2 files changed, 102 insertions, 0 deletions
diff --git a/host/lib/rfnoc/CMakeLists.txt b/host/lib/rfnoc/CMakeLists.txt
index ea774b2c8..4edfe4009 100644
--- a/host/lib/rfnoc/CMakeLists.txt
+++ b/host/lib/rfnoc/CMakeLists.txt
@@ -45,6 +45,7 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/duc_block_control.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/dmafifo_block_control.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/fft_block_control.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/fir_filter_block_control.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/null_block_control.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/radio_control_impl.cpp
 )
diff --git a/host/lib/rfnoc/fir_filter_block_control.cpp b/host/lib/rfnoc/fir_filter_block_control.cpp
new file mode 100644
index 000000000..38a0e4b9c
--- /dev/null
+++ b/host/lib/rfnoc/fir_filter_block_control.cpp
@@ -0,0 +1,101 @@
+//
+// Copyright 2020 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <uhd/exception.hpp>
+#include <uhd/rfnoc/defaults.hpp>
+#include <uhd/rfnoc/fir_filter_block_control.hpp>
+#include <uhd/rfnoc/property.hpp>
+#include <uhd/rfnoc/registry.hpp>
+
+using namespace uhd::rfnoc;
+
+const uint32_t fir_filter_block_control::REG_FIR_MAX_NUM_COEFFS_ADDR  = 0;
+const uint32_t fir_filter_block_control::REG_FIR_LOAD_COEFF_ADDR      = 4;
+const uint32_t fir_filter_block_control::REG_FIR_LOAD_COEFF_LAST_ADDR = 8;
+
+class fir_filter_block_control_impl : public fir_filter_block_control
+{
+public:
+    RFNOC_BLOCK_CONSTRUCTOR(fir_filter_block_control)
+    , _max_num_coeffs(this->regs().peek32(REG_FIR_MAX_NUM_COEFFS_ADDR)),
+        _coeffs(_max_num_coeffs, int16_t(0))
+    {
+        // register edge properties
+        register_property(&_prop_type_in);
+        register_property(&_prop_type_out);
+
+        // add resolvers for type (keeps it constant)
+        add_property_resolver({&_prop_type_in}, {&_prop_type_in}, [this]() {
+            _prop_type_in.set(IO_TYPE_SC16);
+        });
+        add_property_resolver({&_prop_type_out}, {&_prop_type_out}, [this]() {
+            _prop_type_out.set(IO_TYPE_SC16);
+        });
+
+        // initialize hardware with an impulse response
+        _coeffs[0] = std::numeric_limits<int16_t>::max();
+        _program_coefficients();
+    }
+
+    size_t get_max_num_coefficients() const
+    {
+        return _max_num_coeffs;
+    }
+
+    void set_coefficients(const std::vector<int16_t>& coeffs)
+    {
+        if (coeffs.size() > _max_num_coeffs) {
+            std::string error_msg =
+                "Too many filter coefficients specified (max " +
+                std::to_string(_max_num_coeffs) + ")";
+            throw uhd::value_error(error_msg);
+        }
+
+        // save the new coefficients...
+        _coeffs = coeffs;
+        // ...and expand it to the number supported by the hardware,
+        // padding with zeroes
+        _coeffs.resize(_max_num_coeffs, 0);
+        _program_coefficients();
+    }
+
+    std::vector<int16_t> get_coefficients() const
+    {
+        return _coeffs;
+    }
+
+private:
+    void _program_coefficients()
+    {
+        // Write coefficients [0..num_coeffs-2]..
+        std::vector<uint32_t> coeffs_addr(_max_num_coeffs - 1, REG_FIR_LOAD_COEFF_ADDR);
+        std::vector<uint32_t> coeffs_minus_last(_max_num_coeffs - 1);
+        std::transform(_coeffs.begin(), _coeffs.end() - 1, coeffs_minus_last.begin(),
+                [this](int16_t value) -> uint32_t { return static_cast<uint32_t>(value); });
+
+        this->regs().multi_poke32(coeffs_addr, coeffs_minus_last);
+        // ...and the final coefficients (num_coeffs-1)
+        this->regs().poke32(
+            REG_FIR_LOAD_COEFF_LAST_ADDR, _coeffs.at(_max_num_coeffs - 1));
+    }
+
+    //! Number of coefficients supported by the FIR filter
+    const size_t _max_num_coeffs;
+
+    //! Current FIR filter coefficients
+    std::vector<int16_t> _coeffs;
+
+    /**************************************************************************
+     * Attributes
+     *************************************************************************/
+    property_t<std::string> _prop_type_in = property_t<std::string>{
+        PROP_KEY_TYPE, IO_TYPE_SC16, {res_source_info::INPUT_EDGE}};
+    property_t<std::string> _prop_type_out = property_t<std::string>{
+        PROP_KEY_TYPE, IO_TYPE_SC16, {res_source_info::OUTPUT_EDGE}};
+};
+
+UHD_RFNOC_BLOCK_REGISTER_DIRECT(
+    fir_filter_block_control, FIR_FILTER_BLOCK, "FIR", CLOCK_KEY_GRAPH, "bus_clk")