Solaar/lib/hidapi/udev.py

390 lines
13 KiB
Python

# -*- python-mode -*-
# -*- coding: UTF-8 -*-
## Copyright (C) 2012-2013 Daniel Pavel
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License along
## with this program; if not, write to the Free Software Foundation, Inc.,
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""Generic Human Interface Device API.
It is currently a partial pure-Python implementation of the native HID API
implemented by signal11 (https://github.com/signal11/hidapi), and requires
``pyudev``.
The docstrings are mostly copied from the hidapi API header, with changes where
necessary.
"""
from __future__ import absolute_import, division, print_function, unicode_literals
import errno as _errno
import os as _os
# the tuple object we'll expose when enumerating devices
from collections import namedtuple
from select import select as _select
from time import sleep
from pyudev import Context as _Context
from pyudev import Device as _Device
from pyudev import DeviceNotFoundError
from pyudev import Monitor as _Monitor
native_implementation = 'udev'
DeviceInfo = namedtuple('DeviceInfo', [
'path',
'vendor_id',
'product_id',
'serial',
'release',
'manufacturer',
'product',
'interface',
'driver',
])
del namedtuple
#
# exposed API
# docstrings mostly copied from hidapi.h
#
def init():
"""This function is a no-op, and exists only to match the native hidapi
implementation.
:returns: ``True``.
"""
return True
def exit():
"""This function is a no-op, and exists only to match the native hidapi
implementation.
:returns: ``True``.
"""
return True
# The filter is used to determine whether this is a device of interest to Solaar
def _match(action, device, filter):
vendor_id = filter.get('vendor_id')
product_id = filter.get('product_id')
interface_number = filter.get('usb_interface')
hid_driver = filter.get('hid_driver')
usb_device = device.find_parent('usb', 'usb_device')
# print ("* parent", action, device, "usb:", usb_device)
if not usb_device:
return
vid = usb_device.get('ID_VENDOR_ID')
pid = usb_device.get('ID_MODEL_ID')
if vid is None or pid is None:
return # there are reports that sometimes the usb_device isn't set up right so be defensive
if not ((vendor_id is None or vendor_id == int(vid, 16)) and (product_id is None or product_id == int(pid, 16))):
return
if action == 'add':
hid_device = device.find_parent('hid')
if not hid_device:
return
hid_driver_name = hid_device.get('DRIVER')
# print ("** found hid", action, device, "hid:", hid_device, hid_driver_name)
if hid_driver:
if isinstance(hid_driver, tuple):
if hid_driver_name not in hid_driver:
return
elif hid_driver_name != hid_driver:
return
intf_device = device.find_parent('usb', 'usb_interface')
# print ("*** usb interface", action, device, "usb_interface:", intf_device)
if interface_number is None:
usb_interface = None if intf_device is None else intf_device.attributes.asint('bInterfaceNumber')
else:
usb_interface = None if intf_device is None else intf_device.attributes.asint('bInterfaceNumber')
if usb_interface is None or interface_number != usb_interface:
return
attrs = usb_device.attributes
d_info = DeviceInfo(path=device.device_node,
vendor_id=vid[-4:],
product_id=pid[-4:],
serial=hid_device.get('HID_UNIQ'),
release=attrs.get('bcdDevice'),
manufacturer=attrs.get('manufacturer'),
product=attrs.get('product'),
interface=usb_interface,
driver=hid_driver_name)
return d_info
elif action == 'remove':
# print (dict(device), dict(usb_device))
d_info = DeviceInfo(path=device.device_node,
vendor_id=vid[-4:],
product_id=pid[-4:],
serial=None,
release=None,
manufacturer=None,
product=None,
interface=None,
driver=None)
return d_info
def monitor_glib(callback, *device_filters):
from gi.repository import GLib
c = _Context()
# already existing devices
# for device in c.list_devices(subsystem='hidraw'):
# # print (device, dict(device), dict(device.attributes))
# for filter in device_filters:
# d_info = _match('add', device, *filter)
# if d_info:
# GLib.idle_add(callback, 'add', d_info)
# break
m = _Monitor.from_netlink(c)
m.filter_by(subsystem='hidraw')
def _process_udev_event(monitor, condition, cb, filters):
if condition == GLib.IO_IN:
event = monitor.receive_device()
if event:
action, device = event
# print ("***", action, device)
if action == 'add':
for filter in filters:
d_info = _match(action, device, filter)
if d_info:
GLib.idle_add(cb, action, d_info)
break
elif action == 'remove':
# the GLib notification does _not_ match!
pass
return True
try:
# io_add_watch_full may not be available...
GLib.io_add_watch_full(m, GLib.PRIORITY_LOW, GLib.IO_IN, _process_udev_event, callback, device_filters)
# print ("did io_add_watch_full")
except AttributeError:
try:
# and the priority parameter appeared later in the API
GLib.io_add_watch(m, GLib.PRIORITY_LOW, GLib.IO_IN, _process_udev_event, callback, device_filters)
# print ("did io_add_watch with priority")
except Exception:
GLib.io_add_watch(m, GLib.IO_IN, _process_udev_event, callback, device_filters)
# print ("did io_add_watch")
m.start()
def enumerate(usb_id):
"""Enumerate the HID Devices.
List all the HID devices attached to the system, optionally filtering by
vendor_id, product_id, and/or interface_number.
:returns: a list of matching ``DeviceInfo`` tuples.
"""
for dev in _Context().list_devices(subsystem='hidraw'):
dev_info = _match('add', dev, usb_id)
if dev_info:
yield dev_info
def open(vendor_id, product_id, serial=None):
"""Open a HID device by its Vendor ID, Product ID and optional serial number.
If no serial is provided, the first device with the specified IDs is opened.
:returns: an opaque device handle, or ``None``.
"""
for device in enumerate(vendor_id, product_id):
if serial is None or serial == device.serial:
return open_path(device.path)
def open_path(device_path):
"""Open a HID device by its path name.
:param device_path: the path of a ``DeviceInfo`` tuple returned by
enumerate().
:returns: an opaque device handle, or ``None``.
"""
assert device_path
assert device_path.startswith('/dev/hidraw')
return _os.open(device_path, _os.O_RDWR | _os.O_SYNC)
def close(device_handle):
"""Close a HID device.
:param device_handle: a device handle returned by open() or open_path().
"""
assert device_handle
_os.close(device_handle)
def write(device_handle, data):
"""Write an Output report to a HID device.
:param device_handle: a device handle returned by open() or open_path().
:param data: the data bytes to send including the report number as the
first byte.
The first byte of data[] must contain the Report ID. For
devices which only support a single report, this must be set
to 0x0. The remaining bytes contain the report data. Since
the Report ID is mandatory, calls to hid_write() will always
contain one more byte than the report contains. For example,
if a hid report is 16 bytes long, 17 bytes must be passed to
hid_write(), the Report ID (or 0x0, for devices with a
single report), followed by the report data (16 bytes). In
this example, the length passed in would be 17.
write() will send the data on the first OUT endpoint, if
one exists. If it does not, it will send the data through
the Control Endpoint (Endpoint 0).
"""
assert device_handle
assert data
assert isinstance(data, bytes), (repr(data), type(data))
retrycount = 0
bytes_written = 0
while (retrycount < 3):
try:
bytes_written = _os.write(device_handle, data)
retrycount += 1
except IOError as e:
if e.errno == _errno.EPIPE:
sleep(0.1)
else:
break
if bytes_written != len(data):
raise IOError(_errno.EIO, 'written %d bytes out of expected %d' % (bytes_written, len(data)))
def read(device_handle, bytes_count, timeout_ms=-1):
"""Read an Input report from a HID device.
:param device_handle: a device handle returned by open() or open_path().
:param bytes_count: maximum number of bytes to read.
:param timeout_ms: can be -1 (default) to wait for data indefinitely, 0 to
read whatever is in the device's input buffer, or a positive integer to
wait that many milliseconds.
Input reports are returned to the host through the INTERRUPT IN endpoint.
The first byte will contain the Report number if the device uses numbered
reports.
:returns: the data packet read, an empty bytes string if a timeout was
reached, or None if there was an error while reading.
"""
assert device_handle
timeout = None if timeout_ms < 0 else timeout_ms / 1000.0
rlist, wlist, xlist = _select([device_handle], [], [device_handle], timeout)
if xlist:
assert xlist == [device_handle]
raise IOError(_errno.EIO, 'exception on file descriptor %d' % device_handle)
if rlist:
assert rlist == [device_handle]
data = _os.read(device_handle, bytes_count)
assert data is not None
assert isinstance(data, bytes), (repr(data), type(data))
return data
else:
return b''
_DEVICE_STRINGS = {
0: 'manufacturer',
1: 'product',
2: 'serial',
}
def get_manufacturer(device_handle):
"""Get the Manufacturer String from a HID device.
:param device_handle: a device handle returned by open() or open_path().
"""
return get_indexed_string(device_handle, 0)
def get_product(device_handle):
"""Get the Product String from a HID device.
:param device_handle: a device handle returned by open() or open_path().
"""
return get_indexed_string(device_handle, 1)
def get_serial(device_handle):
"""Get the serial number from a HID device.
:param device_handle: a device handle returned by open() or open_path().
"""
serial = get_indexed_string(device_handle, 2)
if serial is not None:
return ''.join(hex(ord(c)) for c in serial)
def get_indexed_string(device_handle, index):
"""Get a string from a HID device, based on its string index.
Note: currently not working in the ``hidraw`` native implementation.
:param device_handle: a device handle returned by open() or open_path().
:param index: the index of the string to get.
:returns: the value corresponding to index, or None if no value found
:rtype: bytes or NoneType
"""
try:
key = _DEVICE_STRINGS[index]
except KeyError:
return None
assert device_handle
stat = _os.fstat(device_handle)
try:
dev = _Device.from_device_number(_Context(), 'char', stat.st_rdev)
except (DeviceNotFoundError, ValueError):
return None
hid_dev = dev.find_parent('hid')
if hid_dev:
assert 'HID_ID' in hid_dev
bus, _ignore, _ignore = hid_dev['HID_ID'].split(':')
if bus == '0003': # USB
usb_dev = dev.find_parent('usb', 'usb_device')
assert usb_dev
return usb_dev.attributes.get(key)
elif bus == '0005': # BLUETOOTH
# TODO
pass