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1 /*
2  *  output.c - Display Output Switch driver
3  *
4  *  Copyright (C) 2006 Luming Yu <luming.yu@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or (at
11  *  your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24 #include <linux/module.h>
25 #include <linux/video_output.h>
26 #include <linux/slab.h>
27 #include <linux/err.h>
28 #include <linux/ctype.h>
29 
30 
31 MODULE_DESCRIPTION("Display Output Switcher Lowlevel Control Abstraction");
32 MODULE_LICENSE("GPL");
33 MODULE_AUTHOR("Luming Yu <luming.yu@intel.com>");
34 
video_output_show_state(struct device * dev,struct device_attribute * attr,char * buf)35 static ssize_t video_output_show_state(struct device *dev,
36 				       struct device_attribute *attr, char *buf)
37 {
38 	ssize_t ret_size = 0;
39 	struct output_device *od = to_output_device(dev);
40 	if (od->props)
41 		ret_size = sprintf(buf,"%.8x\n",od->props->get_status(od));
42 	return ret_size;
43 }
44 
video_output_store_state(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)45 static ssize_t video_output_store_state(struct device *dev,
46 					struct device_attribute *attr,
47 					const char *buf,size_t count)
48 {
49 	char *endp;
50 	struct output_device *od = to_output_device(dev);
51 	int request_state = simple_strtoul(buf,&endp,0);
52 	size_t size = endp - buf;
53 
54 	if (isspace(*endp))
55 		size++;
56 	if (size != count)
57 		return -EINVAL;
58 
59 	if (od->props) {
60 		od->request_state = request_state;
61 		od->props->set_state(od);
62 	}
63 	return count;
64 }
65 
video_output_release(struct device * dev)66 static void video_output_release(struct device *dev)
67 {
68 	struct output_device *od = to_output_device(dev);
69 	kfree(od);
70 }
71 
72 static struct device_attribute video_output_attributes[] = {
73 	__ATTR(state, 0644, video_output_show_state, video_output_store_state),
74 	__ATTR_NULL,
75 };
76 
77 
78 static struct class video_output_class = {
79 	.name = "video_output",
80 	.dev_release = video_output_release,
81 	.dev_attrs = video_output_attributes,
82 };
83 
video_output_register(const char * name,struct device * dev,void * devdata,struct output_properties * op)84 struct output_device *video_output_register(const char *name,
85 	struct device *dev,
86 	void *devdata,
87 	struct output_properties *op)
88 {
89 	struct output_device *new_dev;
90 	int ret_code = 0;
91 
92 	new_dev = kzalloc(sizeof(struct output_device),GFP_KERNEL);
93 	if (!new_dev) {
94 		ret_code = -ENOMEM;
95 		goto error_return;
96 	}
97 	new_dev->props = op;
98 	new_dev->dev.class = &video_output_class;
99 	new_dev->dev.parent = dev;
100 	dev_set_name(&new_dev->dev, name);
101 	dev_set_drvdata(&new_dev->dev, devdata);
102 	ret_code = device_register(&new_dev->dev);
103 	if (ret_code) {
104 		kfree(new_dev);
105 		goto error_return;
106 	}
107 	return new_dev;
108 
109 error_return:
110 	return ERR_PTR(ret_code);
111 }
112 EXPORT_SYMBOL(video_output_register);
113 
video_output_unregister(struct output_device * dev)114 void video_output_unregister(struct output_device *dev)
115 {
116 	if (!dev)
117 		return;
118 	device_unregister(&dev->dev);
119 }
120 EXPORT_SYMBOL(video_output_unregister);
121 
video_output_class_exit(void)122 static void __exit video_output_class_exit(void)
123 {
124 	class_unregister(&video_output_class);
125 }
126 
video_output_class_init(void)127 static int __init video_output_class_init(void)
128 {
129 	return class_register(&video_output_class);
130 }
131 
132 postcore_initcall(video_output_class_init);
133 module_exit(video_output_class_exit);
134