mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Lukas Wunner <lukas@wunner.de>
To: Francesco Dolcini <francesco@dolcini.it>
Cc: Vignesh Raghavendra <vigneshr@ti.com>, Bin Liu <b-liu@ti.com>,
	linux-serial@vger.kernel.org, Zeng Chao <chao.zeng@siemens.com>,
	Rob Herring <robh@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>,
	ilpo.jarvinen@linux.intel.com, tony@atomide.com,
	andriy.shevchenko@linux.intel.com,
	matthias.schiffer@ew.tq-group.com, linux-kernel@vger.kernel.org,
	Max Krummenacher <max.krummenacher@toradex.com>
Subject: Re: Wrong RS485 RTS polarity in 8250 OMAP UART Driver vs DT binding?
Date: Thu, 16 Mar 2023 10:51:26 +0100	[thread overview]
Message-ID: <20230316095126.GA4235@wunner.de> (raw)
In-Reply-To: <ZBItlBhzo+YETcJO@francesco-nb.int.toradex.com>

On Wed, Mar 15, 2023 at 09:41:56PM +0100, Francesco Dolcini wrote:
> We have working hardware, using another UART that expect
> rs485-rts-active-low, and the exact same HW, when using OMAP uart,
> requires rs485-rts-active-high (the HW is modular, so we are really just
> changing the uart, keeping the same RS485 transceiver / connections).
> 
> What's going on there? Is the semantic of the 8250_omap driver just the
> opposite as it should be?

Yes, sadly, for historic reasons.

See these threads:

https://lore.kernel.org/linux-serial/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/

https://lore.kernel.org/linux-serial/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de/


> Am I doing something wrong in the device tree?

No, but regrettably you need a separate device tree depending on which SoC
you're using.

Thanks,

Lukas

      reply	other threads:[~2023-03-16 10:11 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-15 20:41 Francesco Dolcini
2023-03-16  9:51 ` Lukas Wunner [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230316095126.GA4235@wunner.de \
    --to=lukas@wunner.de \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=b-liu@ti.com \
    --cc=chao.zeng@siemens.com \
    --cc=francesco@dolcini.it \
    --cc=gregkh@linuxfoundation.org \
    --cc=ilpo.jarvinen@linux.intel.com \
    --cc=jirislaby@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=matthias.schiffer@ew.tq-group.com \
    --cc=max.krummenacher@toradex.com \
    --cc=robh@kernel.org \
    --cc=tony@atomide.com \
    --cc=vigneshr@ti.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®