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 
54 struct 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 
67 static 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 
76 static 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 
91 static 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 
110 static 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 
134 static 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 
149 static 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 
165 static 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 
201 static int
202 sc2731_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 
238 static 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 
284 out:
285 	mutex_unlock(&info->lock);
286 	return ret;
287 }
288 
289 static 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 
307 static 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 
313 static 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 
323 static 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 
352 out:
353 	mutex_unlock(&info->lock);
354 }
355 
356 static 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 
369 static 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 
432 error:
433 	regmap_update_bits(info->regmap, SC2731_MODULE_EN1, SC2731_CHARGE_EN, 0);
434 	return ret;
435 }
436 
437 static 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 
455 static 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 
514 static 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 
523 static const struct of_device_id sc2731_charger_of_match[] = {
524 	{ .compatible = "sprd,sc2731-charger", },
525 	{ }
526 };
527 
528 static struct platform_driver sc2731_charger_driver = {
529 	.driver = {
530 		.name = "sc2731-charger",
531 		.of_match_table = sc2731_charger_of_match,
532 	},
533 	.probe = sc2731_charger_probe,
534 	.remove = sc2731_charger_remove,
535 };
536 
537 module_platform_driver(sc2731_charger_driver);
538 
539 MODULE_DESCRIPTION("Spreadtrum SC2731 Charger Driver");
540 MODULE_LICENSE("GPL v2");
541