xref: /linux/drivers/power/supply/ab8500_btemp.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2012
4  *
5  * Battery temperature driver for AB8500
6  *
7  * Author:
8  *	Johan Palsson <johan.palsson@stericsson.com>
9  *	Karl Komierowski <karl.komierowski@stericsson.com>
10  *	Arun R Murthy <arun.murthy@stericsson.com>
11  */
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/component.h>
17 #include <linux/interrupt.h>
18 #include <linux/delay.h>
19 #include <linux/slab.h>
20 #include <linux/platform_device.h>
21 #include <linux/power_supply.h>
22 #include <linux/completion.h>
23 #include <linux/workqueue.h>
24 #include <linux/jiffies.h>
25 #include <linux/of.h>
26 #include <linux/mfd/core.h>
27 #include <linux/mfd/abx500.h>
28 #include <linux/mfd/abx500/ab8500.h>
29 #include <linux/thermal.h>
30 #include <linux/iio/consumer.h>
31 #include <linux/fixp-arith.h>
32 
33 #include "ab8500-bm.h"
34 
35 #define BTEMP_THERMAL_LOW_LIMIT		-10
36 #define BTEMP_THERMAL_MED_LIMIT		0
37 #define BTEMP_THERMAL_HIGH_LIMIT_52	52
38 #define BTEMP_THERMAL_HIGH_LIMIT_57	57
39 #define BTEMP_THERMAL_HIGH_LIMIT_62	62
40 
41 #define BTEMP_BATCTRL_CURR_SRC_7UA	7
42 #define BTEMP_BATCTRL_CURR_SRC_20UA	20
43 
44 #define BTEMP_BATCTRL_CURR_SRC_16UA	16
45 #define BTEMP_BATCTRL_CURR_SRC_18UA	18
46 
47 #define BTEMP_BATCTRL_CURR_SRC_60UA	60
48 #define BTEMP_BATCTRL_CURR_SRC_120UA	120
49 
50 /**
51  * struct ab8500_btemp_interrupts - ab8500 interrupts
52  * @name:	name of the interrupt
53  * @isr		function pointer to the isr
54  */
55 struct ab8500_btemp_interrupts {
56 	char *name;
57 	irqreturn_t (*isr)(int irq, void *data);
58 };
59 
60 struct ab8500_btemp_events {
61 	bool batt_rem;
62 	bool btemp_high;
63 	bool btemp_medhigh;
64 	bool btemp_lowmed;
65 	bool btemp_low;
66 	bool ac_conn;
67 	bool usb_conn;
68 };
69 
70 struct ab8500_btemp_ranges {
71 	int btemp_high_limit;
72 	int btemp_med_limit;
73 	int btemp_low_limit;
74 };
75 
76 /**
77  * struct ab8500_btemp - ab8500 BTEMP device information
78  * @dev:		Pointer to the structure device
79  * @node:		List of AB8500 BTEMPs, hence prepared for reentrance
80  * @curr_source:	What current source we use, in uA
81  * @bat_temp:		Dispatched battery temperature in degree Celsius
82  * @prev_bat_temp	Last measured battery temperature in degree Celsius
83  * @parent:		Pointer to the struct ab8500
84  * @tz:			Thermal zone for the battery
85  * @adc_bat_ctrl:	ADC channel for the battery control
86  * @fg:			Pointer to the struct fg
87  * @bm:           	Platform specific battery management information
88  * @btemp_psy:		Structure for BTEMP specific battery properties
89  * @events:		Structure for information about events triggered
90  * @btemp_ranges:	Battery temperature range structure
91  * @btemp_wq:		Work queue for measuring the temperature periodically
92  * @btemp_periodic_work:	Work for measuring the temperature periodically
93  * @initialized:	True if battery id read.
94  */
95 struct ab8500_btemp {
96 	struct device *dev;
97 	struct list_head node;
98 	int curr_source;
99 	int bat_temp;
100 	int prev_bat_temp;
101 	struct ab8500 *parent;
102 	struct thermal_zone_device *tz;
103 	struct iio_channel *bat_ctrl;
104 	struct ab8500_fg *fg;
105 	struct ab8500_bm_data *bm;
106 	struct power_supply *btemp_psy;
107 	struct ab8500_btemp_events events;
108 	struct ab8500_btemp_ranges btemp_ranges;
109 	struct workqueue_struct *btemp_wq;
110 	struct delayed_work btemp_periodic_work;
111 	bool initialized;
112 };
113 
114 /* BTEMP power supply properties */
115 static enum power_supply_property ab8500_btemp_props[] = {
116 	POWER_SUPPLY_PROP_PRESENT,
117 	POWER_SUPPLY_PROP_ONLINE,
118 	POWER_SUPPLY_PROP_TEMP,
119 };
120 
121 static LIST_HEAD(ab8500_btemp_list);
122 
123 /**
124  * ab8500_btemp_batctrl_volt_to_res() - convert batctrl voltage to resistance
125  * @di:		pointer to the ab8500_btemp structure
126  * @v_batctrl:	measured batctrl voltage
127  * @inst_curr:	measured instant current
128  *
129  * This function returns the battery resistance that is
130  * derived from the BATCTRL voltage.
131  * Returns value in Ohms.
132  */
133 static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
134 	int v_batctrl, int inst_curr)
135 {
136 	if (is_ab8500_1p1_or_earlier(di->parent)) {
137 		/*
138 		 * For ABB cut1.0 and 1.1 BAT_CTRL is internally
139 		 * connected to 1.8V through a 450k resistor
140 		 */
141 		return (450000 * (v_batctrl)) / (1800 - v_batctrl);
142 	}
143 
144 	/*
145 	 * BAT_CTRL is internally
146 	 * connected to 1.8V through a 80k resistor
147 	 */
148 	return (80000 * (v_batctrl)) / (1800 - v_batctrl);
149 }
150 
151 /**
152  * ab8500_btemp_read_batctrl_voltage() - measure batctrl voltage
153  * @di:		pointer to the ab8500_btemp structure
154  *
155  * This function returns the voltage on BATCTRL. Returns value in mV.
156  */
157 static int ab8500_btemp_read_batctrl_voltage(struct ab8500_btemp *di)
158 {
159 	int vbtemp, ret;
160 	static int prev;
161 
162 	ret = iio_read_channel_processed(di->bat_ctrl, &vbtemp);
163 	if (ret < 0) {
164 		dev_err(di->dev,
165 			"%s ADC conversion failed, using previous value",
166 			__func__);
167 		return prev;
168 	}
169 	prev = vbtemp;
170 	return vbtemp;
171 }
172 
173 /**
174  * ab8500_btemp_get_batctrl_res() - get battery resistance
175  * @di:		pointer to the ab8500_btemp structure
176  *
177  * This function returns the battery pack identification resistance.
178  * Returns value in Ohms.
179  */
180 static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di)
181 {
182 	int ret;
183 	int batctrl = 0;
184 	int res;
185 	int inst_curr;
186 	int i;
187 
188 	if (!di->fg)
189 		di->fg = ab8500_fg_get();
190 	if (!di->fg) {
191 		dev_err(di->dev, "No fg found\n");
192 		return -EINVAL;
193 	}
194 
195 	ret = ab8500_fg_inst_curr_start(di->fg);
196 
197 	if (ret) {
198 		dev_err(di->dev, "Failed to start current measurement\n");
199 		return ret;
200 	}
201 
202 	do {
203 		msleep(20);
204 	} while (!ab8500_fg_inst_curr_started(di->fg));
205 
206 	i = 0;
207 
208 	do {
209 		batctrl += ab8500_btemp_read_batctrl_voltage(di);
210 		i++;
211 		msleep(20);
212 	} while (!ab8500_fg_inst_curr_done(di->fg));
213 	batctrl /= i;
214 
215 	ret = ab8500_fg_inst_curr_finalize(di->fg, &inst_curr);
216 	if (ret) {
217 		dev_err(di->dev, "Failed to finalize current measurement\n");
218 		return ret;
219 	}
220 
221 	res = ab8500_btemp_batctrl_volt_to_res(di, batctrl, inst_curr);
222 
223 	dev_dbg(di->dev, "%s batctrl: %d res: %d inst_curr: %d samples: %d\n",
224 		__func__, batctrl, res, inst_curr, i);
225 
226 	return res;
227 }
228 
229 /**
230  * ab8500_btemp_id() - Identify the connected battery
231  * @di:		pointer to the ab8500_btemp structure
232  *
233  * This function will try to identify the battery by reading the ID
234  * resistor. Some brands use a combined ID resistor with a NTC resistor to
235  * both be able to identify and to read the temperature of it.
236  */
237 static int ab8500_btemp_id(struct ab8500_btemp *di)
238 {
239 	struct power_supply_battery_info *bi = di->bm->bi;
240 	int res;
241 
242 	di->curr_source = BTEMP_BATCTRL_CURR_SRC_7UA;
243 
244 	res =  ab8500_btemp_get_batctrl_res(di);
245 	if (res < 0) {
246 		dev_err(di->dev, "%s get batctrl res failed\n", __func__);
247 		return -ENXIO;
248 	}
249 
250 	if (power_supply_battery_bti_in_range(bi, res)) {
251 		dev_info(di->dev, "Battery detected on BATCTRL (pin C3)"
252 			 " resistance %d Ohm = %d Ohm +/- %d%%\n",
253 			 res, bi->bti_resistance_ohm,
254 			 bi->bti_resistance_tolerance);
255 	} else {
256 		dev_warn(di->dev, "Battery identified as unknown"
257 			 ", resistance %d Ohm\n", res);
258 		return -ENXIO;
259 	}
260 
261 	return 0;
262 }
263 
264 /**
265  * ab8500_btemp_periodic_work() - Measuring the temperature periodically
266  * @work:	pointer to the work_struct structure
267  *
268  * Work function for measuring the temperature periodically
269  */
270 static void ab8500_btemp_periodic_work(struct work_struct *work)
271 {
272 	int interval;
273 	int bat_temp;
274 	struct ab8500_btemp *di = container_of(work,
275 		struct ab8500_btemp, btemp_periodic_work.work);
276 	/* Assume 25 degrees celsius as start temperature */
277 	static int prev = 25;
278 	int ret;
279 
280 	if (!di->initialized) {
281 		/* Identify the battery */
282 		if (ab8500_btemp_id(di) < 0)
283 			dev_warn(di->dev, "failed to identify the battery\n");
284 	}
285 
286 	/* Failover if a reading is erroneous, use last meausurement */
287 	ret = thermal_zone_get_temp(di->tz, &bat_temp);
288 	if (ret) {
289 		dev_err(di->dev, "error reading temperature\n");
290 		bat_temp = prev;
291 	} else {
292 		/* Convert from millicentigrades to centigrades */
293 		bat_temp /= 1000;
294 		prev = bat_temp;
295 	}
296 
297 	/*
298 	 * Filter battery temperature.
299 	 * Allow direct updates on temperature only if two samples result in
300 	 * same temperature. Else only allow 1 degree change from previous
301 	 * reported value in the direction of the new measurement.
302 	 */
303 	if ((bat_temp == di->prev_bat_temp) || !di->initialized) {
304 		if ((di->bat_temp != di->prev_bat_temp) || !di->initialized) {
305 			di->initialized = true;
306 			di->bat_temp = bat_temp;
307 			power_supply_changed(di->btemp_psy);
308 		}
309 	} else if (bat_temp < di->prev_bat_temp) {
310 		di->bat_temp--;
311 		power_supply_changed(di->btemp_psy);
312 	} else if (bat_temp > di->prev_bat_temp) {
313 		di->bat_temp++;
314 		power_supply_changed(di->btemp_psy);
315 	}
316 	di->prev_bat_temp = bat_temp;
317 
318 	if (di->events.ac_conn || di->events.usb_conn)
319 		interval = di->bm->temp_interval_chg;
320 	else
321 		interval = di->bm->temp_interval_nochg;
322 
323 	/* Schedule a new measurement */
324 	queue_delayed_work(di->btemp_wq,
325 		&di->btemp_periodic_work,
326 		round_jiffies(interval * HZ));
327 }
328 
329 /**
330  * ab8500_btemp_batctrlindb_handler() - battery removal detected
331  * @irq:       interrupt number
332  * @_di:       void pointer that has to address of ab8500_btemp
333  *
334  * Returns IRQ status(IRQ_HANDLED)
335  */
336 static irqreturn_t ab8500_btemp_batctrlindb_handler(int irq, void *_di)
337 {
338 	struct ab8500_btemp *di = _di;
339 	dev_err(di->dev, "Battery removal detected!\n");
340 
341 	di->events.batt_rem = true;
342 	power_supply_changed(di->btemp_psy);
343 
344 	return IRQ_HANDLED;
345 }
346 
347 /**
348  * ab8500_btemp_templow_handler() - battery temp lower than 10 degrees
349  * @irq:       interrupt number
350  * @_di:       void pointer that has to address of ab8500_btemp
351  *
352  * Returns IRQ status(IRQ_HANDLED)
353  */
354 static irqreturn_t ab8500_btemp_templow_handler(int irq, void *_di)
355 {
356 	struct ab8500_btemp *di = _di;
357 
358 	if (is_ab8500_3p3_or_earlier(di->parent)) {
359 		dev_dbg(di->dev, "Ignore false btemp low irq"
360 			" for ABB cut 1.0, 1.1, 2.0 and 3.3\n");
361 	} else {
362 		dev_crit(di->dev, "Battery temperature lower than -10deg c\n");
363 
364 		di->events.btemp_low = true;
365 		di->events.btemp_high = false;
366 		di->events.btemp_medhigh = false;
367 		di->events.btemp_lowmed = false;
368 		power_supply_changed(di->btemp_psy);
369 	}
370 
371 	return IRQ_HANDLED;
372 }
373 
374 /**
375  * ab8500_btemp_temphigh_handler() - battery temp higher than max temp
376  * @irq:       interrupt number
377  * @_di:       void pointer that has to address of ab8500_btemp
378  *
379  * Returns IRQ status(IRQ_HANDLED)
380  */
381 static irqreturn_t ab8500_btemp_temphigh_handler(int irq, void *_di)
382 {
383 	struct ab8500_btemp *di = _di;
384 
385 	dev_crit(di->dev, "Battery temperature is higher than MAX temp\n");
386 
387 	di->events.btemp_high = true;
388 	di->events.btemp_medhigh = false;
389 	di->events.btemp_lowmed = false;
390 	di->events.btemp_low = false;
391 	power_supply_changed(di->btemp_psy);
392 
393 	return IRQ_HANDLED;
394 }
395 
396 /**
397  * ab8500_btemp_lowmed_handler() - battery temp between low and medium
398  * @irq:       interrupt number
399  * @_di:       void pointer that has to address of ab8500_btemp
400  *
401  * Returns IRQ status(IRQ_HANDLED)
402  */
403 static irqreturn_t ab8500_btemp_lowmed_handler(int irq, void *_di)
404 {
405 	struct ab8500_btemp *di = _di;
406 
407 	dev_dbg(di->dev, "Battery temperature is between low and medium\n");
408 
409 	di->events.btemp_lowmed = true;
410 	di->events.btemp_medhigh = false;
411 	di->events.btemp_high = false;
412 	di->events.btemp_low = false;
413 	power_supply_changed(di->btemp_psy);
414 
415 	return IRQ_HANDLED;
416 }
417 
418 /**
419  * ab8500_btemp_medhigh_handler() - battery temp between medium and high
420  * @irq:       interrupt number
421  * @_di:       void pointer that has to address of ab8500_btemp
422  *
423  * Returns IRQ status(IRQ_HANDLED)
424  */
425 static irqreturn_t ab8500_btemp_medhigh_handler(int irq, void *_di)
426 {
427 	struct ab8500_btemp *di = _di;
428 
429 	dev_dbg(di->dev, "Battery temperature is between medium and high\n");
430 
431 	di->events.btemp_medhigh = true;
432 	di->events.btemp_lowmed = false;
433 	di->events.btemp_high = false;
434 	di->events.btemp_low = false;
435 	power_supply_changed(di->btemp_psy);
436 
437 	return IRQ_HANDLED;
438 }
439 
440 /**
441  * ab8500_btemp_periodic() - Periodic temperature measurements
442  * @di:		pointer to the ab8500_btemp structure
443  * @enable:	enable or disable periodic temperature measurements
444  *
445  * Starts of stops periodic temperature measurements. Periodic measurements
446  * should only be done when a charger is connected.
447  */
448 static void ab8500_btemp_periodic(struct ab8500_btemp *di,
449 	bool enable)
450 {
451 	dev_dbg(di->dev, "Enable periodic temperature measurements: %d\n",
452 		enable);
453 	/*
454 	 * Make sure a new measurement is done directly by cancelling
455 	 * any pending work
456 	 */
457 	cancel_delayed_work_sync(&di->btemp_periodic_work);
458 
459 	if (enable)
460 		queue_delayed_work(di->btemp_wq, &di->btemp_periodic_work, 0);
461 }
462 
463 /**
464  * ab8500_btemp_get_temp() - get battery temperature
465  * @di:		pointer to the ab8500_btemp structure
466  *
467  * Returns battery temperature
468  */
469 static int ab8500_btemp_get_temp(struct ab8500_btemp *di)
470 {
471 	int temp = 0;
472 
473 	/*
474 	 * The BTEMP events are not reliabe on AB8500 cut3.3
475 	 * and prior versions
476 	 */
477 	if (is_ab8500_3p3_or_earlier(di->parent)) {
478 		temp = di->bat_temp * 10;
479 	} else {
480 		if (di->events.btemp_low) {
481 			if (temp > di->btemp_ranges.btemp_low_limit)
482 				temp = di->btemp_ranges.btemp_low_limit * 10;
483 			else
484 				temp = di->bat_temp * 10;
485 		} else if (di->events.btemp_high) {
486 			if (temp < di->btemp_ranges.btemp_high_limit)
487 				temp = di->btemp_ranges.btemp_high_limit * 10;
488 			else
489 				temp = di->bat_temp * 10;
490 		} else if (di->events.btemp_lowmed) {
491 			if (temp > di->btemp_ranges.btemp_med_limit)
492 				temp = di->btemp_ranges.btemp_med_limit * 10;
493 			else
494 				temp = di->bat_temp * 10;
495 		} else if (di->events.btemp_medhigh) {
496 			if (temp < di->btemp_ranges.btemp_med_limit)
497 				temp = di->btemp_ranges.btemp_med_limit * 10;
498 			else
499 				temp = di->bat_temp * 10;
500 		} else
501 			temp = di->bat_temp * 10;
502 	}
503 	return temp;
504 }
505 
506 /**
507  * ab8500_btemp_get_property() - get the btemp properties
508  * @psy:        pointer to the power_supply structure
509  * @psp:        pointer to the power_supply_property structure
510  * @val:        pointer to the power_supply_propval union
511  *
512  * This function gets called when an application tries to get the btemp
513  * properties by reading the sysfs files.
514  * online:	presence of the battery
515  * present:	presence of the battery
516  * technology:	battery technology
517  * temp:	battery temperature
518  * Returns error code in case of failure else 0(on success)
519  */
520 static int ab8500_btemp_get_property(struct power_supply *psy,
521 	enum power_supply_property psp,
522 	union power_supply_propval *val)
523 {
524 	struct ab8500_btemp *di = power_supply_get_drvdata(psy);
525 
526 	switch (psp) {
527 	case POWER_SUPPLY_PROP_PRESENT:
528 	case POWER_SUPPLY_PROP_ONLINE:
529 		if (di->events.batt_rem)
530 			val->intval = 0;
531 		else
532 			val->intval = 1;
533 		break;
534 	case POWER_SUPPLY_PROP_TEMP:
535 		val->intval = ab8500_btemp_get_temp(di);
536 		break;
537 	default:
538 		return -EINVAL;
539 	}
540 	return 0;
541 }
542 
543 static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data)
544 {
545 	struct power_supply *psy;
546 	struct power_supply *ext = dev_get_drvdata(dev);
547 	const char **supplicants = (const char **)ext->supplied_to;
548 	struct ab8500_btemp *di;
549 	union power_supply_propval ret;
550 	int j;
551 
552 	psy = (struct power_supply *)data;
553 	di = power_supply_get_drvdata(psy);
554 
555 	/*
556 	 * For all psy where the name of your driver
557 	 * appears in any supplied_to
558 	 */
559 	j = match_string(supplicants, ext->num_supplicants, psy->desc->name);
560 	if (j < 0)
561 		return 0;
562 
563 	/* Go through all properties for the psy */
564 	for (j = 0; j < ext->desc->num_properties; j++) {
565 		enum power_supply_property prop;
566 		prop = ext->desc->properties[j];
567 
568 		if (power_supply_get_property(ext, prop, &ret))
569 			continue;
570 
571 		switch (prop) {
572 		case POWER_SUPPLY_PROP_PRESENT:
573 			switch (ext->desc->type) {
574 			case POWER_SUPPLY_TYPE_MAINS:
575 				/* AC disconnected */
576 				if (!ret.intval && di->events.ac_conn) {
577 					di->events.ac_conn = false;
578 				}
579 				/* AC connected */
580 				else if (ret.intval && !di->events.ac_conn) {
581 					di->events.ac_conn = true;
582 					if (!di->events.usb_conn)
583 						ab8500_btemp_periodic(di, true);
584 				}
585 				break;
586 			case POWER_SUPPLY_TYPE_USB:
587 				/* USB disconnected */
588 				if (!ret.intval && di->events.usb_conn) {
589 					di->events.usb_conn = false;
590 				}
591 				/* USB connected */
592 				else if (ret.intval && !di->events.usb_conn) {
593 					di->events.usb_conn = true;
594 					if (!di->events.ac_conn)
595 						ab8500_btemp_periodic(di, true);
596 				}
597 				break;
598 			default:
599 				break;
600 			}
601 			break;
602 		default:
603 			break;
604 		}
605 	}
606 	return 0;
607 }
608 
609 /**
610  * ab8500_btemp_external_power_changed() - callback for power supply changes
611  * @psy:       pointer to the structure power_supply
612  *
613  * This function is pointing to the function pointer external_power_changed
614  * of the structure power_supply.
615  * This function gets executed when there is a change in the external power
616  * supply to the btemp.
617  */
618 static void ab8500_btemp_external_power_changed(struct power_supply *psy)
619 {
620 	class_for_each_device(power_supply_class, NULL, psy,
621 			      ab8500_btemp_get_ext_psy_data);
622 }
623 
624 /* ab8500 btemp driver interrupts and their respective isr */
625 static struct ab8500_btemp_interrupts ab8500_btemp_irq[] = {
626 	{"BAT_CTRL_INDB", ab8500_btemp_batctrlindb_handler},
627 	{"BTEMP_LOW", ab8500_btemp_templow_handler},
628 	{"BTEMP_HIGH", ab8500_btemp_temphigh_handler},
629 	{"BTEMP_LOW_MEDIUM", ab8500_btemp_lowmed_handler},
630 	{"BTEMP_MEDIUM_HIGH", ab8500_btemp_medhigh_handler},
631 };
632 
633 static int __maybe_unused ab8500_btemp_resume(struct device *dev)
634 {
635 	struct ab8500_btemp *di = dev_get_drvdata(dev);
636 
637 	ab8500_btemp_periodic(di, true);
638 
639 	return 0;
640 }
641 
642 static int __maybe_unused ab8500_btemp_suspend(struct device *dev)
643 {
644 	struct ab8500_btemp *di = dev_get_drvdata(dev);
645 
646 	ab8500_btemp_periodic(di, false);
647 
648 	return 0;
649 }
650 
651 static char *supply_interface[] = {
652 	"ab8500_chargalg",
653 	"ab8500_fg",
654 };
655 
656 static const struct power_supply_desc ab8500_btemp_desc = {
657 	.name			= "ab8500_btemp",
658 	.type			= POWER_SUPPLY_TYPE_UNKNOWN,
659 	.properties		= ab8500_btemp_props,
660 	.num_properties		= ARRAY_SIZE(ab8500_btemp_props),
661 	.get_property		= ab8500_btemp_get_property,
662 	.external_power_changed	= ab8500_btemp_external_power_changed,
663 };
664 
665 static int ab8500_btemp_bind(struct device *dev, struct device *master,
666 			     void *data)
667 {
668 	struct ab8500_btemp *di = dev_get_drvdata(dev);
669 
670 	/* Create a work queue for the btemp */
671 	di->btemp_wq =
672 		alloc_workqueue("ab8500_btemp_wq", WQ_MEM_RECLAIM, 0);
673 	if (di->btemp_wq == NULL) {
674 		dev_err(dev, "failed to create work queue\n");
675 		return -ENOMEM;
676 	}
677 
678 	/* Kick off periodic temperature measurements */
679 	ab8500_btemp_periodic(di, true);
680 
681 	return 0;
682 }
683 
684 static void ab8500_btemp_unbind(struct device *dev, struct device *master,
685 				void *data)
686 {
687 	struct ab8500_btemp *di = dev_get_drvdata(dev);
688 
689 	/* Delete the work queue */
690 	destroy_workqueue(di->btemp_wq);
691 }
692 
693 static const struct component_ops ab8500_btemp_component_ops = {
694 	.bind = ab8500_btemp_bind,
695 	.unbind = ab8500_btemp_unbind,
696 };
697 
698 static int ab8500_btemp_probe(struct platform_device *pdev)
699 {
700 	struct power_supply_config psy_cfg = {};
701 	struct device *dev = &pdev->dev;
702 	struct ab8500_btemp *di;
703 	int irq, i, ret = 0;
704 	u8 val;
705 
706 	di = devm_kzalloc(dev, sizeof(*di), GFP_KERNEL);
707 	if (!di)
708 		return -ENOMEM;
709 
710 	di->bm = &ab8500_bm_data;
711 
712 	/* get parent data */
713 	di->dev = dev;
714 	di->parent = dev_get_drvdata(pdev->dev.parent);
715 
716 	/* Get thermal zone and ADC */
717 	di->tz = thermal_zone_get_zone_by_name("battery-thermal");
718 	if (IS_ERR(di->tz)) {
719 		ret = PTR_ERR(di->tz);
720 		/*
721 		 * This usually just means we are probing before the thermal
722 		 * zone, so just defer.
723 		 */
724 		if (ret == -ENODEV)
725 			ret = -EPROBE_DEFER;
726 		return dev_err_probe(dev, ret,
727 				     "failed to get battery thermal zone\n");
728 	}
729 	di->bat_ctrl = devm_iio_channel_get(dev, "bat_ctrl");
730 	if (IS_ERR(di->bat_ctrl)) {
731 		ret = dev_err_probe(dev, PTR_ERR(di->bat_ctrl),
732 				    "failed to get BAT CTRL ADC channel\n");
733 		return ret;
734 	}
735 
736 	di->initialized = false;
737 
738 	psy_cfg.supplied_to = supply_interface;
739 	psy_cfg.num_supplicants = ARRAY_SIZE(supply_interface);
740 	psy_cfg.drv_data = di;
741 
742 	/* Init work for measuring temperature periodically */
743 	INIT_DEFERRABLE_WORK(&di->btemp_periodic_work,
744 		ab8500_btemp_periodic_work);
745 
746 	/* Set BTEMP thermal limits. Low and Med are fixed */
747 	di->btemp_ranges.btemp_low_limit = BTEMP_THERMAL_LOW_LIMIT;
748 	di->btemp_ranges.btemp_med_limit = BTEMP_THERMAL_MED_LIMIT;
749 
750 	ret = abx500_get_register_interruptible(dev, AB8500_CHARGER,
751 		AB8500_BTEMP_HIGH_TH, &val);
752 	if (ret < 0) {
753 		dev_err(dev, "%s ab8500 read failed\n", __func__);
754 		return ret;
755 	}
756 	switch (val) {
757 	case BTEMP_HIGH_TH_57_0:
758 	case BTEMP_HIGH_TH_57_1:
759 		di->btemp_ranges.btemp_high_limit =
760 			BTEMP_THERMAL_HIGH_LIMIT_57;
761 		break;
762 	case BTEMP_HIGH_TH_52:
763 		di->btemp_ranges.btemp_high_limit =
764 			BTEMP_THERMAL_HIGH_LIMIT_52;
765 		break;
766 	case BTEMP_HIGH_TH_62:
767 		di->btemp_ranges.btemp_high_limit =
768 			BTEMP_THERMAL_HIGH_LIMIT_62;
769 		break;
770 	}
771 
772 	/* Register BTEMP power supply class */
773 	di->btemp_psy = devm_power_supply_register(dev, &ab8500_btemp_desc,
774 						   &psy_cfg);
775 	if (IS_ERR(di->btemp_psy)) {
776 		dev_err(dev, "failed to register BTEMP psy\n");
777 		return PTR_ERR(di->btemp_psy);
778 	}
779 
780 	/* Register interrupts */
781 	for (i = 0; i < ARRAY_SIZE(ab8500_btemp_irq); i++) {
782 		irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
783 		if (irq < 0)
784 			return irq;
785 
786 		ret = devm_request_threaded_irq(dev, irq, NULL,
787 			ab8500_btemp_irq[i].isr,
788 			IRQF_SHARED | IRQF_NO_SUSPEND | IRQF_ONESHOT,
789 			ab8500_btemp_irq[i].name, di);
790 
791 		if (ret) {
792 			dev_err(dev, "failed to request %s IRQ %d: %d\n"
793 				, ab8500_btemp_irq[i].name, irq, ret);
794 			return ret;
795 		}
796 		dev_dbg(dev, "Requested %s IRQ %d: %d\n",
797 			ab8500_btemp_irq[i].name, irq, ret);
798 	}
799 
800 	platform_set_drvdata(pdev, di);
801 
802 	list_add_tail(&di->node, &ab8500_btemp_list);
803 
804 	return component_add(dev, &ab8500_btemp_component_ops);
805 }
806 
807 static void ab8500_btemp_remove(struct platform_device *pdev)
808 {
809 	component_del(&pdev->dev, &ab8500_btemp_component_ops);
810 }
811 
812 static SIMPLE_DEV_PM_OPS(ab8500_btemp_pm_ops, ab8500_btemp_suspend, ab8500_btemp_resume);
813 
814 static const struct of_device_id ab8500_btemp_match[] = {
815 	{ .compatible = "stericsson,ab8500-btemp", },
816 	{ },
817 };
818 MODULE_DEVICE_TABLE(of, ab8500_btemp_match);
819 
820 struct platform_driver ab8500_btemp_driver = {
821 	.probe = ab8500_btemp_probe,
822 	.remove_new = ab8500_btemp_remove,
823 	.driver = {
824 		.name = "ab8500-btemp",
825 		.of_match_table = ab8500_btemp_match,
826 		.pm = &ab8500_btemp_pm_ops,
827 	},
828 };
829 MODULE_LICENSE("GPL v2");
830 MODULE_AUTHOR("Johan Palsson, Karl Komierowski, Arun R Murthy");
831 MODULE_ALIAS("platform:ab8500-btemp");
832 MODULE_DESCRIPTION("AB8500 battery temperature driver");
833