rs485: redo RS485 support, removed RTS toggle function
diff --git a/serial/serialposix.py b/serial/serialposix.py
index 0c3052a..26fecbd 100644
--- a/serial/serialposix.py
+++ b/serial/serialposix.py
@@ -12,8 +12,15 @@
#
# references: http://www.easysw.com/~mike/serial/serial.html
-import sys, os, fcntl, termios, struct, select, errno, time
+import errno
+import fcntl
import io
+import os
+import select
+import struct
+import sys
+import termios
+import time
from serial.serialutil import *
@@ -23,6 +30,7 @@
plat = sys.platform.lower()
if plat[:5] == 'linux': # Linux (confirmed)
+ import array
def device(port):
return '/dev/ttyS%d' % port
@@ -33,7 +41,6 @@
def set_special_baudrate(port, baudrate):
# right size is 44 on x86_64, allow for some growth
- import array
buf = array.array('i', [0] * 64)
try:
@@ -83,6 +90,41 @@
4000000: 0o010017
}
+ # 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
+
+ def set_rs485_mode(port, rs485_settings):
+ buf = array.array('i', [0] * 8) # flags, delaytx, delayrx, padding
+
+ try:
+ fcntl.ioctl(port.fd, TIOCGRS485, buf)
+ 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
+ buf[1] = int(rs485_settings.delay_rts_before_send * 1000)
+ buf[2] = int(rs485_settings.delay_rts_after_send * 1000)
+ else:
+ buf[0] = 0 # clear SER_RS485_ENABLED
+ res = fcntl.ioctl(port.fd, TIOCSRS485, buf)
+ except IOError as e:
+ raise ValueError('Failed to set RS485 mode: %s' % (e,))
+
+
elif plat == 'cygwin': # cygwin/win32 (confirmed)
def device(port):
@@ -127,13 +169,13 @@
baudrate_constants = {}
elif plat[:6] == 'darwin': # OS X
+ import array
version = os.uname()[2].split('.')
# Tiger or above can support arbitrary serial speeds
if int(version[0]) >= 8:
def set_special_baudrate(port, baudrate):
# use IOKit-specific call to set up high speeds
- import array
buf = array.array('i', [baudrate])
IOSSIOSPEED = 0x80045402 #_IOW('T', 2, speed_t)
fcntl.ioctl(port.fd, IOSSIOSPEED, buf, 1)
@@ -414,6 +456,10 @@
cflag &= ~(termios.CNEW_RTSCTS)
# XXX should there be a warning if setting up rtscts (and xonxoff etc) fails??
+ # XXX linux only
+ if self._rs485_mode is not None:
+ set_rs485_mode(self, self._rs485_mode)
+
# buffer
# vmin "minimal number of characters to be read. 0 for non blocking"
if vmin < 0 or vmin > 255: