summaryrefslogtreecommitdiff
path: root/drivers/usb/common/usb-conn-gpio.c
blob: b39c9f1c375d6e358ae7d62c81aa280f9a007be6 (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
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
// SPDX-License-Identifier: GPL-2.0
/*
 * USB GPIO Based Connection Detection Driver
 *
 * Copyright (C) 2019 MediaTek Inc.
 *
 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
 *
 * Some code borrowed from drivers/extcon/extcon-usb-gpio.c
 */

#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regulator/consumer.h>
#include <linux/usb/role.h>

#define USB_GPIO_DEB_MS		20	/* ms */
#define USB_GPIO_DEB_US		((USB_GPIO_DEB_MS) * 1000)	/* us */

#define USB_CONN_IRQF	\
	(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)

struct usb_conn_info {
	struct device *dev;
	struct usb_role_switch *role_sw;
	enum usb_role last_role;
	struct regulator *vbus;
	struct delayed_work dw_det;
	unsigned long debounce_jiffies;

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

	struct power_supply_desc desc;
	struct power_supply *charger;
};

/*
 * "DEVICE" = VBUS and "HOST" = !ID, so we have:
 * Both "DEVICE" and "HOST" can't be set as active at the same time
 * so if "HOST" is active (i.e. ID is 0)  we keep "DEVICE" inactive
 * even if VBUS is on.
 *
 *  Role          |   ID  |  VBUS
 * ------------------------------------
 *  [1] DEVICE    |   H   |   H
 *  [2] NONE      |   H   |   L
 *  [3] HOST      |   L   |   H
 *  [4] 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_conn_detect_cable(struct work_struct *work)
{
	struct usb_conn_info *info;
	enum usb_role role;
	int id, vbus, ret;

	info = container_of(to_delayed_work(work),
			    struct usb_conn_info, dw_det);

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

	if (!id)
		role = USB_ROLE_HOST;
	else if (vbus)
		role = USB_ROLE_DEVICE;
	else
		role = USB_ROLE_NONE;

	dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
		usb_role_string(info->last_role), usb_role_string(role), id, vbus);

	if (info->last_role == role) {
		dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
		return;
	}

	if (info->last_role == USB_ROLE_HOST && info->vbus)
		regulator_disable(info->vbus);

	ret = usb_role_switch_set_role(info->role_sw, role);
	if (ret)
		dev_err(info->dev, "failed to set role: %d\n", ret);

	if (role == USB_ROLE_HOST && info->vbus) {
		ret = regulator_enable(info->vbus);
		if (ret)
			dev_err(info->dev, "enable vbus regulator failed\n");
	}

	info->last_role = role;

	if (info->vbus)
		dev_dbg(info->dev, "vbus regulator is %s\n",
			regulator_is_enabled(info->vbus) ? "enabled" : "disabled");

	power_supply_changed(info->charger);
}

static void usb_conn_queue_dwork(struct usb_conn_info *info,
				 unsigned long delay)
{
	queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
}

static irqreturn_t usb_conn_isr(int irq, void *dev_id)
{
	struct usb_conn_info *info = dev_id;

	usb_conn_queue_dwork(info, info->debounce_jiffies);

	return IRQ_HANDLED;
}

static enum power_supply_property usb_charger_properties[] = {
	POWER_SUPPLY_PROP_ONLINE,
};

static int usb_charger_get_property(struct power_supply *psy,
				    enum power_supply_property psp,
				    union power_supply_propval *val)
{
	struct usb_conn_info *info = power_supply_get_drvdata(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = info->last_role == USB_ROLE_DEVICE;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int usb_conn_psy_register(struct usb_conn_info *info)
{
	struct device *dev = info->dev;
	struct power_supply_desc *desc = &info->desc;
	struct power_supply_config cfg = {
		.of_node = dev->of_node,
	};

	desc->name = "usb-charger";
	desc->properties = usb_charger_properties;
	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
	desc->get_property = usb_charger_get_property;
	desc->type = POWER_SUPPLY_TYPE_USB;
	cfg.drv_data = info;

	info->charger = devm_power_supply_register(dev, desc, &cfg);
	if (IS_ERR(info->charger))
		dev_err(dev, "Unable to register charger\n");

	return PTR_ERR_OR_ZERO(info->charger);
}

static int usb_conn_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct usb_conn_info *info;
	int ret = 0;

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

	info->dev = dev;
	info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
	if (IS_ERR(info->id_gpiod))
		return PTR_ERR(info->id_gpiod);

	info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
	if (IS_ERR(info->vbus_gpiod))
		return PTR_ERR(info->vbus_gpiod);

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

	if (info->id_gpiod)
		ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
	if (!ret && info->vbus_gpiod)
		ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
	if (ret < 0)
		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);

	INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);

	info->vbus = devm_regulator_get_optional(dev, "vbus");
	if (PTR_ERR(info->vbus) == -ENODEV)
		info->vbus = NULL;

	if (IS_ERR(info->vbus)) {
		ret = PTR_ERR(info->vbus);
		return dev_err_probe(dev, ret, "failed to get vbus :%d\n", ret);
	}

	info->role_sw = usb_role_switch_get(dev);
	if (IS_ERR(info->role_sw))
		return dev_err_probe(dev, PTR_ERR(info->role_sw),
				     "failed to get role switch\n");

	ret = usb_conn_psy_register(info);
	if (ret)
		goto put_role_sw;

	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");
			ret = info->id_irq;
			goto put_role_sw;
		}

		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
						usb_conn_isr, USB_CONN_IRQF,
						pdev->name, info);
		if (ret < 0) {
			dev_err(dev, "failed to request ID IRQ\n");
			goto put_role_sw;
		}
	}

	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");
			ret = info->vbus_irq;
			goto put_role_sw;
		}

		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
						usb_conn_isr, USB_CONN_IRQF,
						pdev->name, info);
		if (ret < 0) {
			dev_err(dev, "failed to request VBUS IRQ\n");
			goto put_role_sw;
		}
	}

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

	/* Perform initial detection */
	usb_conn_queue_dwork(info, 0);

	return 0;

put_role_sw:
	usb_role_switch_put(info->role_sw);
	return ret;
}

static int usb_conn_remove(struct platform_device *pdev)
{
	struct usb_conn_info *info = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&info->dw_det);

	if (info->last_role == USB_ROLE_HOST && info->vbus)
		regulator_disable(info->vbus);

	usb_role_switch_put(info->role_sw);

	return 0;
}

static int __maybe_unused usb_conn_suspend(struct device *dev)
{
	struct usb_conn_info *info = dev_get_drvdata(dev);

	if (device_may_wakeup(dev)) {
		if (info->id_gpiod)
			enable_irq_wake(info->id_irq);
		if (info->vbus_gpiod)
			enable_irq_wake(info->vbus_irq);
		return 0;
	}

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

	pinctrl_pm_select_sleep_state(dev);

	return 0;
}

static int __maybe_unused usb_conn_resume(struct device *dev)
{
	struct usb_conn_info *info = dev_get_drvdata(dev);

	if (device_may_wakeup(dev)) {
		if (info->id_gpiod)
			disable_irq_wake(info->id_irq);
		if (info->vbus_gpiod)
			disable_irq_wake(info->vbus_irq);
		return 0;
	}

	pinctrl_pm_select_default_state(dev);

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

	usb_conn_queue_dwork(info, 0);

	return 0;
}

static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
			 usb_conn_suspend, usb_conn_resume);

static const struct of_device_id usb_conn_dt_match[] = {
	{ .compatible = "gpio-usb-b-connector", },
	{ }
};
MODULE_DEVICE_TABLE(of, usb_conn_dt_match);

static struct platform_driver usb_conn_driver = {
	.probe		= usb_conn_probe,
	.remove		= usb_conn_remove,
	.driver		= {
		.name	= "usb-conn-gpio",
		.pm	= &usb_conn_pm_ops,
		.of_match_table = usb_conn_dt_match,
	},
};

module_platform_driver(usb_conn_driver);

MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
MODULE_DESCRIPTION("USB GPIO based connection detection driver");
MODULE_LICENSE("GPL v2");