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
20struct 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
30static 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
36static 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
71static 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
112static 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
151static 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
172static 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
222static 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
333static 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
426static const struct of_device_id max8903_match_ids[] = {
427	{ .compatible = "maxim,max8903", },
428	{ /* sentinel */ }
429};
430MODULE_DEVICE_TABLE(of, max8903_match_ids);
431
432static 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
440module_platform_driver(max8903_driver);
441
442MODULE_LICENSE("GPL");
443MODULE_DESCRIPTION("MAX8903 Charger Driver");
444MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
445MODULE_ALIAS("platform:max8903-charger");
446