blob: eb315d47d01b8ce43399040836fe2a014cdc3ed1 [file] [log] [blame]
#!/usr/bin/env python
# portable serial port access with python
#
# This is a module that gathers a list of serial ports including details on
# GNU/Linux systems
#
# (C) 2011-2013 Chris Liechti <cliechti@gmx.net>
# this is distributed under a free software license, see license.txt
import glob
import sys
import os
import re
try:
import subprocess
except ImportError:
def popen(argv):
try:
si, so = os.popen4(' '.join(argv))
return so.read().strip()
except:
raise IOError('lsusb failed')
else:
def popen(argv):
try:
return subprocess.check_output(argv, stderr=subprocess.STDOUT).strip()
except:
raise IOError('lsusb failed')
# The comports function is expected to return an iterable that yields tuples of
# 3 strings: port name, human readable description and a hardware ID.
#
# as currently no method is known to get the second two strings easily, they
# are currently just identical to the port name.
# try to detect the OS so that a device can be selected...
plat = sys.platform.lower()
def read_line(filename):
"""help function to read a single line from a file. returns none"""
try:
f = open(filename)
line = f.readline().strip()
f.close()
return line
except IOError:
return None
def re_group(regexp, text):
"""search for regexp in text, return 1st group on match"""
if sys.version < '3':
m = re.search(regexp, text)
else:
# text is bytes-like
m = re.search(regexp, text.decode('ascii', 'replace'))
if m: return m.group(1)
# try to extract descriptions from sysfs. this was done by experimenting,
# no guarantee that it works for all devices or in the future...
def usb_sysfs_hw_string(sysfs_path):
"""given a path to a usb device in sysfs, return a string describing it"""
bus, dev = os.path.basename(os.path.realpath(sysfs_path)).split('-')
snr = read_line(sysfs_path+'/serial')
if snr:
snr_txt = ' SNR=%s' % (snr,)
else:
snr_txt = ''
return 'USB VID:PID=%s:%s%s' % (
read_line(sysfs_path+'/idVendor'),
read_line(sysfs_path+'/idProduct'),
snr_txt
)
def usb_lsusb_string(sysfs_path):
base = os.path.basename(os.path.realpath(sysfs_path))
bus = base.split('-')[0]
try:
dev = int(read_line(os.path.join(sysfs_path, 'devnum')))
desc = popen(['lsusb', '-v', '-s', '%s:%s' % (bus, dev)])
# descriptions from device
iManufacturer = re_group('iManufacturer\s+\w+ (.+)', desc)
iProduct = re_group('iProduct\s+\w+ (.+)', desc)
iSerial = re_group('iSerial\s+\w+ (.+)', desc) or ''
# descriptions from kernel
idVendor = re_group('idVendor\s+0x\w+ (.+)', desc)
idProduct = re_group('idProduct\s+0x\w+ (.+)', desc)
# create descriptions. prefer text from device, fall back to the others
return '%s %s %s' % (iManufacturer or idVendor, iProduct or idProduct, iSerial)
except IOError:
return base
def describe(device):
"""\
Get a human readable description.
For USB-Serial devices try to run lsusb to get a human readable description.
For USB-CDC devices read the description from sysfs.
"""
base = os.path.basename(device)
# USB-Serial devices
sys_dev_path = '/sys/class/tty/%s/device/driver/%s' % (base, base)
if os.path.exists(sys_dev_path):
sys_usb = os.path.dirname(os.path.dirname(os.path.realpath(sys_dev_path)))
return usb_lsusb_string(sys_usb)
# USB-CDC devices
sys_dev_path = '/sys/class/tty/%s/device/interface' % (base,)
if os.path.exists(sys_dev_path):
return read_line(sys_dev_path)
return base
def hwinfo(device):
"""Try to get a HW identification using sysfs"""
base = os.path.basename(device)
if os.path.exists('/sys/class/tty/%s/device' % (base,)):
# PCI based devices
sys_id_path = '/sys/class/tty/%s/device/id' % (base,)
if os.path.exists(sys_id_path):
return read_line(sys_id_path)
# USB-Serial devices
sys_dev_path = '/sys/class/tty/%s/device/driver/%s' % (base, base)
if os.path.exists(sys_dev_path):
sys_usb = os.path.dirname(os.path.dirname(os.path.realpath(sys_dev_path)))
return usb_sysfs_hw_string(sys_usb)
# USB-CDC devices
if base.startswith('ttyACM'):
sys_dev_path = '/sys/class/tty/%s/device' % (base,)
if os.path.exists(sys_dev_path):
return usb_sysfs_hw_string(sys_dev_path + '/..')
return 'n/a' # XXX directly remove these from the list?
def comports():
devices = glob.glob('/dev/ttyS*') + glob.glob('/dev/ttyUSB*') + glob.glob('/dev/ttyACM*')
return [(d, describe(d), hwinfo(d)) for d in devices]
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# test
if __name__ == '__main__':
for port, desc, hwid in sorted(comports()):
print "%s: %s [%s]" % (port, desc, hwid)