aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/extcon/extcon-usb-gpio.c
blob: 9c925b05b7aaa1a479e9f2a49b0479233fd068be (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
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
/**
 * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 * Author: Roger Quadros <rogerq@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/extcon.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/pinctrl/consumer.h>

#define USB_GPIO_DEBOUNCE_MS	20	/* ms */

struct usb_extcon_info {
	struct device *dev;
	struct extcon_dev *edev;

	struct gpio_desc *id_gpiod;
	struct gpio_desc *vbus_gpiod;
	int id_irq;
	int vbus_irq;

	unsigned long debounce_jiffies;
	struct delayed_work wq_detcable;
};

static const unsigned int usb_extcon_cable[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_NONE,
};

/*
 * "USB" = VBUS and "USB-HOST" = !ID, so we have:
 * Both "USB" and "USB-HOST" can't be set as active at the
 * same time so if "USB-HOST" is active (i.e. ID is 0)  we keep "USB" inactive
 * even if VBUS is on.
 *
 *  State              |    ID   |   VBUS
 * ----------------------------------------
 *  [1] USB            |    H    |    H
 *  [2] none           |    H    |    L
 *  [3] USB-HOST       |    L    |    H
 *  [4] USB-HOST       |    L    |    L
 *
 * In case we have only one of these signals:
 * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
 * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
*/
static void usb_extcon_detect_cable(struct work_struct *work)
{
	int id, vbus;
	struct usb_extcon_info *info = container_of(to_delayed_work(work),
						    struct usb_extcon_info,
						    wq_detcable);

	/* check ID and VBUS and update cable state */
	id = info->id_gpiod ?
		gpiod_get_value_cansleep(info->id_gpiod) : 1;
	vbus = info->vbus_gpiod ?
		gpiod_get_value_cansleep(info->vbus_gpiod) : id;

	/* at first we clean states which are no longer active */
	if (id)
		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
	if (!vbus)
		extcon_set_state_sync(info->edev, EXTCON_USB, false);

	if (!id) {
		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
	} else {
		if (vbus)
			extcon_set_state_sync(info->edev, EXTCON_USB, true);
	}
}

static irqreturn_t usb_irq_handler(int irq, void *dev_id)
{
	struct usb_extcon_info *info = dev_id;

	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
			   info->debounce_jiffies);

	return IRQ_HANDLED;
}

static int usb_extcon_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct usb_extcon_info *info;
	int ret;

	if (!np)
		return -EINVAL;

	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	info->dev = dev;
	info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
	info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
						   GPIOD_IN);

	if (!info->id_gpiod && !info->vbus_gpiod) {
		dev_err(dev, "failed to get gpios\n");
		return -ENODEV;
	}

	if (IS_ERR(info->id_gpiod))
		return PTR_ERR(info->id_gpiod);

	if (IS_ERR(info->vbus_gpiod))
		return PTR_ERR(info->vbus_gpiod);

	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
	if (IS_ERR(info->edev)) {
		dev_err(dev, "failed to allocate extcon device\n");
		return -ENOMEM;
	}

	ret = devm_extcon_dev_register(dev, info->edev);
	if (ret < 0) {
		dev_err(dev, "failed to register extcon device\n");
		return ret;
	}

	if (info->id_gpiod)
		ret = gpiod_set_debounce(info->id_gpiod,
					 USB_GPIO_DEBOUNCE_MS * 1000);
	if (!ret && info->vbus_gpiod)
		ret = gpiod_set_debounce(info->vbus_gpiod,
					 USB_GPIO_DEBOUNCE_MS * 1000);

	if (ret < 0)
		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);

	INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);

	if (info->id_gpiod) {
		info->id_irq = gpiod_to_irq(info->id_gpiod);
		if (info->id_irq < 0) {
			dev_err(dev, "failed to get ID IRQ\n");
			return info->id_irq;
		}

		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
						usb_irq_handler,
						IRQF_TRIGGER_RISING |
						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
						pdev->name, info);
		if (ret < 0) {
			dev_err(dev, "failed to request handler for ID IRQ\n");
			return ret;
		}
	}

	if (info->vbus_gpiod) {
		info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
		if (info->vbus_irq < 0) {
			dev_err(dev, "failed to get VBUS IRQ\n");
			return info->vbus_irq;
		}

		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
						usb_irq_handler,
						IRQF_TRIGGER_RISING |
						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
						pdev->name, info);
		if (ret < 0) {
			dev_err(dev, "failed to request handler for VBUS IRQ\n");
			return ret;
		}
	}

	platform_set_drvdata(pdev, info);
	device_set_wakeup_capable(&pdev->dev, true);

	/* Perform initial detection */
	usb_extcon_detect_cable(&info->wq_detcable.work);

	return 0;
}

static int usb_extcon_remove(struct platform_device *pdev)
{
	struct usb_extcon_info *info = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&info->wq_detcable);
	device_init_wakeup(&pdev->dev, false);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int usb_extcon_suspend(struct device *dev)
{
	struct usb_extcon_info *info = dev_get_drvdata(dev);
	int ret = 0;

	if (device_may_wakeup(dev)) {
		if (info->id_gpiod) {
			ret = enable_irq_wake(info->id_irq);
			if (ret)
				return ret;
		}
		if (info->vbus_gpiod) {
			ret = enable_irq_wake(info->vbus_irq);
			if (ret) {
				if (info->id_gpiod)
					disable_irq_wake(info->id_irq);

				return ret;
			}
		}
	}

	/*
	 * We don't want to process any IRQs after this point
	 * as GPIOs used behind I2C subsystem might not be
	 * accessible until resume completes. So disable IRQ.
	 */
	if (info->id_gpiod)
		disable_irq(info->id_irq);
	if (info->vbus_gpiod)
		disable_irq(info->vbus_irq);

	if (!device_may_wakeup(dev))
		pinctrl_pm_select_sleep_state(dev);

	return ret;
}

static int usb_extcon_resume(struct device *dev)
{
	struct usb_extcon_info *info = dev_get_drvdata(dev);
	int ret = 0;

	if (!device_may_wakeup(dev))
		pinctrl_pm_select_default_state(dev);

	if (device_may_wakeup(dev)) {
		if (info->id_gpiod) {
			ret = disable_irq_wake(info->id_irq);
			if (ret)
				return ret;
		}
		if (info->vbus_gpiod) {
			ret = disable_irq_wake(info->vbus_irq);
			if (ret) {
				if (info->id_gpiod)
					enable_irq_wake(info->id_irq);

				return ret;
			}
		}
	}

	if (info->id_gpiod)
		enable_irq(info->id_irq);
	if (info->vbus_gpiod)
		enable_irq(info->vbus_irq);

	queue_delayed_work(system_power_efficient_wq,
			   &info->wq_detcable, 0);

	return ret;
}
#endif

static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
			 usb_extcon_suspend, usb_extcon_resume);

static const struct of_device_id usb_extcon_dt_match[] = {
	{ .compatible = "linux,extcon-usb-gpio", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);

static const struct platform_device_id usb_extcon_platform_ids[] = {
	{ .name = "extcon-usb-gpio", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);

static struct platform_driver usb_extcon_driver = {
	.probe		= usb_extcon_probe,
	.remove		= usb_extcon_remove,
	.driver		= {
		.name	= "extcon-usb-gpio",
		.pm	= &usb_extcon_pm_ops,
		.of_match_table = usb_extcon_dt_match,
	},
	.id_table = usb_extcon_platform_ids,
};

module_platform_driver(usb_extcon_driver);

MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
MODULE_DESCRIPTION("USB GPIO extcon driver");
MODULE_LICENSE("GPL v2");

Privacy Policy