rfnoc: add rx and tx transports, and amend rfnoc_graph

transports:

Transports build on I/O service and implements flow control and
sequence number checking.

The rx streamer subclass extends the streamer implementation to connect
it to the rfnoc graph. It receives configuration values from property
propagation and configures the streamer accordingly. It also implements
the issue_stream_cmd rx_streamer API method.

Add implementation of rx streamer creation and method to connect it to
an rfnoc block.

rfnoc_graph: Cache more connection info, clarify contract

Summary of changes:
- rfnoc_graph stores more information about static connections at the
  beginning. Some search algorithms are replaced by simpler lookups.
- The contract for connect() was clarified. It is required to call
  connect, even for static connections.

1 files changed, 90 insertions, 0 deletions

diff --git a/host/lib/include/uhdlib/rfnoc/rfnoc_tx_streamer.hpp b/host/lib/include/uhdlib/rfnoc/rfnoc_tx_streamer.hpp
new file mode 100644
index 000000000..4acee45cc
--- /dev/null
+++ b/host/lib/include/uhdlib/rfnoc/rfnoc_tx_streamer.hpp
@@ -0,0 +1,90 @@
+//
+// Copyright 2019 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_LIBUHD_RFNOC_TX_STREAMER_HPP
+#define INCLUDED_LIBUHD_RFNOC_TX_STREAMER_HPP
+
+#include <uhd/rfnoc/node.hpp>
+#include <uhdlib/rfnoc/chdr_tx_data_xport.hpp>
+#include <uhdlib/transport/tx_streamer_impl.hpp>
+#include <string>
+
+namespace uhd { namespace rfnoc {
+
+/*!
+ *  Extends the streamer_impl to be an rfnoc node so it can connect to the
+ *  graph. Configures the streamer conversion and rate parameters with values
+ *  received through property propagation.
+ */
+class rfnoc_tx_streamer : public node_t,
+                          public transport::tx_streamer_impl<chdr_tx_data_xport>
+{
+public:
+    /*! Constructor
+     *
+     * \param num_ports The number of ports
+     * \param stream_args Arguments to aid the construction of the streamer
+     */
+    rfnoc_tx_streamer(const size_t num_chans, const uhd::stream_args_t stream_args);
+
+    /*! Returns a unique identifier string for this node. In every RFNoC graph,
+     * no two nodes cannot have the same ID. Returns a string in the form of
+     * "TxStreamer#0".
+     *
+     * \returns The unique ID as a string
+     */
+    std::string get_unique_id() const;
+
+    /*! Returns the number of input ports for this block.
+     *
+     * Always returns 0 for this block.
+     *
+     * \return noc_id The number of ports
+     */
+    size_t get_num_input_ports() const;
+
+    /*! Returns the number of output ports for this block.
+     *
+     * \return noc_id The number of ports
+     */
+    size_t get_num_output_ports() const;
+
+    /*! Returns stream args provided at creation
+     *
+     * \return stream args provided when streamer is created
+     */
+    const uhd::stream_args_t& get_stream_args() const;
+
+    /*! Check that all streamer ports are connected to blocks
+     *
+     * Overrides node_t to ensure there are no unconnected ports.
+     *
+     * \param connected_inputs A list of input ports that are connected
+     * \param connected_outputs A list of output ports that are connected
+     * \returns true if the block can deal with this configuration
+     */
+    bool check_topology(const std::vector<size_t>& connected_inputs,
+        const std::vector<size_t>& connected_outputs);
+
+private:
+    void _register_props(const size_t chan, const std::string& otw_format);
+
+    // Properties
+    std::vector<property_t<double>> _scaling_out;
+    std::vector<property_t<double>> _samp_rate_out;
+    std::vector<property_t<double>> _tick_rate_out;
+    std::vector<property_t<std::string>> _type_out;
+
+    // Streamer unique ID
+    const std::string _unique_id;
+
+    // Stream args provided at construction
+    const uhd::stream_args_t _stream_args;
+};
+
+}} // namespace uhd::rfnoc
+
+#endif /* INCLUDED_LIBUHD_RFNOC_TX_STREAMER_HPP */