litex/migen/bank/description.py

140 lines
4.3 KiB
Python

from migen.util.misc import xdir
from migen.fhdl.std import *
from migen.fhdl.tracer import get_obj_var_name
class _CSRBase(HUID):
def __init__(self, size, name):
HUID.__init__(self)
self.name = get_obj_var_name(name)
if self.name is None:
raise ValueError("Cannot extract CSR name from code, need to specify.")
if len(self.name) > 2 and self.name[:2] == "r_":
self.name = self.name[2:]
self.size = size
class CSR(_CSRBase):
def __init__(self, size=1, name=None):
_CSRBase.__init__(self, size, name)
self.re = Signal(name=self.name + "_re")
self.r = Signal(self.size, name=self.name + "_r")
self.w = Signal(self.size, name=self.name + "_w")
class _CompoundCSR(_CSRBase, Module):
def __init__(self, size, name):
_CSRBase.__init__(self, size, name)
self.simple_csrs = []
def get_simple_csrs(self):
if not self.finalized:
raise FinalizeError
return self.simple_csrs
def do_finalize(self, busword):
raise NotImplementedError
class CSRStatus(_CompoundCSR):
def __init__(self, size=1, name=None):
_CompoundCSR.__init__(self, size, name)
self.status = Signal(self.size)
def do_finalize(self, busword):
nwords = (self.size + busword - 1)//busword
for i in reversed(range(nwords)):
nbits = min(self.size - i*busword, busword)
sc = CSR(nbits, self.name + str(i) if nwords > 1 else self.name)
self.comb += sc.w.eq(self.status[i*busword:i*busword+nbits])
self.simple_csrs.append(sc)
class CSRStorage(_CompoundCSR):
def __init__(self, size=1, reset=0, atomic_write=False, write_from_dev=False, alignment_bits=0, name=None):
_CompoundCSR.__init__(self, size, name)
self.alignment_bits = alignment_bits
self.storage_full = Signal(self.size, reset=reset)
self.storage = Signal(self.size - self.alignment_bits, reset=reset >> alignment_bits)
self.comb += self.storage.eq(self.storage_full[self.alignment_bits:])
self.atomic_write = atomic_write
if write_from_dev:
self.we = Signal()
self.dat_w = Signal(self.size - self.alignment_bits)
self.sync += If(self.we, self.storage_full.eq(self.dat_w << self.alignment_bits))
def do_finalize(self, busword):
nwords = (self.size + busword - 1)//busword
if nwords > 1 and self.atomic_write:
backstore = Signal(self.size - busword, name=self.name + "_backstore")
for i in reversed(range(nwords)):
nbits = min(self.size - i*busword, busword)
sc = CSR(nbits, self.name + str(i) if nwords else self.name)
self.simple_csrs.append(sc)
lo = i*busword
hi = lo+nbits
# read
if lo >= self.alignment_bits:
self.comb += sc.w.eq(self.storage_full[lo:hi])
elif hi > self.alignment_bits:
self.comb += sc.w.eq(Cat(Replicate(0, hi - self.alignment_bits),
self.storage_full[self.alignment_bits:hi]))
else:
self.comb += sc.w.eq(0)
# write
if nwords > 1 and self.atomic_write:
if i:
self.sync += If(sc.re, backstore[lo-busword:hi-busword].eq(sc.r))
else:
self.sync += If(sc.re, self.storage_full.eq(Cat(sc.r, backstore)))
else:
self.sync += If(sc.re, self.storage_full[lo:hi].eq(sc.r))
def csrprefix(prefix, csrs, done):
for csr in csrs:
if csr.huid not in done:
csr.name = prefix + csr.name
done.add(csr.huid)
def memprefix(prefix, memories, done):
for memory in memories:
if memory.huid not in done:
memory.name_override = prefix + memory.name_override
done.add(memory.huid)
class AutoCSR:
def get_memories(self):
try:
exclude = self.autocsr_exclude
except AttributeError:
exclude = {}
try:
prefixed = self.__prefixed
except AttributeError:
prefixed = self.__prefixed = set()
r = []
for k, v in xdir(self, True):
if k not in exclude:
if isinstance(v, Memory):
r.append(v)
elif hasattr(v, "get_memories") and callable(v.get_memories):
memories = v.get_memories()
memprefix(k + "_", memories, prefixed)
r += memories
return sorted(r, key=lambda x: x.huid)
def get_csrs(self):
try:
exclude = self.autocsr_exclude
except AttributeError:
exclude = {}
try:
prefixed = self.__prefixed
except AttributeError:
prefixed = self.__prefixed = set()
r = []
for k, v in xdir(self, True):
if k not in exclude:
if isinstance(v, _CSRBase):
r.append(v)
elif hasattr(v, "get_csrs") and callable(v.get_csrs):
csrs = v.get_csrs()
csrprefix(k + "_", csrs, prefixed)
r += csrs
return sorted(r, key=lambda x: x.huid)