1 /*
2  * Battery driver for Maxim MAX8925
3  *
4  * Copyright (c) 2009-2010 Marvell International Ltd.
5  *	Haojian Zhuang <haojian.zhuang@marvell.com>
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/module.h>
13 #include <linux/err.h>
14 #include <linux/slab.h>
15 #include <linux/of.h>
16 #include <linux/i2c.h>
17 #include <linux/interrupt.h>
18 #include <linux/platform_device.h>
19 #include <linux/power_supply.h>
20 #include <linux/mfd/max8925.h>
21 
22 /* registers in GPM */
23 #define MAX8925_OUT5VEN			0x54
24 #define MAX8925_OUT3VEN			0x58
25 #define MAX8925_CHG_CNTL1		0x7c
26 
27 /* bits definition */
28 #define MAX8925_CHG_STAT_VSYSLOW	(1 << 0)
29 #define MAX8925_CHG_STAT_MODE_MASK	(3 << 2)
30 #define MAX8925_CHG_STAT_EN_MASK	(1 << 4)
31 #define MAX8925_CHG_MBDET		(1 << 1)
32 #define MAX8925_CHG_AC_RANGE_MASK	(3 << 6)
33 
34 /* registers in ADC */
35 #define MAX8925_ADC_RES_CNFG1		0x06
36 #define MAX8925_ADC_AVG_CNFG1		0x07
37 #define MAX8925_ADC_ACQ_CNFG1		0x08
38 #define MAX8925_ADC_ACQ_CNFG2		0x09
39 /* 2 bytes registers in below. MSB is 1st, LSB is 2nd. */
40 #define MAX8925_ADC_AUX2		0x62
41 #define MAX8925_ADC_VCHG		0x64
42 #define MAX8925_ADC_VBBATT		0x66
43 #define MAX8925_ADC_VMBATT		0x68
44 #define MAX8925_ADC_ISNS		0x6a
45 #define MAX8925_ADC_THM			0x6c
46 #define MAX8925_ADC_TDIE		0x6e
47 #define MAX8925_CMD_AUX2		0xc8
48 #define MAX8925_CMD_VCHG		0xd0
49 #define MAX8925_CMD_VBBATT		0xd8
50 #define MAX8925_CMD_VMBATT		0xe0
51 #define MAX8925_CMD_ISNS		0xe8
52 #define MAX8925_CMD_THM			0xf0
53 #define MAX8925_CMD_TDIE		0xf8
54 
55 enum {
56 	MEASURE_AUX2,
57 	MEASURE_VCHG,
58 	MEASURE_VBBATT,
59 	MEASURE_VMBATT,
60 	MEASURE_ISNS,
61 	MEASURE_THM,
62 	MEASURE_TDIE,
63 	MEASURE_MAX,
64 };
65 
66 struct max8925_power_info {
67 	struct max8925_chip	*chip;
68 	struct i2c_client	*gpm;
69 	struct i2c_client	*adc;
70 
71 	struct power_supply	*ac;
72 	struct power_supply	*usb;
73 	struct power_supply	*battery;
74 	int			irq_base;
75 	unsigned		ac_online:1;
76 	unsigned		usb_online:1;
77 	unsigned		bat_online:1;
78 	unsigned		chg_mode:2;
79 	unsigned		batt_detect:1;	/* detecing MB by ID pin */
80 	unsigned		topoff_threshold:2;
81 	unsigned		fast_charge:3;
82 	unsigned		no_temp_support:1;
83 	unsigned		no_insert_detect:1;
84 
85 	int (*set_charger) (int);
86 };
87 
88 static int __set_charger(struct max8925_power_info *info, int enable)
89 {
90 	struct max8925_chip *chip = info->chip;
91 	if (enable) {
92 		/* enable charger in platform */
93 		if (info->set_charger)
94 			info->set_charger(1);
95 		/* enable charger */
96 		max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 0);
97 	} else {
98 		/* disable charge */
99 		max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 1 << 7);
100 		if (info->set_charger)
101 			info->set_charger(0);
102 	}
103 	dev_dbg(chip->dev, "%s\n", (enable) ? "Enable charger"
104 		: "Disable charger");
105 	return 0;
106 }
107 
108 static irqreturn_t max8925_charger_handler(int irq, void *data)
109 {
110 	struct max8925_power_info *info = (struct max8925_power_info *)data;
111 	struct max8925_chip *chip = info->chip;
112 
113 	switch (irq - chip->irq_base) {
114 	case MAX8925_IRQ_VCHG_DC_R:
115 		info->ac_online = 1;
116 		__set_charger(info, 1);
117 		dev_dbg(chip->dev, "Adapter inserted\n");
118 		break;
119 	case MAX8925_IRQ_VCHG_DC_F:
120 		info->ac_online = 0;
121 		__set_charger(info, 0);
122 		dev_dbg(chip->dev, "Adapter removed\n");
123 		break;
124 	case MAX8925_IRQ_VCHG_THM_OK_F:
125 		/* Battery is not ready yet */
126 		dev_dbg(chip->dev, "Battery temperature is out of range\n");
127 	case MAX8925_IRQ_VCHG_DC_OVP:
128 		dev_dbg(chip->dev, "Error detection\n");
129 		__set_charger(info, 0);
130 		break;
131 	case MAX8925_IRQ_VCHG_THM_OK_R:
132 		/* Battery is ready now */
133 		dev_dbg(chip->dev, "Battery temperature is in range\n");
134 		break;
135 	case MAX8925_IRQ_VCHG_SYSLOW_R:
136 		/* VSYS is low */
137 		dev_info(chip->dev, "Sys power is too low\n");
138 		break;
139 	case MAX8925_IRQ_VCHG_SYSLOW_F:
140 		dev_dbg(chip->dev, "Sys power is above low threshold\n");
141 		break;
142 	case MAX8925_IRQ_VCHG_DONE:
143 		__set_charger(info, 0);
144 		dev_dbg(chip->dev, "Charging is done\n");
145 		break;
146 	case MAX8925_IRQ_VCHG_TOPOFF:
147 		dev_dbg(chip->dev, "Charging in top-off mode\n");
148 		break;
149 	case MAX8925_IRQ_VCHG_TMR_FAULT:
150 		__set_charger(info, 0);
151 		dev_dbg(chip->dev, "Safe timer is expired\n");
152 		break;
153 	case MAX8925_IRQ_VCHG_RST:
154 		__set_charger(info, 0);
155 		dev_dbg(chip->dev, "Charger is reset\n");
156 		break;
157 	}
158 	return IRQ_HANDLED;
159 }
160 
161 static int start_measure(struct max8925_power_info *info, int type)
162 {
163 	unsigned char buf[2] = {0, 0};
164 	int meas_cmd;
165 	int meas_reg = 0, ret;
166 
167 	switch (type) {
168 	case MEASURE_VCHG:
169 		meas_cmd = MAX8925_CMD_VCHG;
170 		meas_reg = MAX8925_ADC_VCHG;
171 		break;
172 	case MEASURE_VBBATT:
173 		meas_cmd = MAX8925_CMD_VBBATT;
174 		meas_reg = MAX8925_ADC_VBBATT;
175 		break;
176 	case MEASURE_VMBATT:
177 		meas_cmd = MAX8925_CMD_VMBATT;
178 		meas_reg = MAX8925_ADC_VMBATT;
179 		break;
180 	case MEASURE_ISNS:
181 		meas_cmd = MAX8925_CMD_ISNS;
182 		meas_reg = MAX8925_ADC_ISNS;
183 		break;
184 	default:
185 		return -EINVAL;
186 	}
187 
188 	max8925_reg_write(info->adc, meas_cmd, 0);
189 	max8925_bulk_read(info->adc, meas_reg, 2, buf);
190 	ret = ((buf[0]<<8) | buf[1]) >> 4;
191 
192 	return ret;
193 }
194 
195 static int max8925_ac_get_prop(struct power_supply *psy,
196 			       enum power_supply_property psp,
197 			       union power_supply_propval *val)
198 {
199 	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
200 	int ret = 0;
201 
202 	switch (psp) {
203 	case POWER_SUPPLY_PROP_ONLINE:
204 		val->intval = info->ac_online;
205 		break;
206 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
207 		if (info->ac_online) {
208 			ret = start_measure(info, MEASURE_VCHG);
209 			if (ret >= 0) {
210 				val->intval = ret * 2000;	/* unit is uV */
211 				goto out;
212 			}
213 		}
214 		ret = -ENODATA;
215 		break;
216 	default:
217 		ret = -ENODEV;
218 		break;
219 	}
220 out:
221 	return ret;
222 }
223 
224 static enum power_supply_property max8925_ac_props[] = {
225 	POWER_SUPPLY_PROP_ONLINE,
226 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
227 };
228 
229 static int max8925_usb_get_prop(struct power_supply *psy,
230 				enum power_supply_property psp,
231 				union power_supply_propval *val)
232 {
233 	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
234 	int ret = 0;
235 
236 	switch (psp) {
237 	case POWER_SUPPLY_PROP_ONLINE:
238 		val->intval = info->usb_online;
239 		break;
240 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
241 		if (info->usb_online) {
242 			ret = start_measure(info, MEASURE_VCHG);
243 			if (ret >= 0) {
244 				val->intval = ret * 2000;	/* unit is uV */
245 				goto out;
246 			}
247 		}
248 		ret = -ENODATA;
249 		break;
250 	default:
251 		ret = -ENODEV;
252 		break;
253 	}
254 out:
255 	return ret;
256 }
257 
258 static enum power_supply_property max8925_usb_props[] = {
259 	POWER_SUPPLY_PROP_ONLINE,
260 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
261 };
262 
263 static int max8925_bat_get_prop(struct power_supply *psy,
264 				enum power_supply_property psp,
265 				union power_supply_propval *val)
266 {
267 	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
268 	int ret = 0;
269 
270 	switch (psp) {
271 	case POWER_SUPPLY_PROP_ONLINE:
272 		val->intval = info->bat_online;
273 		break;
274 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
275 		if (info->bat_online) {
276 			ret = start_measure(info, MEASURE_VMBATT);
277 			if (ret >= 0) {
278 				val->intval = ret * 2000;	/* unit is uV */
279 				ret = 0;
280 				break;
281 			}
282 		}
283 		ret = -ENODATA;
284 		break;
285 	case POWER_SUPPLY_PROP_CURRENT_NOW:
286 		if (info->bat_online) {
287 			ret = start_measure(info, MEASURE_ISNS);
288 			if (ret >= 0) {
289 				/* assume r_sns is 0.02 */
290 				ret = ((ret * 6250) - 3125) /* uA */;
291 				val->intval = 0;
292 				if (ret > 0)
293 					val->intval = ret; /* unit is mA */
294 				ret = 0;
295 				break;
296 			}
297 		}
298 		ret = -ENODATA;
299 		break;
300 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
301 		if (!info->bat_online) {
302 			ret = -ENODATA;
303 			break;
304 		}
305 		ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
306 		ret = (ret & MAX8925_CHG_STAT_MODE_MASK) >> 2;
307 		switch (ret) {
308 		case 1:
309 			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
310 			break;
311 		case 0:
312 		case 2:
313 			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
314 			break;
315 		case 3:
316 			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
317 			break;
318 		}
319 		ret = 0;
320 		break;
321 	case POWER_SUPPLY_PROP_STATUS:
322 		if (!info->bat_online) {
323 			ret = -ENODATA;
324 			break;
325 		}
326 		ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
327 		if (info->usb_online || info->ac_online) {
328 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
329 			if (ret & MAX8925_CHG_STAT_EN_MASK)
330 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
331 		} else
332 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
333 		ret = 0;
334 		break;
335 	default:
336 		ret = -ENODEV;
337 		break;
338 	}
339 	return ret;
340 }
341 
342 static enum power_supply_property max8925_battery_props[] = {
343 	POWER_SUPPLY_PROP_ONLINE,
344 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
345 	POWER_SUPPLY_PROP_CURRENT_NOW,
346 	POWER_SUPPLY_PROP_CHARGE_TYPE,
347 	POWER_SUPPLY_PROP_STATUS,
348 };
349 
350 static const struct power_supply_desc ac_desc = {
351 	.name		= "max8925-ac",
352 	.type		= POWER_SUPPLY_TYPE_MAINS,
353 	.properties	= max8925_ac_props,
354 	.num_properties	= ARRAY_SIZE(max8925_ac_props),
355 	.get_property	= max8925_ac_get_prop,
356 };
357 
358 static const struct power_supply_desc usb_desc = {
359 	.name		= "max8925-usb",
360 	.type		= POWER_SUPPLY_TYPE_USB,
361 	.properties	= max8925_usb_props,
362 	.num_properties	= ARRAY_SIZE(max8925_usb_props),
363 	.get_property	= max8925_usb_get_prop,
364 };
365 
366 static const struct power_supply_desc battery_desc = {
367 	.name		= "max8925-battery",
368 	.type		= POWER_SUPPLY_TYPE_BATTERY,
369 	.properties	= max8925_battery_props,
370 	.num_properties	= ARRAY_SIZE(max8925_battery_props),
371 	.get_property	= max8925_bat_get_prop,
372 };
373 
374 #define REQUEST_IRQ(_irq, _name)					\
375 do {									\
376 	ret = request_threaded_irq(chip->irq_base + _irq, NULL,		\
377 				    max8925_charger_handler,		\
378 				    IRQF_ONESHOT, _name, info);		\
379 	if (ret)							\
380 		dev_err(chip->dev, "Failed to request IRQ #%d: %d\n",	\
381 			_irq, ret);					\
382 } while (0)
383 
384 static int max8925_init_charger(struct max8925_chip *chip,
385 					  struct max8925_power_info *info)
386 {
387 	int ret;
388 
389 	REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_OVP, "ac-ovp");
390 	if (!info->no_insert_detect) {
391 		REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_F, "ac-remove");
392 		REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_R, "ac-insert");
393 	}
394 	if (!info->no_temp_support) {
395 		REQUEST_IRQ(MAX8925_IRQ_VCHG_THM_OK_R, "batt-temp-in-range");
396 		REQUEST_IRQ(MAX8925_IRQ_VCHG_THM_OK_F, "batt-temp-out-range");
397 	}
398 	REQUEST_IRQ(MAX8925_IRQ_VCHG_SYSLOW_F, "vsys-high");
399 	REQUEST_IRQ(MAX8925_IRQ_VCHG_SYSLOW_R, "vsys-low");
400 	REQUEST_IRQ(MAX8925_IRQ_VCHG_RST, "charger-reset");
401 	REQUEST_IRQ(MAX8925_IRQ_VCHG_DONE, "charger-done");
402 	REQUEST_IRQ(MAX8925_IRQ_VCHG_TOPOFF, "charger-topoff");
403 	REQUEST_IRQ(MAX8925_IRQ_VCHG_TMR_FAULT, "charger-timer-expire");
404 
405 	info->usb_online = 0;
406 	info->bat_online = 0;
407 
408 	/* check for power - can miss interrupt at boot time */
409 	if (start_measure(info, MEASURE_VCHG) * 2000 > 500000)
410 		info->ac_online = 1;
411 	else
412 		info->ac_online = 0;
413 
414 	ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
415 	if (ret >= 0) {
416 		/*
417 		 * If battery detection is enabled, ID pin of battery is
418 		 * connected to MBDET pin of MAX8925. It could be used to
419 		 * detect battery presence.
420 		 * Otherwise, we have to assume that battery is always on.
421 		 */
422 		if (info->batt_detect)
423 			info->bat_online = (ret & MAX8925_CHG_MBDET) ? 0 : 1;
424 		else
425 			info->bat_online = 1;
426 		if (ret & MAX8925_CHG_AC_RANGE_MASK)
427 			info->ac_online = 1;
428 		else
429 			info->ac_online = 0;
430 	}
431 	/* disable charge */
432 	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 1 << 7);
433 	/* set charging current in charge topoff mode */
434 	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 3 << 5,
435 			 info->topoff_threshold << 5);
436 	/* set charing current in fast charge mode */
437 	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 7, info->fast_charge);
438 
439 	return 0;
440 }
441 
442 static int max8925_deinit_charger(struct max8925_power_info *info)
443 {
444 	struct max8925_chip *chip = info->chip;
445 	int irq;
446 
447 	irq = chip->irq_base + MAX8925_IRQ_VCHG_DC_OVP;
448 	for (; irq <= chip->irq_base + MAX8925_IRQ_VCHG_TMR_FAULT; irq++)
449 		free_irq(irq, info);
450 
451 	return 0;
452 }
453 
454 #ifdef CONFIG_OF
455 static struct max8925_power_pdata *
456 max8925_power_dt_init(struct platform_device *pdev)
457 {
458 	struct device_node *nproot = pdev->dev.parent->of_node;
459 	struct device_node *np;
460 	int batt_detect;
461 	int topoff_threshold;
462 	int fast_charge;
463 	int no_temp_support;
464 	int no_insert_detect;
465 	struct max8925_power_pdata *pdata;
466 
467 	if (!nproot)
468 		return pdev->dev.platform_data;
469 
470 	np = of_get_child_by_name(nproot, "charger");
471 	if (!np) {
472 		dev_err(&pdev->dev, "failed to find charger node\n");
473 		return NULL;
474 	}
475 
476 	pdata = devm_kzalloc(&pdev->dev,
477 			sizeof(struct max8925_power_pdata),
478 			GFP_KERNEL);
479 	if (!pdata)
480 		goto ret;
481 
482 	of_property_read_u32(np, "topoff-threshold", &topoff_threshold);
483 	of_property_read_u32(np, "batt-detect", &batt_detect);
484 	of_property_read_u32(np, "fast-charge", &fast_charge);
485 	of_property_read_u32(np, "no-insert-detect", &no_insert_detect);
486 	of_property_read_u32(np, "no-temp-support", &no_temp_support);
487 
488 	pdata->batt_detect = batt_detect;
489 	pdata->fast_charge = fast_charge;
490 	pdata->topoff_threshold = topoff_threshold;
491 	pdata->no_insert_detect = no_insert_detect;
492 	pdata->no_temp_support = no_temp_support;
493 
494 ret:
495 	of_node_put(np);
496 	return pdata;
497 }
498 #else
499 static struct max8925_power_pdata *
500 max8925_power_dt_init(struct platform_device *pdev)
501 {
502 	return pdev->dev.platform_data;
503 }
504 #endif
505 
506 static int max8925_power_probe(struct platform_device *pdev)
507 {
508 	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
509 	struct power_supply_config psy_cfg = {}; /* Only for ac and usb */
510 	struct max8925_power_pdata *pdata = NULL;
511 	struct max8925_power_info *info;
512 	int ret;
513 
514 	pdata = max8925_power_dt_init(pdev);
515 	if (!pdata) {
516 		dev_err(&pdev->dev, "platform data isn't assigned to "
517 			"power supply\n");
518 		return -EINVAL;
519 	}
520 
521 	info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_power_info),
522 				GFP_KERNEL);
523 	if (!info)
524 		return -ENOMEM;
525 	info->chip = chip;
526 	info->gpm = chip->i2c;
527 	info->adc = chip->adc;
528 	platform_set_drvdata(pdev, info);
529 
530 	psy_cfg.supplied_to = pdata->supplied_to;
531 	psy_cfg.num_supplicants = pdata->num_supplicants;
532 
533 	info->ac = power_supply_register(&pdev->dev, &ac_desc, &psy_cfg);
534 	if (IS_ERR(info->ac)) {
535 		ret = PTR_ERR(info->ac);
536 		goto out;
537 	}
538 	info->ac->dev.parent = &pdev->dev;
539 
540 	info->usb = power_supply_register(&pdev->dev, &usb_desc, &psy_cfg);
541 	if (IS_ERR(info->usb)) {
542 		ret = PTR_ERR(info->usb);
543 		goto out_unregister_ac;
544 	}
545 	info->usb->dev.parent = &pdev->dev;
546 
547 	info->battery = power_supply_register(&pdev->dev, &battery_desc, NULL);
548 	if (IS_ERR(info->battery)) {
549 		ret = PTR_ERR(info->battery);
550 		goto out_unregister_usb;
551 	}
552 	info->battery->dev.parent = &pdev->dev;
553 
554 	info->batt_detect = pdata->batt_detect;
555 	info->topoff_threshold = pdata->topoff_threshold;
556 	info->fast_charge = pdata->fast_charge;
557 	info->set_charger = pdata->set_charger;
558 	info->no_temp_support = pdata->no_temp_support;
559 	info->no_insert_detect = pdata->no_insert_detect;
560 
561 	max8925_init_charger(chip, info);
562 	return 0;
563 out_unregister_usb:
564 	power_supply_unregister(info->usb);
565 out_unregister_ac:
566 	power_supply_unregister(info->ac);
567 out:
568 	return ret;
569 }
570 
571 static int max8925_power_remove(struct platform_device *pdev)
572 {
573 	struct max8925_power_info *info = platform_get_drvdata(pdev);
574 
575 	if (info) {
576 		power_supply_unregister(info->ac);
577 		power_supply_unregister(info->usb);
578 		power_supply_unregister(info->battery);
579 		max8925_deinit_charger(info);
580 	}
581 	return 0;
582 }
583 
584 static struct platform_driver max8925_power_driver = {
585 	.probe	= max8925_power_probe,
586 	.remove	= max8925_power_remove,
587 	.driver	= {
588 		.name	= "max8925-power",
589 	},
590 };
591 
592 module_platform_driver(max8925_power_driver);
593 
594 MODULE_LICENSE("GPL");
595 MODULE_DESCRIPTION("Power supply driver for MAX8925");
596 MODULE_ALIAS("platform:max8925-power");
597