1 files changed, 258 insertions, 0 deletions
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
new file mode 100644
index 000000000..dc8eea243
--- /dev/null
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -0,0 +1,258 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program 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 of the License, or
+// (at your option) any later version.
+//
+// This program 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, see <http://www.gnu.org/licenses/>.
+//
+
+#include <complex>
+#include <algorithm>
+#include <boost/format.hpp>
+#include "usrp2_impl.hpp"
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace uhd::transport;
+namespace asio = boost::asio;
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+typedef std::complex<float>          fc32_t;
+typedef std::complex<boost::int16_t> sc16_t;
+
+static const float shorts_per_float = float(1 << 15);
+static const float floats_per_short = float(1.0/shorts_per_float);
+
+/***********************************************************************
+ * Helper Functions
+ **********************************************************************/
+void usrp2_impl::io_init(void){
+    //initially empty copy buffer
+    _rx_copy_buff = asio::buffer("", 0);
+
+    //send a small data packet so the usrp2 knows the udp source port
+    boost::uint32_t zero_data = 0;
+    _data_transport->send(asio::buffer(&zero_data, sizeof(zero_data)));
+}
+
+#define unrolled_loop(__i, __len, __inst) {\
+    size_t __i = 0; \
+    while(__i < (__len & ~0x7)){ \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+    } \
+    while(__i < __len){ \
+        __inst; __i++;\
+    } \
+}
+
+// set a boolean flag that indicates the endianess
+#ifdef HAVE_BIG_ENDIAN
+static const bool is_big_endian = true;
+#else
+static const bool is_big_endian = false;
+#endif
+
+static inline void host_floats_to_usrp2_items(
+    boost::uint32_t *usrp2_items,
+    const fc32_t *host_floats,
+    size_t num_samps
+){
+    unrolled_loop(i, num_samps,{
+        boost::uint16_t real = boost::int16_t(host_floats[i].real()*shorts_per_float);
+        boost::uint16_t imag = boost::int16_t(host_floats[i].imag()*shorts_per_float);
+        usrp2_items[i] = htonl((real << 16) | (imag << 0));
+    });
+}
+
+static inline void usrp2_items_to_host_floats(
+    fc32_t *host_floats,
+    const boost::uint32_t *usrp2_items,
+    size_t num_samps
+){
+    unrolled_loop(i, num_samps,{
+        boost::uint32_t item = ntohl(usrp2_items[i]);
+        boost::int16_t real = boost::uint16_t(item >> 16);
+        boost::int16_t imag = boost::uint16_t(item >> 0);
+        host_floats[i] = fc32_t(float(real*floats_per_short), float(imag*floats_per_short));
+    });
+}
+
+static inline void host_items_to_usrp2_items(
+    boost::uint32_t *usrp2_items,
+    const boost::uint32_t *host_items,
+    size_t num_samps
+){
+    if (is_big_endian){
+        std::memcpy(usrp2_items, host_items, num_samps*sizeof(boost::uint32_t));
+    }
+    else{
+        unrolled_loop(i, num_samps, usrp2_items[i] = htonl(host_items[i]));
+    }
+}
+
+static inline void usrp2_items_to_host_items(
+    boost::uint32_t *host_items,
+    const boost::uint32_t *usrp2_items,
+    size_t num_samps
+){
+    if (is_big_endian){
+        std::memcpy(host_items, usrp2_items, num_samps*sizeof(boost::uint32_t));
+    }
+    else{
+        unrolled_loop(i, num_samps, host_items[i] = ntohl(usrp2_items[i]));
+    }
+}
+
+/***********************************************************************
+ * Receive Raw Data
+ **********************************************************************/
+void usrp2_impl::recv_raw(rx_metadata_t &metadata){
+    //do a receive
+    _rx_smart_buff = _data_transport->recv();
+
+    //unpack the vrt header
+    size_t num_packet_words32 = asio::buffer_size(_rx_smart_buff->get())/sizeof(boost::uint32_t);
+    if (num_packet_words32 == 0){
+        _rx_copy_buff = boost::asio::buffer("", 0);
+        return; //must exit here after setting the buffer
+    }
+    const boost::uint32_t *vrt_hdr = asio::buffer_cast<const boost::uint32_t *>(_rx_smart_buff->get());
+    size_t num_header_words32_out, num_payload_words32_out, packet_count_out;
+    try{
+        vrt::unpack(
+            metadata,                //output
+            vrt_hdr,                 //input
+            num_header_words32_out,  //output
+            num_payload_words32_out, //output
+            num_packet_words32,      //input
+            packet_count_out         //output
+        );
+    }catch(const std::exception &e){
+        std::cerr << "bad vrt header: " << e.what() << std::endl;
+        _rx_copy_buff = boost::asio::buffer("", 0);
+        return; //must exit here after setting the buffer
+    }
+
+    //handle the packet count / sequence number
+    size_t expected_packet_count = _rx_stream_id_to_packet_seq[metadata.stream_id];
+    if (packet_count_out != expected_packet_count){
+        std::cerr << "S" << (packet_count_out - expected_packet_count)%16;
+    }
+    _rx_stream_id_to_packet_seq[metadata.stream_id] = (packet_count_out+1)%16;
+
+    //setup the rx buffer to point to the data
+    _rx_copy_buff = asio::buffer(
+        vrt_hdr + num_header_words32_out,
+        num_payload_words32_out*sizeof(boost::uint32_t)
+    );
+}
+
+/***********************************************************************
+ * Send Data
+ **********************************************************************/
+size_t usrp2_impl::send(
+    const asio::const_buffer &buff,
+    const tx_metadata_t &metadata,
+    const std::string &type
+){
+    boost::uint32_t tx_mem[_mtu/sizeof(boost::uint32_t)];
+    boost::uint32_t *items = tx_mem + vrt::max_header_words32; //offset for data
+    size_t num_samps = _max_tx_samples_per_packet;
+
+    //calculate the number of samples to be copied
+    //and copy the samples into the send buffer
+    if (type == "32fc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(fc32_t), num_samps);
+        host_floats_to_usrp2_items(items, asio::buffer_cast<const fc32_t*>(buff), num_samps);
+    }
+    else if (type == "16sc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(sc16_t), num_samps);
+        host_items_to_usrp2_items(items, asio::buffer_cast<const boost::uint32_t*>(buff), num_samps);
+    }
+    else{
+        throw std::runtime_error(str(boost::format("usrp2 send: cannot handle type \"%s\"") % type));
+    }
+
+    boost::uint32_t vrt_hdr[vrt::max_header_words32];
+    size_t num_header_words32, num_packet_words32;
+    size_t packet_count = _tx_stream_id_to_packet_seq[metadata.stream_id]++;
+
+    //pack metadata into a vrt header
+    vrt::pack(
+        metadata,            //input
+        vrt_hdr,             //output
+        num_header_words32,  //output
+        num_samps,           //input
+        num_packet_words32,  //output
+        packet_count         //input
+    );
+
+    //copy in the vrt header (yes we left space)
+    items -= num_header_words32;
+    std::memcpy(items, vrt_hdr, num_header_words32*sizeof(boost::uint32_t));
+
+    //send and return number of samples
+    _data_transport->send(asio::buffer(items, num_packet_words32*sizeof(boost::uint32_t)));
+    return num_samps;
+}
+
+/***********************************************************************
+ * Receive Data
+ **********************************************************************/
+size_t usrp2_impl::recv(
+    const asio::mutable_buffer &buff,
+    rx_metadata_t &metadata,
+    const std::string &type
+){
+    //perform a receive if no rx data is waiting to be copied
+    if (asio::buffer_size(_rx_copy_buff) == 0){
+        recv_raw(metadata);
+    }
+    //otherwise flag the metadata to show that is is a fragment
+    else{
+        metadata = rx_metadata_t();
+        metadata.is_fragment = true;
+    }
+
+    //extract the number of samples available to copy
+    //and a pointer into the usrp2 received items memory
+    size_t bytes_to_copy = asio::buffer_size(_rx_copy_buff);
+    if (bytes_to_copy == 0) return 0; //nothing to receive
+    size_t num_samps = bytes_to_copy/sizeof(boost::uint32_t);
+    const boost::uint32_t *items = asio::buffer_cast<const boost::uint32_t*>(_rx_copy_buff);
+
+    //calculate the number of samples to be copied
+    //and copy the samples from the recv buffer
+    if (type == "32fc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(fc32_t), num_samps);
+        usrp2_items_to_host_floats(asio::buffer_cast<fc32_t*>(buff), items, num_samps);
+    }
+    else if (type == "16sc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(sc16_t), num_samps);
+        usrp2_items_to_host_items(asio::buffer_cast<boost::uint32_t*>(buff), items, num_samps);
+    }
+    else{
+        throw std::runtime_error(str(boost::format("usrp2 recv: cannot handle type \"%s\"") % type));
+    }
+
+    //update the rx copy buffer to reflect the bytes copied
+    _rx_copy_buff = asio::buffer(
+        items + num_samps, bytes_to_copy - num_samps*sizeof(boost::uint32_t)
+    );
+
+    return num_samps;
+}