From 461b076624ae497d49f4498922f3bdcd7e80995c Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Sun, 16 Sep 2018 00:39:33 +0200
Subject: [PATCH] frontend/ecc: add ecc adapter

---
 litedram/frontend/ecc.py | 55 ++++++++++++++++++++++++++++++++++++++++
 test/test_ecc.py         | 12 +++++++++
 2 files changed, 67 insertions(+)

diff --git a/litedram/frontend/ecc.py b/litedram/frontend/ecc.py
index 4c098be..5ca9773 100644
--- a/litedram/frontend/ecc.py
+++ b/litedram/frontend/ecc.py
@@ -140,3 +140,58 @@ class ECCDecoder(SECDEC, Module):
                 )
             )
         ]
+
+
+class LiteDRAMNativePortECC(Module):
+    def __init__(self, port_from, port_to):
+        _ , n = compute_m_n(port_from.data_width//8)
+        assert port_to.data_width >= n + 1
+
+        self.clear_errors = clear_errors = Signal()
+        self.sec_errors = sec_errors = Signal(32)
+        self.dec_errors = dec_errors = Signal(32)
+
+        # # #
+
+        # cmd
+        self.comb += port_from.cmd.connect(port_to.cmd)
+
+        # wdata (ecc encoding)
+        for i in range(8):
+            encoder = ECCEncoder(port_from.data_width//8)
+            self.submodules += encoder
+            self.comb += [
+                port_from.wdata.connect(port_to.wdata, omit={"data", "we"}),
+                encoder.i.eq(port_from.wdata.data[i*port_from.data_width//8:(i+1)*port_from.data_width//8]),
+                port_to.wdata.data[i*port_to.data_width//8:(i+1)*port_to.data_width//8].eq(encoder.o)
+            ]
+        self.comb += port_to.wdata.we.eq(2**len(port_to.wdata.we)-1) # FIXME: how to handle we?
+
+        # rdata (ecc decoding)
+        sec = Signal(8)
+        dec = Signal(8)
+        for i in range(8):
+            decoder = ECCDecoder(port_from.data_width//8)
+            self.submodules += decoder
+            self.comb += [
+                port_to.rdata.connect(port_from.rdata, omit={"data", "we"}),
+                decoder.i.eq(port_to.rdata.data[i*port_to.data_width//8:(i+1)*port_to.data_width//8]),
+                port_from.rdata.data[i*port_from.data_width//8:(i+1)*port_from.data_width//8].eq(decoder.o),
+                sec[i].eq(decoder.sec),
+                dec[i].eq(decoder.dec)
+            ]
+
+        # errors count
+        self.sync += [
+            If(clear_errors,
+                sec_errors.eq(0),
+                dec_errors.eq(0)
+            ).Else(
+                If(sec_errors != (2**len(sec_errors) - 1),
+                    If(sec != 0, sec_errors.eq(sec_errors + 1))
+                ),
+                If(dec_errors != (2**len(dec_errors) - 1),
+                    If(dec != 0, dec_errors.eq(dec_errors + 1))
+                )
+            )
+        ]
diff --git a/test/test_ecc.py b/test/test_ecc.py
index c3aa62c..c560917 100644
--- a/test/test_ecc.py
+++ b/test/test_ecc.py
@@ -3,6 +3,7 @@ import random
 
 from migen import *
 
+from litedram.common import *
 from litedram.frontend.ecc import *
 
 from litex.gen.sim import *
@@ -93,3 +94,14 @@ class TestECC(unittest.TestCase):
             dut = DUT(k)
             run_simulation(dut, generator(dut, k, 128, i))
             self.assertEqual(dut.errors, 0)
+
+    def test_ecc_wrapper(self):
+        # 32 bits + 8 bits ecc
+        port_from = LiteDRAMNativePort("both", 24, 32*8)
+        port_to = LiteDRAMNativePort("both", 24, 40*8)
+        ecc = LiteDRAMNativePortECC(port_from, port_to)
+
+        # 64 bits + 8 bits ecc
+        port_from = LiteDRAMNativePort("both", 24, 64*8)
+        port_to = LiteDRAMNativePort("both", 24, 72*8)
+        ecc = LiteDRAMNativePortECC(port_from, port_to)