Date: Fri, 21 Oct 2005 22:39:49 +0200 From: Bernd Walter <ticso@cicely12.cicely.de> To: Frank Behrens <frank@pinky.sax.de> Cc: freebsd-hackers@freebsd.org Subject: Re: How disable attachment of sio(4) driver to device? Message-ID: <20051021203948.GQ31913@cicely12.cicely.de> In-Reply-To: <200510210835.j9L8Zn2P001846@pinky.frank-behrens.de> References: <200510210835.j9L8Zn2P001846@pinky.frank-behrens.de>
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On Fri, Oct 21, 2005 at 10:35:43AM +0200, Frank Behrens wrote: > Hi, > > I'm writing a device driver for UART with a protocol, that can not be > handled by the default sio(4) driver. The driver works fine - the > only problem I have is to disable the attachment of sio(4) driver to > the device. If it is just needing tx-enable for RS485 you might use a standard FT232BM chip - they have support to do it transparently. However, if you need 9-bit or complex timing it's problematic. But even with 16550 and special kernel driver timing is hard to do it right. I personally build specialized USB and Ethernet devices for doing Modbus/RTU RS485 timing. -- B.Walter BWCT http://www.bwct.de bernd@bwct.de info@bwct.de
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