| #!/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) |
| |
| # USB Product Information |
| sys_dev_path = '/sys/class/tty/%s/device' % (base,) |
| if os.path.exists(sys_dev_path): |
| product_name_file = os.path.dirname(os.path.realpath(sys_dev_path)) + "/product" |
| if os.path.exists(product_name_file): |
| return read_line(product_name_file) |
| |
| 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) |