Name
drm_ioctl — 
     ioctl callback implementation for DRM drivers
 
Synopsis
| long drm_ioctl ( | struct file * filp, | 
|  | unsigned int cmd, | 
|  | unsigned long arg ); | 
 
Arguments
- filp
- 
     file this ioctl is called on
     
- cmd
- 
     ioctl cmd number
     
- arg
- 
     user argument
     
Looks up the ioctl function in the 
   :ioctls table, checking for root
   previleges if so required, and dispatches to the respective function.
Returns
   Zero on success, negative error code on failure.