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 
69 struct max77650_charger_data {
70 	struct regmap *map;
71 	struct device *dev;
72 };
73 
74 static 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 
80 static const unsigned int max77650_charger_vchgin_min_table[] = {
81 	4000000, 4100000, 4200000, 4300000, 4400000, 4500000, 4600000, 4700000
82 };
83 
84 static const unsigned int max77650_charger_ichgin_lim_table[] = {
85 	95000, 190000, 285000, 380000, 475000
86 };
87 
88 static 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 
109 static 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 
130 static 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 
144 static int 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 	return rv;
156 }
157 
158 static irqreturn_t max77650_charger_check_status(int irq, void *data)
159 {
160 	struct max77650_charger_data *chg = data;
161 	int rv, reg;
162 
163 	rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
164 	if (rv) {
165 		dev_err(chg->dev,
166 			"unable to read the charger status: %d\n", rv);
167 		return IRQ_HANDLED;
168 	}
169 
170 	switch (MAX77650_CHGIN_DETAILS_BITS(reg)) {
171 	case MAX77650_CHGIN_UNDERVOLTAGE_LOCKOUT:
172 		dev_err(chg->dev, "undervoltage lockout detected, disabling charger\n");
173 		max77650_charger_disable(chg);
174 		break;
175 	case MAX77650_CHGIN_OVERVOLTAGE_LOCKOUT:
176 		dev_err(chg->dev, "overvoltage lockout detected, disabling charger\n");
177 		max77650_charger_disable(chg);
178 		break;
179 	case MAX77650_CHGIN_OKAY:
180 		max77650_charger_enable(chg);
181 		break;
182 	default:
183 		/* May be 0x10 - debouncing */
184 		break;
185 	}
186 
187 	return IRQ_HANDLED;
188 }
189 
190 static int max77650_charger_get_property(struct power_supply *psy,
191 					 enum power_supply_property psp,
192 					 union power_supply_propval *val)
193 {
194 	struct max77650_charger_data *chg = power_supply_get_drvdata(psy);
195 	int rv, reg;
196 
197 	switch (psp) {
198 	case POWER_SUPPLY_PROP_STATUS:
199 		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
200 		if (rv)
201 			return rv;
202 
203 		if (MAX77650_CHARGER_CHG_CHARGING(reg)) {
204 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
205 			break;
206 		}
207 
208 		switch (MAX77650_CHG_DETAILS_BITS(reg)) {
209 		case MAX77650_CHG_OFF:
210 		case MAX77650_CHG_SUSP_PREQ_TIM_FAULT:
211 		case MAX77650_CHG_SUSP_FAST_CHG_TIM_FAULT:
212 		case MAX77650_CHG_SUSP_BATT_TEMP_FAULT:
213 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
214 			break;
215 		case MAX77650_CHG_PREQ:
216 		case MAX77650_CHG_ON_CURR:
217 		case MAX77650_CHG_ON_CURR_JEITA:
218 		case MAX77650_CHG_ON_VOLT:
219 		case MAX77650_CHG_ON_VOLT_JEITA:
220 		case MAX77650_CHG_ON_TOPOFF:
221 		case MAX77650_CHG_ON_TOPOFF_JEITA:
222 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
223 			break;
224 		case MAX77650_CHG_DONE:
225 			val->intval = POWER_SUPPLY_STATUS_FULL;
226 			break;
227 		default:
228 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
229 		}
230 		break;
231 	case POWER_SUPPLY_PROP_ONLINE:
232 		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
233 		if (rv)
234 			return rv;
235 
236 		val->intval = MAX77650_CHARGER_CHG_CHARGING(reg);
237 		break;
238 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
239 		rv = regmap_read(chg->map, MAX77650_REG_STAT_CHG_B, &reg);
240 		if (rv)
241 			return rv;
242 
243 		if (!MAX77650_CHARGER_CHG_CHARGING(reg)) {
244 			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
245 			break;
246 		}
247 
248 		switch (MAX77650_CHG_DETAILS_BITS(reg)) {
249 		case MAX77650_CHG_PREQ:
250 		case MAX77650_CHG_ON_CURR:
251 		case MAX77650_CHG_ON_CURR_JEITA:
252 		case MAX77650_CHG_ON_VOLT:
253 		case MAX77650_CHG_ON_VOLT_JEITA:
254 			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
255 			break;
256 		case MAX77650_CHG_ON_TOPOFF:
257 		case MAX77650_CHG_ON_TOPOFF_JEITA:
258 			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
259 			break;
260 		default:
261 			val->intval = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
262 		}
263 		break;
264 	default:
265 		return -EINVAL;
266 	}
267 
268 	return 0;
269 }
270 
271 static const struct power_supply_desc max77650_battery_desc = {
272 	.name		= "max77650",
273 	.type		= POWER_SUPPLY_TYPE_USB,
274 	.get_property	= max77650_charger_get_property,
275 	.properties	= max77650_charger_properties,
276 	.num_properties	= ARRAY_SIZE(max77650_charger_properties),
277 };
278 
279 static int max77650_charger_probe(struct platform_device *pdev)
280 {
281 	struct power_supply_config pscfg = {};
282 	struct max77650_charger_data *chg;
283 	struct power_supply *battery;
284 	struct device *dev, *parent;
285 	int rv, chg_irq, chgin_irq;
286 	unsigned int prop;
287 
288 	dev = &pdev->dev;
289 	parent = dev->parent;
290 
291 	chg = devm_kzalloc(dev, sizeof(*chg), GFP_KERNEL);
292 	if (!chg)
293 		return -ENOMEM;
294 
295 	platform_set_drvdata(pdev, chg);
296 
297 	chg->map = dev_get_regmap(parent, NULL);
298 	if (!chg->map)
299 		return -ENODEV;
300 
301 	chg->dev = dev;
302 
303 	pscfg.of_node = dev->of_node;
304 	pscfg.drv_data = chg;
305 
306 	chg_irq = platform_get_irq_byname(pdev, "CHG");
307 	if (chg_irq < 0)
308 		return chg_irq;
309 
310 	chgin_irq = platform_get_irq_byname(pdev, "CHGIN");
311 	if (chgin_irq < 0)
312 		return chgin_irq;
313 
314 	rv = devm_request_any_context_irq(dev, chg_irq,
315 					  max77650_charger_check_status,
316 					  IRQF_ONESHOT, "chg", chg);
317 	if (rv < 0)
318 		return rv;
319 
320 	rv = devm_request_any_context_irq(dev, chgin_irq,
321 					  max77650_charger_check_status,
322 					  IRQF_ONESHOT, "chgin", chg);
323 	if (rv < 0)
324 		return rv;
325 
326 	battery = devm_power_supply_register(dev,
327 					     &max77650_battery_desc, &pscfg);
328 	if (IS_ERR(battery))
329 		return PTR_ERR(battery);
330 
331 	rv = of_property_read_u32(dev->of_node,
332 				  "input-voltage-min-microvolt", &prop);
333 	if (rv == 0) {
334 		rv = max77650_charger_set_vchgin_min(chg, prop);
335 		if (rv)
336 			return rv;
337 	}
338 
339 	rv = of_property_read_u32(dev->of_node,
340 				  "input-current-limit-microamp", &prop);
341 	if (rv == 0) {
342 		rv = max77650_charger_set_ichgin_lim(chg, prop);
343 		if (rv)
344 			return rv;
345 	}
346 
347 	return max77650_charger_enable(chg);
348 }
349 
350 static int max77650_charger_remove(struct platform_device *pdev)
351 {
352 	struct max77650_charger_data *chg = platform_get_drvdata(pdev);
353 
354 	return max77650_charger_disable(chg);
355 }
356 
357 static struct platform_driver max77650_charger_driver = {
358 	.driver = {
359 		.name = "max77650-charger",
360 	},
361 	.probe = max77650_charger_probe,
362 	.remove = max77650_charger_remove,
363 };
364 module_platform_driver(max77650_charger_driver);
365 
366 MODULE_DESCRIPTION("MAXIM 77650/77651 charger driver");
367 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
368 MODULE_LICENSE("GPL v2");
369 MODULE_ALIAS("platform:max77650-charger");
370