gps: gpsd: Adding gpsd_iface to interface with gpsd.

The gpsd_iface class might be useful for more than just e3x0,
it therefore belongs into lib/usrp instead of lib/usrp/e300.

A new UHD component is being registered, to cope with the additional
dependency. If libgps is not found, UHD and E300 will be compiled
without GPS support.

This has several consequences:
- The E310 GPSDO should now work transparently over network
- Users can use the GPS through gpsd for other applications
  *while* running UHD applications
- We now have a dependency on libgps

We need currently at least version 3.11 (while running 3.14),
on the device. Older versions do work if 3.10 runs on both
sides e.g

Reviewed-by: Martin Braun <martin.braun@ettus.com>
Reviewed-by: Ashish Chaudhari <ashish.chaudhari@ettus.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>

15 files changed, 381 insertions, 1540 deletions

diff --git a/host/cmake/Modules/FindGPSD.cmake b/host/cmake/Modules/FindGPSD.cmake
new file mode 100644
index 000000000..0d56a5380
--- /dev/null
+++ b/host/cmake/Modules/FindGPSD.cmake
@@ -0,0 +1,62 @@
+#
+# Copyright 2015 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/>.
+#
+# - Find libgps
+# Find the Gpsd includes and client library
+# This module defines
+#  LIBGPS_INCLUDE_DIR, where to find gps.h
+#  LIBGPS_LIBRARIES, the libraries needed by a GPSD client.
+#  LIBGPS_FOUND, If false, do not try to use GPSD.
+# also defined, but not for general use are
+#  LIBGPS_LIBRARY, where to find the GPSD library.
+
+INCLUDE(FindPkgConfig)
+PKG_CHECK_MODULES(PC_GPSD "libgps")
+PKG_CHECK_MODULES(PC_GPSD_V3_11 "libgps > 3.11")
+
+IF(PC_GPSD_FOUND AND NOT PC_GPSD_V3_11_FOUND)
+    MESSAGE(WARNING "GPSD version found is too old")
+ENDIF(PC_GPSD_FOUND AND NOT PC_GPSD_V3_11_FOUND)
+
+IF(PC_GPSD_V3_11_FOUND)
+  FIND_PATH(
+      LIBGPS_INCLUDE_DIR
+      NAMES gps.h
+      HINTS ${PC_GPSD_INCLUDE_DIR}
+  )
+
+  SET(
+      LIBGPS_NAMES
+      ${LIBGPS_NAMES} gps
+  )
+
+  FIND_LIBRARY(
+      LIBGPS_LIBRARY
+      NAMES ${LIBGPS_NAMES}
+      HINTS ${PC_GPSD_LIBDIR}
+  )
+ENDIF(PC_GPSD_V3_11_FOUND)
+
+# handle the QUIETLY and REQUIRED arguments and set LIBGPS_FOUND to TRUE if
+# all listed variables are TRUE
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(LIBGPS DEFAULT_MSG LIBGPS_LIBRARY LIBGPS_INCLUDE_DIR)
+
+IF(LIBGPS_FOUND)
+  SET(LIBGPS_LIBRARIES ${LIBGPS_LIBRARY})
+ENDIF(LIBGPS_FOUND)
+
+MARK_AS_ADVANCED(LIBGPS_LIBRARY LIBGPS_INCLUDE_DIR)
diff --git a/host/lib/usrp/CMakeLists.txt b/host/lib/usrp/CMakeLists.txt
index f6788b5ef..ce913aaf6 100644
--- a/host/lib/usrp/CMakeLists.txt
+++ b/host/lib/usrp/CMakeLists.txt
@@ -18,6 +18,10 @@
 ########################################################################
 # This file included, use CMake directory variables
 ########################################################################
+find_package(GPSD)
+
+INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
+
 LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/dboard_base.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/dboard_eeprom.cpp
@@ -30,6 +34,15 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/subdev_spec.cpp
 )
 
+LIBUHD_REGISTER_COMPONENT("GPSD" ENABLE_GPSD OFF "ENABLE_LIBUHD;ENABLE_GPSD;LIBGPS_FOUND" OFF)
+
+IF(ENABLE_GPSD)
+    LIBUHD_APPEND_SOURCES(
+        ${CMAKE_CURRENT_SOURCE_DIR}/gpsd_iface.cpp
+    )
+    LIBUHD_APPEND_LIBS(${LIBGPS_LIBRARY})
+ENDIF(ENABLE_GPSD)
+
 INCLUDE_SUBDIRECTORY(cores)
 INCLUDE_SUBDIRECTORY(dboard)
 INCLUDE_SUBDIRECTORY(common)
diff --git a/host/lib/usrp/e300/CMakeLists.txt b/host/lib/usrp/e300/CMakeLists.txt
index 9ee9b5521..26e34294a 100644
--- a/host/lib/usrp/e300/CMakeLists.txt
+++ b/host/lib/usrp/e300/CMakeLists.txt
@@ -1,5 +1,5 @@
 #
-# Copyright 2013-2014 Ettus Research LLC
+# Copyright 2013-2015 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
@@ -39,8 +39,6 @@ IF(ENABLE_E300)
         ${CMAKE_CURRENT_SOURCE_DIR}/e300_i2c.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/e300_eeprom_manager.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/e300_common.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/e300_async_serial.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/e300_ublox_control_impl.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/e300_remote_codec_ctrl.cpp
     )
     LIBUHD_APPEND_SOURCES(${E300_SOURCES})
@@ -52,4 +50,12 @@ IF(ENABLE_E300)
             PROPERTIES COMPILE_DEFINITIONS "E300_NATIVE=1"
         )
     ENDIF(UDEV_FOUND)
+
+    IF(ENABLE_GPSD)
+        SET_SOURCE_FILES_PROPERTIES(
+            ${CMAKE_CURRENT_SOURCE_DIR}/e300_impl.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/e300_impl.hpp
+            PROPERTIES COMPILE_DEFINITIONS "E300_GPSD=1"
+        )
+    ENDIF(ENABLE_GPSD)
 ENDIF(ENABLE_E300)
diff --git a/host/lib/usrp/e300/e300_async_serial.cpp b/host/lib/usrp/e300/e300_async_serial.cpp
deleted file mode 100644
index cdf18f7f7..000000000
--- a/host/lib/usrp/e300/e300_async_serial.cpp
+++ /dev/null
@@ -1,245 +0,0 @@
-//
-// Copyright 2014 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 "e300_async_serial.hpp"
-
-namespace uhd { namespace usrp { namespace gps {
-
-async_serial::async_serial()
-    : _io(),
-      _port(_io),
-      _background_thread(),
-      _open(false),
-      _error(false)
-{
-}
-
-async_serial::async_serial(
-        const std::string &node,
-        const size_t baud_rate,
-        boost::asio::serial_port_base::parity opt_parity,
-        boost::asio::serial_port_base::character_size opt_csize,
-        boost::asio::serial_port_base::flow_control opt_flow,
-        boost::asio::serial_port_base::stop_bits opt_stop)
-    : _io(),
-      _port(_io),
-      _background_thread(),
-      _open(false),
-      _error(false)
-{
-    open(node, baud_rate, opt_parity, opt_csize, opt_flow, opt_stop);
-}
-
-void async_serial::open(
-        const std::string &node,
-        const size_t baud_rate,
-        boost::asio::serial_port_base::parity opt_parity,
-        boost::asio::serial_port_base::character_size opt_csize,
-        boost::asio::serial_port_base::flow_control opt_flow,
-        boost::asio::serial_port_base::stop_bits opt_stop)
-{
-    if(is_open())
-        close();
-
-    _set_error_status(true);
-    _port.open(node);
-    _port.set_option(
-        boost::asio::serial_port_base::baud_rate(baud_rate));
-    _port.set_option(opt_parity);
-    _port.set_option(opt_csize);
-    _port.set_option(opt_flow);
-    _port.set_option(opt_stop);
-
-    _io.post(boost::bind(&async_serial::_do_read, this));
-
-    boost::thread t(boost::bind(&boost::asio::io_service::run, &_io));
-    _background_thread.swap(t);
-    _set_error_status(false);
-    _open=true;
-}
-
-bool async_serial::is_open() const
-{
-    return _open;
-}
-
-bool async_serial::error_status() const
-{
-    boost::lock_guard<boost::mutex> l(_error_mutex);
-    return _error;
-}
-
-void async_serial::close()
-{
-    if(!is_open())
-        return;
-
-    _open=false;
-    _io.post(boost::bind(&async_serial::_do_close, this));
-    _background_thread.join();
-    _io.reset();
-    if(error_status())
-        throw(boost::system::system_error(boost::system::error_code(),
-                "Error while closing the device"));
-}
-
-void async_serial::write(const char *data, size_t size)
-{
-    {
-        boost::lock_guard<boost::mutex> l(_write_queue_mutex);
-        _write_queue.insert(_write_queue.end(), data, data+size);
-    }
-    _io.post(boost::bind(&async_serial::_do_write, this));
-}
-
-void async_serial::write(const std::vector<char> &data)
-{
-    {
-        boost::lock_guard<boost::mutex> l(_write_queue_mutex);
-        _write_queue.insert(
-            _write_queue.end(),
-            data.begin(),
-            data.end());
-    }
-    _io.post(boost::bind(&async_serial::_do_write, this));
-}
-
-void async_serial::write_string(const std::string &s)
-{
-    {
-        boost::lock_guard<boost::mutex> l(_write_queue_mutex);
-        _write_queue.insert(
-            _write_queue.end(),
-            s.begin(),
-            s.end());
-    }
-    _io.post(boost::bind(&async_serial::_do_write, this));
-}
-
-async_serial::~async_serial()
-{
-    if(is_open()) {
-        try {
-            close();
-        } catch(...) {
-            //Don't throw from a destructor
-        }
-    }
-}
-
-void async_serial::_do_read()
-{
-    _port.async_read_some(boost::asio::buffer(
-        _read_buffer,READ_BUFFER_SIZE),
-        boost::bind(&async_serial::_read_end,
-        this,
-        boost::asio::placeholders::error,
-        boost::asio::placeholders::bytes_transferred));
-}
-
-void async_serial::_read_end(
-    const boost::system::error_code& error,
-    size_t bytes_transferred)
-{
-    if(error) {
-        if(is_open()) {
-            _do_close();
-            _set_error_status(true);
-        }
-    } else {
-        if(_callback)
-            _callback(
-                _read_buffer,
-                bytes_transferred);
-        _do_read();
-    }
-}
-
-void async_serial::_do_write()
-{
-    // if a write operation is already in progress, do nothing
-    if(_write_buffer == 0) {
-        boost::lock_guard<boost::mutex> l(_write_queue_mutex);
-        _write_buffer_size=_write_queue.size();
-        _write_buffer.reset(new char[_write_queue.size()]);
-        std::copy(_write_queue.begin(),_write_queue.end(),
-                _write_buffer.get());
-        _write_queue.clear();
-        async_write(
-            _port, boost::asio::buffer(_write_buffer.get(),
-               _write_buffer_size),
-            boost::bind(
-                &async_serial::_write_end,
-                this,
-                boost::asio::placeholders::error));
-    }
-}
-
-void async_serial::_write_end(const boost::system::error_code& error)
-{
-    if(!error) {
-        boost::lock_guard<boost::mutex> l(_write_queue_mutex);
-        if(_write_queue.empty()) {
-            _write_buffer.reset();
-            _write_buffer_size=0;
-            return;
-        }
-        _write_buffer_size = _write_queue.size();
-        _write_buffer.reset(new char[_write_queue.size()]);
-        std::copy(_write_queue.begin(),_write_queue.end(),
-             _write_buffer.get());
-        _write_queue.clear();
-        async_write(
-            _port,
-            boost::asio::buffer(_write_buffer.get(),
-            _write_buffer_size),
-            boost::bind(
-               &async_serial::_write_end,
-               this,
-               boost::asio::placeholders::error));
-    } else {
-        _set_error_status(true);
-        _do_close();
-    }
-}
-
-void async_serial::_do_close()
-{
-    boost::system::error_code ec;
-    _port.cancel(ec);
-    if(ec)
-        _set_error_status(true);
-    _port.close(ec);
-    if(ec)
-        _set_error_status(true);
-}
-
-void async_serial::_set_error_status(const bool e)
-{
-    boost::lock_guard<boost::mutex> l(_error_mutex);
-    _error = e;
-}
-
-
-void async_serial::set_read_callback(
-    const boost::function<void (const char*, size_t)> &callback)
-{
-    _callback = callback;
-}
-
-
-}}} // namespace
diff --git a/host/lib/usrp/e300/e300_async_serial.hpp b/host/lib/usrp/e300/e300_async_serial.hpp
deleted file mode 100644
index fafc7de3d..000000000
--- a/host/lib/usrp/e300/e300_async_serial.hpp
+++ /dev/null
@@ -1,113 +0,0 @@
-//
-// Copyright 2013-2014 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/>.
-//
-
-#ifndef INCLUDED_ASYNC_SERIAL_HPP
-#define INCLUDED_ASYNC_SERIAL_HPP
-
-#include <boost/asio.hpp>
-#include <boost/bind.hpp>
-#include <boost/thread.hpp>
-#include <boost/utility.hpp>
-#include <boost/function.hpp>
-#include <boost/shared_array.hpp>
-
-namespace uhd { namespace usrp { namespace gps {
-
-class async_serial : private boost::noncopyable
-{
-public:
-    async_serial();
-    ~async_serial();
-
-    async_serial(const std::string &node, const size_t baud_rate,
-        boost::asio::serial_port_base::parity opt_parity=
-            boost::asio::serial_port_base::parity(
-                boost::asio::serial_port_base::parity::none),
-        boost::asio::serial_port_base::character_size opt_csize=
-            boost::asio::serial_port_base::character_size(8),
-        boost::asio::serial_port_base::flow_control opt_flow=
-            boost::asio::serial_port_base::flow_control(
-                boost::asio::serial_port_base::flow_control::none),
-        boost::asio::serial_port_base::stop_bits opt_stop=
-            boost::asio::serial_port_base::stop_bits(
-                boost::asio::serial_port_base::stop_bits::one));
-
-   void open(const std::string& node, const size_t baud_rate,
-        boost::asio::serial_port_base::parity opt_parity=
-            boost::asio::serial_port_base::parity(
-                boost::asio::serial_port_base::parity::none),
-        boost::asio::serial_port_base::character_size opt_csize=
-            boost::asio::serial_port_base::character_size(8),
-        boost::asio::serial_port_base::flow_control opt_flow=
-            boost::asio::serial_port_base::flow_control(
-                boost::asio::serial_port_base::flow_control::none),
-        boost::asio::serial_port_base::stop_bits opt_stop=
-            boost::asio::serial_port_base::stop_bits(
-                boost::asio::serial_port_base::stop_bits::one));
-
-   bool is_open(void) const;
-
-   bool error_status(void) const;
-
-   void close(void);
-
-   void write(const char *data, const size_t size);
-   void write(const std::vector<char> &data);
-
-   void write_string(const std::string &s);
-
-   static const size_t READ_BUFFER_SIZE=512;
-
-   void set_read_callback(
-       const boost::function<void (const char*, size_t)>& callback);
-
-   void clear_callback();
-
-private: // methods
-   void _do_read();
-
-   void _read_end(
-       const boost::system::error_code &error,
-       size_t bytes_transferred);
-
-   void _do_write();
-
-   void _write_end(const boost::system::error_code &error);
-
-   void _do_close();
-
-   void _set_error_status(const bool e);
-private: // members
-    boost::asio::io_service         _io;
-    boost::asio::serial_port        _port;
-    boost::thread                   _background_thread;
-    bool                            _open;
-    bool                            _error;
-    mutable boost::mutex            _error_mutex;
-
-    std::vector<char>              _write_queue;
-    boost::shared_array<char>      _write_buffer;
-    size_t                         _write_buffer_size;
-    boost::mutex                   _write_queue_mutex;
-    char                           _read_buffer[READ_BUFFER_SIZE];
-
-    boost::function<void (const char*, size_t)> _callback;
-};
-
-}}} // namespace
-
-#endif //INCLUDED_ASYNC_SERIAL_HPP
diff --git a/host/lib/usrp/e300/e300_impl.cpp b/host/lib/usrp/e300/e300_impl.cpp
index 9a695b57e..ee4ee5ca4 100644
--- a/host/lib/usrp/e300/e300_impl.cpp
+++ b/host/lib/usrp/e300/e300_impl.cpp
@@ -394,19 +394,35 @@ e300_impl::e300_impl(const uhd::device_addr_t &device_addr)
         // This is horrible ... why do I have to sleep here?
         boost::this_thread::sleep(boost::posix_time::milliseconds(100));
         _eeprom_manager = boost::make_shared<e300_eeprom_manager>(i2c::make_i2cdev(E300_I2CDEV_DEVICE));
+        _sensor_manager = e300_sensor_manager::make_local(_global_regs);
     }
     _codec_mgr = ad936x_manager::make(_codec_ctrl, fpga::NUM_RADIOS);
 
-    UHD_MSG(status) << "Detecting internal GPSDO.... " << std::flush;
-    if (_xport_path == AXI) {
-        try {
-            _gps = gps::ublox::ubx::control::make("/dev/ttyPS1", 9600);
-        } catch (std::exception &e) {
-            UHD_MSG(error) << "An error occured making GPSDO control: " << e.what() << std::endl;
+#ifdef E300_GPSD
+    UHD_MSG(status) << "Detecting internal GPSDO " << std::flush;
+    try {
+        if (_xport_path == AXI)
+            _gps = gpsd_iface::make("localhost", 2947);
+        else
+            _gps = gpsd_iface::make(device_addr["addr"], 2947);
+    } catch (std::exception &e) {
+        UHD_MSG(error) << "An error occured making GPSDd interface: " << e.what() << std::endl;
+    }
+
+    if (_gps) {
+        for (size_t i = 0; i < _GPS_TIMEOUT; i++)
+        {
+            boost::this_thread::sleep(boost::posix_time::seconds(1));
+            if (!_gps->gps_detected())
+                std::cout << "." << std::flush;
+            else {
+                std::cout << ".... " << std::flush;
+                break;
+            }
         }
-        _sensor_manager = e300_sensor_manager::make_local(_gps, _global_regs);
+        UHD_MSG(status) << (_gps->gps_detected() ? "found" : "not found") << std::endl;
     }
-    UHD_MSG(status) << (_sensor_manager->get_gps_found() ? "found" : "not found")  << std::endl;
+#endif
 
     // Verify we can talk to the e300 core control registers ...
     UHD_MSG(status) << "Initializing core control..." << std::endl;
@@ -451,6 +467,15 @@ e300_impl::e300_impl(const uhd::device_addr_t &device_addr)
         _tree->create<sensor_value_t>(mb_path / "sensors" / name)
             .publish(boost::bind(&e300_sensor_manager::get_sensor, _sensor_manager, name));
     }
+#ifdef E300_GPSD
+    if (_gps) {
+        BOOST_FOREACH(const std::string &name, _gps->get_sensors())
+        {
+            _tree->create<sensor_value_t>(mb_path / "sensors" / name)
+                .publish(boost::bind(&gpsd_iface::get_sensor, _gps, name));
+        }
+    }
+#endif
 
     ////////////////////////////////////////////////////////////////////
     // setup the mboard eeprom
@@ -513,7 +538,11 @@ e300_impl::e300_impl(const uhd::device_addr_t &device_addr)
     _tree->create<std::string>(mb_path / "time_source" / "value")
         .subscribe(boost::bind(&e300_impl::_update_time_source, this, _1))
         .set(e300::DEFAULT_TIME_SRC);
+#ifdef E300_GPSD
     static const std::vector<std::string> time_sources = boost::assign::list_of("none")("internal")("external")("gpsdo");
+#else
+    static const std::vector<std::string> time_sources = boost::assign::list_of("none")("internal")("external");
+#endif
     _tree->create<std::vector<std::string> >(mb_path / "time_source" / "options").set(time_sources);
     //setup reference source props
     _tree->create<std::string>(mb_path / "clock_source" / "value")
@@ -593,12 +622,25 @@ e300_impl::e300_impl(const uhd::device_addr_t &device_addr)
     _tree->access<subdev_spec_t>(mb_path / "rx_subdev_spec").set(rx_spec);
     _tree->access<subdev_spec_t>(mb_path / "tx_subdev_spec").set(tx_spec);
 
-    UHD_MSG(status) << "Initializing time to the internal GPSDO" << std::endl;
-    const time_t tp = time_t(_sensor_manager->get_sensor("gps_time").to_int()+1);
-    _tree->access<time_spec_t>(mb_path / "time" / "pps").set(time_spec_t(tp));
+#ifdef E300_GPSD
+    //GPS installed: use external ref, time, and init time spec
+    if (_gps and _gps->gps_detected()) {
+        UHD_MSG(status) << "Setting references to the internal GPSDO"
+                        << std::endl;
+        _tree->access<std::string>(mb_path / "time_source" / "value").set("gpsdo");
+        UHD_MSG(status) << "Initializing time to the internal GPSDO"
+                        << std::endl;
+        const time_t tp = time_t(_gps->get_sensor("gps_time").to_int()+1);
+        _tree->access<time_spec_t>(mb_path / "time" / "pps").set(time_spec_t(tp));
+
+        // wait for time to be actually set
+        boost::this_thread::sleep(boost::posix_time::seconds(1));
+    }
+#else
+    //init to internal clock and time source
+    _tree->access<std::string>(mb_path / "time_source/value").set("internal");
+#endif// E300_GPSD
 
-    // wait for time to be actually set
-    boost::this_thread::sleep(boost::posix_time::seconds(1));
 }
 
 boost::uint8_t e300_impl::_get_internal_gpio(gpio_core_200::sptr gpio)
@@ -792,8 +834,10 @@ void e300_impl::_update_time_source(const std::string &source)
     UHD_MSG(status) << boost::format("Setting time source to %s") % source << std::endl;
     if (source == "none" or source == "internal") {
         _misc.pps_sel = global_regs::PPS_INT;
+#ifdef E300_GPSD
     } else if (source == "gpsdo") {
         _misc.pps_sel = global_regs::PPS_GPS;
+#endif
     } else if (source == "external") {
         _misc.pps_sel = global_regs::PPS_EXT;
     } else {
diff --git a/host/lib/usrp/e300/e300_impl.hpp b/host/lib/usrp/e300/e300_impl.hpp
index d61b95387..8aff51466 100644
--- a/host/lib/usrp/e300/e300_impl.hpp
+++ b/host/lib/usrp/e300/e300_impl.hpp
@@ -47,7 +47,11 @@
 #include "e300_i2c.hpp"
 #include "e300_eeprom_manager.hpp"
 #include "e300_sensor_manager.hpp"
-#include "e300_ublox_control.hpp"
+
+/* if we don't compile with gpsd support, don't bother */
+#ifdef E300_GPSD
+#include "gpsd_iface.hpp"
+#endif
 
 namespace uhd { namespace usrp { namespace e300 {
 
@@ -299,7 +303,10 @@ private: // members
     std::string                            _idle_image;
     bool                                   _do_not_reload;
     gpio_t                                 _misc;
-    gps::ublox::ubx::control::sptr _gps;
+#ifdef E300_GPSD
+    gpsd_iface::sptr                       _gps;
+    static const size_t                    _GPS_TIMEOUT = 5;
+#endif
 };
 
 }}} // namespace
diff --git a/host/lib/usrp/e300/e300_network.cpp b/host/lib/usrp/e300/e300_network.cpp
index d68dc4541..96387d6f7 100644
--- a/host/lib/usrp/e300/e300_network.cpp
+++ b/host/lib/usrp/e300/e300_network.cpp
@@ -349,19 +349,9 @@ static void e300_sensor_tunnel(
                 // TODO: This is ugly ... use proper serialization
                 in->value = uhd::htonx<boost::uint32_t>(
                     e300_sensor_manager::pack_float_in_uint32_t(temp.to_real()));
-            } else if (uhd::ntohx(in->which) == GPS_FOUND) {
-                in->value = uhd::htonx<boost::uint32_t>(
-                    sensor_manager->get_gps_found() ? 1 : 0);
-
-            } else if (uhd::ntohx(in->which) == GPS_LOCK) {
-                in->value = uhd::htonx<boost::uint32_t>(
-                    sensor_manager->get_gps_lock().to_bool() ? 1 : 0);
             } else if (uhd::ntohx(in->which) == REF_LOCK) {
                 in->value = uhd::htonx<boost::uint32_t>(
                     sensor_manager->get_ref_lock().to_bool() ? 1 : 0);
-            } else if (uhd::ntohx(in->which) == GPS_TIME) {
-                in->value = uhd::htonx<boost::uint32_t>(
-                    sensor_manager->get_gps_time().to_int());
             } else
                 UHD_MSG(status) << "Got unknown request?!" << std::endl;
 
@@ -648,8 +638,7 @@ network_server_impl::network_server_impl(const uhd::device_addr_t &device_addr)
     _codec_ctrl = ad9361_ctrl::make_spi(client_settings, spi::make(E300_SPIDEV_DEVICE), 1);
     // This is horrible ... why do I have to sleep here?
     boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-    _sensor_manager = e300_sensor_manager::make_local(
-        gps::ublox::ubx::control::make("/dev/ttyPS1", 9600), _global_regs);
+    _sensor_manager = e300_sensor_manager::make_local(_global_regs);
 }
 
 }}} // namespace
diff --git a/host/lib/usrp/e300/e300_sensor_manager.cpp b/host/lib/usrp/e300/e300_sensor_manager.cpp
index 527cfb91a..a4319fa4b 100644
--- a/host/lib/usrp/e300/e300_sensor_manager.cpp
+++ b/host/lib/usrp/e300/e300_sensor_manager.cpp
@@ -24,7 +24,6 @@
 #include <cstring>
 #include <uhd/exception.hpp>
 #include <uhd/utils/byteswap.hpp>
-#include <uhd/usrp/gps_ctrl.hpp>
 
 namespace uhd { namespace usrp { namespace e300 {
 
@@ -38,17 +37,13 @@ public:
 
     std::vector<std::string> get_sensors()
     {
-        return boost::assign::list_of("temp")("gps_locked")("gps_time")("ref_locked");
+        return boost::assign::list_of("temp")("ref_locked");
     }
 
     uhd::sensor_value_t get_sensor(const std::string &key)
     {
         if (key == "temp")
             return get_mb_temp();
-        else if (key == "gps_locked")
-            return get_gps_lock();
-        else if (key == "gps_time")
-            return get_gps_time();
         else if (key == "ref_locked")
             return get_ref_lock();
         else
@@ -94,108 +89,6 @@ public:
             "C");
     }
 
-    uhd::sensor_value_t get_gps_time(void)
-    {
-        boost::mutex::scoped_lock(_mutex);
-        sensor_transaction_t transaction;
-        transaction.which = uhd::htonx<boost::uint32_t>(GPS_TIME);
-        {
-            uhd::transport::managed_send_buffer::sptr buff
-                = _xport->get_send_buff(1.0);
-            if (not buff or buff->size() < sizeof(transaction)) {
-                throw uhd::runtime_error("sensor proxy send timeout");
-            }
-            std::memcpy(
-                buff->cast<void *>(),
-                &transaction,
-                sizeof(transaction));
-            buff->commit(sizeof(transaction));
-        }
-        {
-            uhd::transport::managed_recv_buffer::sptr buff
-                = _xport->get_recv_buff(1.0);
-
-            if (not buff or buff->size() < sizeof(transaction))
-                throw uhd::runtime_error("sensor proxy recv timeout");
-
-            std::memcpy(
-                &transaction,
-                buff->cast<const void *>(),
-                sizeof(transaction));
-        }
-        UHD_ASSERT_THROW(uhd::ntohx<boost::uint32_t>(transaction.which) == GPS_TIME);
-        // TODO: Use proper serialization here ...
-        return sensor_value_t("GPS epoch time", int(uhd::ntohx<boost::uint32_t>(transaction.value)), "seconds");
-    }
-
-    bool get_gps_found(void)
-    {
-        boost::mutex::scoped_lock(_mutex);
-        sensor_transaction_t transaction;
-        transaction.which = uhd::htonx<boost::uint32_t>(GPS_FOUND);
-        {
-            uhd::transport::managed_send_buffer::sptr buff
-                = _xport->get_send_buff(1.0);
-            if (not buff or buff->size() < sizeof(transaction)) {
-                throw uhd::runtime_error("sensor proxy send timeout");
-            }
-            std::memcpy(
-                buff->cast<void *>(),
-                &transaction,
-                sizeof(transaction));
-            buff->commit(sizeof(transaction));
-        }
-        {
-            uhd::transport::managed_recv_buffer::sptr buff
-                = _xport->get_recv_buff(1.0);
-
-            if (not buff or buff->size() < sizeof(transaction))
-                throw uhd::runtime_error("sensor proxy recv timeout");
-
-            std::memcpy(
-                &transaction,
-                buff->cast<const void *>(),
-                sizeof(transaction));
-        }
-        UHD_ASSERT_THROW(uhd::ntohx<boost::uint32_t>(transaction.which) == GPS_FOUND);
-        // TODO: Use proper serialization here ...
-        return (uhd::ntohx(transaction.value) > 0);
-    }
-
-    uhd::sensor_value_t get_gps_lock(void)
-    {
-        boost::mutex::scoped_lock(_mutex);
-        sensor_transaction_t transaction;
-        transaction.which = uhd::htonx<boost::uint32_t>(GPS_LOCK);
-        {
-            uhd::transport::managed_send_buffer::sptr buff
-                = _xport->get_send_buff(1.0);
-            if (not buff or buff->size() < sizeof(transaction)) {
-                throw uhd::runtime_error("sensor proxy send timeout");
-            }
-            std::memcpy(
-                buff->cast<void *>(),
-                &transaction,
-                sizeof(transaction));
-            buff->commit(sizeof(transaction));
-        }
-        {
-            uhd::transport::managed_recv_buffer::sptr buff
-                = _xport->get_recv_buff(1.0);
-
-            if (not buff or buff->size() < sizeof(transaction))
-                throw uhd::runtime_error("sensor proxy recv timeout");
-
-            std::memcpy(
-                &transaction,
-                buff->cast<const void *>(),
-                sizeof(transaction));
-        }
-        UHD_ASSERT_THROW(uhd::ntohx<boost::uint32_t>(transaction.which) == GPS_LOCK);
-        // TODO: Use proper serialization here ...
-        return sensor_value_t("GPS lock status", (uhd::ntohx(transaction.value) > 0), "locked", "unlocked");
-    }
-
     uhd::sensor_value_t get_ref_lock(void)
     {
         boost::mutex::scoped_lock(_mutex);
@@ -255,24 +148,20 @@ static const std::string E300_TEMP_SYSFS = "iio:device0";
 class e300_sensor_local : public e300_sensor_manager
 {
 public:
-    e300_sensor_local(uhd::gps_ctrl::sptr gps_ctrl, global_regs::sptr global_regs) :
-        _gps_ctrl(gps_ctrl), _global_regs(global_regs)
+    e300_sensor_local(global_regs::sptr global_regs) :
+        _global_regs(global_regs)
     {
     }
 
     std::vector<std::string> get_sensors()
     {
-        return boost::assign::list_of("temp")("gps_locked")("gps_time")("ref_locked");
+        return boost::assign::list_of("temp")("ref_locked");
     }
 
     uhd::sensor_value_t get_sensor(const std::string &key)
     {
         if (key == "temp")
             return get_mb_temp();
-        else if (key == "gps_locked")
-            return get_gps_lock();
-        else if (key == "gps_time")
-            return get_gps_time();
         else if (key == "ref_locked")
             return get_ref_lock();
         else
@@ -291,21 +180,6 @@ public:
         return sensor_value_t("temp", (raw + offset) * scale / 1000, "C");
     }
 
-    bool get_gps_found(void)
-    {
-        return _gps_ctrl->gps_detected();
-    }
-
-    uhd::sensor_value_t get_gps_lock(void)
-    {
-        return _gps_ctrl->get_sensor("gps_locked");
-    }
-
-    uhd::sensor_value_t get_gps_time(void)
-    {
-        return _gps_ctrl->get_sensor("gps_time");
-    }
-
     uhd::sensor_value_t get_ref_lock(void)
     {
         //PPSLOOP_LOCKED_MASK is asserted in the following cases:
@@ -322,22 +196,21 @@ public:
     }
 
 private:
-    gps_ctrl::sptr      _gps_ctrl;
     global_regs::sptr   _global_regs;
 };
 }}}
 
 using namespace uhd::usrp::e300;
 e300_sensor_manager::sptr e300_sensor_manager::make_local(
-    uhd::gps_ctrl::sptr gps_ctrl, global_regs::sptr global_regs)
+    global_regs::sptr global_regs)
 {
-    return sptr(new e300_sensor_local(gps_ctrl, global_regs));
+    return sptr(new e300_sensor_local(global_regs));
 }
 
 #else
 using namespace uhd::usrp::e300;
 e300_sensor_manager::sptr e300_sensor_manager::make_local(
-    uhd::gps_ctrl::sptr, global_regs::sptr)
+    global_regs::sptr)
 {
     throw uhd::assertion_error("e300_sensor_manager::make_local() !E300_NATIVE");
 }
diff --git a/host/lib/usrp/e300/e300_sensor_manager.hpp b/host/lib/usrp/e300/e300_sensor_manager.hpp
index 09f889251..bfaf8e90c 100644
--- a/host/lib/usrp/e300/e300_sensor_manager.hpp
+++ b/host/lib/usrp/e300/e300_sensor_manager.hpp
@@ -39,25 +39,22 @@ struct sensor_transaction_t {
 
 
 
-enum sensor {ZYNQ_TEMP=0, GPS_FOUND=1, GPS_TIME=2,
-             GPS_LOCK=3, REF_LOCK=4};
+enum sensor {ZYNQ_TEMP=0, REF_LOCK=4};
 
 class e300_sensor_manager : boost::noncopyable
 {
 public:
     typedef boost::shared_ptr<e300_sensor_manager> sptr;
-    virtual bool get_gps_found(void) = 0;
 
     virtual uhd::sensor_value_t get_sensor(const std::string &key) = 0;
     virtual std::vector<std::string> get_sensors(void) = 0;
 
     virtual uhd::sensor_value_t get_mb_temp(void) = 0;
-    virtual uhd::sensor_value_t get_gps_lock(void) = 0;
-    virtual uhd::sensor_value_t get_gps_time(void) = 0;
     virtual uhd::sensor_value_t get_ref_lock(void) = 0;
 
+
     static sptr make_proxy(uhd::transport::zero_copy_if::sptr xport);
-    static sptr make_local(uhd::gps_ctrl::sptr gps_ctrl, global_regs::sptr global_regs);
+    static sptr make_local(global_regs::sptr global_regs);
 
     // Note: This is a hack
     static boost::uint32_t pack_float_in_uint32_t(const float &v)
diff --git a/host/lib/usrp/e300/e300_ublox_control.hpp b/host/lib/usrp/e300/e300_ublox_control.hpp
deleted file mode 100644
index 8705d6c52..000000000
--- a/host/lib/usrp/e300/e300_ublox_control.hpp
+++ /dev/null
@@ -1,50 +0,0 @@
-#ifndef INCLUDED_UHD_USRP_UBLOX_CONTROL_HPP
-#define INCLUDED_UHD_USRP_UBLOX_CONTROL_HPP
-
-#include <boost/cstdint.hpp>
-#include <boost/shared_ptr.hpp>
-#include <boost/asio.hpp>
-#include <uhd/config.hpp>
-#include <uhd/usrp/gps_ctrl.hpp>
-#include <uhd/types/sensors.hpp>
-
-#include "e300_async_serial.hpp"
-
-namespace uhd { namespace usrp { namespace gps {
-
-namespace ublox { namespace ubx {
-
-class control : public virtual uhd::gps_ctrl
-{
-public:
-    typedef boost::shared_ptr<control> sptr;
-
-    static sptr make(const std::string &node, const size_t baud_rate);
-
-    virtual void configure_message_rate(
-        const boost::uint16_t msg,
-        const boost::uint8_t rate) = 0;
-
-    virtual void configure_antenna(
-        const boost::uint16_t flags,
-        const boost::uint16_t pins) = 0;
-
-    virtual void configure_pps(
-        const boost::uint32_t interval,
-        const boost::uint32_t length,
-        const boost::int8_t status,
-        const boost::uint8_t time_ref,
-        const boost::uint8_t flags,
-        const boost::int16_t antenna_delay,
-        const boost::int16_t rf_group_delay,
-        const boost::int32_t user_delay) = 0;
-
-    virtual void configure_rates(
-        boost::uint16_t meas_rate,
-        boost::uint16_t nav_rate,
-        boost::uint16_t time_ref) = 0;
-};
-}} // namespace ublox::ubx
-
-}}} // namespace
-#endif // INCLUDED_UHD_USRP_UBLOX_CONTROL_HPP
diff --git a/host/lib/usrp/e300/e300_ublox_control_impl.cpp b/host/lib/usrp/e300/e300_ublox_control_impl.cpp
deleted file mode 100644
index 389bf79fa..000000000
--- a/host/lib/usrp/e300/e300_ublox_control_impl.cpp
+++ /dev/null
@@ -1,505 +0,0 @@
-#include <boost/format.hpp>
-#include <boost/foreach.hpp>
-#include <boost/bind.hpp>
-#include <boost/make_shared.hpp>
-#include <boost/lexical_cast.hpp>
-#include <boost/assign/list_of.hpp>
-#include "boost/date_time/posix_time/posix_time.hpp"
-
-#include <iostream>
-
-
-#include <uhd/utils/byteswap.hpp>
-#include <uhd/utils/msg.hpp>
-#include <uhd/exception.hpp>
-
-#include "e300_ublox_control.hpp"
-
-#ifdef E300_NATIVE
-#include "e300_ublox_control_impl.hpp"
-
-
-namespace uhd { namespace usrp { namespace gps {
-
-namespace ublox { namespace ubx {
-
-control_impl::control_impl(const std::string &node, const size_t baud_rate)
-{
-    _decode_init();
-    _serial = boost::make_shared<async_serial>(node, baud_rate);
-    _serial->set_read_callback(boost::bind(&control_impl::_rx_callback, this, _1, _2));
-
-    _detect();
-
-    configure_message_rate(MSG_GLL, 0);
-    configure_message_rate(MSG_GSV, 0);
-    configure_message_rate(MSG_GGA, 0);
-    configure_message_rate(MSG_GSA, 0);
-    configure_message_rate(MSG_RMC, 0);
-    configure_message_rate(MSG_VTG, 0);
-    configure_message_rate(MSG_NAV_TIMEUTC, 1);
-    configure_message_rate(MSG_NAV_SOL, 1);
-
-    configure_antenna(0x001b, 0x8251);
-
-    configure_pps(0xf4240, 0x3d090, 1, 0 /* utc */, 1, 0, 0, 0);
-
-    _sensors = boost::assign::list_of("gps_locked")("gps_time");
-}
-
-bool control_impl::gps_detected(void)
-{
-    return _detected;
-}
-
-void control_impl::_detect(void)
-{
-    _send_message(MSG_MON_VER, NULL, 0);
-}
-
-std::vector<std::string> control_impl::get_sensors(void)
-{
-    return _sensors;
-}
-
-uhd::sensor_value_t control_impl::get_sensor(std::string key)
-{
-    if (key == "gps_time") {
-        bool lock;
-        _locked.wait_and_see(lock);
-        return sensor_value_t("GPS epoch time",
-            lock ? int(_get_epoch_time()) : 0, "seconds");
-    } else if (key == "gps_locked") {
-        bool lock;
-        _locked.wait_and_see(lock);
-        return sensor_value_t("GPS lock status", lock, "locked", "unlocked");
-    } else
-        throw uhd::key_error(str(boost::format("sensor %s unknown.") % key));
-}
-
-std::time_t control_impl::_get_epoch_time(void)
-{
-    boost::posix_time::ptime ptime;
-    _ptime.wait_and_see(ptime);
-    return (ptime - boost::posix_time::from_time_t(0)).total_seconds();
-}
-
-control_impl::~control_impl(void)
-{
-}
-
-void control_impl::_decode_init(void)
-{
-    _decode_state = DECODE_SYNC1;
-    _rx_ck_a = 0;
-    _rx_ck_b = 0;
-    _rx_payload_length = 0;
-    _rx_payload_index  = 0;
-}
-
-void control_impl::_add_byte_to_checksum(const boost::uint8_t b)
-{
-    _rx_ck_a = _rx_ck_a + b;
-    _rx_ck_b = _rx_ck_b + _rx_ck_a;
-}
-
-void control_impl::_calc_checksum(
-    const boost::uint8_t *buffer,
-    const boost::uint16_t length,
-    checksum_t &checksum)
-{
-    for (size_t i = 0; i < length; i++)
-    {
-        checksum.ck_a = checksum.ck_a + buffer[i];
-        checksum.ck_b = checksum.ck_b + checksum.ck_a;
-    }
-}
-
-void control_impl::configure_rates(
-    boost::uint16_t meas_rate,
-    boost::uint16_t nav_rate,
-    boost::uint16_t time_ref)
-{
-    payload_tx_cfg_rate_t cfg_rate;
-    cfg_rate.meas_rate = uhd::htowx<boost::uint16_t>(meas_rate);
-    cfg_rate.nav_rate = uhd::htowx<boost::uint16_t>(nav_rate);
-    cfg_rate.time_ref = uhd::htowx<boost::uint16_t>(time_ref);
-
-    _send_message(
-        MSG_CFG_RATE,
-        reinterpret_cast<const uint8_t*>(&cfg_rate),
-        sizeof(cfg_rate));
-
-    _wait_for_ack(MSG_CFG_RATE, 1.0);
-}
-
-void control_impl::configure_message_rate(
-    const boost::uint16_t msg,
-    const uint8_t rate)
-{
-    payload_tx_cfg_msg_t cfg_msg;
-    cfg_msg.msg  = uhd::htowx<boost::uint16_t>(msg);
-    cfg_msg.rate[0] = 0;//rate;
-    cfg_msg.rate[1] = rate;
-    cfg_msg.rate[2] = 0;//rate;
-    cfg_msg.rate[3] = 0;//rate;
-    cfg_msg.rate[4] = 0;//rate;
-    cfg_msg.rate[5] = 0;//rate;
-    _send_message(
-        MSG_CFG_MSG,
-        reinterpret_cast<const uint8_t*>(&cfg_msg),
-        sizeof(cfg_msg));
-
-    _wait_for_ack(MSG_CFG_MSG, 1.0);
-}
-
-void control_impl::configure_antenna(
-    const boost::uint16_t flags,
-    const boost::uint16_t pins)
-{
-    payload_tx_cfg_ant_t cfg_ant;
-    cfg_ant.pins = uhd::htowx<boost::uint16_t>(pins);
-    cfg_ant.flags = uhd::htowx<boost::uint16_t>(flags);
-    _send_message(
-        MSG_CFG_ANT,
-        reinterpret_cast<const uint8_t*>(&cfg_ant),
-        sizeof(cfg_ant));
-    if (_wait_for_ack(MSG_CFG_ANT, 1.0) < 0) {
-        throw uhd::runtime_error("Didn't get an ACK for antenna configuration.");
-    }
-
-}
-
-void control_impl::configure_pps(
-    const boost::uint32_t interval,
-    const boost::uint32_t length,
-    const boost::int8_t status,
-    const boost::uint8_t time_ref,
-    const boost::uint8_t flags,
-    const boost::int16_t antenna_delay,
-    const boost::int16_t rf_group_delay,
-    const boost::int32_t user_delay)
-{
-    payload_tx_cfg_tp_t cfg_tp;
-    cfg_tp.interval = uhd::htowx<boost::uint32_t>(interval);
-    cfg_tp.length = uhd::htowx<boost::uint32_t>(length);
-    cfg_tp.status = status;
-    cfg_tp.time_ref = time_ref;
-    cfg_tp.flags = flags;
-    cfg_tp.antenna_delay = uhd::htowx<boost::int16_t>(antenna_delay);
-    cfg_tp.rf_group_delay = uhd::htowx<boost::int16_t>(rf_group_delay);
-    cfg_tp.user_delay = uhd::htowx<boost::int32_t>(user_delay);
-    _send_message(
-        MSG_CFG_TP,
-        reinterpret_cast<const uint8_t*>(&cfg_tp),
-        sizeof(cfg_tp));
-    if (_wait_for_ack(MSG_CFG_TP, 1.0) < 0) {
-        throw uhd::runtime_error("Didn't get an ACK for PPS configuration.");
-    }
-}
-
-
-void control_impl::_rx_callback(const char *data, unsigned int len)
-{
-    //std::cout << "IN RX CALLBACK" << std::flush << std::endl;
-    std::vector<char> v(data, data+len);
-    BOOST_FOREACH(const char &c, v)
-    {
-        _parse_char(c);
-    }
-}
-
-void control_impl::_parse_char(const boost::uint8_t b)
-{
-    int ret = 0;
-
-    switch (_decode_state) {
-
-    // we're expecting the first sync byte
-    case DECODE_SYNC1:
-        if (b == SYNC1) { // sync1 found goto next step
-            _decode_state = DECODE_SYNC2;
-        } // else stay around
-        break;
-
-    // we're expecting the second sync byte
-    case DECODE_SYNC2:
-        if (b == SYNC2) { // sync2 found goto next step
-            _decode_state = DECODE_CLASS;
-        } else {
-            // failed, reset
-            _decode_init();
-        }
-        break;
-
-    // we're expecting the class byte
-    case DECODE_CLASS:
-        _add_byte_to_checksum(b);
-        _rx_msg = b;
-        _decode_state = DECODE_ID;
-        break;
-
-    // we're expecting the id byte
-    case DECODE_ID:
-        _add_byte_to_checksum(b);
-        _rx_msg |= (b << 8);
-        _decode_state = DECODE_LENGTH1;
-        break;
-
-    // we're expecting the first length byte
-    case DECODE_LENGTH1:
-        _add_byte_to_checksum(b);
-        _rx_payload_length = b;
-        _decode_state = DECODE_LENGTH2;
-        break;
-
-    // we're expecting the second length byte
-    case DECODE_LENGTH2:
-        _add_byte_to_checksum(b);
-        _rx_payload_length |= (b << 8);
-        if(_payload_rx_init()) {
-            _decode_init(); // we failed, give up for this one
-        } else {
-            _decode_state = _rx_payload_length ?
-                DECODE_PAYLOAD : DECODE_CHKSUM1;
-        }
-        break;
-
-    // we're expecting payload
-    case DECODE_PAYLOAD:
-        _add_byte_to_checksum(b);
-        switch(_rx_msg) {
-        default:
-            ret = _payload_rx_add(b);
-            break;
-        };
-        if (ret < 0) {
-            // we couldn't deal with the payload, discard the whole thing
-            _decode_init();
-        } else if (ret > 0) {
-            // payload was complete, let's check the checksum;
-            _decode_state = DECODE_CHKSUM1;
-        } else {
-            // more payload expected, don't move
-        }
-        ret = 0;
-        break;
-
-    case DECODE_CHKSUM1:
-        if (_rx_ck_a != b) {
-            // checksum didn't match, barf
-            std::cout << boost::format("Failed checksum byte1 %lx != %lx")
-                % int(_rx_ck_a) % int(b) << std::endl;
-            _decode_init();
-        } else {
-            _decode_state = DECODE_CHKSUM2;
-        }
-        break;
-
-    case DECODE_CHKSUM2:
-        if (_rx_ck_b != b) {
-            // checksum didn't match, barf
-            std::cout << boost::format("Failed checksum byte2 %lx != %lx")
-                % int(_rx_ck_b) % int(b) << std::endl;
-
-        } else {
-            ret = _payload_rx_done(); // payload done
-        }
-        _decode_init();
-        break;
-
-    default:
-        break;
-    };
-}
-
-int control_impl::_payload_rx_init(void)
-{
-    int ret = 0;
-
-    _rx_state = RXMSG_HANDLE; // by default handle
-    switch(_rx_msg) {
-
-    case MSG_NAV_SOL:
-        if (not (_rx_payload_length == sizeof(payload_rx_nav_sol_t)))
-            _rx_state = RXMSG_ERROR_LENGTH;
-        break;
-
-    case MSG_NAV_TIMEUTC:
-        if (not (_rx_payload_length == sizeof(payload_rx_nav_timeutc_t)))
-            _rx_state = RXMSG_ERROR_LENGTH;
-        break;
-
-    case MSG_MON_VER:
-        break; // always take this one
-
-    case MSG_ACK_ACK:
-        if (not (_rx_payload_length == sizeof(payload_rx_ack_ack_t)))
-            _rx_state = RXMSG_ERROR_LENGTH;
-        break;
-
-    case MSG_ACK_NAK:
-        if (not (_rx_payload_length == sizeof(payload_rx_ack_nak_t)))
-            _rx_state = RXMSG_ERROR_LENGTH;
-        break;
-
-    default:
-        _rx_state = RXMSG_DISABLE;
-        break;
-    };
-
-    switch (_rx_state) {
-    case RXMSG_HANDLE: // handle message
-    case RXMSG_IGNORE: // ignore message but don't report error
-        ret = 0;
-        break;
-    case RXMSG_DISABLE: // ignore message but don't report error
-    case RXMSG_ERROR_LENGTH: // the length doesn't match
-        ret = -1;
-        break;
-    default: // invalid, error
-        ret = -1;
-        break;
-    };
-
-    return ret;
-}
-
-int control_impl::_payload_rx_add(const boost::uint8_t b)
-{
-    int ret = 0;
-    _buf.raw[_rx_payload_index] = b;
-    if (++_rx_payload_index >= _rx_payload_length)
-        ret = 1;
-    return ret;
-}
-
-int control_impl::_payload_rx_done(void)
-{
-    int ret = 0;
-    if (_rx_state != RXMSG_HANDLE) {
-        return 0;
-    }
-
-    switch (_rx_msg) {
-    case MSG_MON_VER:
-        _detected = true;
-        break;
-
-    case MSG_MON_HW:
-        std::cout << "MON-HW" << std::endl;
-        break;
-
-    case MSG_ACK_ACK:
-        if ((_ack_state == ACK_WAITING) and (_buf.payload_rx_ack_ack.msg == _ack_waiting_msg))
-            _ack_state = ACK_GOT_ACK;
-        break;
-
-    case MSG_ACK_NAK:
-        if ((_ack_state == ACK_WAITING) and (_buf.payload_rx_ack_nak.msg == _ack_waiting_msg))
-            _ack_state = ACK_GOT_NAK;
-
-        break;
-
-    case MSG_CFG_ANT:
-        break;
-
-    case MSG_NAV_TIMEUTC:
-        _ptime.update(boost::posix_time::ptime(
-            boost::gregorian::date(
-                boost::gregorian::greg_year(uhd::wtohx<boost::uint16_t>(
-                    _buf.payload_rx_nav_timeutc.year)),
-                boost::gregorian::greg_month(_buf.payload_rx_nav_timeutc.month),
-                boost::gregorian::greg_day(_buf.payload_rx_nav_timeutc.day)),
-            (boost::posix_time::hours(_buf.payload_rx_nav_timeutc.hour)
-            + boost::posix_time::minutes(_buf.payload_rx_nav_timeutc.min)
-            + boost::posix_time::seconds(_buf.payload_rx_nav_timeutc.sec))));
-        break;
-
-    case MSG_NAV_SOL:
-        _locked.update(_buf.payload_rx_nav_sol.gps_fix > 0);
-        break;
-
-    default:
-        std::cout << boost::format("Got unknown message %lx , with good checksum [") % int(_rx_msg);
-        for(size_t i = 0; i < _rx_payload_length; i++)
-            std::cout << boost::format("%lx, ") % int(_buf.raw[i]);
-        std::cout << "]"<< std::endl;
-        break;
-    };
-    return ret;
-}
-
-void control_impl::_send_message(
-    const boost::uint16_t msg,
-    const boost::uint8_t *payload,
-    const boost::uint16_t len)
-{
-    header_t header = {SYNC1, SYNC2, msg, len};
-    checksum_t checksum = {0, 0};
-
-    // calculate checksums, first header without sync
-    // then payload
-    _calc_checksum(
-        reinterpret_cast<boost::uint8_t*>(&header) + 2,
-        sizeof(header) - 2, checksum);
-    if (payload)
-        _calc_checksum(payload, len, checksum);
-
-    _serial->write(
-        reinterpret_cast<const char*>(&header),
-        sizeof(header));
-
-    if (payload)
-        _serial->write((const char *) payload, len);
-
-    _serial->write(
-        reinterpret_cast<const char*>(&checksum),
-        sizeof(checksum));
-}
-
-int control_impl::_wait_for_ack(
-    const boost::uint16_t msg,
-    const double timeout)
-{
-    int ret = -1;
-
-    _ack_state = ACK_WAITING;
-    _ack_waiting_msg = msg;
-
-    boost::system_time timeout_time =
-        boost::get_system_time() +
-        boost::posix_time::milliseconds(timeout * 1000.0);
-
-    do {
-        if(_ack_state == ACK_GOT_ACK)
-            return 0;
-        else if (_ack_state == ACK_GOT_NAK) {
-            return -1;
-        }
-        boost::this_thread::sleep(boost::posix_time::milliseconds(20));
-    } while (boost::get_system_time() < timeout_time);
-
-    // we get here ... it's a timeout
-    _ack_state = ACK_IDLE;
-    return ret;
-}
-
-
-}} // namespace ublox::ubx
-}}} // namespace
-
-using namespace uhd::usrp::gps::ublox::ubx;
-
-control::sptr control::make(const std::string &node, const size_t baud_rate)
-{
-    return control::sptr(new control_impl(node, baud_rate));
-}
-#else
-using namespace uhd::usrp::gps::ublox::ubx;
-
-control::sptr control::make(const std::string& /* node */, const size_t /* baud_rate */)
-{
-    throw uhd::assertion_error("control::sptr::make: !E300_NATIVE");
-}
-#endif // E300_NATIVE
diff --git a/host/lib/usrp/e300/e300_ublox_control_impl.hpp b/host/lib/usrp/e300/e300_ublox_control_impl.hpp
deleted file mode 100644
index a1dcbfe6c..000000000
--- a/host/lib/usrp/e300/e300_ublox_control_impl.hpp
+++ /dev/null
@@ -1,457 +0,0 @@
-#ifndef INCLUDED_UHD_USRP_UBLOX_CONTROL_IMPL_HPP
-#define INCLUDED_UHD_USRP_UBLOX_CONTROL_IMPL_HPP
-
-#include <boost/cstdint.hpp>
-#include <boost/noncopyable.hpp>
-#include <boost/asio.hpp>
-#include <uhd/config.hpp>
-#include <uhd/usrp/gps_ctrl.hpp>
-#include <uhd/types/sensors.hpp>
-
-#include "e300_async_serial.hpp"
-
-namespace uhd { namespace usrp { namespace gps {
-
-namespace ublox { namespace ubx {
-// ublox binary sync words
-static const boost::uint8_t SYNC1 = 0xB5;
-static const boost::uint8_t SYNC2 = 0x62;
-
-// message classes
-static const boost::uint8_t CLASS_NAV  = 0x01;
-static const boost::uint8_t CLASS_ACK  = 0x05;
-static const boost::uint8_t CLASS_CFG  = 0x06;
-static const boost::uint8_t CLASS_MON  = 0x0a;
-static const boost::uint8_t CLASS_NMEA = 0xf0;
-
-// Message IDs
-static const boost::uint8_t ID_NAV_POSLLH  = 0x02;
-static const boost::uint8_t ID_NAV_SOL     = 0x06;
-static const boost::uint8_t ID_NAV_PVT     = 0x07;
-static const boost::uint8_t ID_NAV_VELNED  = 0x12;
-static const boost::uint8_t ID_NAV_TIMEUTC = 0x21;
-static const boost::uint8_t ID_NAV_SVINFO  = 0x30;
-static const boost::uint8_t ID_ACK_NAK     = 0x00;
-static const boost::uint8_t ID_ACK_ACK     = 0x01;
-static const boost::uint8_t ID_CFG_PRT     = 0x00;
-static const boost::uint8_t ID_CFG_ANT     = 0x13;
-static const boost::uint8_t ID_CFG_TP      = 0x07;
-static const boost::uint8_t ID_CFG_MSG     = 0x01;
-static const boost::uint8_t ID_CFG_RATE    = 0x08;
-static const boost::uint8_t ID_CFG_NAV5    = 0x24;
-static const boost::uint8_t ID_MON_VER     = 0x04;
-static const boost::uint8_t ID_MON_HW      = 0x09;
-static const boost::uint8_t ID_GGA         = 0x00;
-static const boost::uint8_t ID_GLL         = 0x01;
-static const boost::uint8_t ID_GSA         = 0x02;
-static const boost::uint8_t ID_GSV         = 0x03;
-static const boost::uint8_t ID_RMC         = 0x04;
-static const boost::uint8_t ID_VTG         = 0x05;
-static const boost::uint8_t ID_GST         = 0x07;
-
-// Message Classes & IDs //
-static const boost::uint16_t MSG_NAV_POSLLH
-    = CLASS_NAV | (ID_NAV_POSLLH << 8);
-static const boost::uint16_t MSG_NAV_SOL
-    = CLASS_NAV | (ID_NAV_SOL << 8);
-static const boost::uint16_t MSG_NAV_PVT
-    = CLASS_NAV | (ID_NAV_PVT << 8);
-static const boost::uint16_t MSG_NAV_VELNED
-    = CLASS_NAV | (ID_NAV_VELNED << 8);
-static const boost::uint16_t MSG_NAV_TIMEUTC
-    = CLASS_NAV | (ID_NAV_TIMEUTC << 8);
-static const boost::uint16_t MSG_NAV_SVINFO
-    = CLASS_NAV | (ID_NAV_SVINFO << 8);
-static const boost::uint16_t MSG_ACK_NAK
-    = CLASS_ACK | (ID_ACK_NAK << 8);
-static const boost::uint16_t MSG_ACK_ACK
-    = CLASS_ACK | (ID_ACK_ACK << 8);
-static const boost::uint16_t MSG_CFG_PRT
-    = CLASS_CFG | (ID_CFG_PRT << 8);
-static const boost::uint16_t MSG_CFG_ANT
-    = CLASS_CFG | (ID_CFG_ANT << 8);
-static const boost::uint16_t MSG_CFG_TP
-    = CLASS_CFG | (ID_CFG_TP << 8);
-static const boost::uint16_t MSG_CFG_MSG
-    = CLASS_CFG | (ID_CFG_MSG << 8);
-static const boost::uint16_t MSG_CFG_RATE
-    = CLASS_CFG | (ID_CFG_RATE << 8);
-static const boost::uint16_t MSG_CFG_NAV5
-    = CLASS_CFG | (ID_CFG_NAV5 << 8);
-static const boost::uint16_t MSG_MON_HW
-    = CLASS_MON | (ID_MON_HW << 8);
-static const boost::uint16_t MSG_MON_VER
-    = CLASS_MON | (ID_MON_VER << 8);
-
-// NMEA ones
-static const boost::uint16_t MSG_GGA
-    = CLASS_NMEA | (ID_GGA << 8);
-static const boost::uint16_t MSG_GLL
-    = CLASS_NMEA | (ID_GLL << 8);
-static const boost::uint16_t MSG_GSA
-    = CLASS_NMEA | (ID_GSA << 8);
-static const boost::uint16_t MSG_GSV
-    = CLASS_NMEA | (ID_GSV << 8);
-static const boost::uint16_t MSG_RMC
-    = CLASS_NMEA | (ID_RMC << 8);
-static const boost::uint16_t MSG_VTG
-    = CLASS_NMEA | (ID_VTG << 8);
-
-// header
-struct header_t
-{
-    boost::uint8_t sync1;
-    boost::uint8_t sync2;
-    boost::uint16_t msg;
-    boost::uint16_t length;
-};
-
-// checksum
-struct checksum_t
-{
-    boost::uint8_t ck_a;
-    boost::uint8_t ck_b;
-};
-
-// rx rx mon-hw (ubx6)
-struct payload_rx_mon_hw_t
-{
-    boost::uint32_t pin_sel;
-    boost::uint32_t pin_bank;
-    boost::uint32_t pin_dir;
-    boost::uint32_t pin_val;
-    boost::uint16_t noise_per_ms;
-    boost::uint16_t agc_cnt;
-    boost::uint8_t  a_status;
-    boost::uint8_t  a_power;
-    boost::uint8_t  flags;
-    boost::uint8_t  reserved1;
-    boost::uint32_t used_mask;
-    boost::uint8_t  vp[25];
-    boost::uint8_t  jam_ind;
-    boost::uint16_t reserved3;
-    boost::uint32_t pin_irq;
-    boost::uint32_t pullh;
-    boost::uint32_t pulll;
-};
-
-// rx mon-ver
-struct payload_rx_mon_ver_part1_t
-{
-    char sw_version[30];
-    char hw_version[10];
-};
-
-struct payload_rx_mon_ver_part2_t
-{
-    boost::uint8_t extension[30];
-};
-
-// rx ack-ack
-typedef union {
-    boost::uint16_t msg;
-    struct {
-        boost::uint8_t cls_id;
-        boost::uint8_t msg_id;
-    };
-} payload_rx_ack_ack_t;
-
-// rx ack-nak
-typedef union {
-    boost::uint16_t msg;
-    struct {
-        boost::uint8_t cls_id;
-        boost::uint8_t msg_id;
-    };
-} payload_rx_ack_nak_t;
-
-// tx cfg-prt (uart)
-struct payload_tx_cfg_prt_t
-{
-    boost::uint8_t  port_id;
-    boost::uint8_t  reserved0;
-    boost::uint16_t tx_ready;
-    boost::uint32_t mode;
-    boost::uint32_t baud_rate;
-    boost::uint16_t in_proto_mask;
-    boost::uint16_t out_proto_mask;
-    boost::uint16_t flags;
-    boost::uint16_t reserved5;
-};
-
-// tx cfg-rate
-struct payload_tx_cfg_rate_t
-{
-    boost::uint16_t meas_rate;
-    boost::uint16_t nav_rate;
-    boost::uint16_t time_ref;
-};
-
-// tx cfg-msg
-struct payload_tx_cfg_msg_t
-{
-    boost::uint16_t msg;
-    boost::uint8_t rate[6];
-};
-
-
-// tx cfg-ant
-struct payload_tx_cfg_ant_t
-{
-    boost::uint16_t flags;
-    boost::uint16_t pins;
-};
-
-// tx cfg-tp
-struct payload_tx_cfg_tp_t
-{
-    boost::uint32_t interval;
-    boost::uint32_t length;
-    boost::int8_t status;
-    boost::uint8_t time_ref;
-    boost::uint8_t flags;
-    boost::uint8_t reserved1;
-    boost::int16_t antenna_delay;
-    boost::int16_t rf_group_delay;
-    boost::int32_t user_delay;
-};
-
-struct payload_rx_nav_sol_t
-{
-    boost::uint32_t i_tow;
-    boost::int32_t f_tow;
-    boost::int16_t week;
-    boost::uint8_t gps_fix;
-    boost::uint8_t flags;
-    boost::int32_t ecef_x;
-    boost::int32_t ecef_y;
-    boost::int32_t ecef_z;
-    boost::uint32_t p_acc;
-    boost::int32_t ecef_vx;
-    boost::int32_t ecef_vy;
-    boost::int32_t ecef_vz;
-    boost::uint32_t s_acc;
-    boost::uint16_t p_dop;
-    boost::uint8_t reserved1;
-    boost::uint8_t num_sv;
-    boost::uint32_t reserved2;
-};
-
-struct payload_rx_nav_timeutc_t
-{
-    boost::uint32_t i_tow;
-    boost::uint32_t t_acc;
-    boost::int32_t nano;
-    boost::uint16_t year;
-    boost::uint8_t month;
-    boost::uint8_t day;
-    boost::uint8_t hour;
-    boost::uint8_t min;
-    boost::uint8_t sec;
-    boost::uint8_t valid;
-};
-
-typedef union {
-    payload_rx_mon_hw_t        payload_rx_mon_hw;
-
-    payload_rx_mon_ver_part1_t payload_rx_mon_ver_part1;
-    payload_rx_mon_ver_part2_t payload_rx_mon_ver_part2;
-
-    payload_rx_ack_ack_t       payload_rx_ack_ack;
-    payload_rx_ack_nak_t       payload_rx_ack_nak;
-
-    payload_tx_cfg_prt_t       payload_tx_cfg_prt;
-    payload_tx_cfg_ant_t       payload_tx_cfg_ant;
-    payload_tx_cfg_rate_t      payload_tx_cfg_rate;
-
-    payload_tx_cfg_msg_t       payload_tx_cfg_msg;
-
-    payload_rx_nav_timeutc_t   payload_rx_nav_timeutc;
-    payload_rx_nav_sol_t   payload_rx_nav_sol;
-    boost::uint8_t             raw[];
-} buf_t;
-
-
-template <typename T>
-class sensor_entry
-{
-public:
-    sensor_entry() : _seen(false)
-    {
-    }
-
-    void update(const T &val)
-    {
-        boost::mutex::scoped_lock l(_mutex);
-        _value = val;
-        _seen = false;
-        l.unlock();
-        _cond.notify_one();
-    }
-
-    bool seen() const
-    {
-        boost::mutex::scoped_lock l(_mutex);
-        return _seen;
-    }
-
-    bool try_and_see(T &val)
-    {
-        boost::mutex::scoped_lock l(_mutex);
-        if (_seen)
-            return false;
-
-        val = _value;
-        _seen = true;
-        return true;
-    }
-
-    void wait_and_see(T &val)
-    {
-        boost::mutex::scoped_lock l(_mutex);
-        while(_seen)
-        {
-            _cond.wait(l);
-            //std::cout << "Already seen ... " << std::endl;
-        }
-        val = _value;
-        _seen = true;
-    }
-
-private: // members
-    T                         _value;
-    boost::mutex              _mutex;
-    boost::condition_variable _cond;
-    bool                _seen;
-};
-
-class control_impl : public control
-{
-public:
-    control_impl(const std::string &node, const size_t baud_rate);
-
-    virtual ~control_impl(void);
-
-    void configure_message_rate(
-        const boost::uint16_t msg,
-        const boost::uint8_t rate);
-
-    void configure_antenna(
-        const boost::uint16_t flags,
-        const boost::uint16_t pins);
-
-    void configure_pps(
-        const boost::uint32_t interval,
-        const boost::uint32_t length,
-        const boost::int8_t status,
-        const boost::uint8_t time_ref,
-        const boost::uint8_t flags,
-        const boost::int16_t antenna_delay,
-        const boost::int16_t rf_group_delay,
-        const boost::int32_t user_delay);
-
-    void configure_rates(
-        boost::uint16_t meas_rate,
-        boost::uint16_t nav_rate,
-        boost::uint16_t time_ref);
-
-    // gps_ctrl interface
-    bool gps_detected(void);
-    std::vector<std::string> get_sensors(void);
-    uhd::sensor_value_t get_sensor(std::string key);
-
-private: // types
-    enum decoder_state_t {
-        DECODE_SYNC1 = 0,
-        DECODE_SYNC2,
-        DECODE_CLASS,
-        DECODE_ID,
-        DECODE_LENGTH1,
-        DECODE_LENGTH2,
-        DECODE_PAYLOAD,
-        DECODE_CHKSUM1,
-        DECODE_CHKSUM2,
-    };
-
-    enum rxmsg_state_t {
-        RXMSG_IGNORE = 0,
-        RXMSG_HANDLE,
-        RXMSG_DISABLE,
-        RXMSG_ERROR_LENGTH
-    };
-
-    enum ack_state_t {
-        ACK_IDLE = 0,
-        ACK_WAITING,
-        ACK_GOT_ACK,
-        ACK_GOT_NAK
-    };
-
-private: // methods
-    std::time_t _get_epoch_time(void);
-
-    void _decode_init(void);
-
-    void _add_byte_to_checksum(const boost::uint8_t b);
-
-    void _detect(void);
-
-    void _send_message(
-        const boost::uint16_t msg,
-        const boost::uint8_t *payload,
-        const boost::uint16_t len);
-
-    int _wait_for_ack(
-        const boost::uint16_t msg,
-        const double timeout);
-
-    void _calc_checksum(
-        const boost::uint8_t *buffer,
-        const boost::uint16_t length,
-        checksum_t &checksum);
-
-    void _rx_callback(const char *data, unsigned len);
-
-    void _parse_char(const boost::uint8_t b);
-
-    int _payload_rx_init(void);
-
-    int _payload_rx_add(const boost::uint8_t b);
-
-    int _payload_rx_done(void);
-
-private: // members
-    // gps_ctrl stuff
-    bool                                   _detected;
-    std::vector<std::string>               _sensors;
-
-    sensor_entry<bool>                     _locked;
-    sensor_entry<boost::posix_time::ptime> _ptime;
-
-    // decoder state
-    decoder_state_t                        _decode_state;
-    rxmsg_state_t                          _rxmsg_state;
-
-    ack_state_t                            _ack_state;
-    boost::uint16_t                        _ack_waiting_msg;
-
-    boost::uint8_t                         _rx_ck_a;
-    boost::uint8_t                         _rx_ck_b;
-
-    boost::uint16_t                        _rx_payload_length;
-    size_t                                 _rx_payload_index;
-    boost::uint16_t                        _rx_msg;
-
-    rxmsg_state_t                          _rx_state;
-
-    boost::shared_ptr<async_serial>        _serial;
-
-    // this has to be at the end of the
-    // class to be valid C++
-    buf_t                                  _buf;
-};
-
-}} // namespace ublox::ubx
-
-}}} // namespace
-#endif // INCLUDED_UHD_USRP_UBLOX_CONTROL_IMPL_HPP
diff --git a/host/lib/usrp/gpsd_iface.cpp b/host/lib/usrp/gpsd_iface.cpp
new file mode 100644
index 000000000..62b6939c5
--- /dev/null
+++ b/host/lib/usrp/gpsd_iface.cpp
@@ -0,0 +1,184 @@
+//
+// Copyright 2015 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 <cmath>
+
+#include <gps.h>
+
+#include <boost/assign/list_of.hpp>
+#include <boost/bind.hpp>
+#include <boost/cstdint.hpp>
+#include "boost/date_time/gregorian/gregorian.hpp"
+#include <boost/format.hpp>
+#include <boost/lexical_cast.hpp>
+#include <boost/thread/shared_mutex.hpp>
+#include <boost/thread.hpp>
+
+#include <uhd/exception.hpp>
+#include <uhd/usrp/gps_ctrl.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/types/dict.hpp>
+
+#include "gpsd_iface.hpp"
+
+namespace uhd { namespace usrp {
+
+static const size_t TIMEOUT = 240;
+static const size_t CLICK_RATE = 250000;
+
+class gpsd_iface_impl : public virtual gpsd_iface {
+public:
+    gpsd_iface_impl(const std::string &addr, boost::uint16_t port)
+        : _detected(false), _bthread(), _timeout_cnt(0)
+    {
+        boost::unique_lock<boost::shared_mutex> l(_d_mutex);
+
+        if (gps_open(addr.c_str(),
+            str(boost::format("%u") % port).c_str(),
+            &_gps_data) < 0) {
+            throw uhd::runtime_error(
+                str((boost::format("Failed to connect to gpsd: %s")
+                    % gps_errstr(errno))));
+        }
+
+        // register for updates, we don't specify a specific device,
+        // therefore no WATCH_DEVICE
+        gps_stream(&_gps_data, WATCH_ENABLE, NULL);
+
+        // create background thread talking to gpsd
+        boost::thread t(boost::bind(&gpsd_iface_impl::_thread_fcn ,this));
+        _bthread.swap(t);
+
+
+        _sensors = boost::assign::list_of("gps_locked")("gps_time")("gps_position");
+    }
+
+    virtual ~gpsd_iface_impl(void)
+    {
+        // interrupt the background thread and wait for it to finish
+        _bthread.interrupt();
+        _bthread.join();
+
+        // clean up ...
+        {
+            boost::unique_lock<boost::shared_mutex> l(_d_mutex);
+
+            gps_stream(&_gps_data, WATCH_DISABLE, NULL);
+            gps_close(&_gps_data);
+        }
+    }
+
+    uhd::sensor_value_t get_sensor(std::string key)
+    {
+        if (key == "gps_locked") {
+            return sensor_value_t(
+                "GPS lock status", _gps_locked(), "locked", "unlocked");
+        } else if (key == "gps_time") {
+            return sensor_value_t(
+                "GPS epoch time", int(_epoch_time()), "seconds");
+        } else if (key == "gps_position") {
+            return sensor_value_t(
+                "GPS Position", str(
+                    boost::format("%s %s %s")
+                    % _gps_position()["lat"]
+                    % _gps_position()["lon"]
+                    % _gps_position()["alt"]), "lat/lon/alt");
+        } else
+            throw uhd::key_error(
+                str(boost::format("sensor %s unknown.") % key));
+    }
+
+    bool gps_detected(void) { return _detected; };
+
+    std::vector<std::string> get_sensors(void) { return _sensors; };
+
+private: // member functions
+    void _thread_fcn()
+    {
+        while (not boost::this_thread::interruption_requested()) {
+            if (!gps_waiting(&_gps_data, CLICK_RATE)) {
+                if (TIMEOUT < _timeout_cnt++)
+                    _detected = false;
+            } else {
+                boost::unique_lock<boost::shared_mutex> l(_d_mutex);
+
+                _timeout_cnt = 0;
+                _detected = true;
+
+                if (gps_read(&_gps_data) < 0)
+                    throw std::runtime_error("error while reading");
+            }
+        }
+    }
+
+    bool _gps_locked(void)
+    {
+        boost::shared_lock<boost::shared_mutex> l(_d_mutex);
+        return _gps_data.fix.mode >= MODE_2D;
+    }
+
+    std::time_t _epoch_time(void)
+    {
+        boost::shared_lock<boost::shared_mutex> l(_d_mutex);
+        return (boost::posix_time::from_time_t(_gps_data.fix.time)
+            - boost::posix_time::from_time_t(0)).total_seconds();
+    }
+
+    boost::gregorian::date _gregorian_date(void)
+    {
+        boost::shared_lock<boost::shared_mutex> l(_d_mutex);
+        return boost::posix_time::from_time_t(_gps_data.fix.time).date();
+    }
+
+    uhd::dict<std::string, std::string> _gps_position(void)
+    {
+        boost::shared_lock<boost::shared_mutex> l(_d_mutex);
+
+        uhd::dict<std::string, std::string> tmp;
+        if (_gps_data.fix.mode >= MODE_2D) {
+            tmp["lon"] = str(boost::format("%f deg")
+                    % _gps_data.fix.longitude);
+            tmp["lat"] = str(boost::format("%f deg")
+                    % _gps_data.fix.latitude);
+            tmp["alt"] = str(boost::format("%fm")
+                    % _gps_data.fix.altitude);
+        } else {
+            tmp["lon"] = "n/a";
+            tmp["lat"] = "n/a";
+            tmp["alt"] = "n/a";
+        }
+        return tmp;
+    }
+
+private: // members
+    std::vector<std::string> _sensors;
+    bool                     _detected;
+
+    gps_data_t               _gps_data;
+    boost::shared_mutex      _d_mutex;
+    boost::thread            _bthread;
+    size_t                   _timeout_cnt;
+};
+
+}} //namespace
+
+using namespace uhd::usrp;
+
+gpsd_iface::sptr gpsd_iface::make(const std::string &addr, const boost::uint16_t port)
+{
+    return gpsd_iface::sptr(new gpsd_iface_impl(addr, port));
+}
diff --git a/host/lib/usrp/gpsd_iface.hpp b/host/lib/usrp/gpsd_iface.hpp
new file mode 100644
index 000000000..7d934ae5c
--- /dev/null
+++ b/host/lib/usrp/gpsd_iface.hpp
@@ -0,0 +1,36 @@
+//
+// Copyright 2015 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/>.
+//
+
+#ifndef INCLUDED_GPSD_IFACE_HPP
+#define INCLUDED_GPSD_IFACE_HPP
+
+#include <boost/cstdint.hpp>
+#include <boost/shared_ptr.hpp>
+
+#include <uhd/usrp/gps_ctrl.hpp>
+
+namespace uhd { namespace usrp {
+
+class gpsd_iface : public virtual uhd::gps_ctrl {
+public:
+    typedef boost::shared_ptr<gpsd_iface> sptr;
+    static sptr make(const std::string &addr, boost::uint16_t port);
+};
+
+}};
+
+#endif /* INCLUDED_GPSD_IFACE_HPP */