1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
4 *
5 * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com
6 * Author: Roger Quadros <rogerq@ti.com>
7 */
8
9#include <linux/extcon-provider.h>
10#include <linux/gpio/consumer.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/workqueue.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/mod_devicetable.h>
21
22#define USB_GPIO_DEBOUNCE_MS	20	/* ms */
23
24struct usb_extcon_info {
25	struct device *dev;
26	struct extcon_dev *edev;
27
28	struct gpio_desc *id_gpiod;
29	struct gpio_desc *vbus_gpiod;
30	int id_irq;
31	int vbus_irq;
32
33	unsigned long debounce_jiffies;
34	struct delayed_work wq_detcable;
35};
36
37static const unsigned int usb_extcon_cable[] = {
38	EXTCON_USB,
39	EXTCON_USB_HOST,
40	EXTCON_NONE,
41};
42
43/*
44 * "USB" = VBUS and "USB-HOST" = !ID, so we have:
45 * Both "USB" and "USB-HOST" can't be set as active at the
46 * same time so if "USB-HOST" is active (i.e. ID is 0)  we keep "USB" inactive
47 * even if VBUS is on.
48 *
49 *  State              |    ID   |   VBUS
50 * ----------------------------------------
51 *  [1] USB            |    H    |    H
52 *  [2] none           |    H    |    L
53 *  [3] USB-HOST       |    L    |    H
54 *  [4] USB-HOST       |    L    |    L
55 *
56 * In case we have only one of these signals:
57 * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
58 * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
59*/
60static void usb_extcon_detect_cable(struct work_struct *work)
61{
62	int id, vbus;
63	struct usb_extcon_info *info = container_of(to_delayed_work(work),
64						    struct usb_extcon_info,
65						    wq_detcable);
66
67	/* check ID and VBUS and update cable state */
68	id = info->id_gpiod ?
69		gpiod_get_value_cansleep(info->id_gpiod) : 1;
70	vbus = info->vbus_gpiod ?
71		gpiod_get_value_cansleep(info->vbus_gpiod) : id;
72
73	/* at first we clean states which are no longer active */
74	if (id)
75		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
76	if (!vbus)
77		extcon_set_state_sync(info->edev, EXTCON_USB, false);
78
79	if (!id) {
80		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
81	} else {
82		if (vbus)
83			extcon_set_state_sync(info->edev, EXTCON_USB, true);
84	}
85}
86
87static irqreturn_t usb_irq_handler(int irq, void *dev_id)
88{
89	struct usb_extcon_info *info = dev_id;
90
91	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
92			   info->debounce_jiffies);
93
94	return IRQ_HANDLED;
95}
96
97static int usb_extcon_probe(struct platform_device *pdev)
98{
99	struct device *dev = &pdev->dev;
100	struct device_node *np = dev->of_node;
101	struct usb_extcon_info *info;
102	int ret;
103
104	if (!np)
105		return -EINVAL;
106
107	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
108	if (!info)
109		return -ENOMEM;
110
111	info->dev = dev;
112	info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
113	info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
114						   GPIOD_IN);
115
116	if (!info->id_gpiod && !info->vbus_gpiod) {
117		dev_err(dev, "failed to get gpios\n");
118		return -ENODEV;
119	}
120
121	if (IS_ERR(info->id_gpiod))
122		return PTR_ERR(info->id_gpiod);
123
124	if (IS_ERR(info->vbus_gpiod))
125		return PTR_ERR(info->vbus_gpiod);
126
127	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
128	if (IS_ERR(info->edev)) {
129		dev_err(dev, "failed to allocate extcon device\n");
130		return -ENOMEM;
131	}
132
133	ret = devm_extcon_dev_register(dev, info->edev);
134	if (ret < 0) {
135		dev_err(dev, "failed to register extcon device\n");
136		return ret;
137	}
138
139	if (info->id_gpiod)
140		ret = gpiod_set_debounce(info->id_gpiod,
141					 USB_GPIO_DEBOUNCE_MS * 1000);
142	if (!ret && info->vbus_gpiod)
143		ret = gpiod_set_debounce(info->vbus_gpiod,
144					 USB_GPIO_DEBOUNCE_MS * 1000);
145
146	if (ret < 0)
147		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
148
149	INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
150
151	if (info->id_gpiod) {
152		info->id_irq = gpiod_to_irq(info->id_gpiod);
153		if (info->id_irq < 0) {
154			dev_err(dev, "failed to get ID IRQ\n");
155			return info->id_irq;
156		}
157
158		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
159						usb_irq_handler,
160						IRQF_TRIGGER_RISING |
161						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
162						pdev->name, info);
163		if (ret < 0) {
164			dev_err(dev, "failed to request handler for ID IRQ\n");
165			return ret;
166		}
167	}
168
169	if (info->vbus_gpiod) {
170		info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
171		if (info->vbus_irq < 0) {
172			dev_err(dev, "failed to get VBUS IRQ\n");
173			return info->vbus_irq;
174		}
175
176		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
177						usb_irq_handler,
178						IRQF_TRIGGER_RISING |
179						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
180						pdev->name, info);
181		if (ret < 0) {
182			dev_err(dev, "failed to request handler for VBUS IRQ\n");
183			return ret;
184		}
185	}
186
187	platform_set_drvdata(pdev, info);
188	device_set_wakeup_capable(&pdev->dev, true);
189
190	/* Perform initial detection */
191	usb_extcon_detect_cable(&info->wq_detcable.work);
192
193	return 0;
194}
195
196static int usb_extcon_remove(struct platform_device *pdev)
197{
198	struct usb_extcon_info *info = platform_get_drvdata(pdev);
199
200	cancel_delayed_work_sync(&info->wq_detcable);
201	device_init_wakeup(&pdev->dev, false);
202
203	return 0;
204}
205
206#ifdef CONFIG_PM_SLEEP
207static int usb_extcon_suspend(struct device *dev)
208{
209	struct usb_extcon_info *info = dev_get_drvdata(dev);
210	int ret = 0;
211
212	if (device_may_wakeup(dev)) {
213		if (info->id_gpiod) {
214			ret = enable_irq_wake(info->id_irq);
215			if (ret)
216				return ret;
217		}
218		if (info->vbus_gpiod) {
219			ret = enable_irq_wake(info->vbus_irq);
220			if (ret) {
221				if (info->id_gpiod)
222					disable_irq_wake(info->id_irq);
223
224				return ret;
225			}
226		}
227	}
228
229	if (!device_may_wakeup(dev))
230		pinctrl_pm_select_sleep_state(dev);
231
232	return ret;
233}
234
235static int usb_extcon_resume(struct device *dev)
236{
237	struct usb_extcon_info *info = dev_get_drvdata(dev);
238	int ret = 0;
239
240	if (!device_may_wakeup(dev))
241		pinctrl_pm_select_default_state(dev);
242
243	if (device_may_wakeup(dev)) {
244		if (info->id_gpiod) {
245			ret = disable_irq_wake(info->id_irq);
246			if (ret)
247				return ret;
248		}
249		if (info->vbus_gpiod) {
250			ret = disable_irq_wake(info->vbus_irq);
251			if (ret) {
252				if (info->id_gpiod)
253					enable_irq_wake(info->id_irq);
254
255				return ret;
256			}
257		}
258	}
259
260	queue_delayed_work(system_power_efficient_wq,
261			   &info->wq_detcable, 0);
262
263	return ret;
264}
265#endif
266
267static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
268			 usb_extcon_suspend, usb_extcon_resume);
269
270static const struct of_device_id usb_extcon_dt_match[] = {
271	{ .compatible = "linux,extcon-usb-gpio", },
272	{ /* sentinel */ }
273};
274MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
275
276static const struct platform_device_id usb_extcon_platform_ids[] = {
277	{ .name = "extcon-usb-gpio", },
278	{ /* sentinel */ }
279};
280MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
281
282static struct platform_driver usb_extcon_driver = {
283	.probe		= usb_extcon_probe,
284	.remove		= usb_extcon_remove,
285	.driver		= {
286		.name	= "extcon-usb-gpio",
287		.pm	= &usb_extcon_pm_ops,
288		.of_match_table = usb_extcon_dt_match,
289	},
290	.id_table = usb_extcon_platform_ids,
291};
292
293module_platform_driver(usb_extcon_driver);
294
295MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
296MODULE_DESCRIPTION("USB GPIO extcon driver");
297MODULE_LICENSE("GPL v2");
298