Accessing the device tree from user space
Thomas Taranowski
details from the device tree, rather than hard coding. If I was
writing a kernel driver, I'd use the of_ routines (e.g.
of_get_property), etc., but i believe these are only accessible from
the kernel. Is there an API that reads the device tree from
userspace?
Thanks
Alan Curry
Thomas Taranowski
> In article <ff9e9a08-6723-43a3-85f7-e0b637821...@h17g2000pri.googlegroups.com>,
> Thomas Taranowski <baringfo...@gmail.com> wrote:
>
> >I'd like to build a userspace driver, and have it pull some hardware
> >details from the device tree, rather than hard coding. If I was
> >writing a kernel driver, I'd use the of_ routines (e.g.
> >of_get_property), etc., but i believe these are only accessible from
> >the kernel. Is there an API that reads the device tree from
> >userspace?
>
> /proc/device-tree
>
> --
> Alan Curry
Thanks. I guess I was hoping there was an additional device tree
library I could use to extract out the device structure for me. /proc/
device-tree has what I want, but it looks like I have to parse the
directory and device files manually.
Felix Palmen
> Thanks. I guess I was hoping there was an additional device tree
> library I could use to extract out the device structure for me. /proc/
> device-tree has what I want, but it looks like I have to parse the
> directory and device files manually.
This may very well be a shot in the dark cause I'm not really familiar
with device handling in linux -- but -- what about hal and libhal? Maybe
you can find something interesting for your problem in the source?
Regards, Felix
--
Felix Palmen (Zirias) + [PGP] Felix Palmen <fe...@palmen-it.de>
web: http://palmen-it.de/ | http://palmen-it.de/pub.txt
my open source projects: | Fingerprint: ED9B 62D0 BE39 32F9 2488
http://palmen-it.de/?pg=pro + 5D0C 8177 9D80 5ECF F683
Alan Curry
What hideous language could you be using where opening and reading regular
files is such a burden that you'd rather have to jump through the unknown
hoops of a specialist library you've never seen before?
--
Alan Curry
phil-new...@ipal.net
Is that a conditional entry only present when the particular module is loaded?
=============================================================================
bessel/phil/c1 /home/phil 14> ls -Alv /{proc,sys}/*dev*
-r--r--r-- 1 root root 0 2010-08-14 13:25 /proc/devices
/sys/dev:
total 0
drwxr-xr-x 2 root root 0 2010-08-14 13:25 block
drwxr-xr-x 2 root root 0 2010-08-14 13:25 char
/sys/devices:
total 0
drwxr-xr-x 15 root root 0 2010-08-14 13:25 LNXSYSTM:00
drwxr-xr-x 29 root root 0 2010-08-14 13:24 pci0000:00
drwxr-xr-x 8 root root 0 2010-08-14 13:25 platform
drwxr-xr-x 17 root root 0 2010-08-14 13:25 pnp0
drwxr-xr-x 13 root root 0 2010-08-14 13:25 system
drwxr-xr-x 15 root root 0 2010-08-14 13:24 virtual
bessel/phil/c1 /home/phil 15>
=============================================================================
--
-----------------------------------------------------------------------------
| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
-----------------------------------------------------------------------------
Alan Curry
>On Mon, 9 Aug 2010 20:52:38 +0000 (UTC) Alan Curry <pac...@kosh.dhis.org> wrote:
>|
>| /proc/device-tree
>
>Is that a conditional entry only present when the particular module is loaded?
>
>=============================================================================
>bessel/phil/c1 /home/phil 14> ls -Alv /{proc,sys}/*dev*
>-r--r--r-- 1 root root 0 2010-08-14 13:25 /proc/devices
It's present when you're on a machine that has a device tree. "Device
tree" is an OpenFirmware term.
Oh yeah, and CONFIG_PROC_DEVICETREE.
--
Alan Curry