All of lore.kernel.org
 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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.