public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Cc: Christian Krafft <krafft@de•ibm.com>,
	openipmi-developer@lists•sourceforge.net
Subject: Re: [Openipmi-developer] [patch 1/1] ipmi: add autosensing of ipmi device on powerpc using device-tree
Date: Mon, 11 Dec 2006 15:25:49 +0100	[thread overview]
Message-ID: <200612111525.50044.arnd@arndb.de> (raw)
In-Reply-To: <1F172C93-90F5-48E5-88D7-4D0BC0E1841A@kernel.crashing.org>

On Monday 11 December 2006 14:18, Segher Boessenkool wrote:
> > We have to include the IPMI information in a way which can be used
> > for controllers which are accessed via memory mapped or legacy I/O.
>=20
> How to access registers is implicit in the device tree;
> just look at the parent bus, it knows how to do it, given
> the "reg" value in your device.

right, though it's a little different if you need special opcodes,
like DCR on ppc4xx or PIO on i386. Let's not worry about those
for now.

> > (2)
> > name =3D ipmi
> > device_type
>=20
> device_type =3D ipmi-kcs
>=20
> There's no real reason to include the IPMI version number
> in here, if you really need the version it's trivial to
> probe for; it's not a property of the hardware but of the
> software on the controller (unless some day the IPMI spec
> breaks backwards compatibility, of course).

Why not this?

device-type =3D ipmi
compatible =3D ipmi-kcs

I thought the device-type tells you what kind of bindings to
use, and the compatible (and/or model) tells you how to
access it. E.g. all PHBs have device-type=3Dpci and compatible=3Dwhatever,
which tells you how to access the config space registers.

> > regs =3D <addr> <len>
> > reg-spacing =3D <number>
> > reg-size =3D <number>
> > reg-shift =3D <number>
> >
> > The main difference between (1) and (2) is that (2) will represent
> > the whole register region within the reg property.
>=20
> Which is the proper thing to do. =A0The "reg" property should
> describe all of the address space your device listens to.
> Some IPMI-KCS devices listen to just the two registers, some
> listen to an 8-reg block, some to a 16-reg block.

ok

	Arnd <><

  reply	other threads:[~2006-12-11 14:26 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-07 16:22 [patch 0/1] ipmi: add autosensing of ipmi device on powerpc using device-tree Christian Krafft
2006-12-07 16:24 ` [patch 1/1] " Christian Krafft
2006-12-08 10:24   ` Heiko Joerg Schick
2006-12-08 17:19   ` [Openipmi-developer] " Corey Minyard
2006-12-11 12:13     ` Christian Krafft
2006-12-08 18:59   ` Corey Minyard
2006-12-08 19:49     ` Arnd Bergmann
2006-12-08 22:50     ` Benjamin Herrenschmidt
2006-12-09  0:00       ` Arnd Bergmann
2006-12-09  0:07         ` Corey Minyard
2006-12-09 11:44           ` Arnd Bergmann
2006-12-10 18:42             ` Heiko J Schick
2006-12-11 10:11               ` Arnd Bergmann
2006-12-11 13:01                 ` Heiko J Schick
2006-12-11 13:37                   ` Segher Boessenkool
2006-12-11 13:18               ` Segher Boessenkool
2006-12-11 14:25                 ` Arnd Bergmann [this message]
2006-12-11 16:28                   ` Heiko J Schick
2006-12-11 16:58                     ` Segher Boessenkool
2006-12-11 17:20                       ` Christian Krafft
2006-12-11 16:54                   ` Segher Boessenkool
2006-12-09  2:14         ` Benjamin Herrenschmidt
2006-12-09  9:46         ` Segher Boessenkool
2006-12-09 11:46           ` Arnd Bergmann
2006-12-08  0:41 ` [patch 0/1] " Paul Mackerras
2006-12-08 14:04   ` Arnd Bergmann
2006-12-08 17:17     ` [Openipmi-developer] " Corey Minyard

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=200612111525.50044.arnd@arndb.de \
    --to=arnd@arndb$(echo .)de \
    --cc=krafft@de$(echo .)ibm.com \
    --cc=linuxppc-dev@ozlabs$(echo .)org \
    --cc=openipmi-developer@lists$(echo .)sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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