nmigen/build/dsl.py

   1 from collections import OrderedDict
   2
   3
   4 __all__ = ["Pins", "PinsN", "DiffPairs", "DiffPairsN",
   5            "Attrs", "Clock", "Subsignal", "Resource", "Connector"]
   6
   7
   8 class Pins:
   9     def __init__(self, names, *, dir="io", conn=None, assert_width=None):
  10         if not isinstance(names, str):
  11             raise TypeError("Names must be a whitespace-separated string, not {!r}"
  12                             .format(names))
  13         names = names.split()
  14
  15         if conn is not None:
  16             conn_name, conn_number = conn
  17             if not (isinstance(conn_name, str) and isinstance(conn_number, int)):
  18                 raise TypeError("Connector must be None or a pair of string and integer, not {!r}"
  19                                 .format(conn))
  20             names = ["{}_{}:{}".format(conn_name, conn_number, name) for name in names]
  21
  22         if dir not in ("i", "o", "io", "oe"):
  23             raise TypeError("Direction must be one of \"i\", \"o\", \"oe\", or \"io\", not {!r}"
  24                             .format(dir))
  25
  26         if assert_width is not None and len(names) != assert_width:
  27             raise AssertionError("{} names are specified ({}), but {} names are expected"
  28                                  .format(len(names), " ".join(names), assert_width))
  29
  30         self.names  = names
  31         self.dir    = dir
  32         self.invert = False
  33
  34     def __len__(self):
  35         return len(self.names)
  36
  37     def __iter__(self):
  38         return iter(self.names)
  39
  40     def map_names(self, mapping, resource):
  41         mapped_names = []
  42         for name in self.names:
  43             while ":" in name:
  44                 if name not in mapping:
  45                     raise NameError("Resource {!r} refers to nonexistent connector pin {}"
  46                                     .format(resource, name))
  47                 name = mapping[name]
  48             mapped_names.append(name)
  49         return mapped_names
  50
  51     def __repr__(self):
  52         return "(pins{} {} {})".format("-n" if self.invert else "",
  53             self.dir, " ".join(self.names))
  54
  55
  56 def PinsN(*args, **kwargs):
  57     pins = Pins(*args, **kwargs)
  58     pins.invert = True
  59     return pins
  60
  61
  62 class DiffPairs:
  63     def __init__(self, p, n, *, dir="io", conn=None, assert_width=None):
  64         self.p = Pins(p, dir=dir, conn=conn, assert_width=assert_width)
  65         self.n = Pins(n, dir=dir, conn=conn, assert_width=assert_width)
  66
  67         if len(self.p.names) != len(self.n.names):
  68             raise TypeError("Positive and negative pins must have the same width, but {!r} "
  69                             "and {!r} do not"
  70                             .format(self.p, self.n))
  71
  72         self.dir    = dir
  73         self.invert = False
  74
  75     def __len__(self):
  76         return len(self.p.names)
  77
  78     def __iter__(self):
  79         return zip(self.p.names, self.n.names)
  80
  81     def __repr__(self):
  82         return "(diffpairs{} {} (p {}) (n {}))".format("-n" if self.invert else "",
  83             self.dir, " ".join(self.p.names), " ".join(self.n.names))
  84
  85
  86 def DiffPairsN(*args, **kwargs):
  87     diff_pairs = DiffPairs(*args, **kwargs)
  88     diff_pairs.invert = True
  89     return diff_pairs
  90
  91
  92 class Attrs(OrderedDict):
  93     def __init__(self, **attrs):
  94         for key, value in attrs.items():
  95             if not (value is None or isinstance(value, str) or hasattr(value, "__call__")):
  96                 raise TypeError("Value of attribute {} must be None, str, or callable, not {!r}"
  97                                 .format(key, value))
  98
  99         super().__init__(**attrs)
 100
 101     def __repr__(self):
 102         items = []
 103         for key, value in self.items():
 104             if value is None:
 105                 items.append("!" + key)
 106             elif hasattr(value, "__call__"):
 107                 items.append(key + "=" + repr(value))
 108             else:
 109                 items.append(key + "=" + value)
 110         return "(attrs {})".format(" ".join(items))
 111
 112
 113 class Clock:
 114     def __init__(self, frequency):
 115         if not isinstance(frequency, (float, int)):
 116             raise TypeError("Clock frequency must be a number")
 117
 118         self.frequency = float(frequency)
 119
 120     @property
 121     def period(self):
 122         return 1 / self.frequency
 123
 124     def __repr__(self):
 125         return "(clock {})".format(self.frequency)
 126
 127
 128 class Subsignal:
 129     def __init__(self, name, *args):
 130         self.name  = name
 131         self.ios   = []
 132         self.attrs = Attrs()
 133         self.clock = None
 134
 135         if not args:
 136             raise ValueError("Missing I/O constraints")
 137         for arg in args:
 138             if isinstance(arg, (Pins, DiffPairs)):
 139                 if not self.ios:
 140                     self.ios.append(arg)
 141                 else:
 142                     raise TypeError("Pins and DiffPairs are incompatible with other location or "
 143                                     "subsignal constraints, but {!r} appears after {!r}"
 144                                     .format(arg, self.ios[-1]))
 145             elif isinstance(arg, Subsignal):
 146                 if not self.ios or isinstance(self.ios[-1], Subsignal):
 147                     self.ios.append(arg)
 148                 else:
 149                     raise TypeError("Subsignal is incompatible with location constraints, but "
 150                                     "{!r} appears after {!r}"
 151                                     .format(arg, self.ios[-1]))
 152             elif isinstance(arg, Attrs):
 153                 self.attrs.update(arg)
 154             elif isinstance(arg, Clock):
 155                 if self.ios and isinstance(self.ios[-1], (Pins, DiffPairs)):
 156                     if self.clock is None:
 157                         self.clock = arg
 158                     else:
 159                         raise ValueError("Clock constraint can be applied only once")
 160                 else:
 161                     raise TypeError("Clock constraint can only be applied to Pins or DiffPairs, "
 162                                     "not {!r}"
 163                                     .format(self.ios[-1]))
 164             else:
 165                 raise TypeError("Constraint must be one of Pins, DiffPairs, Subsignal, Attrs, "
 166                                 "or Clock, not {!r}"
 167                                 .format(arg))
 168
 169     def _content_repr(self):
 170         parts = []
 171         for io in self.ios:
 172             parts.append(repr(io))
 173         if self.clock is not None:
 174             parts.append(repr(self.clock))
 175         if self.attrs:
 176             parts.append(repr(self.attrs))
 177         return " ".join(parts)
 178
 179     def __repr__(self):
 180         return "(subsignal {} {})".format(self.name, self._content_repr())
 181
 182
 183 class Resource(Subsignal):
 184     @classmethod
 185     def family(cls, name_or_number, number=None, *, ios, default_name, name_suffix=""):
 186         # This constructor accepts two different forms:
 187         #  1. Number-only form:
 188         #       Resource.family(0, default_name="name", ios=[Pins("A0 A1")])
 189         #  2. Name-and-number (name override) form:
 190         #       Resource.family("override", 0, default_name="name", ios=...)
 191         # This makes it easier to build abstractions for resources, e.g. an SPIResource abstraction
 192         # could simply delegate to `Resource.family(*args, default_name="spi", ios=ios)`.
 193         # The name_suffix argument is meant to support creating resources with
 194         # similar names, such as spi_flash, spi_flash_2x, etc.
 195         if name_suffix:  # Only add "_" if we actually have a suffix.
 196             name_suffix = "_" + name_suffix
 197
 198         if number is None: # name_or_number is number
 199             return cls(default_name + name_suffix, name_or_number, *ios)
 200         else: # name_or_number is name
 201             return cls(name_or_number + name_suffix, number, *ios)
 202
 203     def __init__(self, name, number, *args):
 204         super().__init__(name, *args)
 205
 206         self.number = number
 207
 208     def __repr__(self):
 209         return "(resource {} {} {})".format(self.name, self.number, self._content_repr())
 210
 211
 212 class Connector:
 213     def __init__(self, name, number, io):
 214         self.name    = name
 215         self.number  = number
 216         self.mapping = OrderedDict()
 217
 218         if isinstance(io, dict):
 219             for conn_pin, plat_pin in io.items():
 220                 if not isinstance(conn_pin, str):
 221                     raise TypeError("Connector pin name must be a string, not {!r}"
 222                                     .format(conn_pin))
 223                 if not isinstance(plat_pin, str):
 224                     raise TypeError("Platform pin name must be a string, not {!r}"
 225                                     .format(plat_pin))
 226                 self.mapping[conn_pin] = plat_pin
 227
 228         elif isinstance(io, str):
 229             for conn_pin, plat_pin in enumerate(io.split(), start=1):
 230                 if plat_pin == "-":
 231                     continue
 232                 self.mapping[str(conn_pin)] = plat_pin
 233
 234         else:
 235             raise TypeError("Connector I/Os must be a dictionary or a string, not {!r}"
 236                             .format(io))
 237
 238     def __repr__(self):
 239         return "(connector {} {} {})".format(self.name, self.number,
 240                                              " ".join("{}=>{}".format(conn, plat)
 241                                                       for conn, plat in self.mapping.items()))
 242
 243     def __len__(self):
 244         return len(self.mapping)
 245
 246     def __iter__(self):
 247         for conn_pin, plat_pin in self.mapping.items():
 248             yield "{}_{}:{}".format(self.name, self.number, conn_pin), plat_pin