1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Spreadtrum Communications Inc.
3
4#include <linux/module.h>
5#include <linux/platform_device.h>
6#include <linux/power_supply.h>
7#include <linux/usb/phy.h>
8#include <linux/regmap.h>
9#include <linux/notifier.h>
10#include <linux/of.h>
11
12/* PMIC global registers definition */
13#define SC2731_CHARGE_STATUS		0xedc
14#define SC2731_CHARGE_FULL		BIT(4)
15#define SC2731_MODULE_EN1		0xc0c
16#define SC2731_CHARGE_EN		BIT(5)
17
18/* SC2731 switch charger registers definition */
19#define SC2731_CHG_CFG0			0x0
20#define SC2731_CHG_CFG1			0x4
21#define SC2731_CHG_CFG2			0x8
22#define SC2731_CHG_CFG3			0xc
23#define SC2731_CHG_CFG4			0x10
24#define SC2731_CHG_CFG5			0x28
25
26/* SC2731_CHG_CFG0 register definition */
27#define SC2731_PRECHG_RNG_SHIFT		11
28#define SC2731_PRECHG_RNG_MASK		GENMASK(12, 11)
29
30#define SC2731_TERMINATION_VOL_MASK	GENMASK(2, 1)
31#define SC2731_TERMINATION_VOL_SHIFT	1
32#define SC2731_TERMINATION_VOL_CAL_MASK	GENMASK(8, 3)
33#define SC2731_TERMINATION_VOL_CAL_SHIFT	3
34#define SC2731_TERMINATION_CUR_MASK	GENMASK(2, 0)
35
36#define SC2731_CC_EN			BIT(13)
37#define SC2731_CHARGER_PD		BIT(0)
38
39/* SC2731_CHG_CFG1 register definition */
40#define SC2731_CUR_MASK			GENMASK(5, 0)
41
42/* SC2731_CHG_CFG5 register definition */
43#define SC2731_CUR_LIMIT_SHIFT		8
44#define SC2731_CUR_LIMIT_MASK		GENMASK(9, 8)
45
46/* Default current definition (unit is mA) */
47#define SC2731_CURRENT_LIMIT_100	100
48#define SC2731_CURRENT_LIMIT_500	500
49#define SC2731_CURRENT_LIMIT_900	900
50#define SC2731_CURRENT_LIMIT_2000	2000
51#define SC2731_CURRENT_PRECHG		450
52#define SC2731_CURRENT_STEP		50
53
54struct sc2731_charger_info {
55	struct device *dev;
56	struct regmap *regmap;
57	struct usb_phy *usb_phy;
58	struct notifier_block usb_notify;
59	struct power_supply *psy_usb;
60	struct work_struct work;
61	struct mutex lock;
62	bool charging;
63	u32 base;
64	u32 limit;
65};
66
67static void sc2731_charger_stop_charge(struct sc2731_charger_info *info)
68{
69	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
70			   SC2731_CC_EN, 0);
71
72	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
73			   SC2731_CHARGER_PD, SC2731_CHARGER_PD);
74}
75
76static int sc2731_charger_start_charge(struct sc2731_charger_info *info)
77{
78	int ret;
79
80	/* Enable charger constant current mode */
81	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
82				 SC2731_CC_EN, SC2731_CC_EN);
83	if (ret)
84		return ret;
85
86	/* Start charging */
87	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
88				  SC2731_CHARGER_PD, 0);
89}
90
91static int sc2731_charger_set_current_limit(struct sc2731_charger_info *info,
92					    u32 limit)
93{
94	u32 val;
95
96	if (limit <= SC2731_CURRENT_LIMIT_100)
97		val = 0;
98	else if (limit <= SC2731_CURRENT_LIMIT_500)
99		val = 3;
100	else if (limit <= SC2731_CURRENT_LIMIT_900)
101		val = 2;
102	else
103		val = 1;
104
105	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG5,
106				  SC2731_CUR_LIMIT_MASK,
107				  val << SC2731_CUR_LIMIT_SHIFT);
108}
109
110static int sc2731_charger_set_current(struct sc2731_charger_info *info, u32 cur)
111{
112	u32 val;
113	int ret;
114
115	if (cur > SC2731_CURRENT_LIMIT_2000)
116		cur = SC2731_CURRENT_LIMIT_2000;
117	else if (cur < SC2731_CURRENT_PRECHG)
118		cur = SC2731_CURRENT_PRECHG;
119
120	/* Calculate the step value, each step is 50 mA */
121	val = (cur - SC2731_CURRENT_PRECHG) / SC2731_CURRENT_STEP;
122
123	/* Set pre-charge current as 450 mA */
124	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
125				 SC2731_PRECHG_RNG_MASK,
126				 0x3 << SC2731_PRECHG_RNG_SHIFT);
127	if (ret)
128		return ret;
129
130	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG1,
131				  SC2731_CUR_MASK, val);
132}
133
134static int sc2731_charger_get_status(struct sc2731_charger_info *info)
135{
136	u32 val;
137	int ret;
138
139	ret = regmap_read(info->regmap, SC2731_CHARGE_STATUS, &val);
140	if (ret)
141		return ret;
142
143	if (val & SC2731_CHARGE_FULL)
144		return POWER_SUPPLY_STATUS_FULL;
145
146	return POWER_SUPPLY_STATUS_CHARGING;
147}
148
149static int sc2731_charger_get_current(struct sc2731_charger_info *info,
150				      u32 *cur)
151{
152	int ret;
153	u32 val;
154
155	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG1, &val);
156	if (ret)
157		return ret;
158
159	val &= SC2731_CUR_MASK;
160	*cur = val * SC2731_CURRENT_STEP + SC2731_CURRENT_PRECHG;
161
162	return 0;
163}
164
165static int sc2731_charger_get_current_limit(struct sc2731_charger_info *info,
166					    u32 *cur)
167{
168	int ret;
169	u32 val;
170
171	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG5, &val);
172	if (ret)
173		return ret;
174
175	val = (val & SC2731_CUR_LIMIT_MASK) >> SC2731_CUR_LIMIT_SHIFT;
176
177	switch (val) {
178	case 0:
179		*cur = SC2731_CURRENT_LIMIT_100;
180		break;
181
182	case 1:
183		*cur = SC2731_CURRENT_LIMIT_2000;
184		break;
185
186	case 2:
187		*cur = SC2731_CURRENT_LIMIT_900;
188		break;
189
190	case 3:
191		*cur = SC2731_CURRENT_LIMIT_500;
192		break;
193
194	default:
195		return -EINVAL;
196	}
197
198	return 0;
199}
200
201static int
202sc2731_charger_usb_set_property(struct power_supply *psy,
203				enum power_supply_property psp,
204				const union power_supply_propval *val)
205{
206	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
207	int ret;
208
209	mutex_lock(&info->lock);
210
211	if (!info->charging) {
212		mutex_unlock(&info->lock);
213		return -ENODEV;
214	}
215
216	switch (psp) {
217	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
218		ret = sc2731_charger_set_current(info, val->intval / 1000);
219		if (ret < 0)
220			dev_err(info->dev, "set charge current failed\n");
221		break;
222
223	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
224		ret = sc2731_charger_set_current_limit(info,
225						       val->intval / 1000);
226		if (ret < 0)
227			dev_err(info->dev, "set input current limit failed\n");
228		break;
229
230	default:
231		ret = -EINVAL;
232	}
233
234	mutex_unlock(&info->lock);
235	return ret;
236}
237
238static int sc2731_charger_usb_get_property(struct power_supply *psy,
239					   enum power_supply_property psp,
240					   union power_supply_propval *val)
241{
242	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
243	int ret = 0;
244	u32 cur;
245
246	mutex_lock(&info->lock);
247
248	switch (psp) {
249	case POWER_SUPPLY_PROP_STATUS:
250		if (info->charging)
251			val->intval = sc2731_charger_get_status(info);
252		else
253			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
254		break;
255
256	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
257		if (!info->charging) {
258			val->intval = 0;
259		} else {
260			ret = sc2731_charger_get_current(info, &cur);
261			if (ret)
262				goto out;
263
264			val->intval = cur * 1000;
265		}
266		break;
267
268	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
269		if (!info->charging) {
270			val->intval = 0;
271		} else {
272			ret = sc2731_charger_get_current_limit(info, &cur);
273			if (ret)
274				goto out;
275
276			val->intval = cur * 1000;
277		}
278		break;
279
280	default:
281		ret = -EINVAL;
282	}
283
284out:
285	mutex_unlock(&info->lock);
286	return ret;
287}
288
289static int sc2731_charger_property_is_writeable(struct power_supply *psy,
290						enum power_supply_property psp)
291{
292	int ret;
293
294	switch (psp) {
295	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
296	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
297		ret = 1;
298		break;
299
300	default:
301		ret = 0;
302	}
303
304	return ret;
305}
306
307static enum power_supply_property sc2731_usb_props[] = {
308	POWER_SUPPLY_PROP_STATUS,
309	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
310	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
311};
312
313static const struct power_supply_desc sc2731_charger_desc = {
314	.name			= "sc2731_charger",
315	.type			= POWER_SUPPLY_TYPE_USB,
316	.properties		= sc2731_usb_props,
317	.num_properties		= ARRAY_SIZE(sc2731_usb_props),
318	.get_property		= sc2731_charger_usb_get_property,
319	.set_property		= sc2731_charger_usb_set_property,
320	.property_is_writeable	= sc2731_charger_property_is_writeable,
321};
322
323static void sc2731_charger_work(struct work_struct *data)
324{
325	struct sc2731_charger_info *info =
326		container_of(data, struct sc2731_charger_info, work);
327	int ret;
328
329	mutex_lock(&info->lock);
330
331	if (info->limit > 0 && !info->charging) {
332		/* set current limitation and start to charge */
333		ret = sc2731_charger_set_current_limit(info, info->limit);
334		if (ret)
335			goto out;
336
337		ret = sc2731_charger_set_current(info, info->limit);
338		if (ret)
339			goto out;
340
341		ret = sc2731_charger_start_charge(info);
342		if (ret)
343			goto out;
344
345		info->charging = true;
346	} else if (!info->limit && info->charging) {
347		/* Stop charging */
348		info->charging = false;
349		sc2731_charger_stop_charge(info);
350	}
351
352out:
353	mutex_unlock(&info->lock);
354}
355
356static int sc2731_charger_usb_change(struct notifier_block *nb,
357				     unsigned long limit, void *data)
358{
359	struct sc2731_charger_info *info =
360		container_of(nb, struct sc2731_charger_info, usb_notify);
361
362	info->limit = limit;
363
364	schedule_work(&info->work);
365
366	return NOTIFY_OK;
367}
368
369static int sc2731_charger_hw_init(struct sc2731_charger_info *info)
370{
371	struct power_supply_battery_info *bat_info;
372	u32 term_currrent, term_voltage, cur_val, vol_val;
373	int ret;
374
375	/* Enable charger module */
376	ret = regmap_update_bits(info->regmap, SC2731_MODULE_EN1,
377				 SC2731_CHARGE_EN, SC2731_CHARGE_EN);
378	if (ret)
379		return ret;
380
381	ret = power_supply_get_battery_info(info->psy_usb, &bat_info);
382	if (ret) {
383		dev_warn(info->dev, "no battery information is supplied\n");
384
385		/*
386		 * If no battery information is supplied, we should set
387		 * default charge termination current to 120 mA, and default
388		 * charge termination voltage to 4.35V.
389		 */
390		cur_val = 0x2;
391		vol_val = 0x1;
392	} else {
393		term_currrent = bat_info->charge_term_current_ua / 1000;
394
395		if (term_currrent <= 90)
396			cur_val = 0;
397		else if (term_currrent >= 265)
398			cur_val = 0x7;
399		else
400			cur_val = ((term_currrent - 90) / 25) + 1;
401
402		term_voltage = bat_info->constant_charge_voltage_max_uv / 1000;
403
404		if (term_voltage > 4500)
405			term_voltage = 4500;
406
407		if (term_voltage > 4200)
408			vol_val = (term_voltage - 4200) / 100;
409		else
410			vol_val = 0;
411
412		power_supply_put_battery_info(info->psy_usb, bat_info);
413	}
414
415	/* Set charge termination current */
416	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG2,
417				 SC2731_TERMINATION_CUR_MASK, cur_val);
418	if (ret)
419		goto error;
420
421	/* Set charge termination voltage */
422	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
423				 SC2731_TERMINATION_VOL_MASK |
424				 SC2731_TERMINATION_VOL_CAL_MASK,
425				 (vol_val << SC2731_TERMINATION_VOL_SHIFT) |
426				 (0x6 << SC2731_TERMINATION_VOL_CAL_SHIFT));
427	if (ret)
428		goto error;
429
430	return 0;
431
432error:
433	regmap_update_bits(info->regmap, SC2731_MODULE_EN1, SC2731_CHARGE_EN, 0);
434	return ret;
435}
436
437static void sc2731_charger_detect_status(struct sc2731_charger_info *info)
438{
439	unsigned int min, max;
440
441	/*
442	 * If the USB charger status has been USB_CHARGER_PRESENT before
443	 * registering the notifier, we should start to charge with getting
444	 * the charge current.
445	 */
446	if (info->usb_phy->chg_state != USB_CHARGER_PRESENT)
447		return;
448
449	usb_phy_get_charger_current(info->usb_phy, &min, &max);
450	info->limit = min;
451
452	schedule_work(&info->work);
453}
454
455static int sc2731_charger_probe(struct platform_device *pdev)
456{
457	struct device_node *np = pdev->dev.of_node;
458	struct sc2731_charger_info *info;
459	struct power_supply_config charger_cfg = { };
460	int ret;
461
462	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
463	if (!info)
464		return -ENOMEM;
465
466	mutex_init(&info->lock);
467	info->dev = &pdev->dev;
468	INIT_WORK(&info->work, sc2731_charger_work);
469
470	info->regmap = dev_get_regmap(pdev->dev.parent, NULL);
471	if (!info->regmap) {
472		dev_err(&pdev->dev, "failed to get charger regmap\n");
473		return -ENODEV;
474	}
475
476	ret = of_property_read_u32(np, "reg", &info->base);
477	if (ret) {
478		dev_err(&pdev->dev, "failed to get register address\n");
479		return -ENODEV;
480	}
481
482	charger_cfg.drv_data = info;
483	charger_cfg.of_node = np;
484	info->psy_usb = devm_power_supply_register(&pdev->dev,
485						   &sc2731_charger_desc,
486						   &charger_cfg);
487	if (IS_ERR(info->psy_usb)) {
488		dev_err(&pdev->dev, "failed to register power supply\n");
489		return PTR_ERR(info->psy_usb);
490	}
491
492	ret = sc2731_charger_hw_init(info);
493	if (ret)
494		return ret;
495
496	info->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "phys", 0);
497	if (IS_ERR(info->usb_phy)) {
498		dev_err(&pdev->dev, "failed to find USB phy\n");
499		return PTR_ERR(info->usb_phy);
500	}
501
502	info->usb_notify.notifier_call = sc2731_charger_usb_change;
503	ret = usb_register_notifier(info->usb_phy, &info->usb_notify);
504	if (ret) {
505		dev_err(&pdev->dev, "failed to register notifier: %d\n", ret);
506		return ret;
507	}
508
509	sc2731_charger_detect_status(info);
510
511	return 0;
512}
513
514static int sc2731_charger_remove(struct platform_device *pdev)
515{
516	struct sc2731_charger_info *info = platform_get_drvdata(pdev);
517
518	usb_unregister_notifier(info->usb_phy, &info->usb_notify);
519
520	return 0;
521}
522
523static const struct of_device_id sc2731_charger_of_match[] = {
524	{ .compatible = "sprd,sc2731-charger", },
525	{ }
526};
527MODULE_DEVICE_TABLE(of, sc2731_charger_of_match);
528
529static struct platform_driver sc2731_charger_driver = {
530	.driver = {
531		.name = "sc2731-charger",
532		.of_match_table = sc2731_charger_of_match,
533	},
534	.probe = sc2731_charger_probe,
535	.remove = sc2731_charger_remove,
536};
537
538module_platform_driver(sc2731_charger_driver);
539
540MODULE_DESCRIPTION("Spreadtrum SC2731 Charger Driver");
541MODULE_LICENSE("GPL v2");
542