struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
        int err = 0;
-       int tmp;
+       unsigned int arg;
 
        /* Step 1 : check if triggers are trivially valid */
 
        /* step 4: fix up any arguments */
 
        if (cmd->scan_begin_src == TRIG_TIMER) {
-               tmp = cmd->scan_begin_arg;
-               rtd_ns_to_timer(&cmd->scan_begin_arg,
-                               cmd->flags & TRIG_ROUND_MASK);
-               if (tmp != cmd->scan_begin_arg)
-                       err++;
-
+               arg = cmd->scan_begin_arg;
+               rtd_ns_to_timer(&arg, cmd->flags & TRIG_ROUND_MASK);
+               err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
        }
+
        if (cmd->convert_src == TRIG_TIMER) {
-               tmp = cmd->convert_arg;
-               rtd_ns_to_timer(&cmd->convert_arg,
-                               cmd->flags & TRIG_ROUND_MASK);
-               if (tmp != cmd->convert_arg)
-                       err++;
-
-               if (cmd->scan_begin_src == TRIG_TIMER
-                   && (cmd->scan_begin_arg
-                       < (cmd->convert_arg * cmd->scan_end_arg))) {
-                       cmd->scan_begin_arg =
-                           cmd->convert_arg * cmd->scan_end_arg;
-                       err++;
+               arg = cmd->convert_arg;
+               rtd_ns_to_timer(&arg, cmd->flags & TRIG_ROUND_MASK);
+               err |= cfc_check_trigger_arg_is(&cmd->convert_arg, arg);
+
+               if (cmd->scan_begin_src == TRIG_TIMER) {
+                       arg = cmd->convert_arg * cmd->scan_end_arg;
+                       err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
+                                                        arg);
                }
        }