usb_updater: Migrate servo_updater.py to python2/3 compatible

BUG=chromium:1031705
BRANCH=master
TEST=`sudo python3 ./extra/usb_updater/servo_updater.py -b servo_v4
--force` shows "update complete".
TEST=`sudo python2 ./extra/usb_updater/servo_updater.py -b servo_v4
--force` shows "update complete".

Signed-off-by: kerker <kerker@chromium.org>
Change-Id: I632203b9eca4aa99dc63063c37f0ab5fc2e54dbb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2425784
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

4 files changed, 22 insertions, 7 deletions

diff --git a/extra/tigertool/ecusb/pty_driver.py b/extra/tigertool/ecusb/pty_driver.py
index 2aec6fecad..63df230e7e 100644
--- a/extra/tigertool/ecusb/pty_driver.py
+++ b/extra/tigertool/ecusb/pty_driver.py
@@ -155,6 +155,8 @@ class ptyDriver(object):
         # Create a tuple which contains the entire matched string and all
         # the subgroups of the match.
         result = match.group(*range(lastindex + 1)) if match else None
+        if result:
+          result = tuple(res.decode('utf-8') for res in result)
         result_list.append(result)
     except pexpect.TIMEOUT:
       raise ptyError('Timeout waiting for response.')
@@ -188,6 +190,8 @@ class ptyDriver(object):
           # Create a tuple which contains the entire matched string and all
           # the subgroups of the match.
           result = match.group(*range(lastindex + 1)) if match else None
+          if result:
+            result = tuple(res.decode('utf-8') for res in result)
           result_list.append(result)
         except pexpect.TIMEOUT:
           break
diff --git a/extra/tigertool/ecusb/stm32uart.py b/extra/tigertool/ecusb/stm32uart.py
index 21fcbd2cc2..cfbbf485a4 100644
--- a/extra/tigertool/ecusb/stm32uart.py
+++ b/extra/tigertool/ecusb/stm32uart.py
@@ -15,7 +15,7 @@ import time
 import tty
 import usb
 
-import stm32usb
+from . import stm32usb
 
 
 class SuartError(Exception):
diff --git a/extra/tigertool/ecusb/tiny_servo_common.py b/extra/tigertool/ecusb/tiny_servo_common.py
index 185f2a67d1..0e650a2d1d 100644
--- a/extra/tigertool/ecusb/tiny_servo_common.py
+++ b/extra/tigertool/ecusb/tiny_servo_common.py
@@ -12,8 +12,8 @@ import subprocess
 import sys
 import time
 
-import pty_driver
-import stm32uart
+from . import pty_driver
+from . import stm32uart
 
 
 class TinyServoError(Exception):
@@ -40,7 +40,8 @@ def check_usb(vidpid, serialname=None):
   Returns: True if found, False, otherwise.
   """
   if serialname:
-    output = subprocess.check_output(['lsusb', '-v', '-d', vidpid])
+    output = subprocess.check_output(['lsusb', '-v', '-d', vidpid],
+                                     encoding='utf-8')
     m = re.search(r'^\s*iSerial\s+\d+\s+%s$' % serialname, output, flags=re.M)
     if m:
       return True
@@ -63,7 +64,8 @@ def check_usb_sn(vidpid):
 
   Returns: string serial number if found, None otherwise.
   """
-  output = subprocess.check_output(['lsusb', '-v', '-d', vidpid])
+  output = subprocess.check_output(['lsusb', '-v', '-d', vidpid],
+                                   encoding='utf-8')
   m = re.search(r'^\s*iSerial\s+(.*)$', output, flags=re.M)
   if m:
     return m.group(1)
diff --git a/extra/usb_updater/servo_updater.py b/extra/usb_updater/servo_updater.py
index 06c36f37b6..397aa28566 100755
--- a/extra/usb_updater/servo_updater.py
+++ b/extra/usb_updater/servo_updater.py
@@ -1,8 +1,10 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python
 # Copyright 2016 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+# Note: This is a py2/3 compatible file.
+
 from __future__ import print_function
 
 import argparse
@@ -14,6 +16,8 @@ import time
 import tempfile
 
 import json
+import six
+
 import fw_update
 import ecusb.tiny_servo_common as c
 
@@ -236,8 +240,13 @@ def find_available_version(boardname, binfile):
   Returns:
     the version string.
   """
+  args = {}
+  if six.PY3:
+    args['encoding'] = 'utf-8'
+
   rawstrings = subprocess.check_output(
-      ['cbfstool', binfile, 'read', '-r', 'RO_FRID', '-f', '/dev/stdout'])
+      ['cbfstool', binfile, 'read', '-r', 'RO_FRID', '-f', '/dev/stdout'],
+      **args)
   m = re.match(r'%s_v\S+' % boardname, rawstrings)
   if m:
     newvers = m.group(0).strip(' \t\r\n\0')