LXR linux/drivers/video/output.c

   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/err.h>
  27#include <linux/ctype.h>
  28
  29
  30MODULE_DESCRIPTION("Display Output Switcher Lowlevel Control Abstraction");
  31MODULE_LICENSE("GPL");
  32MODULE_AUTHOR("Luming Yu <luming.yu@intel.com>");
  33
  34static ssize_t video_output_show_state(struct device *dev,
  35                                       struct device_attribute *attr, char *buf)
  36{
  37        ssize_t ret_size = 0;
  38        struct output_device *od = to_output_device(dev);
  39        if (od->props)
  40                ret_size = sprintf(buf,"%.8x\n",od->props->get_status(od));
  41        return ret_size;
  42}
  43
  44static ssize_t video_output_store_state(struct device *dev,
  45                                        struct device_attribute *attr,
  46                                        const char *buf,size_t count)
  47{
  48        char *endp;
  49        struct output_device *od = to_output_device(dev);
  50        int request_state = simple_strtoul(buf,&endp,0);
  51        size_t size = endp - buf;
  52
  53        if (*endp && isspace(*endp))
  54                size++;
  55        if (size != count)
  56                return -EINVAL;
  57
  58        if (od->props) {
  59                od->request_state = request_state;
  60                od->props->set_state(od);
  61        }
  62        return count;
  63}
  64
  65static void video_output_release(struct device *dev)
  66{
  67        struct output_device *od = to_output_device(dev);
  68        kfree(od);
  69}
  70
  71static struct device_attribute video_output_attributes[] = {
  72        __ATTR(state, 0644, video_output_show_state, video_output_store_state),
  73        __ATTR_NULL,
  74};
  75
  76
  77static struct class video_output_class = {
  78        .name = "video_output",
  79        .dev_release = video_output_release,
  80        .dev_attrs = video_output_attributes,
  81};
  82
  83struct output_device *video_output_register(const char *name,
  84        struct device *dev,
  85        void *devdata,
  86        struct output_properties *op)
  87{
  88        struct output_device *new_dev;
  89        int ret_code = 0;
  90
  91        new_dev = kzalloc(sizeof(struct output_device),GFP_KERNEL);
  92        if (!new_dev) {
  93                ret_code = -ENOMEM;
  94                goto error_return;
  95        }
  96        new_dev->props = op;
  97        new_dev->dev.class = &video_output_class;
  98        new_dev->dev.parent = dev;
  99        dev_set_name(&new_dev->dev, name);
 100        dev_set_drvdata(&new_dev->dev, devdata);
 101        ret_code = device_register(&new_dev->dev);
 102        if (ret_code) {
 103                kfree(new_dev);
 104                goto error_return;
 105        }
 106        return new_dev;
 107
 108error_return:
 109        return ERR_PTR(ret_code);
 110}
 111EXPORT_SYMBOL(video_output_register);
 112
 113void video_output_unregister(struct output_device *dev)
 114{
 115        if (!dev)
 116                return;
 117        device_unregister(&dev->dev);
 118}
 119EXPORT_SYMBOL(video_output_unregister);
 120
 121static void __exit video_output_class_exit(void)
 122{
 123        class_unregister(&video_output_class);
 124}
 125
 126static int __init video_output_class_init(void)
 127{
 128        return class_register(&video_output_class);
 129}
 130
 131postcore_initcall(video_output_class_init);
 132module_exit(video_output_class_exit);
 133