1/*
2 * Copyright (C) ST-Ericsson SA 2012
3 *
4 * Battery temperature driver for AB8500
5 *
6 * License Terms: GNU General Public License v2
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/interrupt.h>
17#include <linux/delay.h>
18#include <linux/slab.h>
19#include <linux/platform_device.h>
20#include <linux/power_supply.h>
21#include <linux/completion.h>
22#include <linux/workqueue.h>
23#include <linux/jiffies.h>
24#include <linux/of.h>
25#include <linux/mfd/core.h>
26#include <linux/mfd/abx500.h>
27#include <linux/mfd/abx500/ab8500.h>
28#include <linux/mfd/abx500/ab8500-bm.h>
29#include <linux/mfd/abx500/ab8500-gpadc.h>
30
31#define VTVOUT_V			1800
32
33#define BTEMP_THERMAL_LOW_LIMIT		-10
34#define BTEMP_THERMAL_MED_LIMIT		0
35#define BTEMP_THERMAL_HIGH_LIMIT_52	52
36#define BTEMP_THERMAL_HIGH_LIMIT_57	57
37#define BTEMP_THERMAL_HIGH_LIMIT_62	62
38
39#define BTEMP_BATCTRL_CURR_SRC_7UA	7
40#define BTEMP_BATCTRL_CURR_SRC_20UA	20
41
42#define BTEMP_BATCTRL_CURR_SRC_16UA	16
43#define BTEMP_BATCTRL_CURR_SRC_18UA	18
44
45#define BTEMP_BATCTRL_CURR_SRC_60UA	60
46#define BTEMP_BATCTRL_CURR_SRC_120UA	120
47
48/**
49 * struct ab8500_btemp_interrupts - ab8500 interrupts
50 * @name:	name of the interrupt
51 * @isr		function pointer to the isr
52 */
53struct ab8500_btemp_interrupts {
54	char *name;
55	irqreturn_t (*isr)(int irq, void *data);
56};
57
58struct ab8500_btemp_events {
59	bool batt_rem;
60	bool btemp_high;
61	bool btemp_medhigh;
62	bool btemp_lowmed;
63	bool btemp_low;
64	bool ac_conn;
65	bool usb_conn;
66};
67
68struct ab8500_btemp_ranges {
69	int btemp_high_limit;
70	int btemp_med_limit;
71	int btemp_low_limit;
72};
73
74/**
75 * struct ab8500_btemp - ab8500 BTEMP device information
76 * @dev:		Pointer to the structure device
77 * @node:		List of AB8500 BTEMPs, hence prepared for reentrance
78 * @curr_source:	What current source we use, in uA
79 * @bat_temp:		Dispatched battery temperature in degree Celcius
80 * @prev_bat_temp	Last measured battery temperature in degree Celcius
81 * @parent:		Pointer to the struct ab8500
82 * @gpadc:		Pointer to the struct gpadc
83 * @fg:			Pointer to the struct fg
84 * @bm:           	Platform specific battery management information
85 * @btemp_psy:		Structure for BTEMP specific battery properties
86 * @events:		Structure for information about events triggered
87 * @btemp_ranges:	Battery temperature range structure
88 * @btemp_wq:		Work queue for measuring the temperature periodically
89 * @btemp_periodic_work:	Work for measuring the temperature periodically
90 * @initialized:	True if battery id read.
91 */
92struct ab8500_btemp {
93	struct device *dev;
94	struct list_head node;
95	int curr_source;
96	int bat_temp;
97	int prev_bat_temp;
98	struct ab8500 *parent;
99	struct ab8500_gpadc *gpadc;
100	struct ab8500_fg *fg;
101	struct abx500_bm_data *bm;
102	struct power_supply *btemp_psy;
103	struct ab8500_btemp_events events;
104	struct ab8500_btemp_ranges btemp_ranges;
105	struct workqueue_struct *btemp_wq;
106	struct delayed_work btemp_periodic_work;
107	bool initialized;
108};
109
110/* BTEMP power supply properties */
111static enum power_supply_property ab8500_btemp_props[] = {
112	POWER_SUPPLY_PROP_PRESENT,
113	POWER_SUPPLY_PROP_ONLINE,
114	POWER_SUPPLY_PROP_TECHNOLOGY,
115	POWER_SUPPLY_PROP_TEMP,
116};
117
118static LIST_HEAD(ab8500_btemp_list);
119
120/**
121 * ab8500_btemp_get() - returns a reference to the primary AB8500 BTEMP
122 * (i.e. the first BTEMP in the instance list)
123 */
124struct ab8500_btemp *ab8500_btemp_get(void)
125{
126	struct ab8500_btemp *btemp;
127	btemp = list_first_entry(&ab8500_btemp_list, struct ab8500_btemp, node);
128
129	return btemp;
130}
131EXPORT_SYMBOL(ab8500_btemp_get);
132
133/**
134 * ab8500_btemp_batctrl_volt_to_res() - convert batctrl voltage to resistance
135 * @di:		pointer to the ab8500_btemp structure
136 * @v_batctrl:	measured batctrl voltage
137 * @inst_curr:	measured instant current
138 *
139 * This function returns the battery resistance that is
140 * derived from the BATCTRL voltage.
141 * Returns value in Ohms.
142 */
143static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
144	int v_batctrl, int inst_curr)
145{
146	int rbs;
147
148	if (is_ab8500_1p1_or_earlier(di->parent)) {
149		/*
150		 * For ABB cut1.0 and 1.1 BAT_CTRL is internally
151		 * connected to 1.8V through a 450k resistor
152		 */
153		return (450000 * (v_batctrl)) / (1800 - v_batctrl);
154	}
155
156	if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL) {
157		/*
158		 * If the battery has internal NTC, we use the current
159		 * source to calculate the resistance.
160		 */
161		rbs = (v_batctrl * 1000
162		       - di->bm->gnd_lift_resistance * inst_curr)
163		      / di->curr_source;
164	} else {
165		/*
166		 * BAT_CTRL is internally
167		 * connected to 1.8V through a 80k resistor
168		 */
169		rbs = (80000 * (v_batctrl)) / (1800 - v_batctrl);
170	}
171
172	return rbs;
173}
174
175/**
176 * ab8500_btemp_read_batctrl_voltage() - measure batctrl voltage
177 * @di:		pointer to the ab8500_btemp structure
178 *
179 * This function returns the voltage on BATCTRL. Returns value in mV.
180 */
181static int ab8500_btemp_read_batctrl_voltage(struct ab8500_btemp *di)
182{
183	int vbtemp;
184	static int prev;
185
186	vbtemp = ab8500_gpadc_convert(di->gpadc, BAT_CTRL);
187	if (vbtemp < 0) {
188		dev_err(di->dev,
189			"%s gpadc conversion failed, using previous value",
190			__func__);
191		return prev;
192	}
193	prev = vbtemp;
194	return vbtemp;
195}
196
197/**
198 * ab8500_btemp_curr_source_enable() - enable/disable batctrl current source
199 * @di:		pointer to the ab8500_btemp structure
200 * @enable:	enable or disable the current source
201 *
202 * Enable or disable the current sources for the BatCtrl AD channel
203 */
204static int ab8500_btemp_curr_source_enable(struct ab8500_btemp *di,
205	bool enable)
206{
207	int curr;
208	int ret = 0;
209
210	/*
211	 * BATCTRL current sources are included on AB8500 cut2.0
212	 * and future versions
213	 */
214	if (is_ab8500_1p1_or_earlier(di->parent))
215		return 0;
216
217	/* Only do this for batteries with internal NTC */
218	if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL && enable) {
219
220		if (is_ab8540(di->parent)) {
221			if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_60UA)
222				curr = BAT_CTRL_60U_ENA;
223			else
224				curr = BAT_CTRL_120U_ENA;
225		} else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
226			if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_16UA)
227				curr = BAT_CTRL_16U_ENA;
228			else
229				curr = BAT_CTRL_18U_ENA;
230		} else {
231			if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_7UA)
232				curr = BAT_CTRL_7U_ENA;
233			else
234				curr = BAT_CTRL_20U_ENA;
235		}
236
237		dev_dbg(di->dev, "Set BATCTRL %duA\n", di->curr_source);
238
239		ret = abx500_mask_and_set_register_interruptible(di->dev,
240			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
241			FORCE_BAT_CTRL_CMP_HIGH, FORCE_BAT_CTRL_CMP_HIGH);
242		if (ret) {
243			dev_err(di->dev, "%s failed setting cmp_force\n",
244				__func__);
245			return ret;
246		}
247
248		/*
249		 * We have to wait one 32kHz cycle before enabling
250		 * the current source, since ForceBatCtrlCmpHigh needs
251		 * to be written in a separate cycle
252		 */
253		udelay(32);
254
255		ret = abx500_set_register_interruptible(di->dev,
256			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
257			FORCE_BAT_CTRL_CMP_HIGH | curr);
258		if (ret) {
259			dev_err(di->dev, "%s failed enabling current source\n",
260				__func__);
261			goto disable_curr_source;
262		}
263	} else if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL && !enable) {
264		dev_dbg(di->dev, "Disable BATCTRL curr source\n");
265
266		if (is_ab8540(di->parent)) {
267			/* Write 0 to the curr bits */
268			ret = abx500_mask_and_set_register_interruptible(
269				di->dev,
270				AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
271				BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA,
272				~(BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA));
273		} else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
274			/* Write 0 to the curr bits */
275			ret = abx500_mask_and_set_register_interruptible(
276				di->dev,
277				AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
278				BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA,
279				~(BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA));
280		} else {
281			/* Write 0 to the curr bits */
282			ret = abx500_mask_and_set_register_interruptible(
283				di->dev,
284				AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
285				BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
286				~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
287		}
288
289		if (ret) {
290			dev_err(di->dev, "%s failed disabling current source\n",
291				__func__);
292			goto disable_curr_source;
293		}
294
295		/* Enable Pull-Up and comparator */
296		ret = abx500_mask_and_set_register_interruptible(di->dev,
297			AB8500_CHARGER,	AB8500_BAT_CTRL_CURRENT_SOURCE,
298			BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
299			BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
300		if (ret) {
301			dev_err(di->dev, "%s failed enabling PU and comp\n",
302				__func__);
303			goto enable_pu_comp;
304		}
305
306		/*
307		 * We have to wait one 32kHz cycle before disabling
308		 * ForceBatCtrlCmpHigh since this needs to be written
309		 * in a separate cycle
310		 */
311		udelay(32);
312
313		/* Disable 'force comparator' */
314		ret = abx500_mask_and_set_register_interruptible(di->dev,
315			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
316			FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
317		if (ret) {
318			dev_err(di->dev, "%s failed disabling force comp\n",
319				__func__);
320			goto disable_force_comp;
321		}
322	}
323	return ret;
324
325	/*
326	 * We have to try unsetting FORCE_BAT_CTRL_CMP_HIGH one more time
327	 * if we got an error above
328	 */
329disable_curr_source:
330	if (is_ab8540(di->parent)) {
331		/* Write 0 to the curr bits */
332		ret = abx500_mask_and_set_register_interruptible(di->dev,
333			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
334			BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA,
335			~(BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA));
336	} else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
337		/* Write 0 to the curr bits */
338		ret = abx500_mask_and_set_register_interruptible(di->dev,
339			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
340			BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA,
341			~(BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA));
342	} else {
343		/* Write 0 to the curr bits */
344		ret = abx500_mask_and_set_register_interruptible(di->dev,
345			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
346			BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
347			~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
348	}
349
350	if (ret) {
351		dev_err(di->dev, "%s failed disabling current source\n",
352			__func__);
353		return ret;
354	}
355enable_pu_comp:
356	/* Enable Pull-Up and comparator */
357	ret = abx500_mask_and_set_register_interruptible(di->dev,
358		AB8500_CHARGER,	AB8500_BAT_CTRL_CURRENT_SOURCE,
359		BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
360		BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
361	if (ret) {
362		dev_err(di->dev, "%s failed enabling PU and comp\n",
363			__func__);
364		return ret;
365	}
366
367disable_force_comp:
368	/*
369	 * We have to wait one 32kHz cycle before disabling
370	 * ForceBatCtrlCmpHigh since this needs to be written
371	 * in a separate cycle
372	 */
373	udelay(32);
374
375	/* Disable 'force comparator' */
376	ret = abx500_mask_and_set_register_interruptible(di->dev,
377		AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
378		FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
379	if (ret) {
380		dev_err(di->dev, "%s failed disabling force comp\n",
381			__func__);
382		return ret;
383	}
384
385	return ret;
386}
387
388/**
389 * ab8500_btemp_get_batctrl_res() - get battery resistance
390 * @di:		pointer to the ab8500_btemp structure
391 *
392 * This function returns the battery pack identification resistance.
393 * Returns value in Ohms.
394 */
395static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di)
396{
397	int ret;
398	int batctrl = 0;
399	int res;
400	int inst_curr;
401	int i;
402
403	/*
404	 * BATCTRL current sources are included on AB8500 cut2.0
405	 * and future versions
406	 */
407	ret = ab8500_btemp_curr_source_enable(di, true);
408	if (ret) {
409		dev_err(di->dev, "%s curr source enabled failed\n", __func__);
410		return ret;
411	}
412
413	if (!di->fg)
414		di->fg = ab8500_fg_get();
415	if (!di->fg) {
416		dev_err(di->dev, "No fg found\n");
417		return -EINVAL;
418	}
419
420	ret = ab8500_fg_inst_curr_start(di->fg);
421
422	if (ret) {
423		dev_err(di->dev, "Failed to start current measurement\n");
424		return ret;
425	}
426
427	do {
428		msleep(20);
429	} while (!ab8500_fg_inst_curr_started(di->fg));
430
431	i = 0;
432
433	do {
434		batctrl += ab8500_btemp_read_batctrl_voltage(di);
435		i++;
436		msleep(20);
437	} while (!ab8500_fg_inst_curr_done(di->fg));
438	batctrl /= i;
439
440	ret = ab8500_fg_inst_curr_finalize(di->fg, &inst_curr);
441	if (ret) {
442		dev_err(di->dev, "Failed to finalize current measurement\n");
443		return ret;
444	}
445
446	res = ab8500_btemp_batctrl_volt_to_res(di, batctrl, inst_curr);
447
448	ret = ab8500_btemp_curr_source_enable(di, false);
449	if (ret) {
450		dev_err(di->dev, "%s curr source disable failed\n", __func__);
451		return ret;
452	}
453
454	dev_dbg(di->dev, "%s batctrl: %d res: %d inst_curr: %d samples: %d\n",
455		__func__, batctrl, res, inst_curr, i);
456
457	return res;
458}
459
460/**
461 * ab8500_btemp_res_to_temp() - resistance to temperature
462 * @di:		pointer to the ab8500_btemp structure
463 * @tbl:	pointer to the resiatance to temperature table
464 * @tbl_size:	size of the resistance to temperature table
465 * @res:	resistance to calculate the temperature from
466 *
467 * This function returns the battery temperature in degrees Celcius
468 * based on the NTC resistance.
469 */
470static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di,
471	const struct abx500_res_to_temp *tbl, int tbl_size, int res)
472{
473	int i, temp;
474	/*
475	 * Calculate the formula for the straight line
476	 * Simple interpolation if we are within
477	 * the resistance table limits, extrapolate
478	 * if resistance is outside the limits.
479	 */
480	if (res > tbl[0].resist)
481		i = 0;
482	else if (res <= tbl[tbl_size - 1].resist)
483		i = tbl_size - 2;
484	else {
485		i = 0;
486		while (!(res <= tbl[i].resist &&
487			res > tbl[i + 1].resist))
488			i++;
489	}
490
491	temp = tbl[i].temp + ((tbl[i + 1].temp - tbl[i].temp) *
492		(res - tbl[i].resist)) / (tbl[i + 1].resist - tbl[i].resist);
493	return temp;
494}
495
496/**
497 * ab8500_btemp_measure_temp() - measure battery temperature
498 * @di:		pointer to the ab8500_btemp structure
499 *
500 * Returns battery temperature (on success) else the previous temperature
501 */
502static int ab8500_btemp_measure_temp(struct ab8500_btemp *di)
503{
504	int temp;
505	static int prev;
506	int rbat, rntc, vntc;
507	u8 id;
508
509	id = di->bm->batt_id;
510
511	if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL &&
512			id != BATTERY_UNKNOWN) {
513
514		rbat = ab8500_btemp_get_batctrl_res(di);
515		if (rbat < 0) {
516			dev_err(di->dev, "%s get batctrl res failed\n",
517				__func__);
518			/*
519			 * Return out-of-range temperature so that
520			 * charging is stopped
521			 */
522			return BTEMP_THERMAL_LOW_LIMIT;
523		}
524
525		temp = ab8500_btemp_res_to_temp(di,
526			di->bm->bat_type[id].r_to_t_tbl,
527			di->bm->bat_type[id].n_temp_tbl_elements, rbat);
528	} else {
529		vntc = ab8500_gpadc_convert(di->gpadc, BTEMP_BALL);
530		if (vntc < 0) {
531			dev_err(di->dev,
532				"%s gpadc conversion failed,"
533				" using previous value\n", __func__);
534			return prev;
535		}
536		/*
537		 * The PCB NTC is sourced from VTVOUT via a 230kOhm
538		 * resistor.
539		 */
540		rntc = 230000 * vntc / (VTVOUT_V - vntc);
541
542		temp = ab8500_btemp_res_to_temp(di,
543			di->bm->bat_type[id].r_to_t_tbl,
544			di->bm->bat_type[id].n_temp_tbl_elements, rntc);
545		prev = temp;
546	}
547	dev_dbg(di->dev, "Battery temperature is %d\n", temp);
548	return temp;
549}
550
551/**
552 * ab8500_btemp_id() - Identify the connected battery
553 * @di:		pointer to the ab8500_btemp structure
554 *
555 * This function will try to identify the battery by reading the ID
556 * resistor. Some brands use a combined ID resistor with a NTC resistor to
557 * both be able to identify and to read the temperature of it.
558 */
559static int ab8500_btemp_id(struct ab8500_btemp *di)
560{
561	int res;
562	u8 i;
563	if (is_ab8540(di->parent))
564		di->curr_source = BTEMP_BATCTRL_CURR_SRC_60UA;
565	else if (is_ab9540(di->parent) || is_ab8505(di->parent))
566		di->curr_source = BTEMP_BATCTRL_CURR_SRC_16UA;
567	else
568		di->curr_source = BTEMP_BATCTRL_CURR_SRC_7UA;
569
570	di->bm->batt_id = BATTERY_UNKNOWN;
571
572	res =  ab8500_btemp_get_batctrl_res(di);
573	if (res < 0) {
574		dev_err(di->dev, "%s get batctrl res failed\n", __func__);
575		return -ENXIO;
576	}
577
578	/* BATTERY_UNKNOWN is defined on position 0, skip it! */
579	for (i = BATTERY_UNKNOWN + 1; i < di->bm->n_btypes; i++) {
580		if ((res <= di->bm->bat_type[i].resis_high) &&
581			(res >= di->bm->bat_type[i].resis_low)) {
582			dev_dbg(di->dev, "Battery detected on %s"
583				" low %d < res %d < high: %d"
584				" index: %d\n",
585				di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL ?
586				"BATCTRL" : "BATTEMP",
587				di->bm->bat_type[i].resis_low, res,
588				di->bm->bat_type[i].resis_high, i);
589
590			di->bm->batt_id = i;
591			break;
592		}
593	}
594
595	if (di->bm->batt_id == BATTERY_UNKNOWN) {
596		dev_warn(di->dev, "Battery identified as unknown"
597			", resistance %d Ohm\n", res);
598		return -ENXIO;
599	}
600
601	/*
602	 * We only have to change current source if the
603	 * detected type is Type 1.
604	 */
605	if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL &&
606	    di->bm->batt_id == 1) {
607		if (is_ab8540(di->parent)) {
608			dev_dbg(di->dev,
609				"Set BATCTRL current source to 60uA\n");
610			di->curr_source = BTEMP_BATCTRL_CURR_SRC_60UA;
611		} else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
612			dev_dbg(di->dev,
613				"Set BATCTRL current source to 16uA\n");
614			di->curr_source = BTEMP_BATCTRL_CURR_SRC_16UA;
615		} else {
616			dev_dbg(di->dev, "Set BATCTRL current source to 20uA\n");
617			di->curr_source = BTEMP_BATCTRL_CURR_SRC_20UA;
618		}
619	}
620
621	return di->bm->batt_id;
622}
623
624/**
625 * ab8500_btemp_periodic_work() - Measuring the temperature periodically
626 * @work:	pointer to the work_struct structure
627 *
628 * Work function for measuring the temperature periodically
629 */
630static void ab8500_btemp_periodic_work(struct work_struct *work)
631{
632	int interval;
633	int bat_temp;
634	struct ab8500_btemp *di = container_of(work,
635		struct ab8500_btemp, btemp_periodic_work.work);
636
637	if (!di->initialized) {
638		/* Identify the battery */
639		if (ab8500_btemp_id(di) < 0)
640			dev_warn(di->dev, "failed to identify the battery\n");
641	}
642
643	bat_temp = ab8500_btemp_measure_temp(di);
644	/*
645	 * Filter battery temperature.
646	 * Allow direct updates on temperature only if two samples result in
647	 * same temperature. Else only allow 1 degree change from previous
648	 * reported value in the direction of the new measurement.
649	 */
650	if ((bat_temp == di->prev_bat_temp) || !di->initialized) {
651		if ((di->bat_temp != di->prev_bat_temp) || !di->initialized) {
652			di->initialized = true;
653			di->bat_temp = bat_temp;
654			power_supply_changed(di->btemp_psy);
655		}
656	} else if (bat_temp < di->prev_bat_temp) {
657		di->bat_temp--;
658		power_supply_changed(di->btemp_psy);
659	} else if (bat_temp > di->prev_bat_temp) {
660		di->bat_temp++;
661		power_supply_changed(di->btemp_psy);
662	}
663	di->prev_bat_temp = bat_temp;
664
665	if (di->events.ac_conn || di->events.usb_conn)
666		interval = di->bm->temp_interval_chg;
667	else
668		interval = di->bm->temp_interval_nochg;
669
670	/* Schedule a new measurement */
671	queue_delayed_work(di->btemp_wq,
672		&di->btemp_periodic_work,
673		round_jiffies(interval * HZ));
674}
675
676/**
677 * ab8500_btemp_batctrlindb_handler() - battery removal detected
678 * @irq:       interrupt number
679 * @_di:       void pointer that has to address of ab8500_btemp
680 *
681 * Returns IRQ status(IRQ_HANDLED)
682 */
683static irqreturn_t ab8500_btemp_batctrlindb_handler(int irq, void *_di)
684{
685	struct ab8500_btemp *di = _di;
686	dev_err(di->dev, "Battery removal detected!\n");
687
688	di->events.batt_rem = true;
689	power_supply_changed(di->btemp_psy);
690
691	return IRQ_HANDLED;
692}
693
694/**
695 * ab8500_btemp_templow_handler() - battery temp lower than 10 degrees
696 * @irq:       interrupt number
697 * @_di:       void pointer that has to address of ab8500_btemp
698 *
699 * Returns IRQ status(IRQ_HANDLED)
700 */
701static irqreturn_t ab8500_btemp_templow_handler(int irq, void *_di)
702{
703	struct ab8500_btemp *di = _di;
704
705	if (is_ab8500_3p3_or_earlier(di->parent)) {
706		dev_dbg(di->dev, "Ignore false btemp low irq"
707			" for ABB cut 1.0, 1.1, 2.0 and 3.3\n");
708	} else {
709		dev_crit(di->dev, "Battery temperature lower than -10deg c\n");
710
711		di->events.btemp_low = true;
712		di->events.btemp_high = false;
713		di->events.btemp_medhigh = false;
714		di->events.btemp_lowmed = false;
715		power_supply_changed(di->btemp_psy);
716	}
717
718	return IRQ_HANDLED;
719}
720
721/**
722 * ab8500_btemp_temphigh_handler() - battery temp higher than max temp
723 * @irq:       interrupt number
724 * @_di:       void pointer that has to address of ab8500_btemp
725 *
726 * Returns IRQ status(IRQ_HANDLED)
727 */
728static irqreturn_t ab8500_btemp_temphigh_handler(int irq, void *_di)
729{
730	struct ab8500_btemp *di = _di;
731
732	dev_crit(di->dev, "Battery temperature is higher than MAX temp\n");
733
734	di->events.btemp_high = true;
735	di->events.btemp_medhigh = false;
736	di->events.btemp_lowmed = false;
737	di->events.btemp_low = false;
738	power_supply_changed(di->btemp_psy);
739
740	return IRQ_HANDLED;
741}
742
743/**
744 * ab8500_btemp_lowmed_handler() - battery temp between low and medium
745 * @irq:       interrupt number
746 * @_di:       void pointer that has to address of ab8500_btemp
747 *
748 * Returns IRQ status(IRQ_HANDLED)
749 */
750static irqreturn_t ab8500_btemp_lowmed_handler(int irq, void *_di)
751{
752	struct ab8500_btemp *di = _di;
753
754	dev_dbg(di->dev, "Battery temperature is between low and medium\n");
755
756	di->events.btemp_lowmed = true;
757	di->events.btemp_medhigh = false;
758	di->events.btemp_high = false;
759	di->events.btemp_low = false;
760	power_supply_changed(di->btemp_psy);
761
762	return IRQ_HANDLED;
763}
764
765/**
766 * ab8500_btemp_medhigh_handler() - battery temp between medium and high
767 * @irq:       interrupt number
768 * @_di:       void pointer that has to address of ab8500_btemp
769 *
770 * Returns IRQ status(IRQ_HANDLED)
771 */
772static irqreturn_t ab8500_btemp_medhigh_handler(int irq, void *_di)
773{
774	struct ab8500_btemp *di = _di;
775
776	dev_dbg(di->dev, "Battery temperature is between medium and high\n");
777
778	di->events.btemp_medhigh = true;
779	di->events.btemp_lowmed = false;
780	di->events.btemp_high = false;
781	di->events.btemp_low = false;
782	power_supply_changed(di->btemp_psy);
783
784	return IRQ_HANDLED;
785}
786
787/**
788 * ab8500_btemp_periodic() - Periodic temperature measurements
789 * @di:		pointer to the ab8500_btemp structure
790 * @enable:	enable or disable periodic temperature measurements
791 *
792 * Starts of stops periodic temperature measurements. Periodic measurements
793 * should only be done when a charger is connected.
794 */
795static void ab8500_btemp_periodic(struct ab8500_btemp *di,
796	bool enable)
797{
798	dev_dbg(di->dev, "Enable periodic temperature measurements: %d\n",
799		enable);
800	/*
801	 * Make sure a new measurement is done directly by cancelling
802	 * any pending work
803	 */
804	cancel_delayed_work_sync(&di->btemp_periodic_work);
805
806	if (enable)
807		queue_delayed_work(di->btemp_wq, &di->btemp_periodic_work, 0);
808}
809
810/**
811 * ab8500_btemp_get_temp() - get battery temperature
812 * @di:		pointer to the ab8500_btemp structure
813 *
814 * Returns battery temperature
815 */
816int ab8500_btemp_get_temp(struct ab8500_btemp *di)
817{
818	int temp = 0;
819
820	/*
821	 * The BTEMP events are not reliabe on AB8500 cut3.3
822	 * and prior versions
823	 */
824	if (is_ab8500_3p3_or_earlier(di->parent)) {
825		temp = di->bat_temp * 10;
826	} else {
827		if (di->events.btemp_low) {
828			if (temp > di->btemp_ranges.btemp_low_limit)
829				temp = di->btemp_ranges.btemp_low_limit * 10;
830			else
831				temp = di->bat_temp * 10;
832		} else if (di->events.btemp_high) {
833			if (temp < di->btemp_ranges.btemp_high_limit)
834				temp = di->btemp_ranges.btemp_high_limit * 10;
835			else
836				temp = di->bat_temp * 10;
837		} else if (di->events.btemp_lowmed) {
838			if (temp > di->btemp_ranges.btemp_med_limit)
839				temp = di->btemp_ranges.btemp_med_limit * 10;
840			else
841				temp = di->bat_temp * 10;
842		} else if (di->events.btemp_medhigh) {
843			if (temp < di->btemp_ranges.btemp_med_limit)
844				temp = di->btemp_ranges.btemp_med_limit * 10;
845			else
846				temp = di->bat_temp * 10;
847		} else
848			temp = di->bat_temp * 10;
849	}
850	return temp;
851}
852EXPORT_SYMBOL(ab8500_btemp_get_temp);
853
854/**
855 * ab8500_btemp_get_batctrl_temp() - get the temperature
856 * @btemp:      pointer to the btemp structure
857 *
858 * Returns the batctrl temperature in millidegrees
859 */
860int ab8500_btemp_get_batctrl_temp(struct ab8500_btemp *btemp)
861{
862	return btemp->bat_temp * 1000;
863}
864EXPORT_SYMBOL(ab8500_btemp_get_batctrl_temp);
865
866/**
867 * ab8500_btemp_get_property() - get the btemp properties
868 * @psy:        pointer to the power_supply structure
869 * @psp:        pointer to the power_supply_property structure
870 * @val:        pointer to the power_supply_propval union
871 *
872 * This function gets called when an application tries to get the btemp
873 * properties by reading the sysfs files.
874 * online:	presence of the battery
875 * present:	presence of the battery
876 * technology:	battery technology
877 * temp:	battery temperature
878 * Returns error code in case of failure else 0(on success)
879 */
880static int ab8500_btemp_get_property(struct power_supply *psy,
881	enum power_supply_property psp,
882	union power_supply_propval *val)
883{
884	struct ab8500_btemp *di = power_supply_get_drvdata(psy);
885
886	switch (psp) {
887	case POWER_SUPPLY_PROP_PRESENT:
888	case POWER_SUPPLY_PROP_ONLINE:
889		if (di->events.batt_rem)
890			val->intval = 0;
891		else
892			val->intval = 1;
893		break;
894	case POWER_SUPPLY_PROP_TECHNOLOGY:
895		val->intval = di->bm->bat_type[di->bm->batt_id].name;
896		break;
897	case POWER_SUPPLY_PROP_TEMP:
898		val->intval = ab8500_btemp_get_temp(di);
899		break;
900	default:
901		return -EINVAL;
902	}
903	return 0;
904}
905
906static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data)
907{
908	struct power_supply *psy;
909	struct power_supply *ext;
910	struct ab8500_btemp *di;
911	union power_supply_propval ret;
912	int i, j;
913	bool psy_found = false;
914
915	psy = (struct power_supply *)data;
916	ext = dev_get_drvdata(dev);
917	di = power_supply_get_drvdata(psy);
918
919	/*
920	 * For all psy where the name of your driver
921	 * appears in any supplied_to
922	 */
923	for (i = 0; i < ext->num_supplicants; i++) {
924		if (!strcmp(ext->supplied_to[i], psy->desc->name))
925			psy_found = true;
926	}
927
928	if (!psy_found)
929		return 0;
930
931	/* Go through all properties for the psy */
932	for (j = 0; j < ext->desc->num_properties; j++) {
933		enum power_supply_property prop;
934		prop = ext->desc->properties[j];
935
936		if (power_supply_get_property(ext, prop, &ret))
937			continue;
938
939		switch (prop) {
940		case POWER_SUPPLY_PROP_PRESENT:
941			switch (ext->desc->type) {
942			case POWER_SUPPLY_TYPE_MAINS:
943				/* AC disconnected */
944				if (!ret.intval && di->events.ac_conn) {
945					di->events.ac_conn = false;
946				}
947				/* AC connected */
948				else if (ret.intval && !di->events.ac_conn) {
949					di->events.ac_conn = true;
950					if (!di->events.usb_conn)
951						ab8500_btemp_periodic(di, true);
952				}
953				break;
954			case POWER_SUPPLY_TYPE_USB:
955				/* USB disconnected */
956				if (!ret.intval && di->events.usb_conn) {
957					di->events.usb_conn = false;
958				}
959				/* USB connected */
960				else if (ret.intval && !di->events.usb_conn) {
961					di->events.usb_conn = true;
962					if (!di->events.ac_conn)
963						ab8500_btemp_periodic(di, true);
964				}
965				break;
966			default:
967				break;
968			}
969			break;
970		default:
971			break;
972		}
973	}
974	return 0;
975}
976
977/**
978 * ab8500_btemp_external_power_changed() - callback for power supply changes
979 * @psy:       pointer to the structure power_supply
980 *
981 * This function is pointing to the function pointer external_power_changed
982 * of the structure power_supply.
983 * This function gets executed when there is a change in the external power
984 * supply to the btemp.
985 */
986static void ab8500_btemp_external_power_changed(struct power_supply *psy)
987{
988	struct ab8500_btemp *di = power_supply_get_drvdata(psy);
989
990	class_for_each_device(power_supply_class, NULL,
991		di->btemp_psy, ab8500_btemp_get_ext_psy_data);
992}
993
994/* ab8500 btemp driver interrupts and their respective isr */
995static struct ab8500_btemp_interrupts ab8500_btemp_irq[] = {
996	{"BAT_CTRL_INDB", ab8500_btemp_batctrlindb_handler},
997	{"BTEMP_LOW", ab8500_btemp_templow_handler},
998	{"BTEMP_HIGH", ab8500_btemp_temphigh_handler},
999	{"BTEMP_LOW_MEDIUM", ab8500_btemp_lowmed_handler},
1000	{"BTEMP_MEDIUM_HIGH", ab8500_btemp_medhigh_handler},
1001};
1002
1003#if defined(CONFIG_PM)
1004static int ab8500_btemp_resume(struct platform_device *pdev)
1005{
1006	struct ab8500_btemp *di = platform_get_drvdata(pdev);
1007
1008	ab8500_btemp_periodic(di, true);
1009
1010	return 0;
1011}
1012
1013static int ab8500_btemp_suspend(struct platform_device *pdev,
1014	pm_message_t state)
1015{
1016	struct ab8500_btemp *di = platform_get_drvdata(pdev);
1017
1018	ab8500_btemp_periodic(di, false);
1019
1020	return 0;
1021}
1022#else
1023#define ab8500_btemp_suspend      NULL
1024#define ab8500_btemp_resume       NULL
1025#endif
1026
1027static int ab8500_btemp_remove(struct platform_device *pdev)
1028{
1029	struct ab8500_btemp *di = platform_get_drvdata(pdev);
1030	int i, irq;
1031
1032	/* Disable interrupts */
1033	for (i = 0; i < ARRAY_SIZE(ab8500_btemp_irq); i++) {
1034		irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
1035		free_irq(irq, di);
1036	}
1037
1038	/* Delete the work queue */
1039	destroy_workqueue(di->btemp_wq);
1040
1041	flush_scheduled_work();
1042	power_supply_unregister(di->btemp_psy);
1043
1044	return 0;
1045}
1046
1047static char *supply_interface[] = {
1048	"ab8500_chargalg",
1049	"ab8500_fg",
1050};
1051
1052static const struct power_supply_desc ab8500_btemp_desc = {
1053	.name			= "ab8500_btemp",
1054	.type			= POWER_SUPPLY_TYPE_BATTERY,
1055	.properties		= ab8500_btemp_props,
1056	.num_properties		= ARRAY_SIZE(ab8500_btemp_props),
1057	.get_property		= ab8500_btemp_get_property,
1058	.external_power_changed	= ab8500_btemp_external_power_changed,
1059};
1060
1061static int ab8500_btemp_probe(struct platform_device *pdev)
1062{
1063	struct device_node *np = pdev->dev.of_node;
1064	struct abx500_bm_data *plat = pdev->dev.platform_data;
1065	struct power_supply_config psy_cfg = {};
1066	struct ab8500_btemp *di;
1067	int irq, i, ret = 0;
1068	u8 val;
1069
1070	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
1071	if (!di) {
1072		dev_err(&pdev->dev, "%s no mem for ab8500_btemp\n", __func__);
1073		return -ENOMEM;
1074	}
1075
1076	if (!plat) {
1077		dev_err(&pdev->dev, "no battery management data supplied\n");
1078		return -EINVAL;
1079	}
1080	di->bm = plat;
1081
1082	if (np) {
1083		ret = ab8500_bm_of_probe(&pdev->dev, np, di->bm);
1084		if (ret) {
1085			dev_err(&pdev->dev, "failed to get battery information\n");
1086			return ret;
1087		}
1088	}
1089
1090	/* get parent data */
1091	di->dev = &pdev->dev;
1092	di->parent = dev_get_drvdata(pdev->dev.parent);
1093	di->gpadc = ab8500_gpadc_get("ab8500-gpadc.0");
1094
1095	di->initialized = false;
1096
1097	psy_cfg.supplied_to = supply_interface;
1098	psy_cfg.num_supplicants = ARRAY_SIZE(supply_interface);
1099	psy_cfg.drv_data = di;
1100
1101	/* Create a work queue for the btemp */
1102	di->btemp_wq =
1103		create_singlethread_workqueue("ab8500_btemp_wq");
1104	if (di->btemp_wq == NULL) {
1105		dev_err(di->dev, "failed to create work queue\n");
1106		return -ENOMEM;
1107	}
1108
1109	/* Init work for measuring temperature periodically */
1110	INIT_DEFERRABLE_WORK(&di->btemp_periodic_work,
1111		ab8500_btemp_periodic_work);
1112
1113	/* Set BTEMP thermal limits. Low and Med are fixed */
1114	di->btemp_ranges.btemp_low_limit = BTEMP_THERMAL_LOW_LIMIT;
1115	di->btemp_ranges.btemp_med_limit = BTEMP_THERMAL_MED_LIMIT;
1116
1117	ret = abx500_get_register_interruptible(di->dev, AB8500_CHARGER,
1118		AB8500_BTEMP_HIGH_TH, &val);
1119	if (ret < 0) {
1120		dev_err(di->dev, "%s ab8500 read failed\n", __func__);
1121		goto free_btemp_wq;
1122	}
1123	switch (val) {
1124	case BTEMP_HIGH_TH_57_0:
1125	case BTEMP_HIGH_TH_57_1:
1126		di->btemp_ranges.btemp_high_limit =
1127			BTEMP_THERMAL_HIGH_LIMIT_57;
1128		break;
1129	case BTEMP_HIGH_TH_52:
1130		di->btemp_ranges.btemp_high_limit =
1131			BTEMP_THERMAL_HIGH_LIMIT_52;
1132		break;
1133	case BTEMP_HIGH_TH_62:
1134		di->btemp_ranges.btemp_high_limit =
1135			BTEMP_THERMAL_HIGH_LIMIT_62;
1136		break;
1137	}
1138
1139	/* Register BTEMP power supply class */
1140	di->btemp_psy = power_supply_register(di->dev, &ab8500_btemp_desc,
1141					      &psy_cfg);
1142	if (IS_ERR(di->btemp_psy)) {
1143		dev_err(di->dev, "failed to register BTEMP psy\n");
1144		ret = PTR_ERR(di->btemp_psy);
1145		goto free_btemp_wq;
1146	}
1147
1148	/* Register interrupts */
1149	for (i = 0; i < ARRAY_SIZE(ab8500_btemp_irq); i++) {
1150		irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
1151		ret = request_threaded_irq(irq, NULL, ab8500_btemp_irq[i].isr,
1152			IRQF_SHARED | IRQF_NO_SUSPEND,
1153			ab8500_btemp_irq[i].name, di);
1154
1155		if (ret) {
1156			dev_err(di->dev, "failed to request %s IRQ %d: %d\n"
1157				, ab8500_btemp_irq[i].name, irq, ret);
1158			goto free_irq;
1159		}
1160		dev_dbg(di->dev, "Requested %s IRQ %d: %d\n",
1161			ab8500_btemp_irq[i].name, irq, ret);
1162	}
1163
1164	platform_set_drvdata(pdev, di);
1165
1166	/* Kick off periodic temperature measurements */
1167	ab8500_btemp_periodic(di, true);
1168	list_add_tail(&di->node, &ab8500_btemp_list);
1169
1170	return ret;
1171
1172free_irq:
1173	power_supply_unregister(di->btemp_psy);
1174
1175	/* We also have to free all successfully registered irqs */
1176	for (i = i - 1; i >= 0; i--) {
1177		irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
1178		free_irq(irq, di);
1179	}
1180free_btemp_wq:
1181	destroy_workqueue(di->btemp_wq);
1182	return ret;
1183}
1184
1185static const struct of_device_id ab8500_btemp_match[] = {
1186	{ .compatible = "stericsson,ab8500-btemp", },
1187	{ },
1188};
1189
1190static struct platform_driver ab8500_btemp_driver = {
1191	.probe = ab8500_btemp_probe,
1192	.remove = ab8500_btemp_remove,
1193	.suspend = ab8500_btemp_suspend,
1194	.resume = ab8500_btemp_resume,
1195	.driver = {
1196		.name = "ab8500-btemp",
1197		.of_match_table = ab8500_btemp_match,
1198	},
1199};
1200
1201static int __init ab8500_btemp_init(void)
1202{
1203	return platform_driver_register(&ab8500_btemp_driver);
1204}
1205
1206static void __exit ab8500_btemp_exit(void)
1207{
1208	platform_driver_unregister(&ab8500_btemp_driver);
1209}
1210
1211device_initcall(ab8500_btemp_init);
1212module_exit(ab8500_btemp_exit);
1213
1214MODULE_LICENSE("GPL v2");
1215MODULE_AUTHOR("Johan Palsson, Karl Komierowski, Arun R Murthy");
1216MODULE_ALIAS("platform:ab8500-btemp");
1217MODULE_DESCRIPTION("AB8500 battery temperature driver");
1218