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Date:   Wed, 18 May 2022 10:48:26 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     linuxkernel <linuxkernel@firebladeautomationsystems.uk>
Cc:     linux-serial@vger.kernel.org
Subject: Re: Using Serdev is it Possible to Pull RX Low
Message-ID: <YoSy2vnS68wkLpcO@kroah.com>
References: <341d8439-4466-7182-745d-ba613301e009@firebladeautomationsystems.uk>
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On Tue, May 17, 2022 at 07:42:46PM +0100, linuxkernel wrote:
> hello
> 
> I, looking at writing a kernel driver for the Texas instruments
> TPS92662A/TPS92663A
> 
> which uses a "UART bus" e.g
> 
> |-----------| |-----------| |-----------| |-----------| | | | TPS92662A | |
> TPS92662A | | TPS92663A | | UART | | -Q1 | | -Q1 | | -Q1 | | | | | | | | |
> |-----------| |-----------| |-----------| |-----------| | | | | | | | | | |
> | | -------------------------------------------------------------------
> and control communications by specific sequencing.
> configuring this appears to require being able to pull RX Low
> > The MCU unit can reset the device UART and protocol state machine at any
> > time by holding the RX input low for a period of at least 12 bit times
> > (16 × 12 CLK periods).
> practically i can always pull RX low via other means, but if the UART can do
> this it would be better and be more generic.

How can your UART do that in a generic way?

thanks,

greg k-h