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e52817fa RQ |
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/init.h> | |
19 | #include <linux/interrupt.h> | |
20 | #include <linux/irq.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/of_gpio.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/workqueue.h> | |
27 | ||
28 | #define USB_GPIO_DEBOUNCE_MS 20 /* ms */ | |
29 | ||
30 | struct usb_extcon_info { | |
31 | struct device *dev; | |
32 | struct extcon_dev *edev; | |
33 | ||
34 | struct gpio_desc *id_gpiod; | |
35 | int id_irq; | |
36 | ||
37 | unsigned long debounce_jiffies; | |
38 | struct delayed_work wq_detcable; | |
39 | }; | |
40 | ||
41 | /* List of detectable cables */ | |
42 | enum { | |
43 | EXTCON_CABLE_USB = 0, | |
44 | EXTCON_CABLE_USB_HOST, | |
45 | ||
46 | EXTCON_CABLE_END, | |
47 | }; | |
48 | ||
49 | static const char *usb_extcon_cable[] = { | |
50 | [EXTCON_CABLE_USB] = "USB", | |
51 | [EXTCON_CABLE_USB_HOST] = "USB-HOST", | |
52 | NULL, | |
53 | }; | |
54 | ||
55 | static void usb_extcon_detect_cable(struct work_struct *work) | |
56 | { | |
57 | int id; | |
58 | struct usb_extcon_info *info = container_of(to_delayed_work(work), | |
59 | struct usb_extcon_info, | |
60 | wq_detcable); | |
61 | ||
62 | /* check ID and update cable state */ | |
63 | id = gpiod_get_value_cansleep(info->id_gpiod); | |
64 | if (id) { | |
65 | /* | |
66 | * ID = 1 means USB HOST cable detached. | |
67 | * As we don't have event for USB peripheral cable attached, | |
68 | * we simulate USB peripheral attach here. | |
69 | */ | |
70 | extcon_set_cable_state(info->edev, | |
71 | usb_extcon_cable[EXTCON_CABLE_USB_HOST], | |
72 | false); | |
73 | extcon_set_cable_state(info->edev, | |
74 | usb_extcon_cable[EXTCON_CABLE_USB], | |
75 | true); | |
76 | } else { | |
77 | /* | |
78 | * ID = 0 means USB HOST cable attached. | |
79 | * As we don't have event for USB peripheral cable detached, | |
80 | * we simulate USB peripheral detach here. | |
81 | */ | |
82 | extcon_set_cable_state(info->edev, | |
83 | usb_extcon_cable[EXTCON_CABLE_USB], | |
84 | false); | |
85 | extcon_set_cable_state(info->edev, | |
86 | usb_extcon_cable[EXTCON_CABLE_USB_HOST], | |
87 | true); | |
88 | } | |
89 | } | |
90 | ||
91 | static irqreturn_t usb_irq_handler(int irq, void *dev_id) | |
92 | { | |
93 | struct usb_extcon_info *info = dev_id; | |
94 | ||
95 | queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, | |
96 | info->debounce_jiffies); | |
97 | ||
98 | return IRQ_HANDLED; | |
99 | } | |
100 | ||
101 | static int usb_extcon_probe(struct platform_device *pdev) | |
102 | { | |
103 | struct device *dev = &pdev->dev; | |
104 | struct device_node *np = dev->of_node; | |
105 | struct usb_extcon_info *info; | |
106 | int ret; | |
107 | ||
108 | if (!np) | |
109 | return -EINVAL; | |
110 | ||
111 | info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); | |
112 | if (!info) | |
113 | return -ENOMEM; | |
114 | ||
115 | info->dev = dev; | |
116 | info->id_gpiod = devm_gpiod_get(&pdev->dev, "id"); | |
117 | if (IS_ERR(info->id_gpiod)) { | |
118 | dev_err(dev, "failed to get ID GPIO\n"); | |
119 | return PTR_ERR(info->id_gpiod); | |
120 | } | |
121 | ||
122 | ret = gpiod_set_debounce(info->id_gpiod, | |
123 | USB_GPIO_DEBOUNCE_MS * 1000); | |
124 | if (ret < 0) | |
125 | info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS); | |
126 | ||
127 | INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable); | |
128 | ||
129 | info->id_irq = gpiod_to_irq(info->id_gpiod); | |
130 | if (info->id_irq < 0) { | |
131 | dev_err(dev, "failed to get ID IRQ\n"); | |
132 | return info->id_irq; | |
133 | } | |
134 | ||
135 | ret = devm_request_threaded_irq(dev, info->id_irq, NULL, | |
136 | usb_irq_handler, | |
137 | IRQF_TRIGGER_RISING | | |
138 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, | |
139 | pdev->name, info); | |
140 | if (ret < 0) { | |
141 | dev_err(dev, "failed to request handler for ID IRQ\n"); | |
142 | return ret; | |
143 | } | |
144 | ||
145 | info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable); | |
146 | if (IS_ERR(info->edev)) { | |
147 | dev_err(dev, "failed to allocate extcon device\n"); | |
148 | return -ENOMEM; | |
149 | } | |
150 | ||
151 | ret = devm_extcon_dev_register(dev, info->edev); | |
152 | if (ret < 0) { | |
153 | dev_err(dev, "failed to register extcon device\n"); | |
154 | return ret; | |
155 | } | |
156 | ||
157 | platform_set_drvdata(pdev, info); | |
158 | device_init_wakeup(dev, 1); | |
159 | ||
160 | /* Perform initial detection */ | |
161 | usb_extcon_detect_cable(&info->wq_detcable.work); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | static int usb_extcon_remove(struct platform_device *pdev) | |
167 | { | |
168 | struct usb_extcon_info *info = platform_get_drvdata(pdev); | |
169 | ||
170 | cancel_delayed_work_sync(&info->wq_detcable); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | #ifdef CONFIG_PM_SLEEP | |
176 | static int usb_extcon_suspend(struct device *dev) | |
177 | { | |
178 | struct usb_extcon_info *info = dev_get_drvdata(dev); | |
179 | int ret = 0; | |
180 | ||
181 | if (device_may_wakeup(dev)) { | |
182 | ret = enable_irq_wake(info->id_irq); | |
183 | if (ret) | |
184 | return ret; | |
185 | } | |
186 | ||
187 | /* | |
188 | * We don't want to process any IRQs after this point | |
189 | * as GPIOs used behind I2C subsystem might not be | |
190 | * accessible until resume completes. So disable IRQ. | |
191 | */ | |
192 | disable_irq(info->id_irq); | |
193 | ||
194 | return ret; | |
195 | } | |
196 | ||
197 | static int usb_extcon_resume(struct device *dev) | |
198 | { | |
199 | struct usb_extcon_info *info = dev_get_drvdata(dev); | |
200 | int ret = 0; | |
201 | ||
202 | if (device_may_wakeup(dev)) { | |
203 | ret = disable_irq_wake(info->id_irq); | |
204 | if (ret) | |
205 | return ret; | |
206 | } | |
207 | ||
208 | enable_irq(info->id_irq); | |
209 | ||
210 | return ret; | |
211 | } | |
212 | #endif | |
213 | ||
214 | static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops, | |
215 | usb_extcon_suspend, usb_extcon_resume); | |
216 | ||
217 | static struct of_device_id usb_extcon_dt_match[] = { | |
218 | { .compatible = "linux,extcon-usb-gpio", }, | |
219 | { /* sentinel */ } | |
220 | }; | |
221 | MODULE_DEVICE_TABLE(of, usb_extcon_dt_match); | |
222 | ||
223 | static struct platform_driver usb_extcon_driver = { | |
224 | .probe = usb_extcon_probe, | |
225 | .remove = usb_extcon_remove, | |
226 | .driver = { | |
227 | .name = "extcon-usb-gpio", | |
228 | .pm = &usb_extcon_pm_ops, | |
229 | .of_match_table = usb_extcon_dt_match, | |
230 | }, | |
231 | }; | |
232 | ||
233 | module_platform_driver(usb_extcon_driver); | |
234 | ||
235 | MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); | |
236 | MODULE_DESCRIPTION("USB GPIO extcon driver"); | |
237 | MODULE_LICENSE("GPL v2"); |