summaryrefslogtreecommitdiffstats
path: root/drivers/power/supply/gpio-charger.c
blob: f99e8f1eef23367646d1f5ccc375452834078ad9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/*
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 *  Driver for chargers which report their online status through a GPIO pin
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/device.h>
#include <linux/gpio.h> /* For legacy platform data */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/gpio/consumer.h>

#include <linux/power/gpio-charger.h>

struct gpio_charger {
	unsigned int irq;
	unsigned int charge_status_irq;
	bool wakeup_enabled;

	struct power_supply *charger;
	struct power_supply_desc charger_desc;
	struct gpio_desc *gpiod;
	struct gpio_desc *charge_status;
};

static irqreturn_t gpio_charger_irq(int irq, void *devid)
{
	struct power_supply *charger = devid;

	power_supply_changed(charger);

	return IRQ_HANDLED;
}

static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
{
	return power_supply_get_drvdata(psy);
}

static int gpio_charger_get_property(struct power_supply *psy,
		enum power_supply_property psp, union power_supply_propval *val)
{
	struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
		break;
	case POWER_SUPPLY_PROP_STATUS:
		if (gpiod_get_value_cansleep(gpio_charger->charge_status))
			val->intval = POWER_SUPPLY_STATUS_CHARGING;
		else
			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static enum power_supply_type gpio_charger_get_type(struct device *dev)
{
	const char *chargetype;

	if (!device_property_read_string(dev, "charger-type", &chargetype)) {
		if (!strcmp("unknown", chargetype))
			return POWER_SUPPLY_TYPE_UNKNOWN;
		if (!strcmp("battery", chargetype))
			return POWER_SUPPLY_TYPE_BATTERY;
		if (!strcmp("ups", chargetype))
			return POWER_SUPPLY_TYPE_UPS;
		if (!strcmp("mains", chargetype))
			return POWER_SUPPLY_TYPE_MAINS;
		if (!strcmp("usb-sdp", chargetype))
			return POWER_SUPPLY_TYPE_USB;
		if (!strcmp("usb-dcp", chargetype))
			return POWER_SUPPLY_TYPE_USB;
		if (!strcmp("usb-cdp", chargetype))
			return POWER_SUPPLY_TYPE_USB;
		if (!strcmp("usb-aca", chargetype))
			return POWER_SUPPLY_TYPE_USB;
	}
	dev_warn(dev, "unknown charger type %s\n", chargetype);

	return POWER_SUPPLY_TYPE_UNKNOWN;
}

static int gpio_charger_get_irq(struct device *dev, void *dev_id,
				struct gpio_desc *gpio)
{
	int ret, irq = gpiod_to_irq(gpio);

	if (irq > 0) {
		ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
						   IRQF_TRIGGER_RISING |
						   IRQF_TRIGGER_FALLING,
						   dev_name(dev),
						   dev_id);
		if (ret < 0) {
			dev_warn(dev, "Failed to request irq: %d\n", ret);
			irq = 0;
		}
	}

	return irq;
}

static enum power_supply_property gpio_charger_properties[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_STATUS /* Must always be last in the array. */
};

static int gpio_charger_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct gpio_charger_platform_data *pdata = dev->platform_data;
	struct power_supply_config psy_cfg = {};
	struct gpio_charger *gpio_charger;
	struct power_supply_desc *charger_desc;
	struct gpio_desc *charge_status;
	int charge_status_irq;
	unsigned long flags;
	int ret;

	if (!pdata && !dev->of_node) {
		dev_err(dev, "No platform data\n");
		return -ENOENT;
	}

	gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
	if (!gpio_charger)
		return -ENOMEM;

	/*
	 * This will fetch a GPIO descriptor from device tree, ACPI or
	 * boardfile descriptor tables. It's good to try this first.
	 */
	gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);

	/*
	 * If this fails and we're not using device tree, try the
	 * legacy platform data method.
	 */
	if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) {
		/* Non-DT: use legacy GPIO numbers */
		if (!gpio_is_valid(pdata->gpio)) {
			dev_err(dev, "Invalid gpio pin in pdata\n");
			return -EINVAL;
		}
		flags = GPIOF_IN;
		if (pdata->gpio_active_low)
			flags |= GPIOF_ACTIVE_LOW;
		ret = devm_gpio_request_one(dev, pdata->gpio, flags,
					    dev_name(dev));
		if (ret) {
			dev_err(dev, "Failed to request gpio pin: %d\n", ret);
			return ret;
		}
		/* Then convert this to gpiod for now */
		gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
	} else if (IS_ERR(gpio_charger->gpiod)) {
		/* Just try again if this happens */
		if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
			return -EPROBE_DEFER;
		dev_err(dev, "error getting GPIO descriptor\n");
		return PTR_ERR(gpio_charger->gpiod);
	}

	charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN);
	gpio_charger->charge_status = charge_status;
	if (IS_ERR(gpio_charger->charge_status))
		return PTR_ERR(gpio_charger->charge_status);

	charger_desc = &gpio_charger->charger_desc;
	charger_desc->properties = gpio_charger_properties;
	charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
	/* Remove POWER_SUPPLY_PROP_STATUS from the supported properties. */
	if (!gpio_charger->charge_status)
		charger_desc->num_properties -= 1;
	charger_desc->get_property = gpio_charger_get_property;

	psy_cfg.of_node = dev->of_node;
	psy_cfg.drv_data = gpio_charger;

	if (pdata) {
		charger_desc->name = pdata->name;
		charger_desc->type = pdata->type;
		psy_cfg.supplied_to = pdata->supplied_to;
		psy_cfg.num_supplicants = pdata->num_supplicants;
	} else {
		charger_desc->name = dev->of_node->name;
		charger_desc->type = gpio_charger_get_type(dev);
	}

	if (!charger_desc->name)
		charger_desc->name = pdev->name;

	gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
							   &psy_cfg);
	if (IS_ERR(gpio_charger->charger)) {
		ret = PTR_ERR(gpio_charger->charger);
		dev_err(dev, "Failed to register power supply: %d\n", ret);
		return ret;
	}

	gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger,
						 gpio_charger->gpiod);

	charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger,
						 gpio_charger->charge_status);
	gpio_charger->charge_status_irq = charge_status_irq;

	platform_set_drvdata(pdev, gpio_charger);

	device_init_wakeup(dev, 1);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int gpio_charger_suspend(struct device *dev)
{
	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		gpio_charger->wakeup_enabled =
			!enable_irq_wake(gpio_charger->irq);

	return 0;
}

static int gpio_charger_resume(struct device *dev)
{
	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);

	if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
		disable_irq_wake(gpio_charger->irq);
	power_supply_changed(gpio_charger->charger);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
		gpio_charger_suspend, gpio_charger_resume);

static const struct of_device_id gpio_charger_match[] = {
	{ .compatible = "gpio-charger" },
	{ }
};
MODULE_DEVICE_TABLE(of, gpio_charger_match);

static struct platform_driver gpio_charger_driver = {
	.probe = gpio_charger_probe,
	.driver = {
		.name = "gpio-charger",
		.pm = &gpio_charger_pm_ops,
		.of_match_table = gpio_charger_match,
	},
};

module_platform_driver(gpio_charger_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-charger");