/* -*- c++ -*- */
/*
* Copyright 2007 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 3, 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <gmac.h>
#include <mb_mblock.h>
#include <mb_runtime.h>
#include <mb_protocol_class.h>
#include <mb_exception.h>
#include <mb_msg_queue.h>
#include <mb_message.h>
#include <mb_mblock_impl.h>
#include <mb_msg_accepter.h>
#include <mb_class_registry.h>
#include <pmt.h>
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <ui_nco.h>
#include <symbols_usrp_server_cs.h>
#include <symbols_usrp_channel.h>
#include <symbols_usrp_low_level_cs.h>
#include <symbols_usrp_tx.h>
#include <symbols_usrp_rx.h>
#include <gmac_symbols.h>
static bool verbose = true;
gmac::gmac(mb_runtime *rt, const std::string &instance_name, pmt_t user_arg)
: mb_mblock(rt, instance_name, user_arg),
d_us_rx_chan(PMT_NIL), d_us_tx_chan(PMT_NIL)
{
// When the MAC layer is initialized, we must connect to the USRP and setup
// channels. We begin by defining ports to connect to the 'usrp_server' block
// and then initialize the USRP by opening it through the 'usrp_server.'
// Initialize the ports
define_ports();
// Initialize the connection to the USRP
initialize_usrp();
}
gmac::~gmac()
{
}
// The full functionality of GMAC is based on messages passed back and forth
// between the application and a physical layer and/or usrp_server. Each
// message triggers additional events, states, and messages to be sent.
void gmac::handle_message(mb_message_sptr msg)
{
// The MAC functionality is dispatched based on the event, which is the
// driving force of the MAC. The event can be anything from incoming samples
// to a message to change the carrier sense threshold.
pmt_t event = msg->signal();
pmt_t data = msg->data();
pmt_t port_id = msg->port_id();
pmt_t handle = PMT_F;
pmt_t status = PMT_F;
pmt_t dict = PMT_NIL;
std::string error_msg;
switch(d_state) {
//---------------------------- INIT ------------------------------------//
// In the INIT state, there should be no messages across the ports.
case INIT:
error_msg = "no messages should be passed during the INIT state:";
goto unhandled;
//-------------------------- OPENING USRP -------------------------------//
// In this state we expect a response from usrp_server over the CS channel
// as to whether or not the opening of the USRP was successful. If so, we
// switch states to allocating the channels for use.
case OPENING_USRP:
if(pmt_eq(event, s_response_open)
&& pmt_eq(d_us_cs->port_symbol(), port_id)) {
status = pmt_nth(1, data); // PMT_T or PMT_F
if(pmt_eq(status, PMT_T)) { // on success, allocate channels!
allocate_channels();
return;
}
else {
error_msg = "failed to open usrp:";
goto bail;
}
}
goto unhandled; // all other messages not handled in this state
//------------------------ ALLOCATING CHANNELS --------------------------//
// When allocating channels, we need to wait for 2 responses from USRP
// server: one for TX and one for RX. Both are initialized to NIL so we
// know to continue to the next state once both are set.
case ALLOCATING_CHANNELS:
// ************* TX ALLOCATION RESPONSE ***************** //
if(pmt_eq(event, s_response_allocate_channel)
&& pmt_eq(d_us_tx->port_symbol(), port_id))
{
status = pmt_nth(1, data);
if(pmt_eq(status, PMT_T)) { // extract channel on success
d_us_tx_chan = pmt_nth(2, data);
if(verbose)
std::cout << "[GMAC] Received TX allocation"
<< " on channel " << d_us_tx_chan << std::endl;
// If the RX has also been allocated already, we can continue
if(!pmt_eqv(d_us_rx_chan, PMT_NIL)) {
//enter_receiving();
initialize_gmac();
}
return;
}
else { // TX allocation failed
error_msg = "failed to allocate TX channel:";
goto bail;
}
}
// ************* RX ALLOCATION RESPONSE ****************//
if(pmt_eq(event, s_response_allocate_channel)
&& pmt_eq(d_us_rx->port_symbol(), port_id))
{
status = pmt_nth(1, data);
if(pmt_eq(status, PMT_T)) {
d_us_rx_chan = pmt_nth(2, data);
if(verbose)
std::cout << "[GMAC] Received RX allocation"
<< " on channel " << d_us_rx_chan << std::endl;
// If the TX has also been allocated already, we can continue
if(!pmt_eqv(d_us_tx_chan, PMT_NIL)) {
//enter_receiving();
initialize_gmac();
}
return;
}
else { // RX allocation failed
error_msg = "failed to allocate RX channel:";
goto bail;
}
}
goto unhandled;
//----------------------------- INIT GMAC --------------------------------//
// In the INIT_GMAC state, now that the USRP is initialized we can do things
// like right the carrier sense threshold to the FPGA register.
case INIT_GMAC:
goto unhandled;
//----------------------------- IDLE ------------------------------------//
// In the idle state the MAC is not quite 'idle', it is just not doing
// anything specific. It is still being passive with data between the
// application and the lower layer.
case IDLE:
//-------- TX PORT ----------------------------------------------------//
if(pmt_eq(d_tx->port_symbol(), port_id)) {
//-------- INCOMING PACKET ------------------------------------------//
if(pmt_eq(event, s_cmd_tx_pkt)) {
handle_cmd_tx_pkt(data);
return;
}
}
//--------- USRP TX PORT ----------------------------------------------//
if(pmt_eq(d_us_tx->port_symbol(), port_id)) {
//-------- INCOMING PACKET RESPONSE ---------------------------------//
if(pmt_eq(event, s_response_xmit_raw_frame)) {
handle_response_xmit_raw_frame(data);
return;
}
}
//--------- CS PORT ---------------------------------------------------//
if(pmt_eq(d_cs->port_symbol(), port_id)) {
//------- ENABLE CARRIER SENSE --------------------------------------//
if(pmt_eq(event, s_cmd_carrier_sense_enable)) {
handle_cmd_carrier_sense_enable(data);
return;
}
//------- CARRIER SENSE THRESHOLD -----------------------------------//
if(pmt_eq(event, s_cmd_carrier_sense_threshold)) {
handle_cmd_carrier_sense_threshold(data);
return;
}
//------- CARRIER SENSE DEADLINE ------------------------------------//
if(pmt_eq(event, s_cmd_carrier_sense_deadline)) {
handle_cmd_carrier_sense_deadline(data);
return;
}
//------- DISABLE CARRIER SENSE -------------------------------------//
if(pmt_eq(event, s_cmd_carrier_sense_disable)) {
handle_cmd_carrier_sense_disable(data);
return;
}
}
goto unhandled;
//------------------------ CLOSING CHANNELS -----------------------------//
case CLOSING_CHANNELS:
if (pmt_eq(event, s_response_deallocate_channel)
&& pmt_eq(d_us_tx->port_symbol(), port_id))
{
status = pmt_nth(1, data);
if(pmt_eq(status, PMT_T)) {
d_us_tx_chan = PMT_NIL;
if(verbose)
std::cout << "[GMAC] Received TX deallocation\n";
// If the RX is also deallocated, we can close the USRP
if(pmt_eq(d_us_rx_chan, PMT_NIL))
close_usrp();
return;
} else {
error_msg = "failed to deallocate TX channel:";
goto bail;
}
}
if (pmt_eq(event, s_response_deallocate_channel)
&& pmt_eq(d_us_rx->port_symbol(), port_id))
{
status = pmt_nth(1, data);
// If successful, set the port to NIL
if(pmt_eq(status, PMT_T)) {
d_us_rx_chan = PMT_NIL;
if(verbose)
std::cout << "[GMAC] Received RX deallocation\n";
// If the TX is also deallocated, we can close the USRP
if(pmt_eq(d_us_tx_chan, PMT_NIL))
close_usrp();
return;
} else {
error_msg = "failed to deallocate RX channel:";
goto bail;
}
}
goto unhandled;
//-------------------------- CLOSING USRP -------------------------------//
case CLOSING_USRP:
goto unhandled;
}
// An error occured, print it, and shutdown all m-blocks
bail:
std::cerr << error_msg << data
<< "status = " << status << std::endl;
shutdown_all(PMT_F);
return;
// Received an unhandled message for a specific state
unhandled:
if(0 && verbose && !pmt_eq(event, pmt_intern("%shutdown")))
std::cout << "[GMAC] unhandled msg: " << msg
<< "in state "<< d_state << std::endl;
}
// The MAC layer connects to 'usrp_server' which has a control/status channel,
// a TX, and an RX port. The MAC layer can then relay TX/RX data back and
// forth to the application, or a physical layer once available.
void gmac::define_ports()
{
// Ports we use to connect to usrp_server
d_us_tx = define_port("us-tx0", "usrp-tx", false, mb_port::INTERNAL);
d_us_rx = define_port("us-rx0", "usrp-rx", false, mb_port::INTERNAL);
d_us_cs = define_port("us-cs", "usrp-server-cs", false, mb_port::INTERNAL);
// Ports applications used to connect to us
d_tx = define_port("tx0", "gmac-tx", true, mb_port::EXTERNAL);
d_rx = define_port("rx0", "gmac-rx", true, mb_port::EXTERNAL);
d_cs = define_port("cs", "gmac-cs", true, mb_port::EXTERNAL);
}
// To initialize the USRP we must pass several parameters to 'usrp_server' such
// as the RBF to use, and the interpolation/decimation rate. The MAC layer will
// then pass these parameters to the block with a message to establish the
// connection to the USRP.
void gmac::initialize_usrp()
{
if(verbose)
std::cout << "[GMAC] Initializing USRP\n";
// The initialization parameters are passed to usrp_server via a PMT
// dictionary.
pmt_t usrp_dict = pmt_make_dict();
// Specify the RBF to use
pmt_dict_set(usrp_dict,
pmt_intern("rbf"),
pmt_intern("test2.rbf"));
pmt_dict_set(usrp_dict,
pmt_intern("interp-tx"),
pmt_from_long(128));
pmt_dict_set(usrp_dict,
pmt_intern("decim-rx"),
pmt_from_long(16));
// Center frequency
pmt_dict_set(usrp_dict,
pmt_intern("rf-freq"),
pmt_from_long((long)10e6));
// Default is to use USRP considered '0' (incase of multiple)
d_which_usrp = pmt_from_long(0);
define_component("USRP-SERVER", "usrp_server", usrp_dict);
connect("self", "us-tx0", "USRP-SERVER", "tx0");
connect("self", "us-rx0", "USRP-SERVER", "rx0");
connect("self", "us-cs", "USRP-SERVER", "cs");
// Finally, enter the OPENING_USRP state by sending a request to open the
// USRP.
open_usrp();
}
// In the initialization state of the MAC layer we set default values for
// several functionalities.
void gmac::initialize_gmac()
{
// The initial state is the INIT state.
d_state = INIT_GMAC;
// Set carrier sense to enabled by default with the specified threshold and
// the deadline to 0 -- which is wait forever.
set_carrier_sense(true, 25, 0, PMT_NIL);
// Can now notify the application that we are initialized
d_cs->send(s_response_gmac_initialized,
pmt_list2(PMT_NIL, PMT_T));
// The MAC enters an IDLE state where it waits for messages and dispatches
// based on them
enter_idle();
}
// Method for setting the carrier sense and an associated threshold which is
// written to a register on the FPGA, which it will read if the CS flag is set
// and perform carrier sense based on.
//
// We currently do not wait for the successful response for the write to
// register command, we assume it will succeed else the MAC must
void gmac::set_carrier_sense(bool toggle, long threshold, long deadline, pmt_t invocation)
{
d_carrier_sense = toggle;
// Only waste the bandwidth and processing of a C/S packet if needed
if(threshold != d_cs_thresh) {
d_us_tx->send(s_cmd_to_control_channel, // C/S packet
pmt_list2(invocation, // invoc handle
pmt_list1(
pmt_list2(s_op_write_reg,
pmt_list2(
pmt_from_long(REG_CS_THRESH),
pmt_from_long(threshold))))));
d_cs_thresh = threshold;
if(verbose)
std::cout << "[GMAC] Changing CS threshold: " << d_cs_thresh << std::endl;
}
if(deadline != d_cs_deadline) {
d_us_tx->send(s_cmd_to_control_channel, // C/S packet
pmt_list2(invocation, // invoc handle
pmt_list1(
pmt_list2(s_op_write_reg,
pmt_list2(
pmt_from_long(REG_CS_DEADLINE),
pmt_from_long(deadline))))));
d_cs_deadline = deadline;
if(verbose)
std::cout << "[GMAC] Changing CS deadline: " << d_cs_deadline << std::endl;
}
if(verbose)
std::cout << "[GMAC] Setting carrier sense to " << toggle << std::endl;
}
// The following sends a command to open the USRP, which will upload the
// specified RBF when creating the instance of the USRP server and set all other
// relevant parameters.
void gmac::open_usrp()
{
d_state = OPENING_USRP;
d_us_cs->send(s_cmd_open, pmt_list2(PMT_NIL, d_which_usrp));
if(verbose)
std::cout << "[GMAC] Opening USRP "
<< d_which_usrp << std::endl;
}
// Before sending the close to the USRP we wait a couple seconds to let any data
// through the USB exit, else a bug in the driver will kick an error and cause
// an abnormal termination.
void gmac::close_usrp()
{
d_state = CLOSING_USRP;
sleep(2);
d_us_cs->send(s_cmd_close, pmt_list1(PMT_NIL));
}
// RX and TX channels must be allocated so that the USRP server can
// properly share bandwidth across multiple USRPs. No commands will be
// successful to the USRP through the USRP server on the TX or RX channels until
// a bandwidth allocation has been received.
void gmac::allocate_channels()
{
d_state = ALLOCATING_CHANNELS;
if(verbose)
std::cout << "[GMAC] Sending channel allocation requests\n";
long capacity = (long) 16e6;
d_us_tx->send(s_cmd_allocate_channel, pmt_list2(PMT_T, pmt_from_long(capacity)));
d_us_rx->send(s_cmd_allocate_channel, pmt_list2(PMT_T, pmt_from_long(capacity)));
}
// Before closing the USRP connection, we deallocate our channels so that the
// capacity can be reused.
void gmac::close_channels()
{
d_state = CLOSING_CHANNELS;
d_us_tx->send(s_cmd_deallocate_channel, pmt_list2(PMT_NIL, d_us_tx_chan));
d_us_rx->send(s_cmd_deallocate_channel, pmt_list2(PMT_NIL, d_us_rx_chan));
if(verbose)
std::cout << "[GMAC] Closing channels...\n";
}
// Used to enter the receiving state
void gmac::enter_receiving()
{
d_us_rx->send(s_cmd_start_recv_raw_samples,
pmt_list2(PMT_F,
d_us_rx_chan));
if(verbose)
std::cout << "[GMAC] Started RX sample stream\n";
}
// A simple idle state, nothing more to it.
void gmac::enter_idle()
{
d_state = IDLE;
}
// Handles the transmission of a pkt from the application. The invocation
// handle is passed on but a response is not given back to the application until
// the response is passed from usrp_server. This ensures that the MAC passes
// back the success or failure. Furthermore, the MAC could decide to retransmit
// on a failure based on the result of the packet transmission.
//
// This should eventually be connected to a physically layer rather than
// directly to usrp_server. (d_us_tx should be replaced with a different
// connection)
void gmac::handle_cmd_tx_pkt(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
pmt_t dst = pmt_nth(1, data);
pmt_t samples = pmt_nth(2, data);
pmt_t pkt_properties = pmt_nth(3, data);
pmt_t us_tx_properties = pmt_make_dict();
// Set the packet to be carrier sensed?
if(carrier_sense_pkt(pkt_properties))
pmt_dict_set(us_tx_properties,
pmt_intern("carrier-sense"),
PMT_T);
pmt_t timestamp = pmt_from_long(0xffffffff); // NOW
// Construct the proper message for USRP server
d_us_tx->send(s_cmd_xmit_raw_frame,
pmt_list5(invocation_handle,
d_us_tx_chan,
samples,
timestamp,
us_tx_properties));
if(verbose && 0)
std::cout << "[GMAC] Transmitted packet\n";
}
// Handles a response from the USRP server about the transmission of a frame,
// whether it was successful or failed. This should eventually be replaced with
// a response from the PHY layer. This is where a retransmit could be
// implemented.
void gmac::handle_response_xmit_raw_frame(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
pmt_t status = pmt_nth(1, data);
d_tx->send(s_response_tx_pkt,
pmt_list2(invocation_handle,
status));
}
// This method determines whether carrier sense should be enabled based on two
// properties. The first is the MAC setting, which the user can set to carrier
// sense packets by default or not. The second is a per packet setting, which
// can be used to override the MAC setting for the given packet only.
bool gmac::carrier_sense_pkt(pmt_t pkt_properties)
{
// First we extract the per packet properties to check the per packet setting
// if it exists
if(pmt_is_dict(pkt_properties)) {
if(pmt_t pkt_cs = pmt_dict_ref(pkt_properties,
pmt_intern("carrier-sense"),
PMT_NIL)) {
// If the per packet property says true, enable carrier sense regardless
// of the MAC setting
if(pmt_eqv(pkt_cs, PMT_T))
return true;
// If the per packet setting says false, disable carrier sense regardless
// of the MAC setting
else if(pmt_eqv(pkt_cs, PMT_F))
return false;
}
}
// If we've hit this point, the packet properties did not state whether
// carrier sense should be used or not, so we use the MAC setting
if(d_carrier_sense)
return true;
else
return false;
}
// This method is envoked by an incoming cmd-enable-carrier-sense signal on the
// C/S port. It can be used to re-adjust the threshold or simply enabled
// carrier sense. When a threshold is not provided, the MAC will use an
// averaging algorithm to determine the threshold (in the future).
void gmac::handle_cmd_carrier_sense_enable(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
pmt_t threshold = pmt_nth(1, data);
pmt_t deadline = pmt_nth(2, data);
long l_threshold, l_deadline;
// FIXME: for now, if threshold is NIL, we do not change the threshold.
// This should be replaced with an averaging algorithm
if(pmt_eqv(threshold, PMT_NIL))
l_threshold = d_cs_thresh;
else
l_threshold = pmt_to_long(threshold);
// If the deadline is NIL, we do not change the value
if(pmt_eqv(threshold, PMT_NIL))
l_deadline = d_cs_deadline;
else
l_deadline = pmt_to_long(deadline);
set_carrier_sense(true, l_threshold, l_deadline, invocation_handle);
}
// This method is called when an incoming disable carrier sense command is sent
// over the control status channel. It so far does not ellicit a response, this
// needs to be added correctly. It needs to wait for the response for the C/S
// packet from usrp_server.
void gmac::handle_cmd_carrier_sense_disable(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
// We don't change the threshold, we leave it as is because the application
// did not request that it changes, only to disable carrier sense.
set_carrier_sense(false, d_cs_thresh, d_cs_deadline, invocation_handle);
}
// When the app requests that the threshold changes, the state of the carrier
// sense should not change. If it was enabled, it should remain enabled.
// Likewise if it was disabled. The deadline value should also remain
// unchanged.
void gmac::handle_cmd_carrier_sense_threshold(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
pmt_t threshold = pmt_nth(1, data);
long l_threshold;
// FIXME: for now, if threshold is NIL, we do not change the threshold.
// This should be replaced with an averaging algorithm
if(pmt_eqv(threshold, PMT_NIL))
l_threshold = d_cs_thresh;
else
l_threshold = pmt_to_long(threshold);
set_carrier_sense(d_carrier_sense, l_threshold, d_cs_deadline, invocation_handle);
}
// Ability to change the deadline using a C/S packet. The state of all other
// carrier sense parameters should not change.
void gmac::handle_cmd_carrier_sense_deadline(pmt_t data)
{
pmt_t invocation_handle = pmt_nth(0, data);
pmt_t deadline = pmt_nth(1, data);
long l_deadline;
// If the deadline passed is NIL, do *not* change the value.
if(pmt_eqv(deadline, PMT_NIL))
l_deadline = d_cs_deadline;
else
l_deadline = pmt_to_long(deadline);
set_carrier_sense(d_carrier_sense, d_cs_thresh, l_deadline, invocation_handle);
}
REGISTER_MBLOCK_CLASS(gmac);