2 * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
4 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
5 * Author: Roger Quadros <rogerq@ti.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
17 #include <linux/extcon.h>
18 #include <linux/gpio.h>
19 #include <linux/gpio/consumer.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/of_gpio.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_wakeirq.h>
28 #include <linux/slab.h>
29 #include <linux/workqueue.h>
31 #define USB_GPIO_DEBOUNCE_MS 20 /* ms */
33 struct usb_extcon_info {
35 struct extcon_dev *edev;
37 struct gpio_desc *id_gpiod;
40 unsigned long debounce_jiffies;
41 struct delayed_work wq_detcable;
44 static const unsigned int usb_extcon_cable[] = {
50 static void usb_extcon_detect_cable(struct work_struct *work)
53 struct usb_extcon_info *info = container_of(to_delayed_work(work),
54 struct usb_extcon_info,
57 /* check ID and update cable state */
58 id = gpiod_get_value_cansleep(info->id_gpiod);
61 * ID = 1 means USB HOST cable detached.
62 * As we don't have event for USB peripheral cable attached,
63 * we simulate USB peripheral attach here.
65 extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, false);
66 extcon_set_cable_state_(info->edev, EXTCON_USB, true);
69 * ID = 0 means USB HOST cable attached.
70 * As we don't have event for USB peripheral cable detached,
71 * we simulate USB peripheral detach here.
73 extcon_set_cable_state_(info->edev, EXTCON_USB, false);
74 extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, true);
78 static irqreturn_t usb_irq_handler(int irq, void *dev_id)
80 struct usb_extcon_info *info = dev_id;
82 queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
83 info->debounce_jiffies);
88 static int usb_extcon_probe(struct platform_device *pdev)
90 struct device *dev = &pdev->dev;
91 struct device_node *np = dev->of_node;
92 struct usb_extcon_info *info;
98 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
103 info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
104 if (IS_ERR(info->id_gpiod)) {
105 dev_err(dev, "failed to get ID GPIO\n");
106 return PTR_ERR(info->id_gpiod);
109 info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
110 if (IS_ERR(info->edev)) {
111 dev_err(dev, "failed to allocate extcon device\n");
115 ret = devm_extcon_dev_register(dev, info->edev);
117 dev_err(dev, "failed to register extcon device\n");
121 ret = gpiod_set_debounce(info->id_gpiod,
122 USB_GPIO_DEBOUNCE_MS * 1000);
124 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
126 INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
128 info->id_irq = gpiod_to_irq(info->id_gpiod);
129 if (info->id_irq < 0) {
130 dev_err(dev, "failed to get ID IRQ\n");
134 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
136 IRQF_TRIGGER_RISING |
137 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
140 dev_err(dev, "failed to request handler for ID IRQ\n");
144 platform_set_drvdata(pdev, info);
145 device_init_wakeup(dev, true);
146 dev_pm_set_wake_irq(dev, info->id_irq);
148 /* Perform initial detection */
149 usb_extcon_detect_cable(&info->wq_detcable.work);
154 static int usb_extcon_remove(struct platform_device *pdev)
156 struct usb_extcon_info *info = platform_get_drvdata(pdev);
158 cancel_delayed_work_sync(&info->wq_detcable);
160 dev_pm_clear_wake_irq(&pdev->dev);
161 device_init_wakeup(&pdev->dev, false);
166 #ifdef CONFIG_PM_SLEEP
167 static int usb_extcon_suspend(struct device *dev)
169 struct usb_extcon_info *info = dev_get_drvdata(dev);
173 * We don't want to process any IRQs after this point
174 * as GPIOs used behind I2C subsystem might not be
175 * accessible until resume completes. So disable IRQ.
177 disable_irq(info->id_irq);
182 static int usb_extcon_resume(struct device *dev)
184 struct usb_extcon_info *info = dev_get_drvdata(dev);
187 enable_irq(info->id_irq);
193 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
194 usb_extcon_suspend, usb_extcon_resume);
196 static const struct of_device_id usb_extcon_dt_match[] = {
197 { .compatible = "linux,extcon-usb-gpio", },
200 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
202 static struct platform_driver usb_extcon_driver = {
203 .probe = usb_extcon_probe,
204 .remove = usb_extcon_remove,
206 .name = "extcon-usb-gpio",
207 .pm = &usb_extcon_pm_ops,
208 .of_match_table = usb_extcon_dt_match,
212 module_platform_driver(usb_extcon_driver);
214 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
215 MODULE_DESCRIPTION("USB GPIO extcon driver");
216 MODULE_LICENSE("GPL v2");