devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: George Hilliard <ghilliard@kopismobile.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: George Hilliard <ghilliard@kopismobile.com>,
	linux-serial@vger.kernel.org, devicetree@vger.kernel.org,
	NXP Linux Team <linux-imx@nxp.com>,
	kernel@pengutronix.de
Subject: [PATCH v3 0/2] Implement support for inverted serial TX/RX on i.MX
Date: Wed, 12 Feb 2020 10:35:36 -0600	[thread overview]
Message-ID: <20200212163538.3006-1-ghilliard@kopismobile.com> (raw)

This peripheral has dedicated control bits that flip input/output
signals before handing them off to the OS.  This is useful on my
hardware because the UART is connected to an RS-422 transceiver with the
+/- pins hooked up backward.  Instead of a hack flipping all the bits
before sending them, the hardware can do it for free.

Revision 3 sets *and* clears the bit as necessary during startup.  It
also moves init before transmit is enabled.

George Hilliard (2):
  dt-bindings: serial: document fsl,inverted-tx and -rx options
  tty: imx serial: Implement support for reversing TX and RX polarity

 .../bindings/serial/fsl-imx-uart.txt          |  4 +++
 drivers/tty/serial/imx.c                      | 29 +++++++++++++++----
 2 files changed, 27 insertions(+), 6 deletions(-)

-- 
2.25.0


             reply	other threads:[~2020-02-12 16:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-12 16:35 George Hilliard [this message]
2020-02-12 16:35 ` [PATCH v3 1/2] dt-bindings: serial: document fsl,inverted-tx and -rx options George Hilliard
2020-02-18 23:07   ` Rob Herring
2020-02-12 16:35 ` [PATCH v3 2/2] tty: imx serial: Implement support for reversing TX and RX polarity George Hilliard
2020-02-12 20:47   ` Uwe Kleine-König

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=20200212163538.3006-1-ghilliard@kopismobile.com \
    --to=ghilliard@kopismobile.com \
    --cc=devicetree@vger.kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=kernel@pengutronix.de \
    --cc=linux-imx@nxp.com \
    --cc=linux-serial@vger.kernel.org \
    /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;
as well as URLs for NNTP newsgroup(s).