debugfs_create_u8 — create a debugfs file that is used to read and write an unsigned 8-bit value
| struct dentry * debugfs_create_u8 ( | const char * name, | 
| mode_t mode, | |
| struct dentry * parent, | |
| u8 * value ); | 
namea pointer to a string containing the name of the file to create.
modethe permission that the file should have
parent
     a pointer to the parent dentry for this file.  This should be a
     directory dentry if set.  If this parameter is NULL, then the
     file will be created in the root of the debugfs filesystem.
    
valuea pointer to the variable that the file should read to and write from.
   This function creates a file in debugfs with the given name that
   contains the value of the variable value.  If the mode variable is so
   set, it can be read from, and written to.
   
   This function will return a pointer to a dentry if it succeeds.  This
   pointer must be passed to the debugfs_remove function when the file is
   to be removed (no automatic cleanup happens if your module is unloaded,
   you are responsible here.)  If an error occurs, NULL will be returned.
   
   If debugfs is not enabled in the kernel, the value -ENODEV will be
   returned.  It is not wise to check for this value, but rather, check for
   NULL or !NULL instead as to eliminate the need for #ifdef in the calling
   code.