linux/drivers/video/output.c

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/*
* output.c - Display Output Switch driver
*
* Copyright (C) 2006 Luming Yu <luming.yu@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* 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/video_output.h>
#include <linux/err.h>
#include <linux/ctype.h>
MODULE_DESCRIPTION("Display Output Switcher Lowlevel Control Abstraction");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Luming Yu <luming.yu@intel.com>");
static ssize_t video_output_show_state(struct class_device *dev,char *buf)
{
ssize_t ret_size = 0;
struct output_device *od = to_output_device(dev);
if (od->props)
ret_size = sprintf(buf,"%.8x\n",od->props->get_status(od));
return ret_size;
}
static ssize_t video_output_store_state(struct class_device *dev,
const char *buf,size_t count)
{
char *endp;
struct output_device *od = to_output_device(dev);
int request_state = simple_strtoul(buf,&endp,0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
if (od->props) {
od->request_state = request_state;
od->props->set_state(od);
}
return count;
}
static void video_output_class_release(struct class_device *dev)
{
struct output_device *od = to_output_device(dev);
kfree(od);
}
static struct class_device_attribute video_output_attributes[] = {
__ATTR(state, 0644, video_output_show_state, video_output_store_state),
__ATTR_NULL,
};
static struct class video_output_class = {
.name = "video_output",
.release = video_output_class_release,
.class_dev_attrs = video_output_attributes,
};
struct output_device *video_output_register(const char *name,
struct device *dev,
void *devdata,
struct output_properties *op)
{
struct output_device *new_dev;
int ret_code = 0;
new_dev = kzalloc(sizeof(struct output_device),GFP_KERNEL);
if (!new_dev) {
ret_code = -ENOMEM;
goto error_return;
}
new_dev->props = op;
new_dev->class_dev.class = &video_output_class;
new_dev->class_dev.dev = dev;
strlcpy(new_dev->class_dev.class_id,name,KOBJ_NAME_LEN);
class_set_devdata(&new_dev->class_dev,devdata);
ret_code = class_device_register(&new_dev->class_dev);
if (ret_code) {
kfree(new_dev);
goto error_return;
}
return new_dev;
error_return:
return ERR_PTR(ret_code);
}
EXPORT_SYMBOL(video_output_register);
void video_output_unregister(struct output_device *dev)
{
if (!dev)
return;
class_device_unregister(&dev->class_dev);
}
EXPORT_SYMBOL(video_output_unregister);
static void __exit video_output_class_exit(void)
{
class_unregister(&video_output_class);
}
static int __init video_output_class_init(void)
{
return class_register(&video_output_class);
}
postcore_initcall(video_output_class_init);
module_exit(video_output_class_exit);