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Diffstat (limited to 'serial/serialposix.py')
| -rw-r--r-- | serial/serialposix.py | 900 |
1 files changed, 900 insertions, 0 deletions
diff --git a/serial/serialposix.py b/serial/serialposix.py new file mode 100644 index 0000000..7aceb76 --- /dev/null +++ b/serial/serialposix.py @@ -0,0 +1,900 @@ +#!/usr/bin/env python +# +# backend for serial IO for POSIX compatible systems, like Linux, OSX +# +# This file is part of pySerial. https://github.com/pyserial/pyserial +# (C) 2001-2020 Chris Liechti <cliechti@gmx.net> +# +# SPDX-License-Identifier: BSD-3-Clause +# +# parts based on code from Grant B. Edwards <grante@visi.com>: +# ftp://ftp.visi.com/users/grante/python/PosixSerial.py +# +# references: http://www.easysw.com/~mike/serial/serial.html + +# Collection of port names (was previously used by number_to_device which was +# removed. +# - Linux /dev/ttyS%d (confirmed) +# - cygwin/win32 /dev/com%d (confirmed) +# - openbsd (OpenBSD) /dev/cua%02d +# - bsd*, freebsd* /dev/cuad%d +# - darwin (OS X) /dev/cuad%d +# - netbsd /dev/dty%02d (NetBSD 1.6 testing by Erk) +# - irix (IRIX) /dev/ttyf%d (partially tested) names depending on flow control +# - hp (HP-UX) /dev/tty%dp0 (not tested) +# - sunos (Solaris/SunOS) /dev/tty%c (letters, 'a'..'z') (confirmed) +# - aix (AIX) /dev/tty%d + + +from __future__ import absolute_import + +# pylint: disable=abstract-method +import errno +import fcntl +import os +import select +import struct +import sys +import termios + +import serial +from serial.serialutil import SerialBase, SerialException, to_bytes, \ + PortNotOpenError, SerialTimeoutException, Timeout + + +class PlatformSpecificBase(object): + BAUDRATE_CONSTANTS = {} + + def _set_special_baudrate(self, baudrate): + raise NotImplementedError('non-standard baudrates are not supported on this platform') + + def _set_rs485_mode(self, rs485_settings): + raise NotImplementedError('RS485 not supported on this platform') + + def set_low_latency_mode(self, low_latency_settings): + raise NotImplementedError('Low latency not supported on this platform') + + def _update_break_state(self): + """\ + Set break: Controls TXD. When active, no transmitting is possible. + """ + if self._break_state: + fcntl.ioctl(self.fd, TIOCSBRK) + else: + fcntl.ioctl(self.fd, TIOCCBRK) + + +# some systems support an extra flag to enable the two in POSIX unsupported +# paritiy settings for MARK and SPACE +CMSPAR = 0 # default, for unsupported platforms, override below + +# try to detect the OS so that a device can be selected... +# this code block should supply a device() and set_special_baudrate() function +# for the platform +plat = sys.platform.lower() + +if plat[:5] == 'linux': # Linux (confirmed) # noqa + import array + + # extra termios flags + CMSPAR = 0o10000000000 # Use "stick" (mark/space) parity + + # baudrate ioctls + TCGETS2 = 0x802C542A + TCSETS2 = 0x402C542B + BOTHER = 0o010000 + + # RS485 ioctls + TIOCGRS485 = 0x542E + TIOCSRS485 = 0x542F + SER_RS485_ENABLED = 0b00000001 + SER_RS485_RTS_ON_SEND = 0b00000010 + SER_RS485_RTS_AFTER_SEND = 0b00000100 + SER_RS485_RX_DURING_TX = 0b00010000 + + class PlatformSpecific(PlatformSpecificBase): + BAUDRATE_CONSTANTS = { + 0: 0o000000, # hang up + 50: 0o000001, + 75: 0o000002, + 110: 0o000003, + 134: 0o000004, + 150: 0o000005, + 200: 0o000006, + 300: 0o000007, + 600: 0o000010, + 1200: 0o000011, + 1800: 0o000012, + 2400: 0o000013, + 4800: 0o000014, + 9600: 0o000015, + 19200: 0o000016, + 38400: 0o000017, + 57600: 0o010001, + 115200: 0o010002, + 230400: 0o010003, + 460800: 0o010004, + 500000: 0o010005, + 576000: 0o010006, + 921600: 0o010007, + 1000000: 0o010010, + 1152000: 0o010011, + 1500000: 0o010012, + 2000000: 0o010013, + 2500000: 0o010014, + 3000000: 0o010015, + 3500000: 0o010016, + 4000000: 0o010017 + } + + def set_low_latency_mode(self, low_latency_settings): + buf = array.array('i', [0] * 32) + + try: + # get serial_struct + fcntl.ioctl(self.fd, termios.TIOCGSERIAL, buf) + + # set or unset ASYNC_LOW_LATENCY flag + if low_latency_settings: + buf[4] |= 0x2000 + else: + buf[4] &= ~0x2000 + + # set serial_struct + fcntl.ioctl(self.fd, termios.TIOCSSERIAL, buf) + except IOError as e: + raise ValueError('Failed to update ASYNC_LOW_LATENCY flag to {}: {}'.format(low_latency_settings, e)) + + def _set_special_baudrate(self, baudrate): + # right size is 44 on x86_64, allow for some growth + buf = array.array('i', [0] * 64) + try: + # get serial_struct + fcntl.ioctl(self.fd, TCGETS2, buf) + # set custom speed + buf[2] &= ~termios.CBAUD + buf[2] |= BOTHER + buf[9] = buf[10] = baudrate + + # set serial_struct + fcntl.ioctl(self.fd, TCSETS2, buf) + except IOError as e: + raise ValueError('Failed to set custom baud rate ({}): {}'.format(baudrate, e)) + + def _set_rs485_mode(self, rs485_settings): + buf = array.array('i', [0] * 8) # flags, delaytx, delayrx, padding + try: + fcntl.ioctl(self.fd, TIOCGRS485, buf) + buf[0] |= SER_RS485_ENABLED + if rs485_settings is not None: + if rs485_settings.loopback: + buf[0] |= SER_RS485_RX_DURING_TX + else: + buf[0] &= ~SER_RS485_RX_DURING_TX + if rs485_settings.rts_level_for_tx: + buf[0] |= SER_RS485_RTS_ON_SEND + else: + buf[0] &= ~SER_RS485_RTS_ON_SEND + if rs485_settings.rts_level_for_rx: + buf[0] |= SER_RS485_RTS_AFTER_SEND + else: + buf[0] &= ~SER_RS485_RTS_AFTER_SEND + if rs485_settings.delay_before_tx is not None: + buf[1] = int(rs485_settings.delay_before_tx * 1000) + if rs485_settings.delay_before_rx is not None: + buf[2] = int(rs485_settings.delay_before_rx * 1000) + else: + buf[0] = 0 # clear SER_RS485_ENABLED + fcntl.ioctl(self.fd, TIOCSRS485, buf) + except IOError as e: + raise ValueError('Failed to set RS485 mode: {}'.format(e)) + + +elif plat == 'cygwin': # cygwin/win32 (confirmed) + + class PlatformSpecific(PlatformSpecificBase): + BAUDRATE_CONSTANTS = { + 128000: 0x01003, + 256000: 0x01005, + 500000: 0x01007, + 576000: 0x01008, + 921600: 0x01009, + 1000000: 0x0100a, + 1152000: 0x0100b, + 1500000: 0x0100c, + 2000000: 0x0100d, + 2500000: 0x0100e, + 3000000: 0x0100f + } + + +elif plat[:6] == 'darwin': # OS X + import array + IOSSIOSPEED = 0x80045402 # _IOW('T', 2, speed_t) + + class PlatformSpecific(PlatformSpecificBase): + osx_version = os.uname()[2].split('.') + TIOCSBRK = 0x2000747B # _IO('t', 123) + TIOCCBRK = 0x2000747A # _IO('t', 122) + + # Tiger or above can support arbitrary serial speeds + if int(osx_version[0]) >= 8: + def _set_special_baudrate(self, baudrate): + # use IOKit-specific call to set up high speeds + buf = array.array('i', [baudrate]) + fcntl.ioctl(self.fd, IOSSIOSPEED, buf, 1) + + def _update_break_state(self): + """\ + Set break: Controls TXD. When active, no transmitting is possible. + """ + if self._break_state: + fcntl.ioctl(self.fd, PlatformSpecific.TIOCSBRK) + else: + fcntl.ioctl(self.fd, PlatformSpecific.TIOCCBRK) + +elif plat[:3] == 'bsd' or \ + plat[:7] == 'freebsd' or \ + plat[:6] == 'netbsd' or \ + plat[:7] == 'openbsd': + + class ReturnBaudrate(object): + def __getitem__(self, key): + return key + + class PlatformSpecific(PlatformSpecificBase): + # Only tested on FreeBSD: + # The baud rate may be passed in as + # a literal value. + BAUDRATE_CONSTANTS = ReturnBaudrate() + + TIOCSBRK = 0x2000747B # _IO('t', 123) + TIOCCBRK = 0x2000747A # _IO('t', 122) + + + def _update_break_state(self): + """\ + Set break: Controls TXD. When active, no transmitting is possible. + """ + if self._break_state: + fcntl.ioctl(self.fd, PlatformSpecific.TIOCSBRK) + else: + fcntl.ioctl(self.fd, PlatformSpecific.TIOCCBRK) + +else: + class PlatformSpecific(PlatformSpecificBase): + pass + + +# load some constants for later use. +# try to use values from termios, use defaults from linux otherwise +TIOCMGET = getattr(termios, 'TIOCMGET', 0x5415) +TIOCMBIS = getattr(termios, 'TIOCMBIS', 0x5416) +TIOCMBIC = getattr(termios, 'TIOCMBIC', 0x5417) +TIOCMSET = getattr(termios, 'TIOCMSET', 0x5418) + +# TIOCM_LE = getattr(termios, 'TIOCM_LE', 0x001) +TIOCM_DTR = getattr(termios, 'TIOCM_DTR', 0x002) +TIOCM_RTS = getattr(termios, 'TIOCM_RTS', 0x004) +# TIOCM_ST = getattr(termios, 'TIOCM_ST', 0x008) +# TIOCM_SR = getattr(termios, 'TIOCM_SR', 0x010) + +TIOCM_CTS = getattr(termios, 'TIOCM_CTS', 0x020) +TIOCM_CAR = getattr(termios, 'TIOCM_CAR', 0x040) +TIOCM_RNG = getattr(termios, 'TIOCM_RNG', 0x080) +TIOCM_DSR = getattr(termios, 'TIOCM_DSR', 0x100) +TIOCM_CD = getattr(termios, 'TIOCM_CD', TIOCM_CAR) +TIOCM_RI = getattr(termios, 'TIOCM_RI', TIOCM_RNG) +# TIOCM_OUT1 = getattr(termios, 'TIOCM_OUT1', 0x2000) +# TIOCM_OUT2 = getattr(termios, 'TIOCM_OUT2', 0x4000) +if hasattr(termios, 'TIOCINQ'): + TIOCINQ = termios.TIOCINQ +else: + TIOCINQ = getattr(termios, 'FIONREAD', 0x541B) +TIOCOUTQ = getattr(termios, 'TIOCOUTQ', 0x5411) + +TIOCM_zero_str = struct.pack('I', 0) +TIOCM_RTS_str = struct.pack('I', TIOCM_RTS) +TIOCM_DTR_str = struct.pack('I', TIOCM_DTR) + +TIOCSBRK = getattr(termios, 'TIOCSBRK', 0x5427) +TIOCCBRK = getattr(termios, 'TIOCCBRK', 0x5428) + + +class Serial(SerialBase, PlatformSpecific): + """\ + Serial port class POSIX implementation. Serial port configuration is + done with termios and fcntl. Runs on Linux and many other Un*x like + systems. + """ + + def open(self): + """\ + Open port with current settings. This may throw a SerialException + if the port cannot be opened.""" + if self._port is None: + raise SerialException("Port must be configured before it can be used.") + if self.is_open: + raise SerialException("Port is already open.") + self.fd = None + # open + try: + self.fd = os.open(self.portstr, os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK) + except OSError as msg: + self.fd = None + raise SerialException(msg.errno, "could not open port {}: {}".format(self._port, msg)) + #~ fcntl.fcntl(self.fd, fcntl.F_SETFL, 0) # set blocking + + self.pipe_abort_read_r, self.pipe_abort_read_w = None, None + self.pipe_abort_write_r, self.pipe_abort_write_w = None, None + + try: + self._reconfigure_port(force_update=True) + + try: + if not self._dsrdtr: + self._update_dtr_state() + if not self._rtscts: + self._update_rts_state() + except IOError as e: + # ignore Invalid argument and Inappropriate ioctl + if e.errno not in (errno.EINVAL, errno.ENOTTY): + raise + + self._reset_input_buffer() + + self.pipe_abort_read_r, self.pipe_abort_read_w = os.pipe() + self.pipe_abort_write_r, self.pipe_abort_write_w = os.pipe() + fcntl.fcntl(self.pipe_abort_read_r, fcntl.F_SETFL, os.O_NONBLOCK) + fcntl.fcntl(self.pipe_abort_write_r, fcntl.F_SETFL, os.O_NONBLOCK) + except BaseException: + try: + os.close(self.fd) + except Exception: + # ignore any exception when closing the port + # also to keep original exception that happened when setting up + pass + self.fd = None + + if self.pipe_abort_read_w is not None: + os.close(self.pipe_abort_read_w) + self.pipe_abort_read_w = None + if self.pipe_abort_read_r is not None: + os.close(self.pipe_abort_read_r) + self.pipe_abort_read_r = None + if self.pipe_abort_write_w is not None: + os.close(self.pipe_abort_write_w) + self.pipe_abort_write_w = None + if self.pipe_abort_write_r is not None: + os.close(self.pipe_abort_write_r) + self.pipe_abort_write_r = None + + raise + + self.is_open = True + + def _reconfigure_port(self, force_update=False): + """Set communication parameters on opened port.""" + if self.fd is None: + raise SerialException("Can only operate on a valid file descriptor") + + # if exclusive lock is requested, create it before we modify anything else + if self._exclusive is not None: + if self._exclusive: + try: + fcntl.flock(self.fd, fcntl.LOCK_EX | fcntl.LOCK_NB) + except IOError as msg: + raise SerialException(msg.errno, "Could not exclusively lock port {}: {}".format(self._port, msg)) + else: + fcntl.flock(self.fd, fcntl.LOCK_UN) + + custom_baud = None + + vmin = vtime = 0 # timeout is done via select + if self._inter_byte_timeout is not None: + vmin = 1 + vtime = int(self._inter_byte_timeout * 10) + try: + orig_attr = termios.tcgetattr(self.fd) + iflag, oflag, cflag, lflag, ispeed, ospeed, cc = orig_attr + except termios.error as msg: # if a port is nonexistent but has a /dev file, it'll fail here + raise SerialException("Could not configure port: {}".format(msg)) + # set up raw mode / no echo / binary + cflag |= (termios.CLOCAL | termios.CREAD) + lflag &= ~(termios.ICANON | termios.ECHO | termios.ECHOE | + termios.ECHOK | termios.ECHONL | + termios.ISIG | termios.IEXTEN) # |termios.ECHOPRT + for flag in ('ECHOCTL', 'ECHOKE'): # netbsd workaround for Erk + if hasattr(termios, flag): + lflag &= ~getattr(termios, flag) + + oflag &= ~(termios.OPOST | termios.ONLCR | termios.OCRNL) + iflag &= ~(termios.INLCR | termios.IGNCR | termios.ICRNL | termios.IGNBRK) + if hasattr(termios, 'IUCLC'): + iflag &= ~termios.IUCLC + if hasattr(termios, 'PARMRK'): + iflag &= ~termios.PARMRK + + # setup baud rate + try: + ispeed = ospeed = getattr(termios, 'B{}'.format(self._baudrate)) + except AttributeError: + try: + ispeed = ospeed = self.BAUDRATE_CONSTANTS[self._baudrate] + except KeyError: + #~ raise ValueError('Invalid baud rate: %r' % self._baudrate) + + # See if BOTHER is defined for this platform; if it is, use + # this for a speed not defined in the baudrate constants list. + try: + ispeed = ospeed = BOTHER + except NameError: + # may need custom baud rate, it isn't in our list. + ispeed = ospeed = getattr(termios, 'B38400') + + try: + custom_baud = int(self._baudrate) # store for later + except ValueError: + raise ValueError('Invalid baud rate: {!r}'.format(self._baudrate)) + else: + if custom_baud < 0: + raise ValueError('Invalid baud rate: {!r}'.format(self._baudrate)) + + # setup char len + cflag &= ~termios.CSIZE + if self._bytesize == 8: + cflag |= termios.CS8 + elif self._bytesize == 7: + cflag |= termios.CS7 + elif self._bytesize == 6: + cflag |= termios.CS6 + elif self._bytesize == 5: + cflag |= termios.CS5 + else: + raise ValueError('Invalid char len: {!r}'.format(self._bytesize)) + # setup stop bits + if self._stopbits == serial.STOPBITS_ONE: + cflag &= ~(termios.CSTOPB) + elif self._stopbits == serial.STOPBITS_ONE_POINT_FIVE: + cflag |= (termios.CSTOPB) # XXX same as TWO.. there is no POSIX support for 1.5 + elif self._stopbits == serial.STOPBITS_TWO: + cflag |= (termios.CSTOPB) + else: + raise ValueError('Invalid stop bit specification: {!r}'.format(self._stopbits)) + # setup parity + iflag &= ~(termios.INPCK | termios.ISTRIP) + if self._parity == serial.PARITY_NONE: + cflag &= ~(termios.PARENB | termios.PARODD | CMSPAR) + elif self._parity == serial.PARITY_EVEN: + cflag &= ~(termios.PARODD | CMSPAR) + cflag |= (termios.PARENB) + elif self._parity == serial.PARITY_ODD: + cflag &= ~CMSPAR + cflag |= (termios.PARENB | termios.PARODD) + elif self._parity == serial.PARITY_MARK and CMSPAR: + cflag |= (termios.PARENB | CMSPAR | termios.PARODD) + elif self._parity == serial.PARITY_SPACE and CMSPAR: + cflag |= (termios.PARENB | CMSPAR) + cflag &= ~(termios.PARODD) + else: + raise ValueError('Invalid parity: {!r}'.format(self._parity)) + # setup flow control + # xonxoff + if hasattr(termios, 'IXANY'): + if self._xonxoff: + iflag |= (termios.IXON | termios.IXOFF) # |termios.IXANY) + else: + iflag &= ~(termios.IXON | termios.IXOFF | termios.IXANY) + else: + if self._xonxoff: + iflag |= (termios.IXON | termios.IXOFF) + else: + iflag &= ~(termios.IXON | termios.IXOFF) + # rtscts + if hasattr(termios, 'CRTSCTS'): + if self._rtscts: + cflag |= (termios.CRTSCTS) + else: + cflag &= ~(termios.CRTSCTS) + elif hasattr(termios, 'CNEW_RTSCTS'): # try it with alternate constant name + if self._rtscts: + cflag |= (termios.CNEW_RTSCTS) + else: + cflag &= ~(termios.CNEW_RTSCTS) + # XXX should there be a warning if setting up rtscts (and xonxoff etc) fails?? + + # buffer + # vmin "minimal number of characters to be read. 0 for non blocking" + if vmin < 0 or vmin > 255: + raise ValueError('Invalid vmin: {!r}'.format(vmin)) + cc[termios.VMIN] = vmin + # vtime + if vtime < 0 or vtime > 255: + raise ValueError('Invalid vtime: {!r}'.format(vtime)) + cc[termios.VTIME] = vtime + # activate settings + if force_update or [iflag, oflag, cflag, lflag, ispeed, ospeed, cc] != orig_attr: + termios.tcsetattr( + self.fd, + termios.TCSANOW, + [iflag, oflag, cflag, lflag, ispeed, ospeed, cc]) + + # apply custom baud rate, if any + if custom_baud is not None: + self._set_special_baudrate(custom_baud) + + if self._rs485_mode is not None: + self._set_rs485_mode(self._rs485_mode) + + def close(self): + """Close port""" + if self.is_open: + if self.fd is not None: + os.close(self.fd) + self.fd = None + os.close(self.pipe_abort_read_w) + os.close(self.pipe_abort_read_r) + os.close(self.pipe_abort_write_w) + os.close(self.pipe_abort_write_r) + self.pipe_abort_read_r, self.pipe_abort_read_w = None, None + self.pipe_abort_write_r, self.pipe_abort_write_w = None, None + self.is_open = False + + # - - - - - - - - - - - - - - - - - - - - - - - - + + @property + def in_waiting(self): + """Return the number of bytes currently in the input buffer.""" + #~ s = fcntl.ioctl(self.fd, termios.FIONREAD, TIOCM_zero_str) + s = fcntl.ioctl(self.fd, TIOCINQ, TIOCM_zero_str) + return struct.unpack('I', s)[0] + + # select based implementation, proved to work on many systems + def read(self, size=1): + """\ + Read size bytes from the serial port. If a timeout is set it may + return less characters as requested. With no timeout it will block + until the requested number of bytes is read. + """ + if not self.is_open: + raise PortNotOpenError() + read = bytearray() + timeout = Timeout(self._timeout) + while len(read) < size: + try: + ready, _, _ = select.select([self.fd, self.pipe_abort_read_r], [], [], timeout.time_left()) + if self.pipe_abort_read_r in ready: + os.read(self.pipe_abort_read_r, 1000) + break + # If select was used with a timeout, and the timeout occurs, it + # returns with empty lists -> thus abort read operation. + # For timeout == 0 (non-blocking operation) also abort when + # there is nothing to read. + if not ready: + break # timeout + buf = os.read(self.fd, size - len(read)) + except OSError as e: + # this is for Python 3.x where select.error is a subclass of + # OSError ignore BlockingIOErrors and EINTR. other errors are shown + # https://www.python.org/dev/peps/pep-0475. + if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): + raise SerialException('read failed: {}'.format(e)) + except select.error as e: + # this is for Python 2.x + # ignore BlockingIOErrors and EINTR. all errors are shown + # see also http://www.python.org/dev/peps/pep-3151/#select + if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): + raise SerialException('read failed: {}'.format(e)) + else: + # read should always return some data as select reported it was + # ready to read when we get to this point. + if not buf: + # Disconnected devices, at least on Linux, show the + # behavior that they are always ready to read immediately + # but reading returns nothing. + raise SerialException( + 'device reports readiness to read but returned no data ' + '(device disconnected or multiple access on port?)') + read.extend(buf) + + if timeout.expired(): + break + return bytes(read) + + def cancel_read(self): + if self.is_open: + os.write(self.pipe_abort_read_w, b"x") + + def cancel_write(self): + if self.is_open: + os.write(self.pipe_abort_write_w, b"x") + + def write(self, data): + """Output the given byte string over the serial port.""" + if not self.is_open: + raise PortNotOpenError() + d = to_bytes(data) + tx_len = length = len(d) + timeout = Timeout(self._write_timeout) + while tx_len > 0: + try: + n = os.write(self.fd, d) + if timeout.is_non_blocking: + # Zero timeout indicates non-blocking - simply return the + # number of bytes of data actually written + return n + elif not timeout.is_infinite: + # when timeout is set, use select to wait for being ready + # with the time left as timeout + if timeout.expired(): + raise SerialTimeoutException('Write timeout') + abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], timeout.time_left()) + if abort: + os.read(self.pipe_abort_write_r, 1000) + break + if not ready: + raise SerialTimeoutException('Write timeout') + else: + assert timeout.time_left() is None + # wait for write operation + abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], None) + if abort: + os.read(self.pipe_abort_write_r, 1) + break + if not ready: + raise SerialException('write failed (select)') + d = d[n:] + tx_len -= n + except SerialException: + raise + except OSError as e: + # this is for Python 3.x where select.error is a subclass of + # OSError ignore BlockingIOErrors and EINTR. other errors are shown + # https://www.python.org/dev/peps/pep-0475. + if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): + raise SerialException('write failed: {}'.format(e)) + except select.error as e: + # this is for Python 2.x + # ignore BlockingIOErrors and EINTR. all errors are shown + # see also http://www.python.org/dev/peps/pep-3151/#select + if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): + raise SerialException('write failed: {}'.format(e)) + if not timeout.is_non_blocking and timeout.expired(): + raise SerialTimeoutException('Write timeout') + return length - len(d) + + def flush(self): + """\ + Flush of file like objects. In this case, wait until all data + is written. + """ + if not self.is_open: + raise PortNotOpenError() + termios.tcdrain(self.fd) + + def _reset_input_buffer(self): + """Clear input buffer, discarding all that is in the buffer.""" + termios.tcflush(self.fd, termios.TCIFLUSH) + + def reset_input_buffer(self): + """Clear input buffer, discarding all that is in the buffer.""" + if not self.is_open: + raise PortNotOpenError() + self._reset_input_buffer() + + def reset_output_buffer(self): + """\ + Clear output buffer, aborting the current output and discarding all + that is in the buffer. + """ + if not self.is_open: + raise PortNotOpenError() + termios.tcflush(self.fd, termios.TCOFLUSH) + + def send_break(self, duration=0.25): + """\ + Send break condition. Timed, returns to idle state after given + duration. + """ + if not self.is_open: + raise PortNotOpenError() + termios.tcsendbreak(self.fd, int(duration / 0.25)) + + def _update_rts_state(self): + """Set terminal status line: Request To Send""" + if self._rts_state: + fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_RTS_str) + else: + fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_RTS_str) + + def _update_dtr_state(self): + """Set terminal status line: Data Terminal Ready""" + if self._dtr_state: + fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_DTR_str) + else: + fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_DTR_str) + + @property + def cts(self): + """Read terminal status line: Clear To Send""" + if not self.is_open: + raise PortNotOpenError() + s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str) + return struct.unpack('I', s)[0] & TIOCM_CTS != 0 + + @property + def dsr(self): + """Read terminal status line: Data Set Ready""" + if not self.is_open: + raise PortNotOpenError() + s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str) + return struct.unpack('I', s)[0] & TIOCM_DSR != 0 + + @property + def ri(self): + """Read terminal status line: Ring Indicator""" + if not self.is_open: + raise PortNotOpenError() + s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str) + return struct.unpack('I', s)[0] & TIOCM_RI != 0 + + @property + def cd(self): + """Read terminal status line: Carrier Detect""" + if not self.is_open: + raise PortNotOpenError() + s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str) + return struct.unpack('I', s)[0] & TIOCM_CD != 0 + + # - - platform specific - - - - + + @property + def out_waiting(self): + """Return the number of bytes currently in the output buffer.""" + #~ s = fcntl.ioctl(self.fd, termios.FIONREAD, TIOCM_zero_str) + s = fcntl.ioctl(self.fd, TIOCOUTQ, TIOCM_zero_str) + return struct.unpack('I', s)[0] + + def fileno(self): + """\ + For easier use of the serial port instance with select. + WARNING: this function is not portable to different platforms! + """ + if not self.is_open: + raise PortNotOpenError() + return self.fd + + def set_input_flow_control(self, enable=True): + """\ + Manually control flow - when software flow control is enabled. + This will send XON (true) or XOFF (false) to the other device. + WARNING: this function is not portable to different platforms! + """ + if not self.is_open: + raise PortNotOpenError() + if enable: + termios.tcflow(self.fd, termios.TCION) + else: + termios.tcflow(self.fd, termios.TCIOFF) + + def set_output_flow_control(self, enable=True): + """\ + Manually control flow of outgoing data - when hardware or software flow + control is enabled. + WARNING: this function is not portable to different platforms! + """ + if not self.is_open: + raise PortNotOpenError() + if enable: + termios.tcflow(self.fd, termios.TCOON) + else: + termios.tcflow(self.fd, termios.TCOOFF) + + def nonblocking(self): + """DEPRECATED - has no use""" + import warnings + warnings.warn("nonblocking() has no effect, already nonblocking", DeprecationWarning) + + +class PosixPollSerial(Serial): + """\ + Poll based read implementation. Not all systems support poll properly. + However this one has better handling of errors, such as a device + disconnecting while it's in use (e.g. USB-serial unplugged). + """ + + def read(self, size=1): + """\ + Read size bytes from the serial port. If a timeout is set it may + return less characters as requested. With no timeout it will block + until the requested number of bytes is read. + """ + if not self.is_open: + raise PortNotOpenError() + read = bytearray() + timeout = Timeout(self._timeout) + poll = select.poll() + poll.register(self.fd, select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) + poll.register(self.pipe_abort_read_r, select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) + if size > 0: + while len(read) < size: + # print "\tread(): size",size, "have", len(read) #debug + # wait until device becomes ready to read (or something fails) + for fd, event in poll.poll(None if timeout.is_infinite else (timeout.time_left() * 1000)): + if fd == self.pipe_abort_read_r: + break + if event & (select.POLLERR | select.POLLHUP | select.POLLNVAL): + raise SerialException('device reports error (poll)') + # we don't care if it is select.POLLIN or timeout, that's + # handled below + if fd == self.pipe_abort_read_r: + os.read(self.pipe_abort_read_r, 1000) + break + buf = os.read(self.fd, size - len(read)) + read.extend(buf) + if timeout.expired() \ + or (self._inter_byte_timeout is not None and self._inter_byte_timeout > 0) and not buf: + break # early abort on timeout + return bytes(read) + + +class VTIMESerial(Serial): + """\ + Implement timeout using vtime of tty device instead of using select. + This means that no inter character timeout can be specified and that + the error handling is degraded. + + Overall timeout is disabled when inter-character timeout is used. + + Note that this implementation does NOT support cancel_read(), it will + just ignore that. + """ + + def _reconfigure_port(self, force_update=True): + """Set communication parameters on opened port.""" + super(VTIMESerial, self)._reconfigure_port() + fcntl.fcntl(self.fd, fcntl.F_SETFL, 0) # clear O_NONBLOCK + + if self._inter_byte_timeout is not None: + vmin = 1 + vtime = int(self._inter_byte_timeout * 10) + elif self._timeout is None: + vmin = 1 + vtime = 0 + else: + vmin = 0 + vtime = int(self._timeout * 10) + try: + orig_attr = termios.tcgetattr(self.fd) + iflag, oflag, cflag, lflag, ispeed, ospeed, cc = orig_attr + except termios.error as msg: # if a port is nonexistent but has a /dev file, it'll fail here + raise serial.SerialException("Could not configure port: {}".format(msg)) + + if vtime < 0 or vtime > 255: + raise ValueError('Invalid vtime: {!r}'.format(vtime)) + cc[termios.VTIME] = vtime + cc[termios.VMIN] = vmin + + termios.tcsetattr( + self.fd, + termios.TCSANOW, + [iflag, oflag, cflag, lflag, ispeed, ospeed, cc]) + + def read(self, size=1): + """\ + Read size bytes from the serial port. If a timeout is set it may + return less characters as requested. With no timeout it will block + until the requested number of bytes is read. + """ + if not self.is_open: + raise PortNotOpenError() + read = bytearray() + while len(read) < size: + buf = os.read(self.fd, size - len(read)) + if not buf: + break + read.extend(buf) + return bytes(read) + + # hack to make hasattr return false + cancel_read = property() |