1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
4  *
5  * Copyright (C) 2011 Samsung Electronics
6  * MyungJoo Ham <myungjoo.ham@samsung.com>
7  */
8 
9 #include <linux/gpio.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/of_gpio.h>
15 #include <linux/slab.h>
16 #include <linux/power_supply.h>
17 #include <linux/platform_device.h>
18 #include <linux/power/max8903_charger.h>
19 
20 struct max8903_data {
21 	struct max8903_pdata *pdata;
22 	struct device *dev;
23 	struct power_supply *psy;
24 	struct power_supply_desc psy_desc;
25 	bool fault;
26 	bool usb_in;
27 	bool ta_in;
28 };
29 
30 static enum power_supply_property max8903_charger_props[] = {
31 	POWER_SUPPLY_PROP_STATUS, /* Charger status output */
32 	POWER_SUPPLY_PROP_ONLINE, /* External power source */
33 	POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
34 };
35 
36 static int max8903_get_property(struct power_supply *psy,
37 		enum power_supply_property psp,
38 		union power_supply_propval *val)
39 {
40 	struct max8903_data *data = power_supply_get_drvdata(psy);
41 
42 	switch (psp) {
43 	case POWER_SUPPLY_PROP_STATUS:
44 		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
45 		if (gpio_is_valid(data->pdata->chg)) {
46 			if (gpio_get_value(data->pdata->chg) == 0)
47 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
48 			else if (data->usb_in || data->ta_in)
49 				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
50 			else
51 				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
52 		}
53 		break;
54 	case POWER_SUPPLY_PROP_ONLINE:
55 		val->intval = 0;
56 		if (data->usb_in || data->ta_in)
57 			val->intval = 1;
58 		break;
59 	case POWER_SUPPLY_PROP_HEALTH:
60 		val->intval = POWER_SUPPLY_HEALTH_GOOD;
61 		if (data->fault)
62 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
63 		break;
64 	default:
65 		return -EINVAL;
66 	}
67 
68 	return 0;
69 }
70 
71 static irqreturn_t max8903_dcin(int irq, void *_data)
72 {
73 	struct max8903_data *data = _data;
74 	struct max8903_pdata *pdata = data->pdata;
75 	bool ta_in;
76 	enum power_supply_type old_type;
77 
78 	ta_in = gpio_get_value(pdata->dok) ? false : true;
79 
80 	if (ta_in == data->ta_in)
81 		return IRQ_HANDLED;
82 
83 	data->ta_in = ta_in;
84 
85 	/* Set Current-Limit-Mode 1:DC 0:USB */
86 	if (gpio_is_valid(pdata->dcm))
87 		gpio_set_value(pdata->dcm, ta_in ? 1 : 0);
88 
89 	/* Charger Enable / Disable (cen is negated) */
90 	if (gpio_is_valid(pdata->cen))
91 		gpio_set_value(pdata->cen, ta_in ? 0 :
92 				(data->usb_in ? 0 : 1));
93 
94 	dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
95 			"Connected" : "Disconnected");
96 
97 	old_type = data->psy_desc.type;
98 
99 	if (data->ta_in)
100 		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
101 	else if (data->usb_in)
102 		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
103 	else
104 		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
105 
106 	if (old_type != data->psy_desc.type)
107 		power_supply_changed(data->psy);
108 
109 	return IRQ_HANDLED;
110 }
111 
112 static irqreturn_t max8903_usbin(int irq, void *_data)
113 {
114 	struct max8903_data *data = _data;
115 	struct max8903_pdata *pdata = data->pdata;
116 	bool usb_in;
117 	enum power_supply_type old_type;
118 
119 	usb_in = gpio_get_value(pdata->uok) ? false : true;
120 
121 	if (usb_in == data->usb_in)
122 		return IRQ_HANDLED;
123 
124 	data->usb_in = usb_in;
125 
126 	/* Do not touch Current-Limit-Mode */
127 
128 	/* Charger Enable / Disable (cen is negated) */
129 	if (gpio_is_valid(pdata->cen))
130 		gpio_set_value(pdata->cen, usb_in ? 0 :
131 				(data->ta_in ? 0 : 1));
132 
133 	dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
134 			"Connected" : "Disconnected");
135 
136 	old_type = data->psy_desc.type;
137 
138 	if (data->ta_in)
139 		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
140 	else if (data->usb_in)
141 		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
142 	else
143 		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
144 
145 	if (old_type != data->psy_desc.type)
146 		power_supply_changed(data->psy);
147 
148 	return IRQ_HANDLED;
149 }
150 
151 static irqreturn_t max8903_fault(int irq, void *_data)
152 {
153 	struct max8903_data *data = _data;
154 	struct max8903_pdata *pdata = data->pdata;
155 	bool fault;
156 
157 	fault = gpio_get_value(pdata->flt) ? false : true;
158 
159 	if (fault == data->fault)
160 		return IRQ_HANDLED;
161 
162 	data->fault = fault;
163 
164 	if (fault)
165 		dev_err(data->dev, "Charger suffers a fault and stops.\n");
166 	else
167 		dev_err(data->dev, "Charger recovered from a fault.\n");
168 
169 	return IRQ_HANDLED;
170 }
171 
172 static struct max8903_pdata *max8903_parse_dt_data(struct device *dev)
173 {
174 	struct device_node *np = dev->of_node;
175 	struct max8903_pdata *pdata = NULL;
176 
177 	if (!np)
178 		return NULL;
179 
180 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
181 	if (!pdata)
182 		return NULL;
183 
184 	pdata->dc_valid = false;
185 	pdata->usb_valid = false;
186 
187 	pdata->cen = of_get_named_gpio(np, "cen-gpios", 0);
188 	if (!gpio_is_valid(pdata->cen))
189 		pdata->cen = -EINVAL;
190 
191 	pdata->chg = of_get_named_gpio(np, "chg-gpios", 0);
192 	if (!gpio_is_valid(pdata->chg))
193 		pdata->chg = -EINVAL;
194 
195 	pdata->flt = of_get_named_gpio(np, "flt-gpios", 0);
196 	if (!gpio_is_valid(pdata->flt))
197 		pdata->flt = -EINVAL;
198 
199 	pdata->usus = of_get_named_gpio(np, "usus-gpios", 0);
200 	if (!gpio_is_valid(pdata->usus))
201 		pdata->usus = -EINVAL;
202 
203 	pdata->dcm = of_get_named_gpio(np, "dcm-gpios", 0);
204 	if (!gpio_is_valid(pdata->dcm))
205 		pdata->dcm = -EINVAL;
206 
207 	pdata->dok = of_get_named_gpio(np, "dok-gpios", 0);
208 	if (!gpio_is_valid(pdata->dok))
209 		pdata->dok = -EINVAL;
210 	else
211 		pdata->dc_valid = true;
212 
213 	pdata->uok = of_get_named_gpio(np, "uok-gpios", 0);
214 	if (!gpio_is_valid(pdata->uok))
215 		pdata->uok = -EINVAL;
216 	else
217 		pdata->usb_valid = true;
218 
219 	return pdata;
220 }
221 
222 static int max8903_setup_gpios(struct platform_device *pdev)
223 {
224 	struct max8903_data *data = platform_get_drvdata(pdev);
225 	struct device *dev = &pdev->dev;
226 	struct max8903_pdata *pdata = pdev->dev.platform_data;
227 	int ret = 0;
228 	int gpio;
229 	int ta_in = 0;
230 	int usb_in = 0;
231 
232 	if (pdata->dc_valid) {
233 		if (gpio_is_valid(pdata->dok)) {
234 			ret = devm_gpio_request(dev, pdata->dok,
235 						data->psy_desc.name);
236 			if (ret) {
237 				dev_err(dev,
238 					"Failed GPIO request for dok: %d err %d\n",
239 					pdata->dok, ret);
240 				return ret;
241 			}
242 
243 			gpio = pdata->dok; /* PULL_UPed Interrupt */
244 			ta_in = gpio_get_value(gpio) ? 0 : 1;
245 		} else {
246 			dev_err(dev, "When DC is wired, DOK should be wired as well.\n");
247 			return -EINVAL;
248 		}
249 	}
250 
251 	if (gpio_is_valid(pdata->dcm)) {
252 		ret = devm_gpio_request(dev, pdata->dcm, data->psy_desc.name);
253 		if (ret) {
254 			dev_err(dev,
255 				"Failed GPIO request for dcm: %d err %d\n",
256 				pdata->dcm, ret);
257 			return ret;
258 		}
259 
260 		gpio = pdata->dcm; /* Output */
261 		gpio_set_value(gpio, ta_in);
262 	}
263 
264 	if (pdata->usb_valid) {
265 		if (gpio_is_valid(pdata->uok)) {
266 			ret = devm_gpio_request(dev, pdata->uok,
267 						data->psy_desc.name);
268 			if (ret) {
269 				dev_err(dev,
270 					"Failed GPIO request for uok: %d err %d\n",
271 					pdata->uok, ret);
272 				return ret;
273 			}
274 
275 			gpio = pdata->uok;
276 			usb_in = gpio_get_value(gpio) ? 0 : 1;
277 		} else {
278 			dev_err(dev, "When USB is wired, UOK should be wired."
279 					"as well.\n");
280 			return -EINVAL;
281 		}
282 	}
283 
284 	if (gpio_is_valid(pdata->cen)) {
285 		ret = devm_gpio_request(dev, pdata->cen, data->psy_desc.name);
286 		if (ret) {
287 			dev_err(dev,
288 				"Failed GPIO request for cen: %d err %d\n",
289 				pdata->cen, ret);
290 			return ret;
291 		}
292 
293 		gpio_set_value(pdata->cen, (ta_in || usb_in) ? 0 : 1);
294 	}
295 
296 	if (gpio_is_valid(pdata->chg)) {
297 		ret = devm_gpio_request(dev, pdata->chg, data->psy_desc.name);
298 		if (ret) {
299 			dev_err(dev,
300 				"Failed GPIO request for chg: %d err %d\n",
301 				pdata->chg, ret);
302 			return ret;
303 		}
304 	}
305 
306 	if (gpio_is_valid(pdata->flt)) {
307 		ret = devm_gpio_request(dev, pdata->flt, data->psy_desc.name);
308 		if (ret) {
309 			dev_err(dev,
310 				"Failed GPIO request for flt: %d err %d\n",
311 				pdata->flt, ret);
312 			return ret;
313 		}
314 	}
315 
316 	if (gpio_is_valid(pdata->usus)) {
317 		ret = devm_gpio_request(dev, pdata->usus, data->psy_desc.name);
318 		if (ret) {
319 			dev_err(dev,
320 				"Failed GPIO request for usus: %d err %d\n",
321 				pdata->usus, ret);
322 			return ret;
323 		}
324 	}
325 
326 	data->fault = false;
327 	data->ta_in = ta_in;
328 	data->usb_in = usb_in;
329 
330 	return 0;
331 }
332 
333 static int max8903_probe(struct platform_device *pdev)
334 {
335 	struct max8903_data *data;
336 	struct device *dev = &pdev->dev;
337 	struct max8903_pdata *pdata = pdev->dev.platform_data;
338 	struct power_supply_config psy_cfg = {};
339 	int ret = 0;
340 
341 	data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
342 	if (!data)
343 		return -ENOMEM;
344 
345 	if (IS_ENABLED(CONFIG_OF) && !pdata && dev->of_node)
346 		pdata = max8903_parse_dt_data(dev);
347 
348 	if (!pdata) {
349 		dev_err(dev, "No platform data.\n");
350 		return -EINVAL;
351 	}
352 
353 	pdev->dev.platform_data = pdata;
354 	data->pdata = pdata;
355 	data->dev = dev;
356 	platform_set_drvdata(pdev, data);
357 
358 	if (pdata->dc_valid == false && pdata->usb_valid == false) {
359 		dev_err(dev, "No valid power sources.\n");
360 		return -EINVAL;
361 	}
362 
363 	ret = max8903_setup_gpios(pdev);
364 	if (ret)
365 		return ret;
366 
367 	data->psy_desc.name = "max8903_charger";
368 	data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
369 			((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
370 			 POWER_SUPPLY_TYPE_BATTERY);
371 	data->psy_desc.get_property = max8903_get_property;
372 	data->psy_desc.properties = max8903_charger_props;
373 	data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
374 
375 	psy_cfg.of_node = dev->of_node;
376 	psy_cfg.drv_data = data;
377 
378 	data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
379 	if (IS_ERR(data->psy)) {
380 		dev_err(dev, "failed: power supply register.\n");
381 		return PTR_ERR(data->psy);
382 	}
383 
384 	if (pdata->dc_valid) {
385 		ret = devm_request_threaded_irq(dev, gpio_to_irq(pdata->dok),
386 					NULL, max8903_dcin,
387 					IRQF_TRIGGER_FALLING |
388 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
389 					"MAX8903 DC IN", data);
390 		if (ret) {
391 			dev_err(dev, "Cannot request irq %d for DC (%d)\n",
392 					gpio_to_irq(pdata->dok), ret);
393 			return ret;
394 		}
395 	}
396 
397 	if (pdata->usb_valid) {
398 		ret = devm_request_threaded_irq(dev, gpio_to_irq(pdata->uok),
399 					NULL, max8903_usbin,
400 					IRQF_TRIGGER_FALLING |
401 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
402 					"MAX8903 USB IN", data);
403 		if (ret) {
404 			dev_err(dev, "Cannot request irq %d for USB (%d)\n",
405 					gpio_to_irq(pdata->uok), ret);
406 			return ret;
407 		}
408 	}
409 
410 	if (gpio_is_valid(pdata->flt)) {
411 		ret = devm_request_threaded_irq(dev, gpio_to_irq(pdata->flt),
412 					NULL, max8903_fault,
413 					IRQF_TRIGGER_FALLING |
414 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
415 					"MAX8903 Fault", data);
416 		if (ret) {
417 			dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
418 					gpio_to_irq(pdata->flt), ret);
419 			return ret;
420 		}
421 	}
422 
423 	return 0;
424 }
425 
426 static const struct of_device_id max8903_match_ids[] = {
427 	{ .compatible = "maxim,max8903", },
428 	{ /* sentinel */ }
429 };
430 MODULE_DEVICE_TABLE(of, max8903_match_ids);
431 
432 static struct platform_driver max8903_driver = {
433 	.probe	= max8903_probe,
434 	.driver = {
435 		.name	= "max8903-charger",
436 		.of_match_table = max8903_match_ids
437 	},
438 };
439 
440 module_platform_driver(max8903_driver);
441 
442 MODULE_LICENSE("GPL");
443 MODULE_DESCRIPTION("MAX8903 Charger Driver");
444 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
445 MODULE_ALIAS("platform:max8903-charger");
446