drivers/staging/comedi/drivers/comedi_fc.h

   1 /*
   2  * comedi_fc.h
   3  * This is a place for code driver writers wish to share between
   4  * two or more drivers. These functions are meant to be used only
   5  * by drivers, they are NOT part of the kcomedilib API!
   6  *
   7  * Author: Frank Mori Hess <fmhess@users.sourceforge.net>
   8  * Copyright (C) 2002 Frank Mori Hess
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #ifndef _COMEDI_FC_H
  22 #define _COMEDI_FC_H
  23
  24 #include "../comedidev.h"
  25
  26 /**
  27  * cfc_check_trigger_src() - trivially validate a comedi_cmd trigger source
  28  * @src: pointer to the trigger source to validate
  29  * @flags: bitmask of valid TRIG_* for the trigger
  30  *
  31  * This is used in "step 1" of the do_cmdtest functions of comedi drivers
  32  * to vaildate the comedi_cmd triggers. The mask of the @src against the
  33  * @flags allows the userspace comedilib to pass all the comedi_cmd
  34  * triggers as TRIG_ANY and get back a bitmask of the valid trigger sources.
  35  */
  36 static inline int cfc_check_trigger_src(unsigned int *src, unsigned int flags)
  37 {
  38         unsigned int orig_src = *src;
  39
  40         *src = orig_src & flags;
  41         if (*src == TRIG_INVALID || *src != orig_src)
  42                 return -EINVAL;
  43         return 0;
  44 }
  45
  46 /**
  47  * cfc_check_trigger_is_unique() - make sure a trigger source is unique
  48  * @src: the trigger source to check
  49  */
  50 static inline int cfc_check_trigger_is_unique(unsigned int src)
  51 {
  52         /* this test is true if more than one _src bit is set */
  53         if ((src & (src - 1)) != 0)
  54                 return -EINVAL;
  55         return 0;
  56 }
  57
  58 /**
  59  * cfc_check_trigger_arg_is() - trivially validate a trigger argument
  60  * @arg: pointer to the trigger arg to validate
  61  * @val: the value the argument should be
  62  */
  63 static inline int cfc_check_trigger_arg_is(unsigned int *arg, unsigned int val)
  64 {
  65         if (*arg != val) {
  66                 *arg = val;
  67                 return -EINVAL;
  68         }
  69         return 0;
  70 }
  71
  72 /**
  73  * cfc_check_trigger_arg_min() - trivially validate a trigger argument
  74  * @arg: pointer to the trigger arg to validate
  75  * @val: the minimum value the argument should be
  76  */
  77 static inline int cfc_check_trigger_arg_min(unsigned int *arg,
  78                                             unsigned int val)
  79 {
  80         if (*arg < val) {
  81                 *arg = val;
  82                 return -EINVAL;
  83         }
  84         return 0;
  85 }
  86
  87 /**
  88  * cfc_check_trigger_arg_max() - trivially validate a trigger argument
  89  * @arg: pointer to the trigger arg to validate
  90  * @val: the maximum value the argument should be
  91  */
  92 static inline int cfc_check_trigger_arg_max(unsigned int *arg,
  93                                             unsigned int val)
  94 {
  95         if (*arg > val) {
  96                 *arg = val;
  97                 return -EINVAL;
  98         }
  99         return 0;
 100 }
 101
 102 #endif /* _COMEDI_FC_H */