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
24 struct 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
37 static 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 */
usb_extcon_detect_cable(struct work_struct * work)60 static 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73 /* at first we clean states which are no longer active */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
usb_irq_handler(int irq,void * dev_id)87 static 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
usb_extcon_probe(struct platform_device * pdev)97 static 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
usb_extcon_remove(struct platform_device * pdev)196 static 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
usb_extcon_suspend(struct device * dev)207 static 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 /*
230 * We don't want to process any IRQs after this point
231 * as GPIOs used behind I2C subsystem might not be
232 * accessible until resume completes. So disable IRQ.
233 */
234 if (info->id_gpiod)
235 disable_irq(info->id_irq);
236 if (info->vbus_gpiod)
237 disable_irq(info->vbus_irq);
238
239 if (!device_may_wakeup(dev))
240 pinctrl_pm_select_sleep_state(dev);
241
242 return ret;
243 }
244
usb_extcon_resume(struct device * dev)245 static int usb_extcon_resume(struct device *dev)
246 {
247 struct usb_extcon_info *info = dev_get_drvdata(dev);
248 int ret = 0;
249
250 if (!device_may_wakeup(dev))
251 pinctrl_pm_select_default_state(dev);
252
253 if (device_may_wakeup(dev)) {
254 if (info->id_gpiod) {
255 ret = disable_irq_wake(info->id_irq);
256 if (ret)
257 return ret;
258 }
259 if (info->vbus_gpiod) {
260 ret = disable_irq_wake(info->vbus_irq);
261 if (ret) {
262 if (info->id_gpiod)
263 enable_irq_wake(info->id_irq);
264
265 return ret;
266 }
267 }
268 }
269
270 if (info->id_gpiod)
271 enable_irq(info->id_irq);
272 if (info->vbus_gpiod)
273 enable_irq(info->vbus_irq);
274
275 queue_delayed_work(system_power_efficient_wq,
276 &info->wq_detcable, 0);
277
278 return ret;
279 }
280 #endif
281
282 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
283 usb_extcon_suspend, usb_extcon_resume);
284
285 static const struct of_device_id usb_extcon_dt_match[] = {
286 { .compatible = "linux,extcon-usb-gpio", },
287 { /* sentinel */ }
288 };
289 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
290
291 static const struct platform_device_id usb_extcon_platform_ids[] = {
292 { .name = "extcon-usb-gpio", },
293 { /* sentinel */ }
294 };
295 MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
296
297 static struct platform_driver usb_extcon_driver = {
298 .probe = usb_extcon_probe,
299 .remove = usb_extcon_remove,
300 .driver = {
301 .name = "extcon-usb-gpio",
302 .pm = &usb_extcon_pm_ops,
303 .of_match_table = usb_extcon_dt_match,
304 },
305 .id_table = usb_extcon_platform_ids,
306 };
307
308 module_platform_driver(usb_extcon_driver);
309
310 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
311 MODULE_DESCRIPTION("USB GPIO extcon driver");
312 MODULE_LICENSE("GPL v2");
313