linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Jochen Friedrich <jochen@scram.de>
To: Laurent Pinchart <laurentp@cse-semaphore.com>
Cc: "linuxppc-dev@ozlabs.org list" <linuxppc-dev@ozlabs.org>
Subject: Re: [PATCH] powerpc: Implement GPIO LIB API on CPM2 Freescale SoC.
Date: Thu, 17 Apr 2008 14:46:40 +0200	[thread overview]
Message-ID: <480746B0.7070409@scram.de> (raw)
In-Reply-To: <200804171408.46533.laurentp@cse-semaphore.com>

Hi Laurent,

> BTW, what's the purpose of the shadow data register in the CPM GPIO chip 
> structure ? As the set operation is protected by a spinlock, the only use I 
> can think of is to prevent changing bits in the PDAT register for pins 
> configured as inputs. Is that correct ? If so this should be clearly 
> documented in the code.

It's for pins configured as open drain. See the discussion in:

http://ozlabs.org/pipermail/linuxppc-dev/2008-January/050826.html

Thanks,
Jochen

  reply	other threads:[~2008-04-17 12:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-17  9:48 [PATCH] powerpc: Implement GPIO LIB API on CPM2 Freescale SoC Laurent Pinchart
2008-04-17 10:13 ` Jochen Friedrich
2008-04-17 11:11   ` Laurent Pinchart
2008-04-17 11:21     ` Jochen Friedrich
2008-04-17 12:08       ` Laurent Pinchart
2008-04-17 12:46         ` Jochen Friedrich [this message]
2008-04-17 12:48         ` Jochen Friedrich

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=480746B0.7070409@scram.de \
    --to=jochen@scram.de \
    --cc=laurentp@cse-semaphore.com \
    --cc=linuxppc-dev@ozlabs.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).