xref: /linux/drivers/usb/common/usb-conn-gpio.c (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB GPIO Based Connection Detection Driver
4  *
5  * Copyright (C) 2019 MediaTek Inc.
6  *
7  * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
8  *
9  * Some code borrowed from drivers/extcon/extcon-usb-gpio.c
10  */
11 
12 #include <linux/device.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/platform_device.h>
20 #include <linux/power_supply.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/usb/role.h>
23 
24 #define USB_GPIO_DEB_MS		20	/* ms */
25 #define USB_GPIO_DEB_US		((USB_GPIO_DEB_MS) * 1000)	/* us */
26 
27 #define USB_CONN_IRQF	\
28 	(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
29 
30 struct usb_conn_info {
31 	struct device *dev;
32 	struct usb_role_switch *role_sw;
33 	enum usb_role last_role;
34 	struct regulator *vbus;
35 	struct delayed_work dw_det;
36 	unsigned long debounce_jiffies;
37 
38 	struct gpio_desc *id_gpiod;
39 	struct gpio_desc *vbus_gpiod;
40 	int id_irq;
41 	int vbus_irq;
42 
43 	struct power_supply_desc desc;
44 	struct power_supply *charger;
45 	bool initial_detection;
46 };
47 
48 /*
49  * "DEVICE" = VBUS and "HOST" = !ID, so we have:
50  * Both "DEVICE" and "HOST" can't be set as active at the same time
51  * so if "HOST" is active (i.e. ID is 0)  we keep "DEVICE" inactive
52  * even if VBUS is on.
53  *
54  *  Role          |   ID  |  VBUS
55  * ------------------------------------
56  *  [1] DEVICE    |   H   |   H
57  *  [2] NONE      |   H   |   L
58  *  [3] HOST      |   L   |   H
59  *  [4] HOST      |   L   |   L
60  *
61  * In case we have only one of these signals:
62  * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
63  * - ID only - we want to distinguish between [1] and [4], so VBUS = ID
64  */
usb_conn_detect_cable(struct work_struct * work)65 static void usb_conn_detect_cable(struct work_struct *work)
66 {
67 	struct usb_conn_info *info;
68 	enum usb_role role;
69 	int id, vbus, ret;
70 
71 	info = container_of(to_delayed_work(work),
72 			    struct usb_conn_info, dw_det);
73 
74 	/* check ID and VBUS */
75 	id = info->id_gpiod ?
76 		gpiod_get_value_cansleep(info->id_gpiod) : 1;
77 	vbus = info->vbus_gpiod ?
78 		gpiod_get_value_cansleep(info->vbus_gpiod) : id;
79 
80 	if (!id)
81 		role = USB_ROLE_HOST;
82 	else if (vbus)
83 		role = USB_ROLE_DEVICE;
84 	else
85 		role = USB_ROLE_NONE;
86 
87 	dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
88 		usb_role_string(info->last_role), usb_role_string(role), id, vbus);
89 
90 	if (!info->initial_detection && info->last_role == role) {
91 		dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
92 		return;
93 	}
94 
95 	info->initial_detection = false;
96 
97 	if (info->last_role == USB_ROLE_HOST && info->vbus)
98 		regulator_disable(info->vbus);
99 
100 	ret = usb_role_switch_set_role(info->role_sw, role);
101 	if (ret)
102 		dev_err(info->dev, "failed to set role: %d\n", ret);
103 
104 	if (role == USB_ROLE_HOST && info->vbus) {
105 		ret = regulator_enable(info->vbus);
106 		if (ret)
107 			dev_err(info->dev, "enable vbus regulator failed\n");
108 	}
109 
110 	info->last_role = role;
111 
112 	if (info->vbus)
113 		dev_dbg(info->dev, "vbus regulator is %s\n",
114 			regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
115 
116 	power_supply_changed(info->charger);
117 }
118 
usb_conn_queue_dwork(struct usb_conn_info * info,unsigned long delay)119 static void usb_conn_queue_dwork(struct usb_conn_info *info,
120 				 unsigned long delay)
121 {
122 	queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
123 }
124 
usb_conn_isr(int irq,void * dev_id)125 static irqreturn_t usb_conn_isr(int irq, void *dev_id)
126 {
127 	struct usb_conn_info *info = dev_id;
128 
129 	usb_conn_queue_dwork(info, info->debounce_jiffies);
130 
131 	return IRQ_HANDLED;
132 }
133 
134 static enum power_supply_property usb_charger_properties[] = {
135 	POWER_SUPPLY_PROP_ONLINE,
136 };
137 
usb_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)138 static int usb_charger_get_property(struct power_supply *psy,
139 				    enum power_supply_property psp,
140 				    union power_supply_propval *val)
141 {
142 	struct usb_conn_info *info = power_supply_get_drvdata(psy);
143 
144 	switch (psp) {
145 	case POWER_SUPPLY_PROP_ONLINE:
146 		val->intval = info->last_role == USB_ROLE_DEVICE;
147 		break;
148 	default:
149 		return -EINVAL;
150 	}
151 
152 	return 0;
153 }
154 
usb_conn_psy_register(struct usb_conn_info * info)155 static int usb_conn_psy_register(struct usb_conn_info *info)
156 {
157 	struct device *dev = info->dev;
158 	struct power_supply_desc *desc = &info->desc;
159 	struct power_supply_config cfg = {
160 		.of_node = dev->of_node,
161 	};
162 
163 	desc->name = "usb-charger";
164 	desc->properties = usb_charger_properties;
165 	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
166 	desc->get_property = usb_charger_get_property;
167 	desc->type = POWER_SUPPLY_TYPE_USB;
168 	cfg.drv_data = info;
169 
170 	info->charger = devm_power_supply_register(dev, desc, &cfg);
171 	if (IS_ERR(info->charger))
172 		dev_err(dev, "Unable to register charger\n");
173 
174 	return PTR_ERR_OR_ZERO(info->charger);
175 }
176 
usb_conn_probe(struct platform_device * pdev)177 static int usb_conn_probe(struct platform_device *pdev)
178 {
179 	struct device *dev = &pdev->dev;
180 	struct usb_conn_info *info;
181 	int ret = 0;
182 
183 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
184 	if (!info)
185 		return -ENOMEM;
186 
187 	info->dev = dev;
188 	info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
189 	if (IS_ERR(info->id_gpiod))
190 		return PTR_ERR(info->id_gpiod);
191 
192 	info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
193 	if (IS_ERR(info->vbus_gpiod))
194 		return PTR_ERR(info->vbus_gpiod);
195 
196 	if (!info->id_gpiod && !info->vbus_gpiod) {
197 		dev_err(dev, "failed to get gpios\n");
198 		return -ENODEV;
199 	}
200 
201 	if (info->id_gpiod)
202 		ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
203 	if (!ret && info->vbus_gpiod)
204 		ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
205 	if (ret < 0)
206 		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
207 
208 	INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
209 
210 	info->vbus = devm_regulator_get_optional(dev, "vbus");
211 	if (PTR_ERR(info->vbus) == -ENODEV)
212 		info->vbus = NULL;
213 
214 	if (IS_ERR(info->vbus))
215 		return dev_err_probe(dev, PTR_ERR(info->vbus), "failed to get vbus\n");
216 
217 	info->role_sw = usb_role_switch_get(dev);
218 	if (IS_ERR(info->role_sw))
219 		return dev_err_probe(dev, PTR_ERR(info->role_sw),
220 				     "failed to get role switch\n");
221 
222 	ret = usb_conn_psy_register(info);
223 	if (ret)
224 		goto put_role_sw;
225 
226 	if (info->id_gpiod) {
227 		info->id_irq = gpiod_to_irq(info->id_gpiod);
228 		if (info->id_irq < 0) {
229 			dev_err(dev, "failed to get ID IRQ\n");
230 			ret = info->id_irq;
231 			goto put_role_sw;
232 		}
233 
234 		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
235 						usb_conn_isr, USB_CONN_IRQF,
236 						pdev->name, info);
237 		if (ret < 0) {
238 			dev_err(dev, "failed to request ID IRQ\n");
239 			goto put_role_sw;
240 		}
241 	}
242 
243 	if (info->vbus_gpiod) {
244 		info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
245 		if (info->vbus_irq < 0) {
246 			dev_err(dev, "failed to get VBUS IRQ\n");
247 			ret = info->vbus_irq;
248 			goto put_role_sw;
249 		}
250 
251 		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
252 						usb_conn_isr, USB_CONN_IRQF,
253 						pdev->name, info);
254 		if (ret < 0) {
255 			dev_err(dev, "failed to request VBUS IRQ\n");
256 			goto put_role_sw;
257 		}
258 	}
259 
260 	platform_set_drvdata(pdev, info);
261 	device_set_wakeup_capable(&pdev->dev, true);
262 
263 	/* Perform initial detection */
264 	info->initial_detection = true;
265 	usb_conn_queue_dwork(info, 0);
266 
267 	return 0;
268 
269 put_role_sw:
270 	usb_role_switch_put(info->role_sw);
271 	return ret;
272 }
273 
usb_conn_remove(struct platform_device * pdev)274 static void usb_conn_remove(struct platform_device *pdev)
275 {
276 	struct usb_conn_info *info = platform_get_drvdata(pdev);
277 
278 	cancel_delayed_work_sync(&info->dw_det);
279 
280 	if (info->last_role == USB_ROLE_HOST && info->vbus)
281 		regulator_disable(info->vbus);
282 
283 	usb_role_switch_put(info->role_sw);
284 }
285 
usb_conn_suspend(struct device * dev)286 static int __maybe_unused usb_conn_suspend(struct device *dev)
287 {
288 	struct usb_conn_info *info = dev_get_drvdata(dev);
289 
290 	if (device_may_wakeup(dev)) {
291 		if (info->id_gpiod)
292 			enable_irq_wake(info->id_irq);
293 		if (info->vbus_gpiod)
294 			enable_irq_wake(info->vbus_irq);
295 		return 0;
296 	}
297 
298 	if (info->id_gpiod)
299 		disable_irq(info->id_irq);
300 	if (info->vbus_gpiod)
301 		disable_irq(info->vbus_irq);
302 
303 	pinctrl_pm_select_sleep_state(dev);
304 
305 	return 0;
306 }
307 
usb_conn_resume(struct device * dev)308 static int __maybe_unused usb_conn_resume(struct device *dev)
309 {
310 	struct usb_conn_info *info = dev_get_drvdata(dev);
311 
312 	if (device_may_wakeup(dev)) {
313 		if (info->id_gpiod)
314 			disable_irq_wake(info->id_irq);
315 		if (info->vbus_gpiod)
316 			disable_irq_wake(info->vbus_irq);
317 		return 0;
318 	}
319 
320 	pinctrl_pm_select_default_state(dev);
321 
322 	if (info->id_gpiod)
323 		enable_irq(info->id_irq);
324 	if (info->vbus_gpiod)
325 		enable_irq(info->vbus_irq);
326 
327 	usb_conn_queue_dwork(info, 0);
328 
329 	return 0;
330 }
331 
332 static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
333 			 usb_conn_suspend, usb_conn_resume);
334 
335 static const struct of_device_id usb_conn_dt_match[] = {
336 	{ .compatible = "gpio-usb-b-connector", },
337 	{ }
338 };
339 MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
340 
341 static struct platform_driver usb_conn_driver = {
342 	.probe		= usb_conn_probe,
343 	.remove_new	= usb_conn_remove,
344 	.driver		= {
345 		.name	= "usb-conn-gpio",
346 		.pm	= &usb_conn_pm_ops,
347 		.of_match_table = usb_conn_dt_match,
348 	},
349 };
350 
351 module_platform_driver(usb_conn_driver);
352 
353 MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
354 MODULE_DESCRIPTION("USB GPIO based connection detection driver");
355 MODULE_LICENSE("GPL v2");
356