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Dmitry Torokhov0dcd8072007-04-29 23:42:45 -04001/*
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
Joe Perchesda0c4902010-11-29 23:33:07 -080011#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040013#include <linux/jiffies.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040015#include <linux/mutex.h>
Dmitry Torokhove490ebd2011-04-27 23:20:16 -070016#include <linux/workqueue.h>
Paul Gortmakerd2d84422011-07-03 13:53:48 -040017#include <linux/module.h>
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040018#include <linux/input-polldev.h>
19
Eric Piel36bd52a2007-05-22 23:28:03 -040020MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
21MODULE_DESCRIPTION("Generic implementation of a polled input device");
22MODULE_LICENSE("GPL v2");
23MODULE_VERSION("0.1");
24
Samu Onkalodad725d2009-11-13 21:13:22 -080025static void input_polldev_queue_work(struct input_polled_dev *dev)
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040026{
Stephen Hemminger374766b2007-11-21 14:03:37 -050027 unsigned long delay;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040028
Stephen Hemminger374766b2007-11-21 14:03:37 -050029 delay = msecs_to_jiffies(dev->poll_interval);
30 if (delay >= HZ)
31 delay = round_jiffies_relative(delay);
32
Dmitry Torokhove490ebd2011-04-27 23:20:16 -070033 queue_delayed_work(system_freezable_wq, &dev->work, delay);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040034}
35
Samu Onkalodad725d2009-11-13 21:13:22 -080036static void input_polled_device_work(struct work_struct *work)
37{
38 struct input_polled_dev *dev =
39 container_of(work, struct input_polled_dev, work.work);
40
41 dev->poll(dev);
42 input_polldev_queue_work(dev);
43}
44
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040045static int input_open_polled_device(struct input_dev *input)
46{
Dmitry Torokhov3797fec2008-04-02 00:41:00 -040047 struct input_polled_dev *dev = input_get_drvdata(input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040048
Samu Onkalob0aba1e2009-10-18 00:38:57 -070049 if (dev->open)
50 dev->open(dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040051
Samu Onkalo11bb4cc2009-11-23 10:01:33 -080052 /* Only start polling if polling is enabled */
Dmitry Torokhov5e3e4eb2011-08-02 22:22:46 -070053 if (dev->poll_interval > 0) {
54 dev->poll(dev);
55 input_polldev_queue_work(dev);
56 }
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040057
58 return 0;
59}
60
61static void input_close_polled_device(struct input_dev *input)
62{
Dmitry Torokhov3797fec2008-04-02 00:41:00 -040063 struct input_polled_dev *dev = input_get_drvdata(input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040064
Stephen Hemminger374766b2007-11-21 14:03:37 -050065 cancel_delayed_work_sync(&dev->work);
Samu Onkalob0aba1e2009-10-18 00:38:57 -070066
67 if (dev->close)
68 dev->close(dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040069}
70
Samu Onkalodad725d2009-11-13 21:13:22 -080071/* SYSFS interface */
72
73static ssize_t input_polldev_get_poll(struct device *dev,
74 struct device_attribute *attr, char *buf)
75{
76 struct input_polled_dev *polldev = dev_get_drvdata(dev);
77
78 return sprintf(buf, "%d\n", polldev->poll_interval);
79}
80
81static ssize_t input_polldev_set_poll(struct device *dev,
82 struct device_attribute *attr, const char *buf,
83 size_t count)
84{
85 struct input_polled_dev *polldev = dev_get_drvdata(dev);
86 struct input_dev *input = polldev->input;
JJ Ding76496e72011-11-09 10:20:14 -080087 unsigned int interval;
88 int err;
Samu Onkalodad725d2009-11-13 21:13:22 -080089
JJ Ding76496e72011-11-09 10:20:14 -080090 err = kstrtouint(buf, 0, &interval);
91 if (err)
92 return err;
Samu Onkalodad725d2009-11-13 21:13:22 -080093
94 if (interval < polldev->poll_interval_min)
95 return -EINVAL;
96
97 if (interval > polldev->poll_interval_max)
98 return -EINVAL;
99
100 mutex_lock(&input->mutex);
101
102 polldev->poll_interval = interval;
103
104 if (input->users) {
105 cancel_delayed_work_sync(&polldev->work);
106 if (polldev->poll_interval > 0)
107 input_polldev_queue_work(polldev);
108 }
109
110 mutex_unlock(&input->mutex);
111
112 return count;
113}
114
115static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
116 input_polldev_set_poll);
117
118
119static ssize_t input_polldev_get_max(struct device *dev,
120 struct device_attribute *attr, char *buf)
121{
122 struct input_polled_dev *polldev = dev_get_drvdata(dev);
123
124 return sprintf(buf, "%d\n", polldev->poll_interval_max);
125}
126
127static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
128
129static ssize_t input_polldev_get_min(struct device *dev,
130 struct device_attribute *attr, char *buf)
131{
132 struct input_polled_dev *polldev = dev_get_drvdata(dev);
133
134 return sprintf(buf, "%d\n", polldev->poll_interval_min);
135}
136
137static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
138
139static struct attribute *sysfs_attrs[] = {
140 &dev_attr_poll.attr,
141 &dev_attr_max.attr,
142 &dev_attr_min.attr,
143 NULL
144};
145
146static struct attribute_group input_polldev_attribute_group = {
147 .attrs = sysfs_attrs
148};
149
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700150static const struct attribute_group *input_polldev_attribute_groups[] = {
151 &input_polldev_attribute_group,
152 NULL
153};
154
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400155/**
Dmitry Torokhov2546bcc2011-01-31 21:06:34 -0800156 * input_allocate_polled_device - allocate memory for polled device
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400157 *
158 * The function allocates memory for a polled device and also
159 * for an input device associated with this polled device.
160 */
161struct input_polled_dev *input_allocate_polled_device(void)
162{
163 struct input_polled_dev *dev;
164
165 dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
166 if (!dev)
167 return NULL;
168
169 dev->input = input_allocate_device();
170 if (!dev->input) {
171 kfree(dev);
172 return NULL;
173 }
174
175 return dev;
176}
177EXPORT_SYMBOL(input_allocate_polled_device);
178
179/**
180 * input_free_polled_device - free memory allocated for polled device
181 * @dev: device to free
182 *
183 * The function frees memory allocated for polling device and drops
Dmitry Torokhov36203c42009-12-04 10:22:23 -0800184 * reference to the associated input device.
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400185 */
186void input_free_polled_device(struct input_polled_dev *dev)
187{
188 if (dev) {
189 input_free_device(dev->input);
190 kfree(dev);
191 }
192}
193EXPORT_SYMBOL(input_free_polled_device);
194
195/**
196 * input_register_polled_device - register polled device
197 * @dev: device to register
198 *
199 * The function registers previously initialized polled input device
200 * with input layer. The device should be allocated with call to
201 * input_allocate_polled_device(). Callers should also set up poll()
202 * method and set up capabilities (id, name, phys, bits) of the
Dmitry Torokhov2546bcc2011-01-31 21:06:34 -0800203 * corresponding input_dev structure.
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400204 */
205int input_register_polled_device(struct input_polled_dev *dev)
206{
207 struct input_dev *input = dev->input;
Samu Onkalodad725d2009-11-13 21:13:22 -0800208 int error;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400209
Dmitry Torokhov3797fec2008-04-02 00:41:00 -0400210 input_set_drvdata(input, dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400211 INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700212
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400213 if (!dev->poll_interval)
214 dev->poll_interval = 500;
Samu Onkalodad725d2009-11-13 21:13:22 -0800215 if (!dev->poll_interval_max)
216 dev->poll_interval_max = dev->poll_interval;
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700217
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400218 input->open = input_open_polled_device;
219 input->close = input_close_polled_device;
220
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700221 input->dev.groups = input_polldev_attribute_groups;
222
Samu Onkalodad725d2009-11-13 21:13:22 -0800223 error = input_register_device(input);
224 if (error)
225 return error;
226
Dmitry Torokhov36203c42009-12-04 10:22:23 -0800227 /*
228 * Take extra reference to the underlying input device so
229 * that it survives call to input_unregister_polled_device()
230 * and is deleted only after input_free_polled_device()
231 * has been invoked. This is needed to ease task of freeing
232 * sparse keymaps.
233 */
234 input_get_device(input);
235
Samu Onkalodad725d2009-11-13 21:13:22 -0800236 return 0;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400237}
238EXPORT_SYMBOL(input_register_polled_device);
239
240/**
241 * input_unregister_polled_device - unregister polled device
242 * @dev: device to unregister
243 *
244 * The function unregisters previously registered polled input
245 * device from input layer. Polling is stopped and device is
246 * ready to be freed with call to input_free_polled_device().
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400247 */
248void input_unregister_polled_device(struct input_polled_dev *dev)
249{
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400250 input_unregister_device(dev->input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400251}
252EXPORT_SYMBOL(input_unregister_polled_device);