1 /*
2  * Battery charger driver for Dialog Semiconductor DA9030
3  *
4  * Copyright (C) 2008 Compulab, Ltd.
5  * 	Mike Rapoport <mike@compulab.co.il>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/device.h>
17 #include <linux/workqueue.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/power_supply.h>
21 #include <linux/mfd/da903x.h>
22 
23 #include <linux/debugfs.h>
24 #include <linux/seq_file.h>
25 #include <linux/notifier.h>
26 
27 #define DA9030_FAULT_LOG		0x0a
28 #define DA9030_FAULT_LOG_OVER_TEMP	(1 << 7)
29 #define DA9030_FAULT_LOG_VBAT_OVER	(1 << 4)
30 
31 #define DA9030_CHARGE_CONTROL		0x28
32 #define DA9030_CHRG_CHARGER_ENABLE	(1 << 7)
33 
34 #define DA9030_ADC_MAN_CONTROL		0x30
35 #define DA9030_ADC_TBATREF_ENABLE	(1 << 5)
36 #define DA9030_ADC_LDO_INT_ENABLE	(1 << 4)
37 
38 #define DA9030_ADC_AUTO_CONTROL		0x31
39 #define DA9030_ADC_TBAT_ENABLE		(1 << 5)
40 #define DA9030_ADC_VBAT_IN_TXON		(1 << 4)
41 #define DA9030_ADC_VCH_ENABLE		(1 << 3)
42 #define DA9030_ADC_ICH_ENABLE		(1 << 2)
43 #define DA9030_ADC_VBAT_ENABLE		(1 << 1)
44 #define DA9030_ADC_AUTO_SLEEP_ENABLE	(1 << 0)
45 
46 #define DA9030_VBATMON		0x32
47 #define DA9030_VBATMONTXON	0x33
48 #define DA9030_TBATHIGHP	0x34
49 #define DA9030_TBATHIGHN	0x35
50 #define DA9030_TBATLOW		0x36
51 
52 #define DA9030_VBAT_RES		0x41
53 #define DA9030_VBATMIN_RES	0x42
54 #define DA9030_VBATMINTXON_RES	0x43
55 #define DA9030_ICHMAX_RES	0x44
56 #define DA9030_ICHMIN_RES	0x45
57 #define DA9030_ICHAVERAGE_RES	0x46
58 #define DA9030_VCHMAX_RES	0x47
59 #define DA9030_VCHMIN_RES	0x48
60 #define DA9030_TBAT_RES		0x49
61 
62 struct da9030_adc_res {
63 	uint8_t vbat_res;
64 	uint8_t vbatmin_res;
65 	uint8_t vbatmintxon;
66 	uint8_t ichmax_res;
67 	uint8_t ichmin_res;
68 	uint8_t ichaverage_res;
69 	uint8_t vchmax_res;
70 	uint8_t vchmin_res;
71 	uint8_t tbat_res;
72 	uint8_t adc_in4_res;
73 	uint8_t adc_in5_res;
74 };
75 
76 struct da9030_battery_thresholds {
77 	int tbat_low;
78 	int tbat_high;
79 	int tbat_restart;
80 
81 	int vbat_low;
82 	int vbat_crit;
83 	int vbat_charge_start;
84 	int vbat_charge_stop;
85 	int vbat_charge_restart;
86 
87 	int vcharge_min;
88 	int vcharge_max;
89 };
90 
91 struct da9030_charger {
92 	struct power_supply *psy;
93 	struct power_supply_desc psy_desc;
94 
95 	struct device *master;
96 
97 	struct da9030_adc_res adc;
98 	struct delayed_work work;
99 	unsigned int interval;
100 
101 	struct power_supply_info *battery_info;
102 
103 	struct da9030_battery_thresholds thresholds;
104 
105 	unsigned int charge_milliamp;
106 	unsigned int charge_millivolt;
107 
108 	/* charger status */
109 	bool chdet;
110 	uint8_t fault;
111 	int mA;
112 	int mV;
113 	bool is_on;
114 
115 	struct notifier_block nb;
116 
117 	/* platform callbacks for battery low and critical events */
118 	void (*battery_low)(void);
119 	void (*battery_critical)(void);
120 
121 	struct dentry *debug_file;
122 };
123 
124 static inline int da9030_reg_to_mV(int reg)
125 {
126 	return ((reg * 2650) >> 8) + 2650;
127 }
128 
129 static inline int da9030_millivolt_to_reg(int mV)
130 {
131 	return ((mV - 2650) << 8) / 2650;
132 }
133 
134 static inline int da9030_reg_to_mA(int reg)
135 {
136 	return ((reg * 24000) >> 8) / 15;
137 }
138 
139 #ifdef CONFIG_DEBUG_FS
140 static int bat_debug_show(struct seq_file *s, void *data)
141 {
142 	struct da9030_charger *charger = s->private;
143 
144 	seq_printf(s, "charger is %s\n", charger->is_on ? "on" : "off");
145 	if (charger->chdet) {
146 		seq_printf(s, "iset = %dmA, vset = %dmV\n",
147 			   charger->mA, charger->mV);
148 	}
149 
150 	seq_printf(s, "vbat_res = %d (%dmV)\n",
151 		   charger->adc.vbat_res,
152 		   da9030_reg_to_mV(charger->adc.vbat_res));
153 	seq_printf(s, "vbatmin_res = %d (%dmV)\n",
154 		   charger->adc.vbatmin_res,
155 		   da9030_reg_to_mV(charger->adc.vbatmin_res));
156 	seq_printf(s, "vbatmintxon = %d (%dmV)\n",
157 		   charger->adc.vbatmintxon,
158 		   da9030_reg_to_mV(charger->adc.vbatmintxon));
159 	seq_printf(s, "ichmax_res = %d (%dmA)\n",
160 		   charger->adc.ichmax_res,
161 		   da9030_reg_to_mV(charger->adc.ichmax_res));
162 	seq_printf(s, "ichmin_res = %d (%dmA)\n",
163 		   charger->adc.ichmin_res,
164 		   da9030_reg_to_mA(charger->adc.ichmin_res));
165 	seq_printf(s, "ichaverage_res = %d (%dmA)\n",
166 		   charger->adc.ichaverage_res,
167 		   da9030_reg_to_mA(charger->adc.ichaverage_res));
168 	seq_printf(s, "vchmax_res = %d (%dmV)\n",
169 		   charger->adc.vchmax_res,
170 		   da9030_reg_to_mA(charger->adc.vchmax_res));
171 	seq_printf(s, "vchmin_res = %d (%dmV)\n",
172 		   charger->adc.vchmin_res,
173 		   da9030_reg_to_mV(charger->adc.vchmin_res));
174 
175 	return 0;
176 }
177 
178 static int debug_open(struct inode *inode, struct file *file)
179 {
180 	return single_open(file, bat_debug_show, inode->i_private);
181 }
182 
183 static const struct file_operations bat_debug_fops = {
184 	.open		= debug_open,
185 	.read		= seq_read,
186 	.llseek		= seq_lseek,
187 	.release	= single_release,
188 };
189 
190 static struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
191 {
192 	charger->debug_file = debugfs_create_file("charger", 0666, NULL,
193 						  charger, &bat_debug_fops);
194 	return charger->debug_file;
195 }
196 
197 static void da9030_bat_remove_debugfs(struct da9030_charger *charger)
198 {
199 	debugfs_remove(charger->debug_file);
200 }
201 #else
202 static inline struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
203 {
204 	return NULL;
205 }
206 static inline void da9030_bat_remove_debugfs(struct da9030_charger *charger)
207 {
208 }
209 #endif
210 
211 static inline void da9030_read_adc(struct da9030_charger *charger,
212 				   struct da9030_adc_res *adc)
213 {
214 	da903x_reads(charger->master, DA9030_VBAT_RES,
215 		     sizeof(*adc), (uint8_t *)adc);
216 }
217 
218 static void da9030_charger_update_state(struct da9030_charger *charger)
219 {
220 	uint8_t val;
221 
222 	da903x_read(charger->master, DA9030_CHARGE_CONTROL, &val);
223 	charger->is_on = (val & DA9030_CHRG_CHARGER_ENABLE) ? 1 : 0;
224 	charger->mA = ((val >> 3) & 0xf) * 100;
225 	charger->mV = (val & 0x7) * 50 + 4000;
226 
227 	da9030_read_adc(charger, &charger->adc);
228 	da903x_read(charger->master, DA9030_FAULT_LOG, &charger->fault);
229 	charger->chdet = da903x_query_status(charger->master,
230 						     DA9030_STATUS_CHDET);
231 }
232 
233 static void da9030_set_charge(struct da9030_charger *charger, int on)
234 {
235 	uint8_t val;
236 
237 	if (on) {
238 		val = DA9030_CHRG_CHARGER_ENABLE;
239 		val |= (charger->charge_milliamp / 100) << 3;
240 		val |= (charger->charge_millivolt - 4000) / 50;
241 		charger->is_on = 1;
242 	} else {
243 		val = 0;
244 		charger->is_on = 0;
245 	}
246 
247 	da903x_write(charger->master, DA9030_CHARGE_CONTROL, val);
248 
249 	power_supply_changed(charger->psy);
250 }
251 
252 static void da9030_charger_check_state(struct da9030_charger *charger)
253 {
254 	da9030_charger_update_state(charger);
255 
256 	/* we wake or boot with external power on */
257 	if (!charger->is_on) {
258 		if ((charger->chdet) &&
259 		    (charger->adc.vbat_res <
260 		     charger->thresholds.vbat_charge_start)) {
261 			da9030_set_charge(charger, 1);
262 		}
263 	} else {
264 		/* Charger has been pulled out */
265 		if (!charger->chdet) {
266 			da9030_set_charge(charger, 0);
267 			return;
268 		}
269 
270 		if (charger->adc.vbat_res >=
271 		    charger->thresholds.vbat_charge_stop) {
272 			da9030_set_charge(charger, 0);
273 			da903x_write(charger->master, DA9030_VBATMON,
274 				       charger->thresholds.vbat_charge_restart);
275 		} else if (charger->adc.vbat_res >
276 			   charger->thresholds.vbat_low) {
277 			/* we are charging and passed LOW_THRESH,
278 			   so upate DA9030 VBAT threshold
279 			 */
280 			da903x_write(charger->master, DA9030_VBATMON,
281 				     charger->thresholds.vbat_low);
282 		}
283 		if (charger->adc.vchmax_res > charger->thresholds.vcharge_max ||
284 		    charger->adc.vchmin_res < charger->thresholds.vcharge_min ||
285 		    /* Tempreture readings are negative */
286 		    charger->adc.tbat_res < charger->thresholds.tbat_high ||
287 		    charger->adc.tbat_res > charger->thresholds.tbat_low) {
288 			/* disable charger */
289 			da9030_set_charge(charger, 0);
290 		}
291 	}
292 }
293 
294 static void da9030_charging_monitor(struct work_struct *work)
295 {
296 	struct da9030_charger *charger;
297 
298 	charger = container_of(work, struct da9030_charger, work.work);
299 
300 	da9030_charger_check_state(charger);
301 
302 	/* reschedule for the next time */
303 	schedule_delayed_work(&charger->work, charger->interval);
304 }
305 
306 static enum power_supply_property da9030_battery_props[] = {
307 	POWER_SUPPLY_PROP_MODEL_NAME,
308 	POWER_SUPPLY_PROP_STATUS,
309 	POWER_SUPPLY_PROP_HEALTH,
310 	POWER_SUPPLY_PROP_TECHNOLOGY,
311 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
312 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
313 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
314 	POWER_SUPPLY_PROP_CURRENT_AVG,
315 };
316 
317 static void da9030_battery_check_status(struct da9030_charger *charger,
318 				    union power_supply_propval *val)
319 {
320 	if (charger->chdet) {
321 		if (charger->is_on)
322 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
323 		else
324 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
325 	} else {
326 		val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
327 	}
328 }
329 
330 static void da9030_battery_check_health(struct da9030_charger *charger,
331 				    union power_supply_propval *val)
332 {
333 	if (charger->fault & DA9030_FAULT_LOG_OVER_TEMP)
334 		val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
335 	else if (charger->fault & DA9030_FAULT_LOG_VBAT_OVER)
336 		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
337 	else
338 		val->intval = POWER_SUPPLY_HEALTH_GOOD;
339 }
340 
341 static int da9030_battery_get_property(struct power_supply *psy,
342 				   enum power_supply_property psp,
343 				   union power_supply_propval *val)
344 {
345 	struct da9030_charger *charger = power_supply_get_drvdata(psy);
346 
347 	switch (psp) {
348 	case POWER_SUPPLY_PROP_STATUS:
349 		da9030_battery_check_status(charger, val);
350 		break;
351 	case POWER_SUPPLY_PROP_HEALTH:
352 		da9030_battery_check_health(charger, val);
353 		break;
354 	case POWER_SUPPLY_PROP_TECHNOLOGY:
355 		val->intval = charger->battery_info->technology;
356 		break;
357 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
358 		val->intval = charger->battery_info->voltage_max_design;
359 		break;
360 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
361 		val->intval = charger->battery_info->voltage_min_design;
362 		break;
363 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
364 		val->intval = da9030_reg_to_mV(charger->adc.vbat_res) * 1000;
365 		break;
366 	case POWER_SUPPLY_PROP_CURRENT_AVG:
367 		val->intval =
368 			da9030_reg_to_mA(charger->adc.ichaverage_res) * 1000;
369 		break;
370 	case POWER_SUPPLY_PROP_MODEL_NAME:
371 		val->strval = charger->battery_info->name;
372 		break;
373 	default:
374 		break;
375 	}
376 
377 	return 0;
378 }
379 
380 static void da9030_battery_vbat_event(struct da9030_charger *charger)
381 {
382 	da9030_read_adc(charger, &charger->adc);
383 
384 	if (charger->is_on)
385 		return;
386 
387 	if (charger->adc.vbat_res < charger->thresholds.vbat_low) {
388 		/* set VBAT threshold for critical */
389 		da903x_write(charger->master, DA9030_VBATMON,
390 			     charger->thresholds.vbat_crit);
391 		if (charger->battery_low)
392 			charger->battery_low();
393 	} else if (charger->adc.vbat_res <
394 		   charger->thresholds.vbat_crit) {
395 		/* notify the system of battery critical */
396 		if (charger->battery_critical)
397 			charger->battery_critical();
398 	}
399 }
400 
401 static int da9030_battery_event(struct notifier_block *nb, unsigned long event,
402 				void *data)
403 {
404 	struct da9030_charger *charger =
405 		container_of(nb, struct da9030_charger, nb);
406 
407 	switch (event) {
408 	case DA9030_EVENT_CHDET:
409 		cancel_delayed_work_sync(&charger->work);
410 		schedule_work(&charger->work.work);
411 		break;
412 	case DA9030_EVENT_VBATMON:
413 		da9030_battery_vbat_event(charger);
414 		break;
415 	case DA9030_EVENT_CHIOVER:
416 	case DA9030_EVENT_TBAT:
417 		da9030_set_charge(charger, 0);
418 		break;
419 	}
420 
421 	return 0;
422 }
423 
424 static void da9030_battery_convert_thresholds(struct da9030_charger *charger,
425 					      struct da9030_battery_info *pdata)
426 {
427 	charger->thresholds.tbat_low = pdata->tbat_low;
428 	charger->thresholds.tbat_high = pdata->tbat_high;
429 	charger->thresholds.tbat_restart  = pdata->tbat_restart;
430 
431 	charger->thresholds.vbat_low =
432 		da9030_millivolt_to_reg(pdata->vbat_low);
433 	charger->thresholds.vbat_crit =
434 		da9030_millivolt_to_reg(pdata->vbat_crit);
435 	charger->thresholds.vbat_charge_start =
436 		da9030_millivolt_to_reg(pdata->vbat_charge_start);
437 	charger->thresholds.vbat_charge_stop =
438 		da9030_millivolt_to_reg(pdata->vbat_charge_stop);
439 	charger->thresholds.vbat_charge_restart =
440 		da9030_millivolt_to_reg(pdata->vbat_charge_restart);
441 
442 	charger->thresholds.vcharge_min =
443 		da9030_millivolt_to_reg(pdata->vcharge_min);
444 	charger->thresholds.vcharge_max =
445 		da9030_millivolt_to_reg(pdata->vcharge_max);
446 }
447 
448 static void da9030_battery_setup_psy(struct da9030_charger *charger)
449 {
450 	struct power_supply_desc *psy_desc = &charger->psy_desc;
451 	struct power_supply_info *info = charger->battery_info;
452 
453 	psy_desc->name = info->name;
454 	psy_desc->use_for_apm = info->use_for_apm;
455 	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
456 	psy_desc->get_property = da9030_battery_get_property;
457 
458 	psy_desc->properties = da9030_battery_props;
459 	psy_desc->num_properties = ARRAY_SIZE(da9030_battery_props);
460 };
461 
462 static int da9030_battery_charger_init(struct da9030_charger *charger)
463 {
464 	char v[5];
465 	int ret;
466 
467 	v[0] = v[1] = charger->thresholds.vbat_low;
468 	v[2] = charger->thresholds.tbat_high;
469 	v[3] = charger->thresholds.tbat_restart;
470 	v[4] = charger->thresholds.tbat_low;
471 
472 	ret = da903x_writes(charger->master, DA9030_VBATMON, 5, v);
473 	if (ret)
474 		return ret;
475 
476 	/*
477 	 * Enable reference voltage supply for ADC from the LDO_INTERNAL
478 	 * regulator. Must be set before ADC measurements can be made.
479 	 */
480 	ret = da903x_write(charger->master, DA9030_ADC_MAN_CONTROL,
481 			   DA9030_ADC_LDO_INT_ENABLE |
482 			   DA9030_ADC_TBATREF_ENABLE);
483 	if (ret)
484 		return ret;
485 
486 	/* enable auto ADC measuremnts */
487 	return da903x_write(charger->master, DA9030_ADC_AUTO_CONTROL,
488 			    DA9030_ADC_TBAT_ENABLE | DA9030_ADC_VBAT_IN_TXON |
489 			    DA9030_ADC_VCH_ENABLE | DA9030_ADC_ICH_ENABLE |
490 			    DA9030_ADC_VBAT_ENABLE |
491 			    DA9030_ADC_AUTO_SLEEP_ENABLE);
492 }
493 
494 static int da9030_battery_probe(struct platform_device *pdev)
495 {
496 	struct da9030_charger *charger;
497 	struct power_supply_config psy_cfg = {};
498 	struct da9030_battery_info *pdata = pdev->dev.platform_data;
499 	int ret;
500 
501 	if (pdata == NULL)
502 		return -EINVAL;
503 
504 	if (pdata->charge_milliamp >= 1500 ||
505 	    pdata->charge_millivolt < 4000 ||
506 	    pdata->charge_millivolt > 4350)
507 		return -EINVAL;
508 
509 	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
510 	if (charger == NULL)
511 		return -ENOMEM;
512 
513 	charger->master = pdev->dev.parent;
514 
515 	/* 10 seconds between monitor runs unless platform defines other
516 	   interval */
517 	charger->interval = msecs_to_jiffies(
518 		(pdata->batmon_interval ? : 10) * 1000);
519 
520 	charger->charge_milliamp = pdata->charge_milliamp;
521 	charger->charge_millivolt = pdata->charge_millivolt;
522 	charger->battery_info = pdata->battery_info;
523 	charger->battery_low = pdata->battery_low;
524 	charger->battery_critical = pdata->battery_critical;
525 
526 	da9030_battery_convert_thresholds(charger, pdata);
527 
528 	ret = da9030_battery_charger_init(charger);
529 	if (ret)
530 		goto err_charger_init;
531 
532 	INIT_DELAYED_WORK(&charger->work, da9030_charging_monitor);
533 	schedule_delayed_work(&charger->work, charger->interval);
534 
535 	charger->nb.notifier_call = da9030_battery_event;
536 	ret = da903x_register_notifier(charger->master, &charger->nb,
537 				       DA9030_EVENT_CHDET |
538 				       DA9030_EVENT_VBATMON |
539 				       DA9030_EVENT_CHIOVER |
540 				       DA9030_EVENT_TBAT);
541 	if (ret)
542 		goto err_notifier;
543 
544 	da9030_battery_setup_psy(charger);
545 	psy_cfg.drv_data = charger;
546 	charger->psy = power_supply_register(&pdev->dev, &charger->psy_desc,
547 					     &psy_cfg);
548 	if (IS_ERR(charger->psy)) {
549 		ret = PTR_ERR(charger->psy);
550 		goto err_ps_register;
551 	}
552 
553 	charger->debug_file = da9030_bat_create_debugfs(charger);
554 	platform_set_drvdata(pdev, charger);
555 	return 0;
556 
557 err_ps_register:
558 	da903x_unregister_notifier(charger->master, &charger->nb,
559 				   DA9030_EVENT_CHDET | DA9030_EVENT_VBATMON |
560 				   DA9030_EVENT_CHIOVER | DA9030_EVENT_TBAT);
561 err_notifier:
562 	cancel_delayed_work(&charger->work);
563 
564 err_charger_init:
565 	return ret;
566 }
567 
568 static int da9030_battery_remove(struct platform_device *dev)
569 {
570 	struct da9030_charger *charger = platform_get_drvdata(dev);
571 
572 	da9030_bat_remove_debugfs(charger);
573 
574 	da903x_unregister_notifier(charger->master, &charger->nb,
575 				   DA9030_EVENT_CHDET | DA9030_EVENT_VBATMON |
576 				   DA9030_EVENT_CHIOVER | DA9030_EVENT_TBAT);
577 	cancel_delayed_work_sync(&charger->work);
578 	da9030_set_charge(charger, 0);
579 	power_supply_unregister(charger->psy);
580 
581 	return 0;
582 }
583 
584 static struct platform_driver da903x_battery_driver = {
585 	.driver	= {
586 		.name	= "da903x-battery",
587 	},
588 	.probe = da9030_battery_probe,
589 	.remove = da9030_battery_remove,
590 };
591 
592 module_platform_driver(da903x_battery_driver);
593 
594 MODULE_DESCRIPTION("DA9030 battery charger driver");
595 MODULE_AUTHOR("Mike Rapoport, CompuLab");
596 MODULE_LICENSE("GPL");
597