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1 | /** | |
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> | |
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/slab.h> | |
28 | #include <linux/workqueue.h> | |
29 | ||
30 | #define USB_GPIO_DEBOUNCE_MS 20 /* ms */ | |
31 | ||
32 | struct 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 | ||
43 | static const unsigned int usb_extcon_cable[] = { | |
44 | EXTCON_USB, | |
45 | EXTCON_USB_HOST, | |
46 | EXTCON_NONE, | |
47 | }; | |
48 | ||
49 | static 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 | */ | |
64 | extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, false); | |
65 | extcon_set_cable_state_(info->edev, EXTCON_USB, true); | |
66 | } 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 | */ | |
72 | extcon_set_cable_state_(info->edev, EXTCON_USB, false); | |
73 | extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, true); | |
74 | } | |
75 | } | |
76 | ||
77 | static 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 | ||
87 | static 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; | |
102 | info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN); | |
103 | 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 | ||
108 | 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 | ||
120 | 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 | ||
143 | 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 | ||
152 | static 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 | |
162 | static 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 | ||
183 | static 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 | ||
200 | static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops, | |
201 | usb_extcon_suspend, usb_extcon_resume); | |
202 | ||
203 | static const struct of_device_id usb_extcon_dt_match[] = { | |
204 | { .compatible = "linux,extcon-usb-gpio", }, | |
205 | { /* sentinel */ } | |
206 | }; | |
207 | MODULE_DEVICE_TABLE(of, usb_extcon_dt_match); | |
208 | ||
209 | static 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 | ||
219 | module_platform_driver(usb_extcon_driver); | |
220 | ||
221 | MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); | |
222 | MODULE_DESCRIPTION("USB GPIO extcon driver"); | |
223 | MODULE_LICENSE("GPL v2"); |