/* * 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");