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# -*- coding: utf-8 -*-
# Copyright (c) 2007 Johannes Hölzl <johannes.hoelzl@gmx.de>
#
# This library is covered by the GNU LGPL, read LICENSE for details.
"""Provides access to the EEPROM of Silabs CP210x devices
The following classes are available:
class Cp210xProgrammer:
Provides direct access to the CP2101, can be used to write single data
directly or via an EEPROM image.
class EEPROM:
Can be used to read or write a hex file containing the EEPROM content
of an CP2101. Provides also access to the single fields in the EEPROM.
"""
import ctypes
import usb
__all__ = ['Cp210xProgrammer', 'Cp210xError']
CP2101_UART = 0x00
CP2101_CONFIG = 0xFF
CP2101_UART_ENABLE = 0x0001
CP2101_UART_DISABLE = 0x0000
REG_VENDOR_ID = 0x3701
REG_PRODUCT_ID = 0x3702
REG_PRODUCT_STRING = 0x3703
REG_SERIAL_NUMBER = 0x3704
REG_CFG_ATTRIBUTES = 0x3705
REG_MAX_POWER = 0x3706
REG_VERSION = 0x3707
REG_UNKNOWN = 0x3708
REG_EEPROM = 0x3709
REG_LOCK_VALUE = 0x370A
REG_PART_NUMBER = 0x370B
SIZE_EEPROM = 0x0400
SIZE_PRODUCT_STRING = 0x007D
SIZE_SERIAL_NUMBER = 0x003F
SIZE_BAUDRATES = 32
SIZE_BAUDRATE_CFG = 10
SIZE_BAUDRATE_TABLE = SIZE_BAUDRATES * SIZE_BAUDRATE_CFG
SIZE_VENDOR_STRING = 24
LCK_LOCKED = 0x00
LCK_UNLOCKED = 0xFF
VID_SILABS = 0x10C4
PID_CP210x = 0xEA60
VALUES = [
('product_string', 'string'),
('serial_number', 'string'),
('product_id', 'id'),
('vendor_id', 'id'),
('version', 'version'),
('bus_powered', 'boolean'),
('max_power', 'int'),
('locked', 'boolean'),
('part_number', 'int'),
('vendor_string', 'string'),
('baudrate_table', 'list'),
]
def iif(v, a, b):
if v:
return a
else:
return b
def to_div2(p):
value = int(p / 2)
if (value * 2) < p:
value += 1
return value
def to_bcd(i):
assert i >= 0 and i <= 99
return (i // 10) << 4 | (i % 10)
def to_bcd2( (i, j) ):
return to_bcd(i) << 8 | to_bcd(j)
def from_bcd(num):
return num & 0x0F + (num >> 4) * 10
def from_bcd2(data):
return (from_bcd(data >> 8), from_bcd(data & 0xFF))
def from_binary(data, le=True):
value = 0
if le:
data = data[::-1]
for byte in data:
value = value << 8 | ord(byte)
return value
def to_binary(value, size=2, le=True):
data = ''
for i in range(size):
data += chr(value & 0xFF)
value >>= 8
if le:
return data
else:
return data[::-1]
def parse_baudrate_cfg(data):
return (from_binary(data[0:2], le=False),
from_binary(data[2:4], le=False),
from_binary(data[4:5]),
from_binary(data[6:10]))
def build_baudrate_cfg(baudgen, timer0reload, prescaler, baudrate):
return (to_binary(baudgen, le=False) + to_binary(timer0reload, le=False) +
to_binary(prescaler, 1) + '\x00' + to_binary(baudrate, 4))
class Cp210xError(IOError):
pass
class DeviceLocked(Cp210xError):
pass
class Cp210xProgrammer(object):
"""Program an Silabs CP2101, CP2102 or CP2103
This modul provides access to Silabs CP210x devices to set some USB
descriptor fields and some USB descriptor strings.
The following fields can be set:
* Vendor ID
* Product ID
* Product String
* Serial Number
* Device Version
* Bus Powered
* max. Power consumption
Either use libusb to find a device, and provide the device description
to the constructor, or use Cp210xProgrammer.list_device() to list all
devices matching certain pattern.
To progamm the device open() it, set the data, and close() it. To have the
changed fields reread call reset() before closing it.
"""
TIMEOUT = 300 #ms
@classmethod
def list_devices(self, patterns=[{ 'idVendor': VID_SILABS,
'idProduct': PID_CP210x }]):
"""Yields a list of devices matching certain patterns.
param patterns: This must be a list of dictionaries or pairs of string.
Each device in the usb tree is matched against all pattern in the
list.
When an item is a dictionary all fields of the descriptors
are compared against the corresponding values in the dictionary. If
each value is equal, the device is yielded.
When an item is a pair of strings. The first string must be the
dirname of the bus and the second string the filename of the device.
For example:
>> list(Cp210xProgrammer.list_device([{ 'idVendor': VID_SILABS,
'idProduct': PID_CP210x }]))
[device(...)]
"""
usb.find_busses()
usb.find_devices()
bus = usb.get_busses()
while bus:
dev = bus.contents.devices
while dev:
for pattern in patterns:
if isinstance(pattern, dict):
for name, value in pattern.items():
if getattr(dev.contents.descriptor, name) != value:
break
else:
yield self(dev)
break
elif isinstance(pattern, tuple):
if (bus.contents.dirname == pattern[0] and
dev.contents.filename == pattern[1]):
yield self(dev)
break
dev = dev.contents.next
bus = bus.contents.next
def __init__(self, dev_info):
self.dev_info = dev_info
self.handle = None
self._locked = None
def open(self):
"""Opens the device.
Only after an successful call to open() data can be read from and
written to the device.
Claims all resources associated with this device.
"""
self.handle = usb.open(self.dev_info)
if self.handle == 0:
self.handle = None
raise Cp210xError("Can't open device.")
usb.set_configuration(self.handle, 1)
usb.claim_interface(self.handle, 0)
def reset(self):
"""Force the USB stack to reset the device.
Resets the device through an hard reset over the port to which the
device is connected. After that happend the EEPROM content in the device
is reread and the device's descriptors are the one written to it.
"""
assert self.handle is not None
usb.reset(self.handle)
def close(self):
"""Closes the device.
Releases all resources associated with this device.
"""
assert self.handle is not None
usb.release_interface(self.handle, 0)
usb.close(self.handle)
self.handle = None
def __del__(self):
if self.handle is not None:
self.close()
def _set_config(self, value, index=0, data=None, request=CP2101_CONFIG):
assert self.handle is not None
if self.get_locked():
raise DeviceLocked()
if data is not None:
data_length = len(data)
else:
data_length = 0
res = usb.control_msg(self.handle, usb.ENDPOINT_OUT | usb.TYPE_VENDOR,
request, value, index, data, data_length,
self.TIMEOUT)
if res < 0:
raise Cp210xError("Unable to send request %04X result=%d"
% (value, res))
def _set_config_string(self, value, content, max_length):
assert isinstance(content, basestring)
encoded = content.encode('utf-16-le')
assert len(encoded) <= max_length
self._set_config(value, data=chr(len(encoded) + 2) + "\x03" + encoded)
def _get_config(self, value, length, index=0, request=CP2101_CONFIG):
assert self.handle is not None
data = ctypes.create_string_buffer(length)
res = usb.control_msg(self.handle, usb.ENDPOINT_IN | usb.TYPE_VENDOR,
request, value, index, data, length,
self.TIMEOUT)
if res < 0:
raise Cp210xError("Unable to send request, %04X result=%d"
% (value, res))
return data.raw[:res]
def _get_int8_config(self, value, index=0, request=CP2101_CONFIG):
return ord(self._get_config(value, 1, index=index, request=request))
def _get_int16_config(self, value, index=0, request=CP2101_CONFIG):
data = self._get_config(value, 2, index=index, request=request)
return ord(data[0]) << 8 | ord(data[1])
def get_eeprom_content(self):
"""Reads the entire EEPROM content as one big 1024-byte blob.
"""
return self._get_config(REG_EEPROM, SIZE_EEPROM)
def get_baudrate_content(self):
"""Return the baudrate table as binary data.
"""
return self._get_config(REG_EEPROM, SIZE_BAUDRATE_TABLE)
def get_baudrate_table(self):
"""Returns the baudrate table.
A list containing 4-tuples are returnes.
Each tuple containes the following data:
* BaudGen: Value used to generate the real baudrate.
* Time0Reset: Value used to generate the usb timeout.
* Prescaler: Used to generate the real baudrate.
* Baudrate: The baudrate which activates this entry.
"""
data = self.get_baudrate_content()
return [parse_baudrate_cfg(data[pos:pos+SIZE_BAUDRATE_CFG])
for pos in range(0, SIZE_BAUDRATE_TABLE, SIZE_BAUDRATE_CFG)]
def set_baudrate_table(self, baudrates):
"""Writes the baudrate table.
See get_baudrate_table() for the structure of the table.
"""
assert len(baudrates) == SIZE_BAUDRATES
self.set_baudrate_content(data=''.join(build_baudrate_cfg(*cfg)
for cfg in baudrates))
baudrate_table = property(get_baudrate_table, set_baudrate_table)
def get_part_number(self):
""" The part number of the device.
Returns: 1 for an CP2101
2 for an CP2102
3 for an CP2103
"""
return self._get_int8_config(REG_PART_NUMBER)
def get_locked(self):
""" The lock value of the device.
When True is returnes no data can be written to the device.
"""
if self._locked is None:
self._locked = self._get_int8_config(REG_LOCK_VALUE) == LCK_LOCKED
return self._locked
def set_eeprom_content(self, content):
"""Writes an 1024-byte blob to the EEPROM
"""
assert len(content) == SIZE_EEPROM, ("EEPROM data must be %i bytes."
% SIZE_EEPROM)
assert isinstance(content, str), "EEPROM data must be string."
self._set_config(REG_EEPROM, data=content)
def set_product_id(self, pid):
"""Sets the Product ID
"""
assert pid > 0x0000 and pid < 0xFFFF
self._set_config(REG_PRODUCT_ID, pid)
def set_vendor_id(self, vid):
"""Sets the Vendor ID
"""
assert vid > 0x0000 and vid < 0xFFFF
self._set_config(REG_VENDOR_ID, vid)
def set_product_string(self, product_string):
"""Sets the product string.
Be aware that the string will be stored as UTF-16 encoded and should not
exceed SIZE_PRODUCT_STRING
"""
self._set_config_string(REG_PRODUCT_STRING, product_string,
SIZE_PRODUCT_STRING)
def set_serial_number(self, serial_number):
self._set_config_string(REG_SERIAL_NUMBER, serial_number,
SIZE_SERIAL_NUMBER)
def set_max_power(self, max_power):
assert max_power >= 0 and max_power <= 500
self._set_config(REG_MAX_POWER, to_div2(max_power))
def set_bus_powered(self, bus_powered):
if bus_powered:
self._set_config(REG_CFG_ATTRIBUTES, 0xC0)
else:
self._set_config(REG_CFG_ATTRIBUTES, 0x80)
def set_version(self, version):
self._set_config(REG_VERSION, to_bcd2(version))
def set_locked(self, locked):
""" The lock value of the device.
When True is returnes no data can be written to the device.
"""
if locked:
self._set_config(REG_LOCK_VALUE, LCK_LOCKED)
else:
self._set_config(REG_LOCK_VALUE, LCK_UNLOCKED)
def set_values(self, values):
for name, value in values.items():
if name not in ['part_number', 'vendor_string']:
getattr(self, "set_" + name) (value)
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