1// SPDX-License-Identifier: GPL-2.0
2//
3// Copyright (C) 2018 BayLibre SAS
4// Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
5//
6// Battery charger driver for MAXIM 77650/77651 charger/power-supply.
7
8#include <linux/i2c.h>
9#include <linux/interrupt.h>
10#include <linux/mfd/max77650.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/power_supply.h>
14#include <linux/regmap.h>
15
16#define MAX77650_CHARGER_ENABLED		BIT(0)
17#define MAX77650_CHARGER_DISABLED		0x00
18#define MAX77650_CHARGER_CHG_EN_MASK		BIT(0)
19
20#define MAX77650_CHG_DETAILS_MASK		GENMASK(7, 4)
21#define MAX77650_CHG_DETAILS_BITS(_reg) \
22		(((_reg) & MAX77650_CHG_DETAILS_MASK) >> 4)
23
24/* Charger is OFF. */
25#define MAX77650_CHG_OFF			0x00
26/* Charger is in prequalification mode. */
27#define MAX77650_CHG_PREQ			0x01
28/* Charger is in fast-charge constant current mode. */
29#define MAX77650_CHG_ON_CURR			0x02
30/* Charger is in JEITA modified fast-charge constant-current mode. */
31#define MAX77650_CHG_ON_CURR_JEITA		0x03
32/* Charger is in fast-charge constant-voltage mode. */
33#define MAX77650_CHG_ON_VOLT			0x04
34/* Charger is in JEITA modified fast-charge constant-voltage mode. */
35#define MAX77650_CHG_ON_VOLT_JEITA		0x05
36/* Charger is in top-off mode. */
37#define MAX77650_CHG_ON_TOPOFF			0x06
38/* Charger is in JEITA modified top-off mode. */
39#define MAX77650_CHG_ON_TOPOFF_JEITA		0x07
40/* Charger is done. */
41#define MAX77650_CHG_DONE			0x08
42/* Charger is JEITA modified done. */
43#define MAX77650_CHG_DONE_JEITA			0x09
44/* Charger is suspended due to a prequalification timer fault. */
45#define MAX77650_CHG_SUSP_PREQ_TIM_FAULT	0x0a
46/* Charger is suspended due to a fast-charge timer fault. */
47#define MAX77650_CHG_SUSP_FAST_CHG_TIM_FAULT	0x0b
48/* Charger is suspended due to a battery temperature fault. */
49#define MAX77650_CHG_SUSP_BATT_TEMP_FAULT	0x0c
50
51#define MAX77650_CHGIN_DETAILS_MASK		GENMASK(3, 2)
52#define MAX77650_CHGIN_DETAILS_BITS(_reg) \
53		(((_reg) & MAX77650_CHGIN_DETAILS_MASK) >> 2)
54
55#define MAX77650_CHGIN_UNDERVOLTAGE_LOCKOUT	0x00
56#define MAX77650_CHGIN_OVERVOLTAGE_LOCKOUT	0x01
57#define MAX77650_CHGIN_OKAY			0x11
58
59#define MAX77650_CHARGER_CHG_MASK	BIT(1)
60#define MAX77650_CHARGER_CHG_CHARGING(_reg) \
61		(((_reg) & MAX77650_CHARGER_CHG_MASK) > 1)
62
63#define MAX77650_CHARGER_VCHGIN_MIN_MASK	0xc0
64#define MAX77650_CHARGER_VCHGIN_MIN_SHIFT(_val)	((_val) << 5)
65
66#define MAX77650_CHARGER_ICHGIN_LIM_MASK	0x1c
67#define MAX77650_CHARGER_ICHGIN_LIM_SHIFT(_val)	((_val) << 2)
68
69struct max77650_charger_data {
70	struct regmap *map;
71	struct device *dev;
72};
73
74static enum power_supply_property max77650_charger_properties[] = {
75	POWER_SUPPLY_PROP_STATUS,
76	POWER_SUPPLY_PROP_ONLINE,
77	POWER_SUPPLY_PROP_CHARGE_TYPE
78};
79
80static const unsigned int max77650_charger_vchgin_min_table[] = {
81	4000000, 4100000, 4200000, 4300000, 4400000, 4500000, 4600000, 4700000
82};
83
84static const unsigned int max77650_charger_ichgin_lim_table[] = {
85	95000, 190000, 285000, 380000, 475000
86};
87
88static int max77650_charger_set_vchgin_min(struct max77650_charger_data *chg,
89					   unsigned int val)
90{
91	int i, rv;
92
93	for (i = 0; i < ARRAY_SIZE(max77650_charger_vchgin_min_table); i++) {
94		if (val == max77650_charger_vchgin_min_table[i]) {
95			rv = regmap_update_bits(chg->map,
96					MAX77650_REG_CNFG_CHG_B,
97					MAX77650_CHARGER_VCHGIN_MIN_MASK,
98					MAX77650_CHARGER_VCHGIN_MIN_SHIFT(i));
99			if (rv)
100				return rv;
101
102			return 0;
103		}
104	}
105
106	return -EINVAL;
107}
108
109static int max77650_charger_set_ichgin_lim(struct max77650_charger_data *chg,
110					   unsigned int val)
111{
112	int i, rv;
113
114	for (i = 0; i < ARRAY_SIZE(max77650_charger_ichgin_lim_table); i++) {
115		if (val == max77650_charger_ichgin_lim_table[i]) {
116			rv = regmap_update_bits(chg->map,
117					MAX77650_REG_CNFG_CHG_B,
118					MAX77650_CHARGER_ICHGIN_LIM_MASK,
119					MAX77650_CHARGER_ICHGIN_LIM_SHIFT(i));
120			if (rv)
121				return rv;
122
123			return 0;
124		}
125	}
126
127	return -EINVAL;
128}
129
130static int max77650_charger_enable(struct max77650_charger_data *chg)
131{
132	int rv;
133
134	rv = regmap_update_bits(chg->map,
135				MAX77650_REG_CNFG_CHG_B,
136				MAX77650_CHARGER_CHG_EN_MASK,
137				MAX77650_CHARGER_ENABLED);
138	if (rv)
139		dev_err(chg->dev, "unable to enable the charger: %d\n", rv);
140
141	return rv;
142}
143
144static void max77650_charger_disable(struct max77650_charger_data *chg)
145{
146	int rv;
147
148	rv = regmap_update_bits(chg->map,
149				MAX77650_REG_CNFG_CHG_B,
150				MAX77650_CHARGER_CHG_EN_MASK,
151				MAX77650_CHARGER_DISABLED);
152	if (rv)
153		dev_err(chg->dev, "unable to disable the charger: %d\n", rv);
154}
155
156static irqreturn_t max77650_charger_check_status(int irq, void *data)
157{
158	struct max77650_charger_data *chg = data;
159	int rv, reg;
160
161	rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
162	if (rv) {
163		dev_err(chg->dev,
164			"unable to read the charger status: %d\n", rv);
165		return IRQ_HANDLED;
166	}
167
168	switch (MAX77650_CHGIN_DETAILS_BITS(reg)) {
169	case MAX77650_CHGIN_UNDERVOLTAGE_LOCKOUT:
170		dev_err(chg->dev, "undervoltage lockout detected, disabling charger\n");
171		max77650_charger_disable(chg);
172		break;
173	case MAX77650_CHGIN_OVERVOLTAGE_LOCKOUT:
174		dev_err(chg->dev, "overvoltage lockout detected, disabling charger\n");
175		max77650_charger_disable(chg);
176		break;
177	case MAX77650_CHGIN_OKAY:
178		max77650_charger_enable(chg);
179		break;
180	default:
181		/* May be 0x10 - debouncing */
182		break;
183	}
184
185	return IRQ_HANDLED;
186}
187
188static int max77650_charger_get_property(struct power_supply *psy,
189					 enum power_supply_property psp,
190					 union power_supply_propval *val)
191{
192	struct max77650_charger_data *chg = power_supply_get_drvdata(psy);
193	int rv, reg;
194
195	switch (psp) {
196	case POWER_SUPPLY_PROP_STATUS:
197		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
198		if (rv)
199			return rv;
200
201		if (MAX77650_CHARGER_CHG_CHARGING(reg)) {
202			val->intval = POWER_SUPPLY_STATUS_CHARGING;
203			break;
204		}
205
206		switch (MAX77650_CHG_DETAILS_BITS(reg)) {
207		case MAX77650_CHG_OFF:
208		case MAX77650_CHG_SUSP_PREQ_TIM_FAULT:
209		case MAX77650_CHG_SUSP_FAST_CHG_TIM_FAULT:
210		case MAX77650_CHG_SUSP_BATT_TEMP_FAULT:
211			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
212			break;
213		case MAX77650_CHG_PREQ:
214		case MAX77650_CHG_ON_CURR:
215		case MAX77650_CHG_ON_CURR_JEITA:
216		case MAX77650_CHG_ON_VOLT:
217		case MAX77650_CHG_ON_VOLT_JEITA:
218		case MAX77650_CHG_ON_TOPOFF:
219		case MAX77650_CHG_ON_TOPOFF_JEITA:
220			val->intval = POWER_SUPPLY_STATUS_CHARGING;
221			break;
222		case MAX77650_CHG_DONE:
223			val->intval = POWER_SUPPLY_STATUS_FULL;
224			break;
225		default:
226			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
227		}
228		break;
229	case POWER_SUPPLY_PROP_ONLINE:
230		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
231		if (rv)
232			return rv;
233
234		val->intval = MAX77650_CHARGER_CHG_CHARGING(reg);
235		break;
236	case POWER_SUPPLY_PROP_CHARGE_TYPE:
237		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
238		if (rv)
239			return rv;
240
241		if (!MAX77650_CHARGER_CHG_CHARGING(reg)) {
242			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
243			break;
244		}
245
246		switch (MAX77650_CHG_DETAILS_BITS(reg)) {
247		case MAX77650_CHG_PREQ:
248		case MAX77650_CHG_ON_CURR:
249		case MAX77650_CHG_ON_CURR_JEITA:
250		case MAX77650_CHG_ON_VOLT:
251		case MAX77650_CHG_ON_VOLT_JEITA:
252			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
253			break;
254		case MAX77650_CHG_ON_TOPOFF:
255		case MAX77650_CHG_ON_TOPOFF_JEITA:
256			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
257			break;
258		default:
259			val->intval = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
260		}
261		break;
262	default:
263		return -EINVAL;
264	}
265
266	return 0;
267}
268
269static const struct power_supply_desc max77650_battery_desc = {
270	.name		= "max77650",
271	.type		= POWER_SUPPLY_TYPE_USB,
272	.get_property	= max77650_charger_get_property,
273	.properties	= max77650_charger_properties,
274	.num_properties	= ARRAY_SIZE(max77650_charger_properties),
275};
276
277static int max77650_charger_probe(struct platform_device *pdev)
278{
279	struct power_supply_config pscfg = {};
280	struct max77650_charger_data *chg;
281	struct power_supply *battery;
282	struct device *dev, *parent;
283	int rv, chg_irq, chgin_irq;
284	unsigned int prop;
285
286	dev = &pdev->dev;
287	parent = dev->parent;
288
289	chg = devm_kzalloc(dev, sizeof(*chg), GFP_KERNEL);
290	if (!chg)
291		return -ENOMEM;
292
293	platform_set_drvdata(pdev, chg);
294
295	chg->map = dev_get_regmap(parent, NULL);
296	if (!chg->map)
297		return -ENODEV;
298
299	chg->dev = dev;
300
301	pscfg.of_node = dev->of_node;
302	pscfg.drv_data = chg;
303
304	chg_irq = platform_get_irq_byname(pdev, "CHG");
305	if (chg_irq < 0)
306		return chg_irq;
307
308	chgin_irq = platform_get_irq_byname(pdev, "CHGIN");
309	if (chgin_irq < 0)
310		return chgin_irq;
311
312	rv = devm_request_any_context_irq(dev, chg_irq,
313					  max77650_charger_check_status,
314					  IRQF_ONESHOT, "chg", chg);
315	if (rv < 0)
316		return rv;
317
318	rv = devm_request_any_context_irq(dev, chgin_irq,
319					  max77650_charger_check_status,
320					  IRQF_ONESHOT, "chgin", chg);
321	if (rv < 0)
322		return rv;
323
324	battery = devm_power_supply_register(dev,
325					     &max77650_battery_desc, &pscfg);
326	if (IS_ERR(battery))
327		return PTR_ERR(battery);
328
329	rv = of_property_read_u32(dev->of_node,
330				  "input-voltage-min-microvolt", &prop);
331	if (rv == 0) {
332		rv = max77650_charger_set_vchgin_min(chg, prop);
333		if (rv)
334			return rv;
335	}
336
337	rv = of_property_read_u32(dev->of_node,
338				  "input-current-limit-microamp", &prop);
339	if (rv == 0) {
340		rv = max77650_charger_set_ichgin_lim(chg, prop);
341		if (rv)
342			return rv;
343	}
344
345	return max77650_charger_enable(chg);
346}
347
348static int max77650_charger_remove(struct platform_device *pdev)
349{
350	struct max77650_charger_data *chg = platform_get_drvdata(pdev);
351
352	max77650_charger_disable(chg);
353
354	return 0;
355}
356
357static const struct of_device_id max77650_charger_of_match[] = {
358	{ .compatible = "maxim,max77650-charger" },
359	{ }
360};
361MODULE_DEVICE_TABLE(of, max77650_charger_of_match);
362
363static struct platform_driver max77650_charger_driver = {
364	.driver = {
365		.name = "max77650-charger",
366		.of_match_table = max77650_charger_of_match,
367	},
368	.probe = max77650_charger_probe,
369	.remove = max77650_charger_remove,
370};
371module_platform_driver(max77650_charger_driver);
372
373MODULE_DESCRIPTION("MAXIM 77650/77651 charger driver");
374MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
375MODULE_LICENSE("GPL v2");
376MODULE_ALIAS("platform:max77650-charger");
377