public inbox for linux-i2c@vger.kernel.org
 help / color / mirror / Atom feed
From: Guenter Roeck <guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
To: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Michael Lawnick <ml.lawnick-Mmb7MZpHnFY@public.gmane.org>,
	Rodolfo Giometti
	<giometti-AVVDYK/kqiJWk0Htik3J/w@public.gmane.org>
Subject: Re: Driver for pca9541 bus master selector
Date: Wed, 29 Sep 2010 06:54:01 -0700	[thread overview]
Message-ID: <20100929135401.GA11771@ericsson.com> (raw)
In-Reply-To: <20100929091928.16256bb7-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>

On Wed, Sep 29, 2010 at 03:19:28AM -0400, Jean Delvare wrote:
[ ... ]
> 
> I was speaking of the PCA9540. I don't think anyone ever wrote a driver
> for the PCA9541. And in all honestly I don't think the new i2c-mux
> infrastructure is ready for this. It was written with single-master
> topologies in mind. You'll have to rethink a lot of things if you want
> to add support for "inverted" multiplexers. And I don't have the time
> to help, sorry.
> 
Actually, the infrastructure works quite nicely. I use select_chan
to acquire the slave, and release_chan to initiate release.
It behaves like a one-channel multiplexer.

> I don't quite see the point of such chips, BTW. I2C supports
> multi-master already, so two masters talking to the same slave
> sequentially is already supported.
> 
Tell that to our HW team, and to them:

	http://www.lineagepower.com/oem/pdf/CPLI2C.pdf

Guenter

  parent reply	other threads:[~2010-09-29 13:54 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-28 14:33 Driver for pca9541 bus master selector Guenter Roeck
     [not found] ` <20100928143302.GA7593-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
2010-09-28 15:16   ` Jean Delvare
     [not found]     ` <20100928171607.395f7736-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-09-28 16:07       ` Guenter Roeck
     [not found]         ` <20100928160746.GB7976-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
2010-09-28 16:42           ` Jean Delvare
     [not found]             ` <20100928184215.00f82717-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-09-28 17:16               ` Guenter Roeck
     [not found]                 ` <20100928171627.GA8415-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
2010-09-29  7:19                   ` Jean Delvare
     [not found]                     ` <20100929091928.16256bb7-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-09-29 13:54                       ` Guenter Roeck [this message]
     [not found]                         ` <20100929135401.GA11771-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
2010-09-30  5:59                           ` Michael Lawnick
     [not found]                             ` <4CA42750.5020500-Mmb7MZpHnFY@public.gmane.org>
2010-09-30  7:48                               ` Guenter Roeck
2010-10-13 16:05                           ` Guenter Roeck
2010-10-13 15:45                     ` Guenter Roeck

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=20100929135401.GA11771@ericsson.com \
    --to=guenter.roeck-izefyvvap7pwk0htik3j/w@public.gmane.org \
    --cc=giometti-AVVDYK/kqiJWk0Htik3J/w@public.gmane.org \
    --cc=khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org \
    --cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=ml.lawnick-Mmb7MZpHnFY@public.gmane.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