&pdev->dev);
716 	if (!match)
717 		return -EINVAL;
718 
719 	if (!match->data) {
720 		dev_err(&pdev->dev, "no configuration data found\n");
721 
722 		return -ENODEV;
723 	}
724 
725 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
726 	if (!ddata)
727 		return -ENOMEM;
728 
729 	INIT_LIST_HEAD(&ddata->irq_list);
730 	ddata->dev = &pdev->dev;
731 	memcpy(&ddata->config, match->data, sizeof(ddata->config));
732 
733 	ddata->reg = dev_get_regmap(ddata->dev->parent, NULL);
734 	if (!ddata->reg)
735 		return -ENODEV;
736 
737 	error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
738 	if (error)
739 		return error;
740 
741 	platform_set_drvdata(pdev, ddata);
742 
743 	error = regmap_update_bits(ddata->reg, CPCAP_REG_CCM,
744 				   0xffff, ddata->config.ccm);
745 	if (error)
746 		return error;
747 
748 	error = cpcap_battery_init_interrupts(pdev, ddata);
749 	if (error)
750 		return error;
751 
752 	error = cpcap_battery_init_iio(ddata);
753 	if (error)
754 		return error;
755 
756 	psy_desc = devm_kzalloc(ddata->dev, sizeof(*psy_desc), GFP_KERNEL);
757 	if (!psy_desc)
758 		return -ENOMEM;
759 
760 	psy_desc->name = "battery",
761 	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY,
762 	psy_desc->properties = cpcap_battery_props,
763 	psy_desc->num_properties = ARRAY_SIZE(cpcap_battery_props),
764 	psy_desc->get_property = cpcap_battery_get_property,
765 
766 	psy_cfg.of_node = pdev->dev.of_node;
767 	psy_cfg.drv_data = ddata;
768 
769 	ddata->psy = devm_power_supply_register(ddata->dev, psy_desc,
770 						&psy_cfg);
771 	error = PTR_ERR_OR_ZERO(ddata->psy);
772 	if (error) {
773 		dev_err(ddata->dev, "failed to register power supply\n");
774 		return error;
775 	}
776 
777 	atomic_set(&ddata->active, 1);
778 
779 	return 0;
780 }
781 
782 static int cpcap_battery_remove(struct platform_device *pdev)
783 {
784 	struct cpcap_battery_ddata *ddata = platform_get_drvdata(pdev);
785 	int error;
786 
787 	atomic_set(&ddata->active, 0);
788 	error = regmap_update_bits(ddata->reg, CPCAP_REG_BPEOL,
789 				   0xffff, 0);
790 	if (error)
791 		dev_err(&pdev->dev, "could not disable: %i\n", error);
792 
793 	return 0;
794 }
795 
796 static struct platform_driver cpcap_battery_driver = {
797 	.driver	= {
798 		.name		= "cpcap_battery",
799 		.of_match_table = of_match_ptr(cpcap_battery_id_table),
800 	},
801 	.probe	= cpcap_battery_probe,
802 	.remove = cpcap_battery_remove,
803 };
804 module_platform_driver(cpcap_battery_driver);
805 
806 MODULE_LICENSE("GPL v2");
807 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
808 MODULE_DESCRIPTION("CPCAP PMIC Battery Driver");
809