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 mutually compatible */
  45
  46         /* these tests are true if more than one _src bit is set */
  47         if ((cmd->start_src & (cmd->start_src - 1)) != 0)
  48                 err++;
  49         if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
  50                 err++;
  51         if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
  52                 err++;
  53         if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
  54                 err++;
  55         if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
  56                 err++;
  57
  58         if (err)
  59                 return 2;
  60
  61         /* step 3: make sure arguments are trivially compatible */
  62
  63         /* cmd->start_src == TRIG_NOW || cmd->start_src == TRIG_INT */
  64         if (cmd->start_arg != 0) {
  65                 cmd->start_arg = 0;
  66                 err++;
  67         }
  68
  69         /* cmd->scan_begin_src == TRIG_EXT */
  70         if (cmd->scan_begin_arg != 0) {
  71                 cmd->scan_begin_arg = 0;
  72                 err++;
  73         }
  74
  75         /* cmd->convert_src == TRIG_NOW */
  76         if (cmd->convert_arg != 0) {
  77                 cmd->convert_arg = 0;
  78                 err++;
  79         }
  80
  81         /* cmd->scan_end_src == TRIG_COUNT */
  82         if (cmd->scan_end_arg != cmd->chanlist_len) {
  83                 cmd->scan_end_arg = cmd->chanlist_len;
  84                 err++;
  85         }
  86
  87         switch (cmd->stop_src) {
  88         case TRIG_COUNT:
  89                 /* any count allowed */
  90                 break;
  91         case TRIG_NONE:
  92                 if (cmd->stop_arg != 0) {
  93                         cmd->stop_arg = 0;
  94                         err++;
  95                 }
  96                 break;
  97         default:
  98                 break;
  99         }
 100
 101         if (err)
 102                 return 3;
 103
 104         /* step 4: fix up any arguments */
 105
 106         /* if (err) return 4; */
 107
 108         return 0;
 109 }
 110
 111 EXPORT_SYMBOL(comedi_pcm_cmdtest);