1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/*
* display-sysfs.c - Display output driver sysfs interface
*
* Copyright (C) 2007 James Simmons <jsimmons@infradead.org>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/module.h>
#include <linux/display.h>
#include <linux/ctype.h>
#include <linux/idr.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/slab.h>
static ssize_t display_show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct display_device *dsp = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name);
}
static ssize_t display_show_type(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct display_device *dsp = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%s\n", dsp->type);
}
static ssize_t display_show_contrast(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct display_device *dsp = dev_get_drvdata(dev);
ssize_t rc = -ENXIO;
mutex_lock(&dsp->lock);
if (likely(dsp->driver) && dsp->driver->get_contrast)
rc = sprintf(buf, "%d\n", dsp->driver->get_contrast(dsp));
mutex_unlock(&dsp->lock);
return rc;
}
static ssize_t display_store_contrast(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct display_device *dsp = dev_get_drvdata(dev);
ssize_t ret = -EINVAL, size;
int contrast;
char *endp;
contrast = simple_strtoul(buf, &endp, 0);
size = endp - buf;
if (isspace(*endp))
size++;
if (size != count)
return ret;
mutex_lock(&dsp->lock);
if (likely(dsp->driver && dsp->driver->set_contrast)) {
pr_debug("display: set contrast to %d\n", contrast);
dsp->driver->set_contrast(dsp, contrast);
ret = count;
}
mutex_unlock(&dsp->lock);
return ret;
}
static ssize_t display_show_max_contrast(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct display_device *dsp = dev_get_drvdata(dev);
ssize_t rc = -ENXIO;
mutex_lock(&dsp->lock);
if (likely(dsp->driver))
rc = sprintf(buf, "%d\n", dsp->driver->max_contrast);
mutex_unlock(&dsp->lock);
return rc;
}
static struct device_attribute display_attrs[] = {
__ATTR(name, S_IRUGO, display_show_name, NULL),
__ATTR(type, S_IRUGO, display_show_type, NULL),
__ATTR(contrast, S_IRUGO | S_IWUSR, display_show_contrast, display_store_contrast),
__ATTR(max_contrast, S_IRUGO, display_show_max_contrast, NULL),
};
static int display_suspend(struct device *dev, pm_message_t state)
{
struct display_device *dsp = dev_get_drvdata(dev);
mutex_lock(&dsp->lock);
if (likely(dsp->driver->suspend))
dsp->driver->suspend(dsp, state);
mutex_unlock(&dsp->lock);
return 0;
};
static int display_resume(struct device *dev)
{
struct display_device *dsp = dev_get_drvdata(dev);
mutex_lock(&dsp->lock);
if (likely(dsp->driver->resume))
dsp->driver->resume(dsp);
mutex_unlock(&dsp->lock);
return 0;
};
static struct mutex allocated_dsp_lock;
static DEFINE_IDR(allocated_dsp);
static struct class *display_class;
struct display_device *display_device_register(struct display_driver *driver,
struct device *parent, void *devdata)
{
struct display_device *new_dev = NULL;
int ret = -EINVAL;
if (unlikely(!driver))
return ERR_PTR(ret);
mutex_lock(&allocated_dsp_lock);
ret = idr_pre_get(&allocated_dsp, GFP_KERNEL);
mutex_unlock(&allocated_dsp_lock);
if (!ret)
return ERR_PTR(ret);
new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
if (likely(new_dev) && unlikely(driver->probe(new_dev, devdata))) {
// Reserve the index for this display
mutex_lock(&allocated_dsp_lock);
ret = idr_get_new(&allocated_dsp, new_dev, &new_dev->idx);
mutex_unlock(&allocated_dsp_lock);
if (!ret) {
new_dev->dev = device_create(display_class, parent,
MKDEV(0, 0), new_dev,
"display%d", new_dev->idx);
if (!IS_ERR(new_dev->dev)) {
new_dev->parent = parent;
new_dev->driver = driver;
mutex_init(&new_dev->lock);
return new_dev;
}
mutex_lock(&allocated_dsp_lock);
idr_remove(&allocated_dsp, new_dev->idx);
mutex_unlock(&allocated_dsp_lock);
ret = -EINVAL;
}
}
kfree(new_dev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(display_device_register);
void display_device_unregister(struct display_device *ddev)
{
if (!ddev)
return;
// Free device
mutex_lock(&ddev->lock);
device_unregister(ddev->dev);
mutex_unlock(&ddev->lock);
// Mark device index as avaliable
mutex_lock(&allocated_dsp_lock);
idr_remove(&allocated_dsp, ddev->idx);
mutex_unlock(&allocated_dsp_lock);
kfree(ddev);
}
EXPORT_SYMBOL(display_device_unregister);
static int __init display_class_init(void)
{
display_class = class_create(THIS_MODULE, "display");
if (IS_ERR(display_class)) {
printk(KERN_ERR "Failed to create display class\n");
display_class = NULL;
return -EINVAL;
}
display_class->dev_attrs = display_attrs;
display_class->suspend = display_suspend;
display_class->resume = display_resume;
mutex_init(&allocated_dsp_lock);
return 0;
}
static void __exit display_class_exit(void)
{
class_destroy(display_class);
}
module_init(display_class_init);
module_exit(display_class_exit);
MODULE_DESCRIPTION("Display Hardware handling");
MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
MODULE_LICENSE("GPL");
|
