Check subdevice type.

diff --git a/demo/gpct_pulse_generator.c b/demo/gpct_pulse_generator.c
index 94bdb7cc8867aaba4c1729acd858e84be3779c26..7c85ae91b0d2c4ed6a53952e35b10dfec5af657e 100644 (file)
--- a/demo/gpct_pulse_generator.c
+++ b/demo/gpct_pulse_generator.c
@@ -102,6 +102,7 @@ int main(int argc, char *argv[])
        unsigned up_time;
        unsigned period_ns;
        int retval;
+       int subdevice_type;
        struct parsed_options options;
 
        init_parsed_options(&options);
@@ -125,7 +126,18 @@ int main(int argc, char *argv[])
                comedi_perror(options.filename);
                exit(-1);
        }
-       /*FIXME: check that device is counter */
+       subdevice_type = comedi_get_subdevice_type(device, options.subdevice);
+       if(subdevice_type < 0)
+       {
+               comedi_perror("comedi_get_subdevice_type()");
+               return -1;
+       }
+       if(subdevice_type != COMEDI_SUBD_COUNTER)
+       {
+               fprintf(stderr, "Subdevice is not a counter (type %i), but of type %i.\n",
+                       COMEDI_SUBD_COUNTER, subdevice_type);
+               return -1;
+       }
        printf("Generating pulse train on subdevice %d.\n", options.subdevice);
        printf("Period = %d ns.\n", period_ns);
        printf("Up Time = %d ns.\n", up_time);