From: Mitch Bradley <wmb@firmworks•com>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linux-pci@vger•kernel.org, devicetree-discuss@lists•ozlabs.org,
linuxppc-dev <linuxppc-dev@lists•ozlabs.org>,
Rob Herring <rob.herring@calxeda•com>
Subject: Re: pci and pcie device-tree binding - range No cells
Date: Mon, 10 Dec 2012 13:11:38 -1000 [thread overview]
Message-ID: <50C66C2A.7010102@firmworks.com> (raw)
In-Reply-To: <1355179097.19932.5.camel@pasglop>
On 12/10/2012 12:38 PM, Benjamin Herrenschmidt wrote:
> On Mon, 2012-12-10 at 21:43 +0000, Grant Likely wrote:
>>> Sorry for my pci ignorance (have never got hw for mb/zynq)
>>> I just want to get better overview how we should we our drivers to
>> be compatible.
>>>
>>> Does it mean that pci is supposed be always 64 bit wide?
>>> And there is no option to have just 32bit values.
>>
>> Yes, PCIe addressing is always 64 bits wide. Even on 32bit PCI systems
>> we use 64 bit PCI addressing in the device tree.
>
> Right. The size & format of an address cell for PCI is specified in the
> OF PCI bindings and we follow that binding. It's always 3 cells.
.. and the reason why it must be 3 cells, even if the host PCI bus only
supports 32-bit addressing, is because a plug-in PCI card has no way of
knowing what the host supports.
>
> Cheers,
> Ben.
>
>
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss@lists•ozlabs.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss
>
next prev parent reply other threads:[~2012-12-10 23:18 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-10 12:20 pci and pcie device-tree binding - range No cells Michal Simek
2012-12-10 14:26 ` Rob Herring
2012-12-10 15:05 ` Michal Simek
2012-12-10 15:21 ` Rob Herring
2012-12-10 15:37 ` Michal Simek
2012-12-10 15:52 ` David Laight
2012-12-10 16:05 ` Michal Simek
2012-12-10 17:15 ` Thomas Petazzoni
2012-12-10 23:24 ` Rob Herring
2012-12-12 16:16 ` Thomas Petazzoni
2012-12-12 17:22 ` Grant Likely
2012-12-12 17:29 ` Rob Herring
2012-12-10 16:02 ` Rob Herring
2012-12-10 16:11 ` Michal Simek
2012-12-10 21:43 ` Grant Likely
2012-12-10 22:38 ` Benjamin Herrenschmidt
2012-12-10 23:11 ` Mitch Bradley [this message]
2012-12-10 21:41 ` Grant Likely
2012-12-12 10:37 ` Michal Simek
2012-12-12 10:49 ` Grant Likely
[not found] ` <CAPcvp5EJH-Q6wd7my+V+FUVE1=hzwMN-yOfHiukGvDmkcoRcsQ@mail.gmail.com>
2012-12-12 12:19 ` Andrew Murray
2012-12-12 13:34 ` Thierry Reding
2012-12-12 16:44 ` Andrew Murray
2012-12-12 16:55 ` Michal Simek
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=50C66C2A.7010102@firmworks.com \
--to=wmb@firmworks$(echo .)com \
--cc=benh@kernel$(echo .)crashing.org \
--cc=devicetree-discuss@lists$(echo .)ozlabs.org \
--cc=linux-pci@vger$(echo .)kernel.org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=rob.herring@calxeda$(echo .)com \
/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