drivers/staging/comedi/drivers/pcm_common.c

   1 #include "../comedidev.h"
   2 #include "pcm_common.h"
   3
   4 /*
   5  * 'do_cmdtest' function for an 'INTERRUPT' subdevice.  This is for
   6  * the PCM drivers.
   7  */
   8 int comedi_pcm_cmdtest(struct comedi_device *dev,
   9                        struct comedi_subdevice *s, struct comedi_cmd *cmd)
  10 {
  11         int err = 0;
  12         unsigned int tmp;
  13
  14         /* step 1: make sure trigger sources are trivially valid */
  15
  16         tmp = cmd->start_src;
  17         cmd->start_src &= (TRIG_NOW | TRIG_INT);
  18         if (!cmd->start_src || tmp != cmd->start_src)
  19                 err++;
  20
  21         tmp = cmd->scan_begin_src;
  22         cmd->scan_begin_src &= TRIG_EXT;
  23         if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
  24                 err++;
  25
  26         tmp = cmd->convert_src;
  27         cmd->convert_src &= TRIG_NOW;
  28         if (!cmd->convert_src || tmp != cmd->convert_src)
  29                 err++;
  30
  31         tmp = cmd->scan_end_src;
  32         cmd->scan_end_src &= TRIG_COUNT;
  33         if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
  34                 err++;
  35
  36         tmp = cmd->stop_src;
  37         cmd->stop_src &= (TRIG_COUNT | TRIG_NONE);
  38         if (!cmd->stop_src || tmp != cmd->stop_src)
  39                 err++;
  40
  41         if (err)
  42                 return 1;
  43
  44         /* step 2: make sure trigger sources are unique and
  45          * mutually compatible */
  46
  47         /* these tests are true if more than one _src bit is set */
  48         if ((cmd->start_src & (cmd->start_src - 1)) != 0)
  49                 err++;
  50         if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
  51                 err++;
  52         if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
  53                 err++;
  54         if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
  55                 err++;
  56         if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
  57                 err++;
  58
  59         if (err)
  60                 return 2;
  61
  62         /* step 3: make sure arguments are trivially compatible */
  63
  64         /* cmd->start_src == TRIG_NOW || cmd->start_src == TRIG_INT */
  65         if (cmd->start_arg != 0) {
  66                 cmd->start_arg = 0;
  67                 err++;
  68         }
  69
  70         /* cmd->scan_begin_src == TRIG_EXT */
  71         if (cmd->scan_begin_arg != 0) {
  72                 cmd->scan_begin_arg = 0;
  73                 err++;
  74         }
  75
  76         /* cmd->convert_src == TRIG_NOW */
  77         if (cmd->convert_arg != 0) {
  78                 cmd->convert_arg = 0;
  79                 err++;
  80         }
  81
  82         /* cmd->scan_end_src == TRIG_COUNT */
  83         if (cmd->scan_end_arg != cmd->chanlist_len) {
  84                 cmd->scan_end_arg = cmd->chanlist_len;
  85                 err++;
  86         }
  87
  88         switch (cmd->stop_src) {
  89         case TRIG_COUNT:
  90                 /* any count allowed */
  91                 break;
  92         case TRIG_NONE:
  93                 if (cmd->stop_arg != 0) {
  94                         cmd->stop_arg = 0;
  95                         err++;
  96                 }
  97                 break;
  98         default:
  99                 break;
 100         }
 101
 102         if (err)
 103                 return 3;
 104
 105         /* step 4: fix up any arguments */
 106
 107         /* if (err) return 4; */
 108
 109         return 0;
 110 }
 111 EXPORT_SYMBOL(comedi_pcm_cmdtest);
 112
 113 MODULE_AUTHOR("Comedi http://www.comedi.org");
 114 MODULE_DESCRIPTION("Comedi low-level driver");
 115 MODULE_LICENSE("GPL");