litex/soc/tools/remote/comm_uart.py

   1 import serial
   2 import struct
   3
   4
   5 class CommUART:
   6     msg_type = {
   7         "write": 0x01,
   8         "read":  0x02
   9     }
  10     def __init__(self, port, baudrate=115200, debug=False):
  11         self.port = port
  12         self.baudrate = str(baudrate)
  13         self.csr_data_width = None
  14         self.debug = debug
  15         self.port = serial.serial_for_url(port, baudrate)
  16
  17     def open(self, csr_data_width):
  18         self.csr_data_width = csr_data_width
  19         if hasattr(self, "port"):
  20             return
  21         self.port.open()
  22
  23     def close(self):
  24         if not hasattr(self, "port"):
  25             return
  26         del self.port
  27
  28     def _read(self, length):
  29         r = bytes()
  30         while len(r) < length:
  31             r += self.port.read(length - len(r))
  32         return r
  33
  34     def _write(self, data):
  35         remaining = len(data)
  36         pos = 0
  37         while remaining:
  38             written = self.port.write(data[pos:])
  39             remaining -= written
  40             pos += written
  41
  42     def read(self, addr, length=None):
  43         r = []
  44         length_int = 1 if length is None else length
  45         self._write([self.msg_type["read"], length_int])
  46         self._write(list((addr//4).to_bytes(4, byteorder="big")))
  47         for i in range(length_int):
  48             data = int.from_bytes(self._read(4), "big")
  49             if self.debug:
  50                 print("read {:08x} @ {:08x}".format(data, addr + 4*i))
  51             if length is None:
  52                 return data
  53             r.append(data)
  54         return r
  55
  56     def write(self, addr, data):
  57         data = data if isinstance(data, list) else [data]
  58         length = len(data)
  59         self._write([self.msg_type["write"], length])
  60         self._write(list((addr//4).to_bytes(4, byteorder="big")))
  61         for i in range(len(data)):
  62             self._write(list(data[i].to_bytes(4, byteorder="big")))
  63             if self.debug:
  64                 print("write {:08x} @ {:08x}".format(data[i], addr + 4*i))