From: Jochen <jochen@mades.net>
To: linux-serial@vger.kernel.org
Subject: Extending serial port linux driver to toggle RS485 direction pin (GPIO)
Date: Tue, 2 Nov 2021 18:55:56 +0100 [thread overview]
Message-ID: <731e2516-9703-8c9a-7e56-e7e7b362de94@mades.net> (raw)
Hello,
I have a RS485 hardware shield connected to the hardware uart of a raspberry PI3, where you have to toggle the RS485 driver DIRECTION-pin from within your software during write-commands. The DIR-Pin is connected to a GPIO pin of the PI.
As I do not want to do that in every application software, I thought it could be a good idea to enhance the serial-port driver (locally on my PI) with that functionality. Looking to the sources of amba-pl011.c I thought the "pl011_write"-function could be the right place to do so....but to be honest it seems not to work
Could you please give me a hint where to do that best in the serial port driver? (or is there already a RS485 driver with configurable Dir-GPIO-pin).
Is there a documentation of the serial-port architecture available which could help me to solve my problem?
Bests
Jochen
next reply other threads:[~2021-11-02 18:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-02 17:55 Jochen [this message]
2021-11-02 18:58 ` Extending serial port linux driver to toggle RS485 direction pin (GPIO) Greg KH
2021-11-03 7:23 ` Jochen Mades
2021-11-03 8:23 ` Greg KH
2021-11-16 6:43 ` Jochen Mades
2021-11-16 8:28 ` Greg KH
2021-11-16 11:47 ` Jochen Mades
2021-11-16 14:21 ` Greg KH
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