fifo ctrl: use regular iface for U2_REG_MISC_CTRL_CLOCK

2 files changed, 136 insertions, 6 deletions

diff --git a/host/examples/test_timed_commands.cpp b/host/examples/test_timed_commands.cpp
new file mode 100644
index 000000000..34c83dfd6
--- /dev/null
+++ b/host/examples/test_timed_commands.cpp
@@ -0,0 +1,129 @@
+//
+// Copyright 2012 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 <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/safe_main.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
+#include <boost/program_options.hpp>
+#include <boost/format.hpp>
+#include <iostream>
+#include <complex>
+
+namespace po = boost::program_options;
+
+int UHD_SAFE_MAIN(int argc, char *argv[]){
+    uhd::set_thread_priority_safe();
+
+    //variables to be set by po
+    std::string args;
+
+    //setup the program options
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+    ;
+    po::variables_map vm;
+    po::store(po::parse_command_line(argc, argv, desc), vm);
+    po::notify(vm);
+
+    //print the help message
+    if (vm.count("help")){
+        std::cout << boost::format("UHD Test Timed Commands %s") % desc << std::endl;
+        return ~0;
+    }
+
+    //create a usrp device
+    std::cout << std::endl;
+    std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
+
+    //check if timed commands are supported
+    std::cout << std::endl;
+    std::cout << "Testing support for timed commands on this hardware... " << std::flush;
+    try{
+        usrp->set_command_time(uhd::time_spec_t(0.0));
+        usrp->clear_command_time();
+    }
+    catch (const std::exception &e){
+        std::cout << "fail" << std::endl;
+        std::cerr << "Got exception: " << e.what() << std::endl;
+        std::cerr << "Timed commands are not supported on this hardware." << std::endl;
+        return ~0;
+    }
+    std::cout << "pass" << std::endl;
+
+    //readback time really fast, time diff is small
+    std::cout << std::endl;
+    std::cout << "Perform fast readback of registers:" << std::endl;
+    uhd::time_spec_t total_time;
+    for (size_t i = 0; i < 100; i++){
+        const uhd::time_spec_t t0 = usrp->get_time_now();
+        const uhd::time_spec_t t1 = usrp->get_time_now();
+        total_time += (t1-t0);
+    }
+    std::cout << boost::format(
+        "Difference between paired reads: %f us"
+    ) % (total_time.get_real_secs()/100*1e6) << std::endl;
+
+    //use a timed command to start a stream at a specific time
+    //this is not the right way start streaming at time x,
+    //but it should approximate it within control RTT/2
+    //setup streaming
+    std::cout << std::endl;
+    std::cout << "About to start streaming using timed command:" << std::endl;
+    
+    //create a receive streamer
+    uhd::stream_args_t stream_args("fc32"); //complex floats
+    uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);
+    
+    uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
+    stream_cmd.num_samps = 100;
+    stream_cmd.stream_now = true;
+    const uhd::time_spec_t stream_time = usrp->get_time_now() + uhd::time_spec_t(0.1);
+    usrp->set_command_time(stream_time);
+    usrp->issue_stream_cmd(stream_cmd);
+    usrp->clear_command_time();
+
+    //meta-data will be filled in by recv()
+    uhd::rx_metadata_t md;
+
+    //allocate buffer to receive with samples
+    std::vector<std::complex<float> > buff(stream_cmd.num_samps);
+
+    const size_t num_rx_samps = rx_stream->recv(&buff.front(), buff.size(), md);
+    if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE){
+        throw std::runtime_error(str(boost::format(
+            "Unexpected error code 0x%x"
+        ) % md.error_code));
+    }
+    std::cout << boost::format(
+        "Received packet: %u samples, %u full secs, %f frac secs"
+    ) % num_rx_samps % md.time_spec.get_full_secs() % md.time_spec.get_frac_secs() << std::endl;
+    std::cout << boost::format(
+        "Stream time was: %u full secs, %f frac secs"
+    ) % stream_time.get_full_secs() % stream_time.get_frac_secs() << std::endl;
+    std::cout << boost::format(
+        "Difference between stream time and first packet: %f us"
+    ) % ((md.time_spec-stream_time).get_real_secs()/100*1e6) << std::endl;
+
+    //finished
+    std::cout << std::endl << "Done!" << std::endl << std::endl;
+
+    return 0;
+}
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index cbe64635b..ec6a82572 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -727,24 +727,25 @@ meta_range_t usrp2_impl::get_tx_dsp_freq_range(const std::string &mb){
 }
 
 void usrp2_impl::update_clock_source(const std::string &mb, const std::string &source){
+    //NOTICE: U2_REG_MISC_CTRL_CLOCK is on the wb clock, and cannot be set from fifo_ctrl
     //clock source ref 10mhz
     switch(_mbc[mb].iface->get_rev()){
     case usrp2_iface::USRP_N200:
     case usrp2_iface::USRP_N210:
     case usrp2_iface::USRP_N200_R4:
     case usrp2_iface::USRP_N210_R4:
-        if (source == "internal")       _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x12);
-        else if (source == "external")  _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x1C);
-        else if (source == "mimo")      _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x15);
+        if      (source == "internal")  _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x12);
+        else if (source == "external")  _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x1C);
+        else if (source == "mimo")      _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x15);
         else throw uhd::value_error("unhandled clock configuration reference source: " + source);
         _mbc[mb].clock->enable_external_ref(true); //USRP2P has an internal 10MHz TCXO
         break;
 
     case usrp2_iface::USRP2_REV3:
     case usrp2_iface::USRP2_REV4:
-        if (source == "internal")       _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x10);
-        else if (source == "external")  _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x1C);
-        else if (source == "mimo")      _mbc[mb].fifo_ctrl->poke32(U2_REG_MISC_CTRL_CLOCK, 0x15);
+        if      (source == "internal")  _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x10);
+        else if (source == "external")  _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x1C);
+        else if (source == "mimo")      _mbc[mb].iface->poke32(U2_REG_MISC_CTRL_CLOCK, 0x15);
         else throw uhd::value_error("unhandled clock configuration reference source: " + source);
         _mbc[mb].clock->enable_external_ref(source != "internal");
         break;