litex/milkymist/framebuffer/__init__.py

262 lines
7.5 KiB
Python

from migen.fhdl.structure import *
from migen.flow.actor import *
from migen.flow.network import *
from migen.flow import plumbing
from migen.actorlib import ala, misc, dma_asmi, structuring
from migen.bank.description import *
from migen.bank import csrgen
_hbits = 11
_vbits = 11
_bpp = 32
_bpc = 10
_pixel_layout = [
("b", BV(_bpc)),
("g", BV(_bpc)),
("r", BV(_bpc)),
("pad", BV(_bpp-3*_bpc))
]
_bpc_dac = 8
_dac_layout = [
("hsync", BV(1)),
("vsync", BV(1)),
("b", BV(_bpc_dac)),
("g", BV(_bpc_dac)),
("r", BV(_bpc_dac))
]
class _FrameInitiator(Actor):
def __init__(self, asmi_bits, length_bits, alignment_bits):
self._alignment_bits = alignment_bits
self._enable = RegisterField("enable")
self._hres = RegisterField("hres", _hbits, reset=640)
self._hsync_start = RegisterField("hsync_start", _hbits, reset=656)
self._hsync_end = RegisterField("hsync_end", _hbits, reset=752)
self._hscan = RegisterField("hscan", _hbits, reset=799)
self._vres = RegisterField("vres", _vbits, reset=480)
self._vsync_start = RegisterField("vsync_start", _vbits, reset=492)
self._vsync_end = RegisterField("vsync_end", _vbits, reset=494)
self._vscan = RegisterField("vscan", _vbits, reset=524)
self._base = RegisterField("base", asmi_bits + self._alignment_bits)
self._length = RegisterField("length", length_bits + self._alignment_bits, reset=640*480*4)
layout = [
("hres", BV(_hbits)),
("hsync_start", BV(_hbits)),
("hsync_end", BV(_hbits)),
("hscan", BV(_hbits)),
("vres", BV(_vbits)),
("vsync_start", BV(_vbits)),
("vsync_end", BV(_vbits)),
("vscan", BV(_vbits)),
("base", BV(asmi_bits)),
("length", BV(length_bits))
]
super().__init__(("frame", Source, layout))
def get_registers(self):
return [self._enable,
self._hres, self._hsync_start, self._hsync_end, self._hscan,
self._vres, self._vsync_start, self._vsync_end, self._vscan,
self._base, self._length]
def get_fragment(self):
# TODO: make address updates atomic
token = self.token("frame")
comb = [
self.busy.eq(0),
self.endpoints["frame"].stb.eq(self._enable.field.r),
token.hres.eq(self._hres.field.r),
token.hsync_start.eq(self._hsync_start.field.r),
token.hsync_end.eq(self._hsync_end.field.r),
token.hscan.eq(self._hscan.field.r),
token.vres.eq(self._vres.field.r),
token.vsync_start.eq(self._vsync_start.field.r),
token.vsync_end.eq(self._vsync_end.field.r),
token.vscan.eq(self._vscan.field.r),
token.base.eq(self._base.field.r[self._alignment_bits:]),
token.length.eq(self._length.field.r[self._alignment_bits:])
]
return Fragment(comb)
class VTG(Actor):
def __init__(self):
super().__init__(
("timing", Sink, [
("hres", BV(_hbits)),
("hsync_start", BV(_hbits)),
("hsync_end", BV(_hbits)),
("hscan", BV(_hbits)),
("vres", BV(_vbits)),
("vsync_start", BV(_vbits)),
("vsync_end", BV(_vbits)),
("vscan", BV(_vbits))]),
("pixels", Sink, _pixel_layout),
("dac", Source, _dac_layout)
)
def get_fragment(self):
hactive = Signal()
vactive = Signal()
active = Signal()
generate_en = Signal()
hcounter = Signal(BV(_hbits))
vcounter = Signal(BV(_vbits))
comb = [
active.eq(hactive & vactive),
If(active,
self.token("dac").r.eq(self.token("pixels").r[:_bpc_dac]),
self.token("dac").g.eq(self.token("pixels").g[:_bpc_dac]),
self.token("dac").b.eq(self.token("pixels").b[:_bpc_dac])
),
generate_en.eq(self.endpoints["timing"].stb & self.endpoints["dac"].ack \
& (~active | self.endpoints["pixels"].stb)),
self.endpoints["pixels"].ack.eq(self.endpoints["dac"].ack & active),
self.endpoints["dac"].stb.eq(generate_en)
]
tp = self.token("timing")
sync = [
self.endpoints["timing"].ack.eq(0),
If(generate_en,
hcounter.eq(hcounter + 1),
If(hcounter == 0, hactive.eq(1)),
If(hcounter == tp.hres, hactive.eq(0)),
If(hcounter == tp.hsync_start, self.token("dac").hsync.eq(1)),
If(hcounter == tp.hsync_end, self.token("dac").hsync.eq(0)),
If(hcounter == tp.hscan,
hcounter.eq(0),
If(vcounter == tp.vscan,
vcounter.eq(0)
).Else(
vcounter.eq(vcounter + 1)
)
),
If(vcounter == 0, vactive.eq(1)),
If(vcounter == tp.vres, vactive.eq(0)),
If(vcounter == tp.vsync_start, self.token("dac").vsync.eq(1)),
If(vcounter == tp.vsync_end,
self.token("dac").vsync.eq(0),
self.endpoints["timing"].ack.eq(1)
)
)
]
return Fragment(comb, sync)
class FIFO(Actor):
def __init__(self):
super().__init__(("dac", Sink, _dac_layout))
self.vga_clk = Signal()
self.vga_hsync_n = Signal()
self.vga_vsync_n = Signal()
self.vga_r = Signal(BV(_bpc_dac))
self.vga_g = Signal(BV(_bpc_dac))
self.vga_b = Signal(BV(_bpc_dac))
def get_fragment(self):
data_width = 2+3*_bpc_dac
asfifo = Instance("asfifo",
[
("data_out", BV(data_width)),
("empty", BV(1)),
("full", BV(1))
], [
("read_en", BV(1)),
("clk_read", self.vga_clk),
("data_in", BV(data_width)),
("write_en", BV(1)),
("rst", BV(1))
],
parameters=[
("data_width", data_width),
("address_width", 8)
],
clkport="clk_write")
t = self.token("dac")
return Fragment([
asfifo.ins["read_en"].eq(1),
self.endpoints["dac"].ack.eq(~asfifo.outs["full"]),
asfifo.ins["write_en"].eq(self.endpoints["dac"].stb),
asfifo.ins["data_in"].eq(Cat(~t.hsync, ~t.vsync, t.r, t.g, t.b)),
self.busy.eq(0),
asfifo.ins["rst"].eq(0)
], [
Cat(self.vga_hsync_n, self.vga_vsync_n, self.vga_r, self.vga_g, self.vga_b).eq(asfifo.outs["data_out"])
],
instances=[asfifo])
class Framebuffer:
def __init__(self, address, asmiport):
asmi_bits = asmiport.hub.aw
alignment_bits = bits_for(asmiport.hub.dw//8)
length_bits = _hbits + _vbits + 2 - alignment_bits
pack_factor = asmiport.hub.dw//_bpp
packed_pixels = structuring.pack_layout(_pixel_layout, pack_factor)
fi = ActorNode(_FrameInitiator(asmi_bits, length_bits, alignment_bits))
adrloop = ActorNode(misc.IntSequence(length_bits))
adrbase = ActorNode(ala.Add(BV(asmi_bits)))
adrbuffer = ActorNode(plumbing.Buffer)
dma = ActorNode(dma_asmi.SequentialReader(asmiport))
cast = ActorNode(structuring.Cast(asmiport.hub.dw, packed_pixels))
unpack = ActorNode(structuring.Unpack(pack_factor, _pixel_layout))
vtg = ActorNode(VTG())
fifo = ActorNode(FIFO())
g = DataFlowGraph()
g.add_connection(fi, adrloop, source_subr=["length"])
g.add_connection(adrloop, adrbase, sink_subr=["a"])
g.add_connection(fi, adrbase, source_subr=["base"], sink_subr=["b"])
g.add_connection(adrbase, adrbuffer)
g.add_connection(adrbuffer, dma)
g.add_connection(dma, cast)
g.add_connection(cast, unpack)
g.add_connection(unpack, vtg, sink_ep="pixels")
g.add_connection(fi, vtg, sink_ep="timing", source_subr=[
"hres", "hsync_start", "hsync_end", "hscan",
"vres", "vsync_start", "vsync_end", "vscan"])
g.add_connection(vtg, fifo)
self._comp_actor = CompositeActor(g)
self.bank = csrgen.Bank(fi.actor.get_registers(), address=address)
# VGA clock input
self.vga_clk = fifo.actor.vga_clk
# Pads
self.vga_psave_n = Signal()
self.vga_hsync_n = fifo.actor.vga_hsync_n
self.vga_vsync_n = fifo.actor.vga_vsync_n
self.vga_sync_n = Signal()
self.vga_blank_n = Signal()
self.vga_r = fifo.actor.vga_r
self.vga_g = fifo.actor.vga_g
self.vga_b = fifo.actor.vga_b
def get_fragment(self):
comb = [
self.vga_sync_n.eq(0),
self.vga_psave_n.eq(1),
self.vga_blank_n.eq(1)
]
return self.bank.get_fragment() \
+ self._comp_actor.get_fragment() \
+ Fragment(comb)