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Roger Quadrose52817f2015-02-02 12:21:59 +02001/**
2 * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
3 *
4 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
5 * Author: Roger Quadros <rogerq@ti.com>
6 *
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.
10 *
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.
15 */
16
17#include <linux/extcon.h>
Roger Quadros92b7cb52015-08-03 17:40:51 +030018#include <linux/gpio.h>
Geert Uytterhoeven638f9582015-05-05 18:32:20 +020019#include <linux/gpio/consumer.h>
Roger Quadrose52817f2015-02-02 12:21:59 +020020#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/slab.h>
28#include <linux/workqueue.h>
29
30#define USB_GPIO_DEBOUNCE_MS 20 /* ms */
31
32struct usb_extcon_info {
33 struct device *dev;
34 struct extcon_dev *edev;
35
36 struct gpio_desc *id_gpiod;
37 int id_irq;
38
39 unsigned long debounce_jiffies;
40 struct delayed_work wq_detcable;
41};
42
Chanwoo Choi73b6ecd2015-06-12 11:10:06 +090043static const unsigned int usb_extcon_cable[] = {
Chanwoo Choi2a9de9c2015-04-24 19:16:05 +090044 EXTCON_USB,
45 EXTCON_USB_HOST,
46 EXTCON_NONE,
Roger Quadrose52817f2015-02-02 12:21:59 +020047};
48
49static void usb_extcon_detect_cable(struct work_struct *work)
50{
51 int id;
52 struct usb_extcon_info *info = container_of(to_delayed_work(work),
53 struct usb_extcon_info,
54 wq_detcable);
55
56 /* check ID and update cable state */
57 id = gpiod_get_value_cansleep(info->id_gpiod);
58 if (id) {
59 /*
60 * ID = 1 means USB HOST cable detached.
61 * As we don't have event for USB peripheral cable attached,
62 * we simulate USB peripheral attach here.
63 */
Chanwoo Choi2a9de9c2015-04-24 19:16:05 +090064 extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, false);
65 extcon_set_cable_state_(info->edev, EXTCON_USB, true);
Roger Quadrose52817f2015-02-02 12:21:59 +020066 } else {
67 /*
68 * ID = 0 means USB HOST cable attached.
69 * As we don't have event for USB peripheral cable detached,
70 * we simulate USB peripheral detach here.
71 */
Chanwoo Choi2a9de9c2015-04-24 19:16:05 +090072 extcon_set_cable_state_(info->edev, EXTCON_USB, false);
73 extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, true);
Roger Quadrose52817f2015-02-02 12:21:59 +020074 }
75}
76
77static irqreturn_t usb_irq_handler(int irq, void *dev_id)
78{
79 struct usb_extcon_info *info = dev_id;
80
81 queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
82 info->debounce_jiffies);
83
84 return IRQ_HANDLED;
85}
86
87static int usb_extcon_probe(struct platform_device *pdev)
88{
89 struct device *dev = &pdev->dev;
90 struct device_node *np = dev->of_node;
91 struct usb_extcon_info *info;
92 int ret;
93
94 if (!np)
95 return -EINVAL;
96
97 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
98 if (!info)
99 return -ENOMEM;
100
101 info->dev = dev;
Uwe Kleine-König35eed7a2015-05-19 14:18:30 +0200102 info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
Roger Quadrose52817f2015-02-02 12:21:59 +0200103 if (IS_ERR(info->id_gpiod)) {
104 dev_err(dev, "failed to get ID GPIO\n");
105 return PTR_ERR(info->id_gpiod);
106 }
107
Robert Baldygabc1aaba2015-04-02 15:13:02 +0200108 info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
109 if (IS_ERR(info->edev)) {
110 dev_err(dev, "failed to allocate extcon device\n");
111 return -ENOMEM;
112 }
113
114 ret = devm_extcon_dev_register(dev, info->edev);
115 if (ret < 0) {
116 dev_err(dev, "failed to register extcon device\n");
117 return ret;
118 }
119
Roger Quadrose52817f2015-02-02 12:21:59 +0200120 ret = gpiod_set_debounce(info->id_gpiod,
121 USB_GPIO_DEBOUNCE_MS * 1000);
122 if (ret < 0)
123 info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
124
125 INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
126
127 info->id_irq = gpiod_to_irq(info->id_gpiod);
128 if (info->id_irq < 0) {
129 dev_err(dev, "failed to get ID IRQ\n");
130 return info->id_irq;
131 }
132
133 ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
134 usb_irq_handler,
135 IRQF_TRIGGER_RISING |
136 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
137 pdev->name, info);
138 if (ret < 0) {
139 dev_err(dev, "failed to request handler for ID IRQ\n");
140 return ret;
141 }
142
Roger Quadrose52817f2015-02-02 12:21:59 +0200143 platform_set_drvdata(pdev, info);
144 device_init_wakeup(dev, 1);
145
146 /* Perform initial detection */
147 usb_extcon_detect_cable(&info->wq_detcable.work);
148
149 return 0;
150}
151
152static int usb_extcon_remove(struct platform_device *pdev)
153{
154 struct usb_extcon_info *info = platform_get_drvdata(pdev);
155
156 cancel_delayed_work_sync(&info->wq_detcable);
157
158 return 0;
159}
160
161#ifdef CONFIG_PM_SLEEP
162static int usb_extcon_suspend(struct device *dev)
163{
164 struct usb_extcon_info *info = dev_get_drvdata(dev);
165 int ret = 0;
166
167 if (device_may_wakeup(dev)) {
168 ret = enable_irq_wake(info->id_irq);
169 if (ret)
170 return ret;
171 }
172
173 /*
174 * We don't want to process any IRQs after this point
175 * as GPIOs used behind I2C subsystem might not be
176 * accessible until resume completes. So disable IRQ.
177 */
178 disable_irq(info->id_irq);
179
180 return ret;
181}
182
183static int usb_extcon_resume(struct device *dev)
184{
185 struct usb_extcon_info *info = dev_get_drvdata(dev);
186 int ret = 0;
187
188 if (device_may_wakeup(dev)) {
189 ret = disable_irq_wake(info->id_irq);
190 if (ret)
191 return ret;
192 }
193
194 enable_irq(info->id_irq);
195
196 return ret;
197}
198#endif
199
200static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
201 usb_extcon_suspend, usb_extcon_resume);
202
Chanwoo Choi34825e52015-03-07 01:41:36 +0900203static const struct of_device_id usb_extcon_dt_match[] = {
Roger Quadrose52817f2015-02-02 12:21:59 +0200204 { .compatible = "linux,extcon-usb-gpio", },
205 { /* sentinel */ }
206};
207MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
208
209static struct platform_driver usb_extcon_driver = {
210 .probe = usb_extcon_probe,
211 .remove = usb_extcon_remove,
212 .driver = {
213 .name = "extcon-usb-gpio",
214 .pm = &usb_extcon_pm_ops,
215 .of_match_table = usb_extcon_dt_match,
216 },
217};
218
219module_platform_driver(usb_extcon_driver);
220
221MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
222MODULE_DESCRIPTION("USB GPIO extcon driver");
223MODULE_LICENSE("GPL v2");