Commit | Line | Data |
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0dcd8073 DT |
1 | /* |
2 | * Generic implementation of a polled input device | |
3 | ||
4 | * Copyright (c) 2007 Dmitry Torokhov | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published by | |
8 | * the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/jiffies.h> | |
12 | #include <linux/mutex.h> | |
13 | #include <linux/input-polldev.h> | |
14 | ||
36bd52a4 EP |
15 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); |
16 | MODULE_DESCRIPTION("Generic implementation of a polled input device"); | |
17 | MODULE_LICENSE("GPL v2"); | |
18 | MODULE_VERSION("0.1"); | |
19 | ||
0dcd8073 DT |
20 | static DEFINE_MUTEX(polldev_mutex); |
21 | static int polldev_users; | |
22 | static struct workqueue_struct *polldev_wq; | |
23 | ||
24 | static int input_polldev_start_workqueue(void) | |
25 | { | |
26 | int retval; | |
27 | ||
28 | retval = mutex_lock_interruptible(&polldev_mutex); | |
29 | if (retval) | |
30 | return retval; | |
31 | ||
32 | if (!polldev_users) { | |
33 | polldev_wq = create_singlethread_workqueue("ipolldevd"); | |
34 | if (!polldev_wq) { | |
35 | printk(KERN_ERR "input-polldev: failed to create " | |
36 | "ipolldevd workqueue\n"); | |
37 | retval = -ENOMEM; | |
38 | goto out; | |
39 | } | |
40 | } | |
41 | ||
42 | polldev_users++; | |
43 | ||
44 | out: | |
45 | mutex_unlock(&polldev_mutex); | |
46 | return retval; | |
47 | } | |
48 | ||
49 | static void input_polldev_stop_workqueue(void) | |
50 | { | |
51 | mutex_lock(&polldev_mutex); | |
52 | ||
53 | if (!--polldev_users) | |
54 | destroy_workqueue(polldev_wq); | |
55 | ||
56 | mutex_unlock(&polldev_mutex); | |
57 | } | |
58 | ||
59 | static void input_polled_device_work(struct work_struct *work) | |
60 | { | |
61 | struct input_polled_dev *dev = | |
62 | container_of(work, struct input_polled_dev, work.work); | |
63 | ||
64 | dev->poll(dev); | |
65 | queue_delayed_work(polldev_wq, &dev->work, | |
66 | msecs_to_jiffies(dev->poll_interval)); | |
67 | } | |
68 | ||
69 | static int input_open_polled_device(struct input_dev *input) | |
70 | { | |
71 | struct input_polled_dev *dev = input->private; | |
72 | int error; | |
14134b31 | 73 | unsigned long ticks; |
0dcd8073 DT |
74 | |
75 | error = input_polldev_start_workqueue(); | |
76 | if (error) | |
77 | return error; | |
78 | ||
79 | if (dev->flush) | |
80 | dev->flush(dev); | |
81 | ||
14134b31 SH |
82 | ticks = msecs_to_jiffies(dev->poll_interval); |
83 | if (ticks >= HZ) | |
84 | ticks = round_jiffies(ticks); | |
85 | queue_delayed_work(polldev_wq, &dev->work, ticks); | |
0dcd8073 DT |
86 | |
87 | return 0; | |
88 | } | |
89 | ||
90 | static void input_close_polled_device(struct input_dev *input) | |
91 | { | |
92 | struct input_polled_dev *dev = input->private; | |
93 | ||
94 | cancel_rearming_delayed_workqueue(polldev_wq, &dev->work); | |
95 | input_polldev_stop_workqueue(); | |
96 | } | |
97 | ||
98 | /** | |
99 | * input_allocate_polled_device - allocated memory polled device | |
100 | * | |
101 | * The function allocates memory for a polled device and also | |
102 | * for an input device associated with this polled device. | |
103 | */ | |
104 | struct input_polled_dev *input_allocate_polled_device(void) | |
105 | { | |
106 | struct input_polled_dev *dev; | |
107 | ||
108 | dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL); | |
109 | if (!dev) | |
110 | return NULL; | |
111 | ||
112 | dev->input = input_allocate_device(); | |
113 | if (!dev->input) { | |
114 | kfree(dev); | |
115 | return NULL; | |
116 | } | |
117 | ||
118 | return dev; | |
119 | } | |
120 | EXPORT_SYMBOL(input_allocate_polled_device); | |
121 | ||
122 | /** | |
123 | * input_free_polled_device - free memory allocated for polled device | |
124 | * @dev: device to free | |
125 | * | |
126 | * The function frees memory allocated for polling device and drops | |
127 | * reference to the associated input device (if present). | |
128 | */ | |
129 | void input_free_polled_device(struct input_polled_dev *dev) | |
130 | { | |
131 | if (dev) { | |
132 | input_free_device(dev->input); | |
133 | kfree(dev); | |
134 | } | |
135 | } | |
136 | EXPORT_SYMBOL(input_free_polled_device); | |
137 | ||
138 | /** | |
139 | * input_register_polled_device - register polled device | |
140 | * @dev: device to register | |
141 | * | |
142 | * The function registers previously initialized polled input device | |
143 | * with input layer. The device should be allocated with call to | |
144 | * input_allocate_polled_device(). Callers should also set up poll() | |
145 | * method and set up capabilities (id, name, phys, bits) of the | |
146 | * corresponing input_dev structure. | |
147 | */ | |
148 | int input_register_polled_device(struct input_polled_dev *dev) | |
149 | { | |
150 | struct input_dev *input = dev->input; | |
151 | ||
152 | INIT_DELAYED_WORK(&dev->work, input_polled_device_work); | |
153 | if (!dev->poll_interval) | |
154 | dev->poll_interval = 500; | |
155 | input->private = dev; | |
156 | input->open = input_open_polled_device; | |
157 | input->close = input_close_polled_device; | |
158 | ||
159 | return input_register_device(input); | |
160 | } | |
161 | EXPORT_SYMBOL(input_register_polled_device); | |
162 | ||
163 | /** | |
164 | * input_unregister_polled_device - unregister polled device | |
165 | * @dev: device to unregister | |
166 | * | |
167 | * The function unregisters previously registered polled input | |
168 | * device from input layer. Polling is stopped and device is | |
169 | * ready to be freed with call to input_free_polled_device(). | |
170 | * Callers should not attempt to access dev->input pointer | |
171 | * after calling this function. | |
172 | */ | |
173 | void input_unregister_polled_device(struct input_polled_dev *dev) | |
174 | { | |
175 | input_unregister_device(dev->input); | |
176 | dev->input = NULL; | |
177 | } | |
178 | EXPORT_SYMBOL(input_unregister_polled_device); | |
179 |