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/* -*- c++ -*- */
/*
* Copyright 2005 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/mman.h>
#include <comedi_sink_s.h>
#include <gr_io_signature.h>
#include <stdio.h>
#include <errno.h>
#include <iostream>
#include <stdexcept>
#include <gri_comedi.h>
/*
* comedi_sink_s is untested because I don't own appropriate hardware.
* Feedback is welcome! --SF
*/
static std::string
default_device_name ()
{
return "/dev/comedi0";
}
// ----------------------------------------------------------------
comedi_sink_s_sptr
comedi_make_sink_s (int sampling_freq, const std::string dev)
{
return comedi_sink_s_sptr (new comedi_sink_s (sampling_freq, dev));
}
comedi_sink_s::comedi_sink_s (int sampling_freq,
const std::string device_name)
: gr_sync_block ("comedi_sink_s",
gr_make_io_signature (0, 0, 0),
gr_make_io_signature (0, 0, 0)),
d_sampling_freq (sampling_freq),
d_device_name (device_name.empty() ? default_device_name() : device_name),
d_dev (0),
d_subdevice (COMEDI_SUBD_AO),
d_n_chan (1), // number of input channels
d_map (0),
d_buffer_size (0),
d_buf_front (0),
d_buf_back (0)
{
int aref=AREF_GROUND;
int range=0;
d_dev = comedi_open(d_device_name.c_str());
if (d_dev == 0){
comedi_perror(d_device_name.c_str());
throw std::runtime_error ("comedi_sink_s");
}
unsigned int chanlist[256];
for(int i=0; i<d_n_chan; i++){
chanlist[i]=CR_PACK(i,range,aref);
}
comedi_cmd cmd;
int ret;
ret = comedi_get_cmd_generic_timed(d_dev,d_subdevice,&cmd,(unsigned int)(1e9/sampling_freq));
if(ret<0)
bail ("comedi_get_cmd_generic_timed", comedi_errno());
// TODO: check period_ns is not to far off sampling_freq
d_buffer_size = comedi_get_buffer_size(d_dev, d_subdevice);
if (d_buffer_size <= 0)
bail ("comedi_get_buffer_size", comedi_errno());
d_map = mmap(NULL,d_buffer_size,PROT_WRITE,MAP_SHARED,comedi_fileno(d_dev),0);
if (d_map == MAP_FAILED)
bail ("mmap", errno);
cmd.chanlist = chanlist;
cmd.chanlist_len = d_n_chan;
cmd.scan_end_arg = d_n_chan;
cmd.stop_src=TRIG_NONE;
cmd.stop_arg=0;
/* comedi_command_test() tests a command to see if the
* trigger sources and arguments are valid for the subdevice.
* If a trigger source is invalid, it will be logically ANDed
* with valid values (trigger sources are actually bitmasks),
* which may or may not result in a valid trigger source.
* If an argument is invalid, it will be adjusted to the
* nearest valid value. In this way, for many commands, you
* can test it multiple times until it passes. Typically,
* if you can't get a valid command in two tests, the original
* command wasn't specified very well. */
ret = comedi_command_test(d_dev,&cmd);
if(ret<0)
bail ("comedi_command_test", comedi_errno());
ret = comedi_command_test(d_dev,&cmd);
if(ret<0)
bail ("comedi_command_test", comedi_errno());
/* start the command */
ret = comedi_command(d_dev,&cmd);
if(ret<0)
bail ("comedi_command", comedi_errno());
set_output_multiple (d_n_chan*sizeof(sampl_t));
assert(sizeof(sampl_t) == sizeof(short));
set_output_signature (gr_make_io_signature (1, 1, sizeof (sampl_t)));
}
bool
comedi_sink_s::check_topology (int ninputs, int noutputs)
{
if (ninputs > d_n_chan)
throw std::runtime_error ("comedi_sink_s");
return true;
}
comedi_sink_s::~comedi_sink_s ()
{
if (d_map) {
munmap(d_map, d_buffer_size);
d_map = 0;
}
comedi_close(d_dev);
}
int
comedi_sink_s::work (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
int ret;
int work_left = noutput_items * sizeof(sampl_t) * d_n_chan;
sampl_t *pbuf = (sampl_t*)d_map;
do {
do {
ret = comedi_get_buffer_contents(d_dev,d_subdevice);
if (ret < 0)
bail ("comedi_get_buffer_contents", comedi_errno());
assert(ret % sizeof(sampl_t) == 0);
assert(work_left % sizeof(sampl_t) == 0);
ret = std::min(ret, work_left);
d_buf_front += ret;
assert(d_buffer_size%d_n_chan == 0);
if (d_buf_front-d_buf_back > (unsigned)d_buffer_size) {
d_buf_front+=d_buffer_size;
d_buf_back +=d_buffer_size;
}
if(d_buf_front==d_buf_back){
usleep(1000000*std::min(work_left,d_buffer_size/2)/(d_sampling_freq*sizeof(sampl_t)*d_n_chan));
continue;
}
} while (d_buf_front==d_buf_back);
for(unsigned i=d_buf_back/sizeof(sampl_t);i<d_buf_front/sizeof(sampl_t);i++){
int chan = i%d_n_chan;
int i_idx = noutput_items-work_left/d_n_chan/sizeof(sampl_t)+(i-d_buf_back/sizeof(sampl_t))/d_n_chan;
pbuf[i%(d_buffer_size/sizeof(sampl_t))] = input_items[chan]==0 ? 0 :
(int)((short*)(input_items[chan]))[i_idx] + 32767;
}
// FIXME: how to tell comedi the buffer is *written* ?
ret = comedi_mark_buffer_read(d_dev,d_subdevice,d_buf_front-d_buf_back);
if(ret<0)
bail ("comedi_mark_buffer_read", comedi_errno());
work_left -= d_buf_front-d_buf_back;
d_buf_back = d_buf_front;
} while(work_left>0);
return noutput_items;
}
void
comedi_sink_s::output_error_msg (const char *msg, int err)
{
fprintf (stderr, "comedi_sink_s[%s]: %s: %s\n",
d_device_name.c_str(), msg, comedi_strerror(err));
}
void
comedi_sink_s::bail (const char *msg, int err) throw (std::runtime_error)
{
output_error_msg (msg, err);
throw std::runtime_error ("comedi_sink_s");
}
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