drivers/staging/comedi/drivers/comedi_fc.h

   1 /*
   2     comedi_fc.h
   3
   4     This is a place for code driver writers wish to share between
   5     two or more drivers. These functions are meant to be used only
   6     by drivers, they are NOT part of the kcomedilib API!
   7
   8     Author:  Frank Mori Hess <fmhess@users.sourceforge.net>
   9     Copyright (C) 2002 Frank Mori Hess
  10
  11     This program is free software; you can redistribute it and/or modify
  12     it under the terms of the GNU General Public License as published by
  13     the Free Software Foundation; either version 2 of the License, or
  14     (at your option) any later version.
  15
  16     This program is distributed in the hope that it will be useful,
  17     but WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19     GNU General Public License for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with this program; if not, write to the Free Software
  23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ************************************************************************/
  26
  27 #ifndef _COMEDI_FC_H
  28 #define _COMEDI_FC_H
  29
  30 #include "../comedidev.h"
  31
  32 /* Writes an array of data points to comedi's buffer */
  33 extern unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *subd,
  34                                               void *data,
  35                                               unsigned int num_bytes);
  36
  37 static inline unsigned int cfc_write_to_buffer(struct comedi_subdevice *subd,
  38                                                short data)
  39 {
  40         return cfc_write_array_to_buffer(subd, &data, sizeof(data));
  41 };
  42
  43 static inline unsigned int cfc_write_long_to_buffer(struct comedi_subdevice
  44                                                     *subd, unsigned int data)
  45 {
  46         return cfc_write_array_to_buffer(subd, &data, sizeof(data));
  47 };
  48
  49 extern unsigned int cfc_read_array_from_buffer(struct comedi_subdevice *subd,
  50                                                void *data,
  51                                                unsigned int num_bytes);
  52
  53 extern unsigned int cfc_handle_events(struct comedi_device *dev,
  54                                       struct comedi_subdevice *subd);
  55
  56 static inline unsigned int cfc_bytes_per_scan(struct comedi_subdevice *subd)
  57 {
  58         int num_samples;
  59         int bits_per_sample;
  60
  61         switch (subd->type) {
  62         case COMEDI_SUBD_DI:
  63         case COMEDI_SUBD_DO:
  64         case COMEDI_SUBD_DIO:
  65                 bits_per_sample = 8 * bytes_per_sample(subd);
  66                 num_samples = (subd->async->cmd.chanlist_len +
  67                                bits_per_sample - 1) / bits_per_sample;
  68                 break;
  69         default:
  70                 num_samples = subd->async->cmd.chanlist_len;
  71                 break;
  72         }
  73         return num_samples * bytes_per_sample(subd);
  74 }
  75
  76 /**
  77  * cfc_check_trigger_src() - trivially validate a comedi_cmd trigger source
  78  * @src: pointer to the trigger source to validate
  79  * @flags: bitmask of valid TRIG_* for the trigger
  80  *
  81  * This is used in "step 1" of the do_cmdtest functions of comedi drivers
  82  * to vaildate the comedi_cmd triggers. The mask of the @src against the
  83  * @flags allows the userspace comedilib to pass all the comedi_cmd
  84  * triggers as TRIG_ANY and get back a bitmask of the valid trigger sources.
  85  */
  86 static inline int cfc_check_trigger_src(unsigned int *src, unsigned int flags)
  87 {
  88         unsigned int orig_src = *src;
  89
  90         *src = orig_src & flags;
  91         if (*src == TRIG_INVALID || *src != orig_src)
  92                 return -EINVAL;
  93         return 0;
  94 }
  95
  96 /**
  97  * cfc_check_trigger_is_unique() - make sure a trigger source is unique
  98  * @src: the trigger source to check
  99  */
 100 static inline int cfc_check_trigger_is_unique(unsigned int src)
 101 {
 102         /* this test is true if more than one _src bit is set */
 103         if ((src & (src - 1)) != 0)
 104                 return -EINVAL;
 105         return 0;
 106 }
 107
 108 /**
 109  * cfc_check_trigger_arg_is() - trivially validate a trigger argument
 110  * @arg: pointer to the trigger arg to validate
 111  * @val: the value the argument should be
 112  */
 113 static inline int cfc_check_trigger_arg_is(unsigned int *arg, unsigned int val)
 114 {
 115         if (*arg != val) {
 116                 *arg = val;
 117                 return -EINVAL;
 118         }
 119         return 0;
 120 }
 121
 122 /**
 123  * cfc_check_trigger_arg_min() - trivially validate a trigger argument
 124  * @arg: pointer to the trigger arg to validate
 125  * @val: the minimum value the argument should be
 126  */
 127 static inline int cfc_check_trigger_arg_min(unsigned int *arg,
 128                                             unsigned int val)
 129 {
 130         if (*arg < val) {
 131                 *arg = val;
 132                 return -EINVAL;
 133         }
 134         return 0;
 135 }
 136
 137 /**
 138  * cfc_check_trigger_arg_max() - trivially validate a trigger argument
 139  * @arg: pointer to the trigger arg to validate
 140  * @val: the maximum value the argument should be
 141  */
 142 static inline int cfc_check_trigger_arg_max(unsigned int *arg,
 143                                             unsigned int val)
 144 {
 145         if (*arg > val) {
 146                 *arg = val;
 147                 return -EINVAL;
 148         }
 149         return 0;
 150 }
 151
 152 #endif /* _COMEDI_FC_H */