105 lines
2.0 KiB
C
105 lines
2.0 KiB
C
|
/*
|
||
|
|
* linux/drivers/video/fb_sys_read.c - Generic file operations where
|
||
|
|
* framebuffer is in system RAM
|
||
|
|
*
|
||
|
|
* Copyright (C) 2007 Antonino Daplas <adaplas@pol.net>
|
||
|
|
*
|
||
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
||
|
|
* License. See the file COPYING in the main directory of this archive
|
||
|
|
* for more details.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
#include <linux/fb.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
|
||
|
|
ssize_t fb_sys_read(struct fb_info *info, char __user *buf, size_t count,
|
||
|
|
loff_t *ppos)
|
||
|
|
{
|
||
|
|
unsigned long p = *ppos;
|
||
|
|
void *src;
|
||
|
|
int err = 0;
|
||
|
|
unsigned long total_size;
|
||
|
|
|
||
|
|
if (info->state != FBINFO_STATE_RUNNING)
|
||
|
|
return -EPERM;
|
||
|
|
|
||
|
|
total_size = info->screen_size;
|
||
|
|
|
||
|
|
if (total_size == 0)
|
||
|
|
total_size = info->fix.smem_len;
|
||
|
|
|
||
|
|
if (p >= total_size)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (count >= total_size)
|
||
|
|
count = total_size;
|
||
|
|
|
||
|
|
if (count + p > total_size)
|
||
|
|
count = total_size - p;
|
||
|
|
|
||
|
|
src = (void __force *)(info->screen_base + p);
|
||
|
|
|
||
|
|
if (info->fbops->fb_sync)
|
||
|
|
info->fbops->fb_sync(info);
|
||
|
|
|
||
|
|
if (copy_to_user(buf, src, count))
|
||
|
|
err = -EFAULT;
|
||
|
|
|
||
|
|
if (!err)
|
||
|
|
*ppos += count;
|
||
|
|
|
||
|
|
return (err) ? err : count;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(fb_sys_read);
|
||
|
|
|
||
|
|
ssize_t fb_sys_write(struct fb_info *info, const char __user *buf,
|
||
|
|
size_t count, loff_t *ppos)
|
||
|
|
{
|
||
|
|
unsigned long p = *ppos;
|
||
|
|
void *dst;
|
||
|
|
int err = 0;
|
||
|
|
unsigned long total_size;
|
||
|
|
|
||
|
|
if (info->state != FBINFO_STATE_RUNNING)
|
||
|
|
return -EPERM;
|
||
|
|
|
||
|
|
total_size = info->screen_size;
|
||
|
|
|
||
|
|
if (total_size == 0)
|
||
|
|
total_size = info->fix.smem_len;
|
||
|
|
|
||
|
|
if (p > total_size)
|
||
|
|
return -EFBIG;
|
||
|
|
|
||
|
|
if (count > total_size) {
|
||
|
|
err = -EFBIG;
|
||
|
|
count = total_size;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (count + p > total_size) {
|
||
|
|
if (!err)
|
||
|
|
err = -ENOSPC;
|
||
|
|
|
||
|
|
count = total_size - p;
|
||
|
|
}
|
||
|
|
|
||
|
|
dst = (void __force *) (info->screen_base + p);
|
||
|
|
|
||
|
|
if (info->fbops->fb_sync)
|
||
|
|
info->fbops->fb_sync(info);
|
||
|
|
|
||
|
|
if (copy_from_user(dst, buf, count))
|
||
|
|
err = -EFAULT;
|
||
|
|
|
||
|
|
if (!err)
|
||
|
|
*ppos += count;
|
||
|
|
|
||
|
|
return (err) ? err : count;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(fb_sys_write);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
|
||
|
|
MODULE_DESCRIPTION("Generic file read (fb in system RAM)");
|
||
|
|
MODULE_LICENSE("GPL");
|