vmod/lib/libvmod12a22dioaio.c

   1 /**
   2    @file   libvmod12a2.c
   3    @brief  Library file for the vmod12a2 driver
   4    @author Juan David Gonzalez Cobas
   5    @date   October 17 2009
   6  */
   7
   8 #include <sys/ioctl.h>
   9 #include <fcntl.h>
  10 #include <unistd.h>
  11 #include <stdio.h>
  12 #include "libvmod12a22dioaio.h"
  13 #include <gm/moduletypes.h>
  14 #include <dioaiolib.h>
  15
  16 #define VMOD12A2_MAX_MODULES    64
  17
  18 /**
  19  * @brief Get a handle for a vmod12a2 device and channel
  20  *
  21  * A channel is selected by giving the LUN for the board
  22  * and the channel number. The handle returned allows
  23  * further reference to the same channel
  24  *
  25  * @param carrier_lun - carrier LUN for vmod card
  26  * @param channel     - selected channel for reading
  27  *
  28  * @return >0 - on success, device file descriptor number
  29  * @return <0 - if failure
  30  *
  31  */
  32 int vmod12a2_get_handle(unsigned int carrier_lun)
  33 {
  34         if(carrier_lun < 0 || carrier_lun >= VMOD12A2_MAX_MODULES){
  35                 fprintf(stderr, "libvmod12a22dioaio : Invalid lun %d\n", carrier_lun);
  36                 return -1;
  37         }
  38         return carrier_lun;
  39 }
  40
  41 /**
  42  * @brief perform a digital-to-analog conversion
  43  *
  44  * The output voltage depends on hardware configuration (default
  45  * -10V..10V, configurable by jumpers to 0-10V range).
  46  *
  47  * @param  fd           Device handle identifying board
  48  * @param  channel      Channel on the board to write to
  49  * @param  datum        Digital 12-bit value (0x000-0xfff)
  50  *
  51  * @return 0 on success, <0 on failure
  52  */
  53 int vmod12a2_convert(int fd, int channel, int datum)
  54 {
  55         int ret;
  56         char *error;
  57
  58         ret = DioChannelWrite(IocVMOD12A2, fd, channel, 2, datum);
  59         if (ret < 0){
  60                 DioGetErrorMessage(ret, &error);
  61                 fprintf(stderr, "libvmod12a22dioaio : %s\n", error);
  62         }
  63         return ret;
  64 }
  65
  66 /**
  67  * @brief close a channel handle
  68  *
  69  * @param fd - Handle to close
  70  */
  71 int vmod12a2_close(int fd)
  72 {
  73         return 0;
  74 }