Files
PeakRDL-regblock/peakrdl/regblock/hwif.py
2021-07-16 13:02:05 -07:00

248 lines
8.7 KiB
Python

from typing import TYPE_CHECKING, Union, List
from systemrdl.node import Node, SignalNode, FieldNode, AddressableNode
from systemrdl.rdltypes import PropertyReference
if TYPE_CHECKING:
from .exporter import RegblockExporter
class Hwif:
"""
Defines how the hardware input/output signals are generated:
- Field outputs
- Field inputs
- Signal inputs (except those that are promoted to the top)
"""
def __init__(self, exporter: 'RegblockExporter', top_node: Node, package_name: str):
self.exporter = exporter
self.top_node = top_node
self.package_name = package_name
self.has_input_struct = None
self.has_output_struct = None
self._indent_level = 0
def get_package_declaration(self) -> str:
"""
If this hwif requires a package, generate the string
"""
lines = []
lines.append(f"package {self.package_name};")
self._indent_level += 1
self.has_input_struct = self._do_struct_addressable(lines, self.top_node, is_input=True)
self.has_output_struct = self._do_struct_addressable(lines, self.top_node, is_input=False)
self._indent_level -= 1
lines.append("")
lines.append("endpackage")
return "\n".join(lines)
@property
def port_declaration(self) -> str:
"""
Returns the declaration string for all I/O ports in the hwif group
"""
# Assume get_package_declaration() is always called prior to this
assert self.has_input_struct is not None
assert self.has_output_struct is not None
lines = []
if self.has_input_struct:
lines.append(f"input {self.package_name}::{self._get_struct_name(self.top_node, is_input=True)} hwif_in")
if self.has_output_struct:
lines.append(f"output {self.package_name}::{self._get_struct_name(self.top_node, is_input=False)} hwif_out")
return ",\n".join(lines)
#---------------------------------------------------------------------------
# Struct generation functions
#---------------------------------------------------------------------------
@property
def _indent(self) -> str:
return " " * self._indent_level
def _get_node_array_suffix(self, node:AddressableNode) -> str:
if node.is_array:
return "".join([f'[{dim}]' for dim in node.array_dimensions])
return ""
def _get_struct_name(self, node:Node, is_input:bool = True) -> str:
base = node.get_rel_path(
self.top_node.parent,
hier_separator="__",
array_suffix="x",
empty_array_suffix="x"
)
if is_input:
return f'{base}_in_t'
return f'{base}__out_t'
def _do_struct_addressable(self, lines:list, node:AddressableNode, is_input:bool = True) -> bool:
struct_children = []
# Generate structs for children first
for child in node.children():
if isinstance(child, AddressableNode):
if self._do_struct_addressable(lines, child, is_input):
struct_children.append(child)
elif isinstance(child, FieldNode):
if self._do_struct_field(lines, child, is_input):
struct_children.append(child)
elif is_input and isinstance(child, SignalNode):
# No child struct needed here
# TODO: Skip if this is a top-level child
struct_children.append(child)
# Generate this addressable node's struct
if struct_children:
lines.append("")
lines.append(f"{self._indent}// {node.get_rel_path(self.top_node.parent)}")
lines.append(f"{self._indent}typedef struct {{")
self._indent_level += 1
for child in struct_children:
if isinstance(child, AddressableNode):
lines.append(f"{self._indent}{self._get_struct_name(child, is_input)} {child.inst_name}{self._get_node_array_suffix(child)};")
elif isinstance(child, FieldNode):
lines.append(f"{self._indent}{self._get_struct_name(child, is_input)} {child.inst_name};")
elif isinstance(child, SignalNode):
if child.width == 1:
lines.append(f"{self._indent}logic {child.inst_name};")
else:
lines.append(f"{self._indent}logic [{child.msb}:{child.lsb}] {child.inst_name};")
self._indent_level -= 1
lines.append(f"{self._indent}}} {self._get_struct_name(node, is_input)};")
return bool(struct_children)
def _do_struct_field(self, lines:list, node:FieldNode, is_input:bool = True) -> bool:
contents = []
if is_input:
contents = self._get_struct_input_field_contents(node)
else:
contents = self._get_struct_output_field_contents(node)
if contents:
lines.append("")
lines.append(f"{self._indent}// {node.get_rel_path(self.top_node.parent)}")
lines.append(f"{self._indent}typedef struct {{")
self._indent_level += 1
for member in contents:
lines.append(self._indent + member)
self._indent_level -= 1
lines.append(f"{self._indent}}} {self._get_struct_name(node, is_input)};")
return bool(contents)
def _get_struct_input_field_contents(self, node:FieldNode) -> List[str]:
contents = []
# Provide input to field's value if it is writable by hw
if self.has_value_input(node):
if node.width == 1:
contents.append("logic value;")
else:
contents.append(f"logic [{node.width-1}:0] value;")
# TODO:
"""
we/wel
if either is boolean, and true
not part of external hwif if reference
mutually exclusive
hwclr/hwset
if either is boolean, and true
not part of external hwif if reference
incr/decr
if counter=true, generate BOTH
incrvalue/decrvalue
if either incrwidth/decrwidth are set
signals!
any signal instances instantiated in the scope
"""
return contents
def _get_struct_output_field_contents(self, node:FieldNode) -> List[str]:
contents = []
# Expose field's value if it is readable by hw
if self.has_value_output(node):
if node.width == 1:
contents.append("logic value;")
else:
contents.append(f"logic [{node.width-1}:0] value;")
# TODO:
"""
bitwise reductions
if anded, ored, xored == True, output a signal
swmod/swacc
event strobes
Are there was_written/was_read strobes too?
"""
return contents
#---------------------------------------------------------------------------
# hwif utility functions
#---------------------------------------------------------------------------
def has_value_input(self, obj: Union[FieldNode, SignalNode]) -> bool:
"""
Returns True if the object infers an input wire in the hwif
"""
if isinstance(obj, FieldNode):
return obj.is_hw_writable
elif isinstance(obj, SignalNode):
# Signals are implicitly always inputs
return True
else:
raise RuntimeError
def has_value_output(self, obj: FieldNode) -> bool:
"""
Returns True if the object infers an output wire in the hwif
"""
# TODO: Extend this for signals and prop references?
return obj.is_hw_readable
def get_input_identifier(self, obj: Union[FieldNode, SignalNode, PropertyReference]) -> str:
"""
Returns the identifier string that best represents the input object.
if obj is:
Field: the fields input value port
Signal: signal input value
Prop reference:
could be an implied hwclr/hwset/swwe/swwel/we/wel input
Raise a runtime error if an illegal prop ref is requested, or if
the prop ref is not actually implied, but explicitly ref a component
TODO: finish this
raises an exception if obj is invalid
"""
raise NotImplementedError()
def get_output_identifier(self, obj: FieldNode) -> str:
"""
Returns the identifier string that best represents the output object.
if obj is:
Field: the fields output value port
Property ref: this is also part of the struct
TODO: finish this
raises an exception if obj is invalid
"""
raise NotImplementedError()