csr-test: add simple program to test CSRs

Signed-off-by: Sean Cross <sean@xobs.io>

csr-test.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+# This variable defines all the external programs that this module
+# relies on.  lxbuildenv reads this variable in order to ensure
+# the build will finish without exiting due to missing third-party
+# programs.
+LX_DEPENDENCIES = ["riscv", "icestorm", "yosys"]
+
+# Import lxbuildenv to integrate the deps/ directory
+import lxbuildenv
+
+# Disable pylint's E1101, which breaks completely on migen
+#pylint:disable=E1101
+
+from migen import Module, Signal, Instance, ClockDomain, If, run_simulation
+from migen.genlib.resetsync import AsyncResetSynchronizer
+from litex.build.lattice.platform import LatticePlatform
+from litex.build.generic_platform import Pins, IOStandard, Misc, Subsignal
+from litex.soc.integration import SoCCore
+from litex.soc.integration.builder import Builder
+from litex.soc.integration.soc_core import csr_map_update
+from litex.soc.interconnect import wishbone
+from litex.soc.interconnect.csr import CSR, CSRStorage, AutoCSR
+
+def csr_test(dut):
+    for i in range(20):
+        counter = yield dut.counter
+        # test_value = yield dut.test_value.w
+        (test_value) = yield from dut.test_value.read()
+        print("CSR value: {} / {}".format(counter, test_value))
+        # yield from CSRStorage.update_csrs()
+        yield
+
+class TestCSR(Module, AutoCSR):
+    def __init__(self):
+        # self.counter = Signal(8)
+        # self.test_value = CSR(8)
+        # self.result = Signal(8)
+        # self.read_result = Signal()
+        # self.sync += [
+        #     self.counter.eq(self.counter+1),
+        #     self.test_value.w.eq(self.counter),
+        #     self.result.eq(self.test_value.r),
+        #     self.read_result.eq(self.test_value.re),
+        # ]
+        self.counter = Signal(8)
+        self.test_value = CSRStorage(8, write_from_dev=True)
+        self.result = Signal(8)
+        self.result_re = Signal()
+        self.sync += [
+            self.counter.eq(self.counter+1),
+            self.test_value.we.eq(1),
+            self.test_value.dat_w.eq(self.counter),
+            self.result.eq(self.test_value.storage),
+            self.result_re.eq(self.test_value.re),
+        ]
+
+def main():
+    dut = TestCSR()
+    for x in dir(dut):
+        print("x: {}".format(x))
+    for csr in dut.get_csrs():
+        print("csr: {}".format(csr))
+        if isinstance(csr, CSRStorage) and hasattr(csr, "dat_w"):
+            print("Adding CSRStorage patch")
+            dut.sync += [
+                If(csr.we,
+                    csr.storage.eq(csr.dat_w),
+                    csr.re.eq(1),
+                ).Else(
+                    csr.re.eq(0),
+                )
+            ]
+    run_simulation(dut, csr_test(dut), vcd_name="csr-test.vcd")
+
+if __name__ == "__main__":
+    main()