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.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of_gpio.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/workqueue.h>
21 #include <linux/pinctrl/consumer.h>
22
23 #define USB_GPIO_DEBOUNCE_MS 20 /* ms */
24
25 struct usb_extcon_info {
26 struct device *dev;
27 struct extcon_dev *edev;
28
29 struct gpio_desc *id_gpiod;
30 struct gpio_desc *vbus_gpiod;
31 int id_irq;
32 int vbus_irq;
33
34 unsigned long debounce_jiffies;
35 struct delayed_work wq_detcable;
36 };
37
38 static const unsigned int usb_extcon_cable[] = {
39 EXTCON_USB,
40 EXTCON_USB_HOST,
41 EXTCON_NONE,
42 };
43
44 /*
45 * "USB" = VBUS and "USB-HOST" = !ID, so we have:
46 * Both "USB" and "USB-HOST" can't be set as active at the
47 * same time so if "USB-HOST" is active (i.e. ID is 0) we keep "USB" inactive
48 * even if VBUS is on.
49 *
50 * State | ID | VBUS
51 * ----------------------------------------
52 * [1] USB | H | H
53 * [2] none | H | L
54 * [3] USB-HOST | L | H
55 * [4] USB-HOST | L | L
56 *
57 * In case we have only one of these signals:
58 * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
59 * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
60 */
usb_extcon_detect_cable(struct work_struct * work)61 static void usb_extcon_detect_cable(struct work_struct *work)
62 {
63 int id, vbus;
64 struct usb_extcon_info *info = container_of(to_delayed_work(work),
65 struct usb_extcon_info,
66 wq_detcable);
67
68 /* check ID and VBUS and update cable state */
69 id = info->id_gpiod ?
70 gpiod_get_value_cansleep(info->id_gpiod) : 1;
71 vbus = info->vbus_gpiod ?
72 gpiod_get_value_cansleep(info->vbus_gpiod) : id;
73
74 /* at first we clean states which are no longer active */
75 if (id)
76 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
77 if (!vbus)
78 extcon_set_state_sync(info->edev, EXTCON_USB, false);
79
80 if (!id) {
81 extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
82 } else {
83 if (vbus)
84 extcon_set_state_sync(info->edev, EXTCON_USB, true);
85 }
86 }
87
usb_irq_handler(int irq,void * dev_id)88 static irqreturn_t usb_irq_handler(int irq, void *dev_id)
89 {
90 struct usb_extcon_info *info = dev_id;
91
92 queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
93 info->debounce_jiffies);
94
95 return IRQ_HANDLED;
96 }
97
usb_extcon_probe(struct platform_device * pdev)98 static int usb_extcon_probe(struct platform_device *pdev)
99 {
100 struct device *dev = &pdev->dev;
101 struct device_node *np = dev->of_node;
102 struct usb_extcon_info *info;
103 int ret;
104
105 if (!np)
106 return -EINVAL;
107
108 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
109 if (!info)
110 return -ENOMEM;
111
112 info->dev = dev;
113 info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
114 info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
115 GPIOD_IN);
116
117 if (!info->id_gpiod && !info->vbus_gpiod) {
118 dev_err(dev, "failed to get gpios\n");
119 return -ENODEV;
120 }
121
122 if (IS_ERR(info->id_gpiod))
123 return PTR_ERR(info->id_gpiod);
124
125 if (IS_ERR(info->vbus_gpiod))
126 return PTR_ERR(info->vbus_gpiod);
127
128 info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
129 if (IS_ERR(info->edev)) {
130 dev_err(dev, "failed to allocate extcon device\n");
131 return -ENOMEM;
132 }
133
134 ret = devm_extcon_dev_register(dev, info->edev);
135 if (ret < 0) {
136 dev_err(dev, "failed to register extcon device\n");
137 return ret;
138 }
139
140 if (info->id_gpiod)
141 ret = gpiod_set_debounce(info->id_gpiod,
142 USB_GPIO_DEBOUNCE_MS * 1000);
143 if (!ret && info->vbus_gpiod)
144 ret = gpiod_set_debounce(info->vbus_gpiod,
145 USB_GPIO_DEBOUNCE_MS * 1000);
146
147 if (ret < 0)
148 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
149
150 INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
151
152 if (info->id_gpiod) {
153 info->id_irq = gpiod_to_irq(info->id_gpiod);
154 if (info->id_irq < 0) {
155 dev_err(dev, "failed to get ID IRQ\n");
156 return info->id_irq;
157 }
158
159 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
160 usb_irq_handler,
161 IRQF_TRIGGER_RISING |
162 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
163 pdev->name, info);
164 if (ret < 0) {
165 dev_err(dev, "failed to request handler for ID IRQ\n");
166 return ret;
167 }
168 }
169
170 if (info->vbus_gpiod) {
171 info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
172 if (info->vbus_irq < 0) {
173 dev_err(dev, "failed to get VBUS IRQ\n");
174 return info->vbus_irq;
175 }
176
177 ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
178 usb_irq_handler,
179 IRQF_TRIGGER_RISING |
180 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
181 pdev->name, info);
182 if (ret < 0) {
183 dev_err(dev, "failed to request handler for VBUS IRQ\n");
184 return ret;
185 }
186 }
187
188 platform_set_drvdata(pdev, info);
189 device_set_wakeup_capable(&pdev->dev, true);
190
191 /* Perform initial detection */
192 usb_extcon_detect_cable(&info->wq_detcable.work);
193
194 return 0;
195 }
196
usb_extcon_remove(struct platform_device * pdev)197 static int usb_extcon_remove(struct platform_device *pdev)
198 {
199 struct usb_extcon_info *info = platform_get_drvdata(pdev);
200
201 cancel_delayed_work_sync(&info->wq_detcable);
202 device_init_wakeup(&pdev->dev, false);
203
204 return 0;
205 }
206
207 #ifdef CONFIG_PM_SLEEP
usb_extcon_suspend(struct device * dev)208 static int usb_extcon_suspend(struct device *dev)
209 {
210 struct usb_extcon_info *info = dev_get_drvdata(dev);
211 int ret = 0;
212
213 if (device_may_wakeup(dev)) {
214 if (info->id_gpiod) {
215 ret = enable_irq_wake(info->id_irq);
216 if (ret)
217 return ret;
218 }
219 if (info->vbus_gpiod) {
220 ret = enable_irq_wake(info->vbus_irq);
221 if (ret) {
222 if (info->id_gpiod)
223 disable_irq_wake(info->id_irq);
224
225 return ret;
226 }
227 }
228 }
229
230 /*
231 * We don't want to process any IRQs after this point
232 * as GPIOs used behind I2C subsystem might not be
233 * accessible until resume completes. So disable IRQ.
234 */
235 if (info->id_gpiod)
236 disable_irq(info->id_irq);
237 if (info->vbus_gpiod)
238 disable_irq(info->vbus_irq);
239
240 if (!device_may_wakeup(dev))
241 pinctrl_pm_select_sleep_state(dev);
242
243 return ret;
244 }
245
usb_extcon_resume(struct device * dev)246 static int usb_extcon_resume(struct device *dev)
247 {
248 struct usb_extcon_info *info = dev_get_drvdata(dev);
249 int ret = 0;
250
251 if (!device_may_wakeup(dev))
252 pinctrl_pm_select_default_state(dev);
253
254 if (device_may_wakeup(dev)) {
255 if (info->id_gpiod) {
256 ret = disable_irq_wake(info->id_irq);
257 if (ret)
258 return ret;
259 }
260 if (info->vbus_gpiod) {
261 ret = disable_irq_wake(info->vbus_irq);
262 if (ret) {
263 if (info->id_gpiod)
264 enable_irq_wake(info->id_irq);
265
266 return ret;
267 }
268 }
269 }
270
271 if (info->id_gpiod)
272 enable_irq(info->id_irq);
273 if (info->vbus_gpiod)
274 enable_irq(info->vbus_irq);
275
276 queue_delayed_work(system_power_efficient_wq,
277 &info->wq_detcable, 0);
278
279 return ret;
280 }
281 #endif
282
283 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
284 usb_extcon_suspend, usb_extcon_resume);
285
286 static const struct of_device_id usb_extcon_dt_match[] = {
287 { .compatible = "linux,extcon-usb-gpio", },
288 { /* sentinel */ }
289 };
290 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
291
292 static const struct platform_device_id usb_extcon_platform_ids[] = {
293 { .name = "extcon-usb-gpio", },
294 { /* sentinel */ }
295 };
296 MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
297
298 static struct platform_driver usb_extcon_driver = {
299 .probe = usb_extcon_probe,
300 .remove = usb_extcon_remove,
301 .driver = {
302 .name = "extcon-usb-gpio",
303 .pm = &usb_extcon_pm_ops,
304 .of_match_table = usb_extcon_dt_match,
305 },
306 .id_table = usb_extcon_platform_ids,
307 };
308
309 module_platform_driver(usb_extcon_driver);
310
311 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
312 MODULE_DESCRIPTION("USB GPIO extcon driver");
313 MODULE_LICENSE("GPL v2");
314