frontend: avoid breaking api with last rbank change (use bankbits_max), some cleanup

litedram/common.py

@@ -1,6 +1,10 @@
 from migen import *
 from litex.soc.interconnect import stream
 
+
+bankbits_max = 3
+
+
 class PhySettings:
     def __init__(self, memtype, dfi_databits,
                  nphases,
@@ -56,12 +60,12 @@ def cmd_layout(aw):
     ]
 
 
-def data_layout(dw, bankbits):
+def data_layout(dw):
     return [
-        ("wdata",       dw, DIR_M_TO_S),
-        ("wdata_we", dw//8, DIR_M_TO_S),
-        ("rdata",       dw, DIR_S_TO_M),
-        ("rbank",   bankbits, DIR_S_TO_M)
+        ("wdata",           dw, DIR_M_TO_S),
+        ("wdata_we",     dw//8, DIR_M_TO_S),
+        ("rdata",           dw, DIR_S_TO_M),
+        ("rbank", bankbits_max, DIR_S_TO_M)
     ]
 
 
@@ -73,7 +77,7 @@ class LiteDRAMInterface(Record):
         self.settings = settings
 
         layout = [("bank"+str(i), cmd_layout(self.aw)) for i in range(self.nbanks)]
-        layout += data_layout(self.dw, settings.geom.bankbits)
+        layout += data_layout(self.dw)
         Record.__init__(self, layout)
 
 def cmd_description(aw):
@@ -88,12 +92,12 @@ def wdata_description(dw):
         ("we",   dw//8)
     ]
 
-def rdata_description(dw, nbanks):
-    return [("data", dw), ("bank", nbanks)]
+def rdata_description(dw):
+    return [("data", dw), ("bank", bankbits_max)]
 
 
 class LiteDRAMPort:
-    def __init__(self, mode, aw, dw, bankbits, cd="sys", id=0):
+    def __init__(self, mode, aw, dw, cd="sys", id=0):
         self.mode = mode
         self.aw = aw
         self.dw = dw
@@ -104,7 +108,7 @@ class LiteDRAMPort:
 
         self.cmd = stream.Endpoint(cmd_description(aw))
         self.wdata = stream.Endpoint(wdata_description(dw))
-        self.rdata = stream.Endpoint(rdata_description(dw, bankbits))
+        self.rdata = stream.Endpoint(rdata_description(dw))
 
         self.flush = Signal()
 

litedram/frontend/crossbar.py

@@ -33,12 +33,12 @@ class LiteDRAMCrossbar(Module):
             dw = self.dw
 
         # crossbar port
-        port = LiteDRAMPort(mode, self.rca_bits + self.bank_bits, self.dw, self.bank_bits, "sys", len(self.masters))
+        port = LiteDRAMPort(mode, self.rca_bits + self.bank_bits, self.dw, "sys", len(self.masters))
         self.masters.append(port)
 
         # clock domain crossing
         if cd != "sys":
-            new_port = LiteDRAMPort(mode, port.aw, port.dw, self.bank_bits, cd, port.id)
+            new_port = LiteDRAMPort(mode, port.aw, port.dw, cd, port.id)
             self.submodules += LiteDRAMPortCDC(new_port, port)
             port = new_port
 
@@ -48,7 +48,7 @@ class LiteDRAMCrossbar(Module):
                 adr_shift = -log2_int(dw//self.dw)
             else:
                 adr_shift = log2_int(self.dw//dw)
-            new_port = LiteDRAMPort(mode, port.aw + adr_shift, dw, self.bank_bits, cd, port.id)
+            new_port = LiteDRAMPort(mode, port.aw + adr_shift, dw, cd, port.id)
             self.submodules += ClockDomainsRenamer(cd)(LiteDRAMPortConverter(new_port, port, reverse))
             port = new_port
 
@@ -68,7 +68,7 @@ class LiteDRAMCrossbar(Module):
 
         arbiters = [roundrobin.RoundRobin(nmasters, roundrobin.SP_CE) for n in range(self.nbanks)]
         self.submodules += arbiters
-        
+
         rbank = Signal(max=self.nbanks)
         for nb, arbiter in enumerate(arbiters):
             bank = getattr(controller, "bank"+str(nb))
@@ -92,10 +92,7 @@ class LiteDRAMCrossbar(Module):
             ]
 
             # Get rdata source bank
-            self.sync += \
-                If((arbiter.grant == nm) & bank.rdata_valid,
-                    rbank.eq(nb)
-                )
+            self.sync += If((arbiter.grant == nm) & bank.rdata_valid, rbank.eq(nb))
 
             # route requests
             self.comb += [