upsilon/gateware/csr2mp.py

241 lines
7.2 KiB
Python

#!/usr/bin/python3
# Copyright 2023 (C) Peter McGoron
#
# This file is a part of Upsilon, a free and open source software project.
# For license terms, refer to the files in `doc/copying` in the Upsilon
# source distribution.
#######################################################################
#
# This file generates a Micropython module "mmio" with functions that
# do raw reads and writes to MMIO registers.
#
# TODO: Devicetree?
import collections
import argparse
import json
import sys
class MMIORegister:
def __init__(self, name, read_only=False, number=1, exntype=None):
"""
Describes a MMIO register.
:param name: The name of the MMIO register, excluding the prefix
defining its module (i.e. ``base_``) and excluding its
numerical suffix.
:param read_only: True if the register is read only. Defaults to
``False``.
:param number: The number of MMIO registers with the same name
and number suffixes. The number suffixes must go from 0
to ``number - 1`` with no gaps.
"""
self.name = name
self.read_only = read_only
self.number = number
self.exntype = exntype
# These are filled in by the CSR file.
self.size = None
def mmio_factory(num, exntype):
"""
Return a function that simplifies the creation of instances of
:py:class:`MMIORegister` with the same number and exception type.
:param num: Number of registers with the same name (minus suffix).
:param exntype: MicroPython exception type.
:return: A function ``f(name, read_only=False)``. Each argument is
the same as the one in the initializer of py:class:`MMIORegister`.
"""
def f(name, read_only=False):
return MMIORegister(name, read_only, number=num, exntype=exntype)
return f
class CSRHandler:
"""
Class that wraps the CSR file and fills in registers with information
from those files.
"""
def __init__(self, csrjson, bitwidthjson, registers):
"""
Reads in the CSR files.
:param csrjson: Filename of a LiteX "csr.json" file.
:param bitwidthjson: Filename of an Upsilon "bitwidthjson" file.
:param registers: A list of :py:class:`MMIORegister`s.
:param outf: Output file.
"""
self.registers = registers
self.csrs = json.load(open(csrjson))
self.bws = json.load(open(bitwidthjson))
def update_reg(self, reg):
"""
Fill in size information from bitwidth json file.
:param reg: The register.
:raises Exception: When the bit width exceeds 64.
"""
b = self.bws[reg.name]
if b <= 8:
reg.size = 8
elif b <= 16:
reg.size = 16
elif b <= 32:
reg.size = 32
elif b <= 64:
reg.size = 64
else:
raise Exception(f"unsupported width {b} in {reg.name}")
def get_reg_addr(self, reg, num=None):
"""
Get address of register.
:param reg: The register.
:param num: Select which register number. Registers without
numerical suffixes require ``None``.
:return: The address.
"""
if num is None:
regname = f"base_{reg.name}"
else:
regname = f"base_{reg.name}_{num}"
return self.csrs["csr_registers"][regname]["addr"]
class InterfaceGenerator:
"""
Interface for file generation. Implement the unimplemented functions
to generate a CSR interface for another language.
"""
def __init__(self, csr, outf):
"""
:param CSRHandler csr:
:param FileIO outf:
"""
self.outf = outf
self.csr = csr
def print(self, *args):
"""
Print to the file specified in the initializer and without
newlines.
"""
print(*args, end='', file=self.outf)
def fun(self, reg, optype):
""" Print function for reads/writes to register. """
pass
def header(self):
""" Print header of file. """
pass
def print_file(self):
self.print(self.header())
for r in self.csr.registers:
self.print(self.fun(r, "read"))
if not r.read_only:
self.print(self.fun(r, "write"))
class MicropythonGenerator(InterfaceGenerator):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def get_accessor(self, reg, num):
addr = self.csr.get_reg_addr(reg, num)
if reg.size in [8, 16, 32]:
return [f"machine.mem{reg.size}[{addr}]"]
return [f"machine.mem32[{addr}]", f"machine.mem32[{addr + 4}]"]
def print_write_register(self, indent, varname, reg, num):
acc = self.get_accessor(reg, num)
if len(acc) == 1:
return f'{indent}{acc[0]} = {varname}\n'
else:
assert len(acc) == 2
return f'{indent}{acc[0]} = {varname} & 0xFFFFFFFF\n' + \
f'{indent}{acc[1]} = {varname} >> 32\n'
def print_read_register(self, indent, varname, reg, num):
acc = self.get_accessor(reg, num)
if len(acc) == 1:
return f'{indent}return {acc[0]}\n'
else:
assert len(acc) == 2
return f'{indent}return {acc[0]} | ({acc[1]} << 32)\n'
def fun(self, reg, optype):
rs = ""
def a(s):
nonlocal rs
rs = rs + s
a(f'def {optype}_{reg.name}(')
printed_argument = False
if optype == 'write':
a('val')
printed_argument = True
pfun = self.print_write_register
else:
pfun = self.print_read_register
if reg.number != 1:
if printed_argument:
a(', ')
a('num')
a('):\n')
if reg.number == 1:
a(pfun('\t', 'val', reg, None))
else:
for i in range(0,reg.number):
if i == 0:
a(f'\tif ')
else:
a(f'\telif ')
a(f'num == {i}:\n')
a(pfun('\t\t', 'val', reg, i))
a(f'\telse:\n')
a(f'\t\traise {r.exntype}(regnum)\n')
a('\n')
return rs
def header(self):
return """import machine
class InvalidDACException(Exception):
pass
class InvalidADCException(Exception):
pass
"""
if __name__ == "__main__":
dac_num = 8
adc_num = 8
dac_reg = mmio_factory(dac_num, "InvalidDACException")
adc_reg = mmio_factory(adc_num, "InvalidADCException")
registers = [
dac_reg("dac_sel"),
dac_reg("dac_finished", read_only=True),
dac_reg("dac_arm"),
dac_reg("dac_recv_buf", read_only=True),
dac_reg("dac_send_buf"),
adc_reg("adc_finished", read_only=True),
adc_reg("adc_arm"),
adc_reg("adc_recv_buf", read_only=True),
adc_reg("adc_sel"),
MMIORegister("cl_in_loop", read_only=True),
MMIORegister("cl_cmd"),
MMIORegister("cl_word_in"),
MMIORegister("cl_start_cmd"),
MMIORegister("cl_finish_cmd", read_only=True),
]
csrh = CSRHandler(sys.argv[1], sys.argv[2], registers)
for r in registers:
csrh.update_reg(r)
MicropythonGenerator(csrh, sys.stdout).print_file()