From: Jerry Van Baren <gerald.vanbaren@smiths-aerospace•com>
To: Timur Tabi <timur@freescale•com>
Cc: linuxppc-dev <linuxppc-dev@ozlabs•org>,
Zhang Wei-r63237 <Wei.Zhang@freescale•com>
Subject: Re: [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon and Rev 1.02hardware
Date: Fri, 18 May 2007 13:59:57 -0400 [thread overview]
Message-ID: <464DE99D.1040904@smiths-aerospace.com> (raw)
In-Reply-To: <464DE4C7.7030906@freescale.com>
Timur Tabi wrote:
> Jerry Van Baren wrote:
[snip]
>> * The above should result in reasonable board-specific code.
>> * We may want to invent a libfdt move/copy subtree function (I don't
>> recall one being in there). Board specific code would want to
>> move selected subtrees out of /u-boot,hwoptions into the
>> appropriate final node. All the pieces are in libfdt, just would
>> need to be hooked together in a utility subroutine.
>
> Just being able to delete a given node/property would be enough. By
> default, the nodes with conditionals would be present in the device
> tree. The boot loader would then also strip out all conditionals from
> the device tree before passing it to the kernel. The kernel would then
> receive a standard device tree like it does today.
Deleting isn't really enough because you would want to copy/move the
configuration from a subnode of the hwoptions node to the final resting
place in the standard tree (assuming there is a final resting place in
the standard tree - I'm picturing SOC configuration choices here).
Simple deletion isn't adequate in general because
* It would be silly to change linux to look in a new location for things
that already exist in standard locations (e.g. SOC stuff)
* Deleting a node inherently deletes all of the subnodes. In order to
do only delete operations, you would end up with an ugly path like:
/u-boot,hwoptions/J1/on/tree/&usb/phy_type (set to "ulpi")
where I suspect the &usb/phy_type portion should be glued into a SOC
(or other) pre-existing subnode.
* It is possible some choices can be used multiple times - the above
example specifies a PHY. There are very often multiple instances of
only type of PHY and copying one "prototype" selection into multiple
final destination nodes could save space and effort.
>> * With the above, nothing in the infrastructure (dtc, libfdt) needs to
>> change.
>>
>> On a related note, would it be better to name the node
>> "/u-boot/hwoptions" (two levels deep)? It seems very desirable to me to
>
> It's not a u-boot-specific concept. The idea of representing jumpers
> (and other hardware options) in the device tree is not something that's
> unique to u-boot or any boot loader. The conditionals, however, are a
> bootloader-specific concept. We don't want Linux to see them.
Well, then we shouldn't name it u-boot,hwoptions. Ahh, nevermind, Scott
beat me to that point.
Best regards,
gvb
next prev parent reply other threads:[~2007-05-18 18:00 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-15 16:17 [PATCH 0/5] MPC8641 HPCN fixes Wade Farnsworth
2007-05-15 16:23 ` [PATCH 1/5] Add MTD support to mpc8641_hpcn.dts Wade Farnsworth
2007-05-15 16:27 ` [PATCH 2/5] Add legacy devices " Wade Farnsworth
2007-05-16 16:37 ` Jon Loeliger
2007-05-16 17:59 ` Wade Farnsworth
2007-05-16 19:59 ` Segher Boessenkool
2007-05-16 19:55 ` Segher Boessenkool
2007-05-16 20:03 ` Sergei Shtylyov
2007-05-16 20:17 ` Wade Farnsworth
2007-05-16 23:40 ` Segher Boessenkool
2007-05-16 23:47 ` Segher Boessenkool
2007-05-17 0:11 ` Wade Farnsworth
2007-05-17 0:09 ` Wade Farnsworth
2007-05-18 16:44 ` Jon Loeliger
2007-05-21 16:04 ` Wade Farnsworth
2007-05-21 16:10 ` Jon Loeliger
2007-05-21 16:51 ` Wade Farnsworth
2007-05-16 20:29 ` Wade Farnsworth
2007-07-07 18:29 ` Sergei Shtylyov
2007-07-07 18:39 ` Arnd Bergmann
2007-07-08 13:13 ` Segher Boessenkool
2007-07-08 20:36 ` Arnd Bergmann
2007-07-08 23:42 ` Segher Boessenkool
2007-07-09 12:43 ` Sergei Shtylyov
2007-07-09 14:43 ` Segher Boessenkool
2007-07-07 18:59 ` Sergei Shtylyov
2007-07-07 19:23 ` Arnd Bergmann
2007-05-15 16:32 ` [PATCH 3/5] Support for the LPC47M192 SuperIO on the MPC8641 HPCN Wade Farnsworth
2007-05-15 16:36 ` [PATCH 4/5] Add RTC CMOS support for " Wade Farnsworth
2007-05-15 16:50 ` [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon and Rev 1.02 hardware Wade Farnsworth
2007-05-16 16:44 ` Jon Loeliger
2007-05-16 18:06 ` Wade Farnsworth
2007-05-18 6:52 ` [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon and Rev1.02 hardware Jin Zhengxiong-R64188
2007-05-21 15:59 ` Wade Farnsworth
2007-05-17 2:50 ` [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon and Rev 1.02hardware Zhang Wei-r63237
2007-05-17 16:03 ` Wade Farnsworth
2007-05-17 16:14 ` Kumar Gala
2007-05-17 16:58 ` Wade Farnsworth
2007-05-17 18:46 ` Timur Tabi
2007-05-17 18:48 ` Timur Tabi
2007-05-17 18:53 ` Scott Wood
2007-05-17 18:59 ` Timur Tabi
2007-05-17 19:16 ` Jerry Van Baren
2007-05-18 13:48 ` Matt Sealey
2007-05-17 22:34 ` Wade Farnsworth
2007-05-18 0:56 ` David Gibson
2007-05-18 3:49 ` Jerry Van Baren
2007-05-18 14:34 ` Timur Tabi
2007-05-18 15:22 ` Jerry Van Baren
2007-05-18 16:46 ` Scott Wood
2007-05-18 17:30 ` Jerry Van Baren
2007-05-18 17:39 ` Timur Tabi
2007-05-18 17:43 ` Scott Wood
2007-05-18 17:47 ` Timur Tabi
2007-05-18 17:52 ` Scott Wood
2007-05-18 17:56 ` Timur Tabi
2007-05-18 18:02 ` Scott Wood
2007-05-18 18:03 ` Jerry Van Baren
2007-05-18 18:19 ` Jon Loeliger
2007-05-18 18:23 ` Scott Wood
2007-05-18 19:05 ` Jon Loeliger
2007-05-18 19:09 ` Scott Wood
2007-05-18 18:30 ` Timur Tabi
2007-05-18 17:59 ` Jerry Van Baren [this message]
2007-05-18 10:20 ` [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon and Rev1.02hardware Zhang Wei-r63237
2007-05-21 16:01 ` Wade Farnsworth
2007-05-22 2:53 ` [PATCH 5/5] PCI fixes for the MPC8641 Rev 2.0 silicon andRev1.02hardware Zhang Wei-r63237
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