1/*
2 * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
3 *
4 * Copyright (C) 2011 Samsung Electronics
5 * MyungJoo Ham <myungjoo.ham@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20 *
21 */
22
23#include <linux/gpio.h>
24#include <linux/interrupt.h>
25#include <linux/module.h>
26#include <linux/slab.h>
27#include <linux/power_supply.h>
28#include <linux/platform_device.h>
29#include <linux/power/max8903_charger.h>
30
31struct max8903_data {
32	struct max8903_pdata pdata;
33	struct device *dev;
34	struct power_supply *psy;
35	struct power_supply_desc psy_desc;
36	bool fault;
37	bool usb_in;
38	bool ta_in;
39};
40
41static enum power_supply_property max8903_charger_props[] = {
42	POWER_SUPPLY_PROP_STATUS, /* Charger status output */
43	POWER_SUPPLY_PROP_ONLINE, /* External power source */
44	POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
45};
46
47static int max8903_get_property(struct power_supply *psy,
48		enum power_supply_property psp,
49		union power_supply_propval *val)
50{
51	struct max8903_data *data = power_supply_get_drvdata(psy);
52
53	switch (psp) {
54	case POWER_SUPPLY_PROP_STATUS:
55		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
56		if (data->pdata.chg) {
57			if (gpio_get_value(data->pdata.chg) == 0)
58				val->intval = POWER_SUPPLY_STATUS_CHARGING;
59			else if (data->usb_in || data->ta_in)
60				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
61			else
62				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
63		}
64		break;
65	case POWER_SUPPLY_PROP_ONLINE:
66		val->intval = 0;
67		if (data->usb_in || data->ta_in)
68			val->intval = 1;
69		break;
70	case POWER_SUPPLY_PROP_HEALTH:
71		val->intval = POWER_SUPPLY_HEALTH_GOOD;
72		if (data->fault)
73			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
74		break;
75	default:
76		return -EINVAL;
77	}
78	return 0;
79}
80
81static irqreturn_t max8903_dcin(int irq, void *_data)
82{
83	struct max8903_data *data = _data;
84	struct max8903_pdata *pdata = &data->pdata;
85	bool ta_in;
86	enum power_supply_type old_type;
87
88	ta_in = gpio_get_value(pdata->dok) ? false : true;
89
90	if (ta_in == data->ta_in)
91		return IRQ_HANDLED;
92
93	data->ta_in = ta_in;
94
95	/* Set Current-Limit-Mode 1:DC 0:USB */
96	if (pdata->dcm)
97		gpio_set_value(pdata->dcm, ta_in ? 1 : 0);
98
99	/* Charger Enable / Disable (cen is negated) */
100	if (pdata->cen)
101		gpio_set_value(pdata->cen, ta_in ? 0 :
102				(data->usb_in ? 0 : 1));
103
104	dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
105			"Connected" : "Disconnected");
106
107	old_type = data->psy_desc.type;
108
109	if (data->ta_in)
110		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
111	else if (data->usb_in)
112		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
113	else
114		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
115
116	if (old_type != data->psy_desc.type)
117		power_supply_changed(data->psy);
118
119	return IRQ_HANDLED;
120}
121
122static irqreturn_t max8903_usbin(int irq, void *_data)
123{
124	struct max8903_data *data = _data;
125	struct max8903_pdata *pdata = &data->pdata;
126	bool usb_in;
127	enum power_supply_type old_type;
128
129	usb_in = gpio_get_value(pdata->uok) ? false : true;
130
131	if (usb_in == data->usb_in)
132		return IRQ_HANDLED;
133
134	data->usb_in = usb_in;
135
136	/* Do not touch Current-Limit-Mode */
137
138	/* Charger Enable / Disable (cen is negated) */
139	if (pdata->cen)
140		gpio_set_value(pdata->cen, usb_in ? 0 :
141				(data->ta_in ? 0 : 1));
142
143	dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
144			"Connected" : "Disconnected");
145
146	old_type = data->psy_desc.type;
147
148	if (data->ta_in)
149		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
150	else if (data->usb_in)
151		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
152	else
153		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
154
155	if (old_type != data->psy_desc.type)
156		power_supply_changed(data->psy);
157
158	return IRQ_HANDLED;
159}
160
161static irqreturn_t max8903_fault(int irq, void *_data)
162{
163	struct max8903_data *data = _data;
164	struct max8903_pdata *pdata = &data->pdata;
165	bool fault;
166
167	fault = gpio_get_value(pdata->flt) ? false : true;
168
169	if (fault == data->fault)
170		return IRQ_HANDLED;
171
172	data->fault = fault;
173
174	if (fault)
175		dev_err(data->dev, "Charger suffers a fault and stops.\n");
176	else
177		dev_err(data->dev, "Charger recovered from a fault.\n");
178
179	return IRQ_HANDLED;
180}
181
182static int max8903_probe(struct platform_device *pdev)
183{
184	struct max8903_data *data;
185	struct device *dev = &pdev->dev;
186	struct max8903_pdata *pdata = pdev->dev.platform_data;
187	struct power_supply_config psy_cfg = {};
188	int ret = 0;
189	int gpio;
190	int ta_in = 0;
191	int usb_in = 0;
192
193	data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
194	if (data == NULL) {
195		dev_err(dev, "Cannot allocate memory.\n");
196		return -ENOMEM;
197	}
198	memcpy(&data->pdata, pdata, sizeof(struct max8903_pdata));
199	data->dev = dev;
200	platform_set_drvdata(pdev, data);
201
202	if (pdata->dc_valid == false && pdata->usb_valid == false) {
203		dev_err(dev, "No valid power sources.\n");
204		ret = -EINVAL;
205		goto err;
206	}
207
208	if (pdata->dc_valid) {
209		if (pdata->dok && gpio_is_valid(pdata->dok) &&
210				pdata->dcm && gpio_is_valid(pdata->dcm)) {
211			gpio = pdata->dok; /* PULL_UPed Interrupt */
212			ta_in = gpio_get_value(gpio) ? 0 : 1;
213
214			gpio = pdata->dcm; /* Output */
215			gpio_set_value(gpio, ta_in);
216		} else {
217			dev_err(dev, "When DC is wired, DOK and DCM should"
218					" be wired as well.\n");
219			ret = -EINVAL;
220			goto err;
221		}
222	} else {
223		if (pdata->dcm) {
224			if (gpio_is_valid(pdata->dcm))
225				gpio_set_value(pdata->dcm, 0);
226			else {
227				dev_err(dev, "Invalid pin: dcm.\n");
228				ret = -EINVAL;
229				goto err;
230			}
231		}
232	}
233
234	if (pdata->usb_valid) {
235		if (pdata->uok && gpio_is_valid(pdata->uok)) {
236			gpio = pdata->uok;
237			usb_in = gpio_get_value(gpio) ? 0 : 1;
238		} else {
239			dev_err(dev, "When USB is wired, UOK should be wired."
240					"as well.\n");
241			ret = -EINVAL;
242			goto err;
243		}
244	}
245
246	if (pdata->cen) {
247		if (gpio_is_valid(pdata->cen)) {
248			gpio_set_value(pdata->cen, (ta_in || usb_in) ? 0 : 1);
249		} else {
250			dev_err(dev, "Invalid pin: cen.\n");
251			ret = -EINVAL;
252			goto err;
253		}
254	}
255
256	if (pdata->chg) {
257		if (!gpio_is_valid(pdata->chg)) {
258			dev_err(dev, "Invalid pin: chg.\n");
259			ret = -EINVAL;
260			goto err;
261		}
262	}
263
264	if (pdata->flt) {
265		if (!gpio_is_valid(pdata->flt)) {
266			dev_err(dev, "Invalid pin: flt.\n");
267			ret = -EINVAL;
268			goto err;
269		}
270	}
271
272	if (pdata->usus) {
273		if (!gpio_is_valid(pdata->usus)) {
274			dev_err(dev, "Invalid pin: usus.\n");
275			ret = -EINVAL;
276			goto err;
277		}
278	}
279
280	data->fault = false;
281	data->ta_in = ta_in;
282	data->usb_in = usb_in;
283
284	data->psy_desc.name = "max8903_charger";
285	data->psy_desc.type = (ta_in) ? POWER_SUPPLY_TYPE_MAINS :
286			((usb_in) ? POWER_SUPPLY_TYPE_USB :
287			 POWER_SUPPLY_TYPE_BATTERY);
288	data->psy_desc.get_property = max8903_get_property;
289	data->psy_desc.properties = max8903_charger_props;
290	data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
291
292	psy_cfg.drv_data = data;
293
294	data->psy = power_supply_register(dev, &data->psy_desc, &psy_cfg);
295	if (IS_ERR(data->psy)) {
296		dev_err(dev, "failed: power supply register.\n");
297		ret = PTR_ERR(data->psy);
298		goto err;
299	}
300
301	if (pdata->dc_valid) {
302		ret = request_threaded_irq(gpio_to_irq(pdata->dok),
303				NULL, max8903_dcin,
304				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
305				"MAX8903 DC IN", data);
306		if (ret) {
307			dev_err(dev, "Cannot request irq %d for DC (%d)\n",
308					gpio_to_irq(pdata->dok), ret);
309			goto err_psy;
310		}
311	}
312
313	if (pdata->usb_valid) {
314		ret = request_threaded_irq(gpio_to_irq(pdata->uok),
315				NULL, max8903_usbin,
316				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
317				"MAX8903 USB IN", data);
318		if (ret) {
319			dev_err(dev, "Cannot request irq %d for USB (%d)\n",
320					gpio_to_irq(pdata->uok), ret);
321			goto err_dc_irq;
322		}
323	}
324
325	if (pdata->flt) {
326		ret = request_threaded_irq(gpio_to_irq(pdata->flt),
327				NULL, max8903_fault,
328				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
329				"MAX8903 Fault", data);
330		if (ret) {
331			dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
332					gpio_to_irq(pdata->flt), ret);
333			goto err_usb_irq;
334		}
335	}
336
337	return 0;
338
339err_usb_irq:
340	if (pdata->usb_valid)
341		free_irq(gpio_to_irq(pdata->uok), data);
342err_dc_irq:
343	if (pdata->dc_valid)
344		free_irq(gpio_to_irq(pdata->dok), data);
345err_psy:
346	power_supply_unregister(data->psy);
347err:
348	return ret;
349}
350
351static int max8903_remove(struct platform_device *pdev)
352{
353	struct max8903_data *data = platform_get_drvdata(pdev);
354
355	if (data) {
356		struct max8903_pdata *pdata = &data->pdata;
357
358		if (pdata->flt)
359			free_irq(gpio_to_irq(pdata->flt), data);
360		if (pdata->usb_valid)
361			free_irq(gpio_to_irq(pdata->uok), data);
362		if (pdata->dc_valid)
363			free_irq(gpio_to_irq(pdata->dok), data);
364		power_supply_unregister(data->psy);
365	}
366
367	return 0;
368}
369
370static struct platform_driver max8903_driver = {
371	.probe	= max8903_probe,
372	.remove	= max8903_remove,
373	.driver = {
374		.name	= "max8903-charger",
375	},
376};
377
378module_platform_driver(max8903_driver);
379
380MODULE_LICENSE("GPL");
381MODULE_DESCRIPTION("MAX8903 Charger Driver");
382MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
383MODULE_ALIAS("platform:max8903-charger");
384