From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/8] gpio: 74x164: Add output pin support
Date: Wed, 5 Sep 2012 11:20:12 +0200 [thread overview]
Message-ID: <20120905112012.13ce2c86@skate> (raw)
In-Reply-To: <1346834457-6257-5-git-send-email-maxime.ripard@free-electrons.com>
Le Wed, 5 Sep 2012 10:40:54 +0200,
Maxime Ripard <maxime.ripard@free-electrons.com> a ?crit :
> The shift registers have an output that, when enabled, propagates the
> values of its internal register to the pins. Make use of this pin
> through the output-latch-gpio dt property.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Well, thinking more about this, and reviewing the i.MX 28 datasheet a
bit more thoroughly, I don't think you need this GPIO thing. It is an
active-low pin that should be kept low during the entire duration of
the transfer, which basically is a chip select. And in turns out that
the CFA10049 board uses pins that can be controlled as chip selects
directly by the SPI controller, so you should rather use this rather
than introduce a specially handled GPIO. This needs testing, but I
don't see why it wouldn't work.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2012-09-05 9:20 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-05 8:40 [PATCH 1/8] gpio: 74x164: Use module_spi_driver boiler plate function Maxime Ripard
2012-09-05 8:40 ` [PATCH 2/8] gpio: 74x164: Use devm_kzalloc Maxime Ripard
2012-09-05 8:46 ` Florian Fainelli
2012-09-05 9:16 ` Thomas Petazzoni
2012-09-06 7:22 ` Linus Walleij
2012-09-07 21:02 ` Linus Walleij
2012-09-05 8:40 ` [PATCH 3/8] gpio: 74x164: Remove platform data and use dynamic gpio number assignment Maxime Ripard
2012-09-05 8:48 ` Florian Fainelli
2012-09-05 9:15 ` Thomas Petazzoni
2012-09-05 9:17 ` Thomas Petazzoni
2012-09-05 8:40 ` [PATCH 4/8] gpio: 74x164: Add device tree support Maxime Ripard
2012-09-05 8:50 ` Florian Fainelli
2012-09-05 9:17 ` Thomas Petazzoni
2012-09-06 7:22 ` Linus Walleij
2012-09-05 8:40 ` [PATCH 5/8] gpio: 74x164: Add output pin support Maxime Ripard
2012-09-05 9:20 ` Thomas Petazzoni [this message]
2012-09-05 9:46 ` Eric Bénard
2012-09-05 10:09 ` Thomas Petazzoni
2012-09-05 10:26 ` Eric Bénard
2012-09-05 11:56 ` Thomas Petazzoni
2012-09-05 12:22 ` Eric Bénard
2012-09-05 12:29 ` Thomas Petazzoni
2012-09-05 12:54 ` Eric Bénard
2012-09-05 13:02 ` Maxime Ripard
2012-09-05 13:27 ` Eric Bénard
2012-09-05 8:40 ` [PATCH 6/8] gpio: 74x164: Add support for daisy-chaining Maxime Ripard
2012-09-05 8:56 ` Thomas Petazzoni
2012-09-05 8:40 ` [PATCH 7/8] gpio: 74x164: dts: Add documentation for the dt binding Maxime Ripard
2012-09-05 8:40 ` [PATCH 8/8] ARM: dts: cfa10049: Add the 74HC595 gpio expanders Maxime Ripard
2012-09-05 8:46 ` [PATCH 1/8] gpio: 74x164: Use module_spi_driver boiler plate function Florian Fainelli
2012-09-05 9:16 ` Thomas Petazzoni
2012-09-06 7:21 ` Linus Walleij
2012-09-06 14:10 ` Maxime Ripard
2012-09-07 21:09 ` Linus Walleij
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=20120905112012.13ce2c86@skate \
--to=thomas.petazzoni@free-electrons.com \
--cc=linux-arm-kernel@lists.infradead.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).