eth: Add APB register interface to US/US+ transceiver wrappers

Signed-off-by: Alex Forencich <alex@alexforencich.com>

src/eth/tb/taxi_eth_mac_25g_us/test_taxi_eth_mac_25g_us.py

@@ -28,6 +28,7 @@ from cocotb.regression import TestFactory
 
 from cocotbext.eth import XgmiiFrame, PtpClockSimTime
 from cocotbext.axi import AxiStreamBus, AxiStreamSource, AxiStreamSink, AxiStreamFrame
+from cocotbext.axi import ApbBus, ApbMaster
 
 try:
     from baser import BaseRSerdesSource, BaseRSerdesSink
@@ -51,6 +52,8 @@ class TB:
         cocotb.start_soon(Clock(dut.stat_clk, 8, units="ns").start())
         cocotb.start_soon(Clock(dut.xcvr_gtrefclk00_in, 6.206, units="ns").start())
 
+        self.apb_ctrl = ApbMaster(ApbBus.from_entity(dut.s_apb_ctrl), dut.xcvr_ctrl_clk, dut.xcvr_ctrl_rst)
+
         self.serdes_sources = []
         self.serdes_sinks = []
 
@@ -179,6 +182,24 @@ class TB:
         await RisingEdge(self.dut.xcvr_ctrl_clk)
 
 
+async def run_test_regs(dut):
+    tb = TB(dut)
+    await tb.reset()
+
+    data = await tb.apb_ctrl.read(0x00000, 2)
+    data = await tb.apb_ctrl.read(0x04000, 2)
+    data = await tb.apb_ctrl.read(0x08000, 2)
+    data = await tb.apb_ctrl.read(0x0C000, 2)
+
+    data = await tb.apb_ctrl.read(0x10000, 2)
+    data = await tb.apb_ctrl.read(0x14000, 2)
+    data = await tb.apb_ctrl.read(0x18000, 2)
+    data = await tb.apb_ctrl.read(0x1C000, 2)
+
+    for k in range(10):
+        await RisingEdge(dut.xcvr_ctrl_clk)
+
+
 async def run_test_rx(dut, port=0, payload_lengths=None, payload_data=None, ifg=12):
 
     if dut.DATA_W.value == 64:
@@ -915,6 +936,9 @@ def cycle_en():
 
 if getattr(cocotb, 'top', None) is not None:
 
+    factory = TestFactory(run_test_regs)
+    factory.generate_tests()
+
     for test in [run_test_rx, run_test_tx]:
 
         factory = TestFactory(test)

src/eth/tb/taxi_eth_mac_25g_us/test_taxi_eth_mac_25g_us.sv

@@ -75,6 +75,12 @@ localparam RX_USER_W = (PTP_TS_EN ? PTP_TS_W : 0) + 1;
 logic xcvr_ctrl_clk;
 logic xcvr_ctrl_rst;
 
+// transceiver control
+taxi_apb_if #(
+    .ADDR_W(24),
+    .DATA_W(16)
+) s_apb_ctrl();
+
 logic xcvr_gtpowergood_out;
 logic xcvr_gtrefclk00_in;
 logic xcvr_qpll0pd_in;
@@ -276,6 +282,11 @@ uut (
     .xcvr_ctrl_clk(xcvr_ctrl_clk),
     .xcvr_ctrl_rst(xcvr_ctrl_rst),
 
+    /*
+     * Transceiver control
+     */
+    .s_apb_ctrl(s_apb_ctrl),
+
     /*
      * Common
      */