rfnoc: Augment FFT RFNoC block controller

This commit augments the existing FFT RFNoC block controller with
C++ functions through which the block can be configured, as well as
adding range checking to the various properties that sit atop the FFT
RFNoC block registers.

2 files changed, 130 insertions, 26 deletions

diff --git a/host/include/uhd/rfnoc/defaults.hpp b/host/include/uhd/rfnoc/defaults.hpp
index e44e3fa49..e8f1c11e7 100644
--- a/host/include/uhd/rfnoc/defaults.hpp
+++ b/host/include/uhd/rfnoc/defaults.hpp
@@ -72,13 +72,14 @@ static const device_type_t N320 = 0x1320;
 static const device_type_t X300 = 0xA300;
 
 // block identifiers
-static const noc_id_t ADDSUB_BLOCK     = 0xADD00000;
-static const noc_id_t DUC_BLOCK        = 0xD0C00000;
-static const noc_id_t DDC_BLOCK        = 0xDDC00000;
-static const noc_id_t FIR_FILTER_BLOCK = 0xf1120000;
-static const noc_id_t FOSPHOR_BLOCK    = 0x666F0000;
+static const noc_id_t ADDSUB_BLOCK       = 0xADD00000;
+static const noc_id_t DUC_BLOCK          = 0xD0C00000;
+static const noc_id_t DDC_BLOCK          = 0xDDC00000;
+static const noc_id_t FFT_BLOCK          = 0xFF700000;
+static const noc_id_t FIR_FILTER_BLOCK   = 0xF1120000;
+static const noc_id_t FOSPHOR_BLOCK      = 0x666F0000;
 static const noc_id_t SPLIT_STREAM_BLOCK = 0x57570000;
-static const noc_id_t RADIO_BLOCK      = 0x12AD1000;
-static const noc_id_t VECTOR_IIR_BLOCK = 0x11120000;
+static const noc_id_t RADIO_BLOCK        = 0x12AD1000;
+static const noc_id_t VECTOR_IIR_BLOCK   = 0x11120000;
 
 }} // namespace uhd::rfnoc
diff --git a/host/include/uhd/rfnoc/fft_block_control.hpp b/host/include/uhd/rfnoc/fft_block_control.hpp
index d4278b840..38ad70561 100644
--- a/host/include/uhd/rfnoc/fft_block_control.hpp
+++ b/host/include/uhd/rfnoc/fft_block_control.hpp
@@ -16,33 +16,136 @@ enum class fft_direction { REVERSE, FORWARD };
 enum class fft_magnitude { COMPLEX, MAGNITUDE, MAGNITUDE_SQUARED };
 
 // Custom property keys
-static const std::string PROP_KEY_MAGNITUDE   = "magnitude";
-static const std::string PROP_KEY_DIRECTION   = "direction";
-static const std::string PROP_KEY_FFT_LEN     = "fft_len";
-static const std::string PROP_KEY_FFT_SCALING = "fft_scaling";
-static const std::string PROP_KEY_FFT_SHIFT   = "fft_shift";
+static const std::string PROP_KEY_MAGNITUDE    = "magnitude";
+static const std::string PROP_KEY_DIRECTION    = "direction";
+static const std::string PROP_KEY_LENGTH       = "length";
+static const std::string PROP_KEY_FFT_SCALING  = "fft_scaling";
+static const std::string PROP_KEY_SHIFT_CONFIG = "shift_config";
 
 /*! FFT Block Control Class
+ *
+ * The FFT block is an RFNoC block that accepts signed complex 16-bit data
+ * at its input and computes the forward or reverse FFT of the input data,
+ * outputting signed complex 16-bit data at its output. The output data
+ * may be configured as complex, magnitude, or mag-squared values, its
+ * spectrum shifted and/or reversed, and scaled by a scaled factor.
+ *
+ * The FFT length is configured via the length parameter, up to a maximum
+ * of 2048 samples. The FFT IP requires a power-of-two number of samples;
+ * the length will be coerced to the closest power of two which is smaller
+ * than length. The block will output packets of the same length in the
+ * desired format as configured via the API.
  */
 class UHD_API fft_block_control : public noc_block_base
 {
 public:
     RFNOC_DECLARE_BLOCK(fft_block_control)
 
-    // Readback addresses
-    static const uint32_t RB_FFT_RESET;
-    static const uint32_t RB_MAGNITUDE_OUT;
-    static const uint32_t RB_FFT_SIZE_LOG2;
-    static const uint32_t RB_FFT_DIRECTION;
-    static const uint32_t RB_FFT_SCALING;
-    static const uint32_t RB_FFT_SHIFT_CONFIG;
-    // Write addresses
-    static const uint32_t SR_FFT_RESET;
-    static const uint32_t SR_FFT_SIZE_LOG2;
-    static const uint32_t SR_MAGNITUDE_OUT;
-    static const uint32_t SR_FFT_DIRECTION;
-    static const uint32_t SR_FFT_SCALING;
-    static const uint32_t SR_FFT_SHIFT_CONFIG;
+    static const uint32_t REG_RESET_ADDR;
+    static const uint32_t REG_LENGTH_LOG2_ADDR;
+    static const uint32_t REG_MAGNITUDE_OUT_ADDR;
+    static const uint32_t REG_DIRECTION_ADDR;
+    static const uint32_t REG_SCALING_ADDR;
+    static const uint32_t REG_SHIFT_CONFIG_ADDR;
+
+    /*! Set the FFT direction
+     *
+     * Sets the direction of the FFT, either forward (FORWARD) or inverse
+     * (REVERSE).
+     *
+     * \param direction FFT direction
+     */
+    virtual void set_direction(const fft_direction direction) = 0;
+
+    /*! Get the FFT direction
+     *
+     * Returns the current direction of the FFT.
+     *
+     * \returns FFT direction
+     */
+    virtual fft_direction get_direction() const = 0;
+
+    /*! Set the format of the returned FFT output data
+     *
+     * Sets the format in which the FFT output data is returned. The following
+     * formats are supported:
+     *
+     *     * amplitude/phase data (COMPLEX)
+     *     * magnitude data (MAGNITUDE)
+     *     * mag-squared data (MAGNITUDE_SQUARED)
+     *
+     * \param magnitude Format of the returned FFT output data
+     */
+    virtual void set_magnitude(const fft_magnitude magnitude) = 0;
+
+    /*! Get the format of the returned FFT output data
+     *
+     * Returns the current output format of the FFT data.
+     *
+     * \returns Format of the returned FFT output data
+     */
+    virtual fft_magnitude get_magnitude() const = 0;
+
+    /*! Set the shift configuration of the output FFT data
+     *
+     * Sets how the FFT output data is shifted (to get the zero frequency bin
+     * to the center of the output data). The following output data shift
+     * configurations are supported:
+     *
+     *     * Negative frequencies first, then positive frequencies (NORMAL)
+     *     * Positive frequencies first, then negative frequencies (REVERSE)
+     *     * Bypass the shift altogether, leaving the zero frequency bin
+     *       returned first (NATURAL).
+     *
+     * \param shift Configuration for shifting FFT output data
+     */
+    virtual void set_shift_config(const fft_shift shift) = 0;
+
+    /*! Get the shift configuration of the output FFT data
+     *
+     * Returns the current shift configuration of the output FFT data.
+     *
+     * \returns Shift configuration of the output FFT data
+     */
+    virtual fft_shift get_shift_config() const = 0;
+
+    /*! Set the scaling schedule for the FFT block
+     *
+     * Sets the scaling for each stage of the FFT. This value maps directly
+     * to the scale schedule field in the configuration channel data that is
+     * passed to the Xilinx AXI FFT IP. For more information on the format
+     * of this data, see Xilinx document PG109, Fast Fourier Transform
+     * LogiCORE IP Product Guide.
+     *
+     * \param scaling Scaling schedule for the FFT block
+     */
+    virtual void set_scaling(const uint16_t scaling) = 0;
+
+    /*! Get the scaling schedule for the FFT block
+     *
+     * Returns the current scaling schedule for the FFT block.
+     *
+     * \returns Scaling schedule for the FFT block
+     */
+    virtual uint16_t get_scaling() const = 0;
+
+    /*! Set the length of the FFT
+     *
+     * Sets the length of the FFT in number of samples. Note that the FFT
+     * IP requires a power-of-two number of samples; the incoming value will
+     * be coerced to the closest smaller power of two.
+     *
+     * \param length Desired FFT length
+     */
+    virtual void set_length(const size_t length) = 0;
+
+    /*! Get the length of the FFT
+     *
+     * Returns the current length of the FFT.
+     *
+     * \returns Current FFT length
+     */
+    virtual size_t get_length() const = 0;
 };
 
 }} // namespace uhd::rfnoc