Subject: Problems with of_find_compatible_node

Subject: Problems with of_find_compatible_node

[Vishwas Srivastava]

Hi Chris,
              probably you can do cat /proc/device-tree o/p to see if such
a node exist in the device tree file.
also you can check
arch/ppc/boot/dts/  directory and check the .dts file to check if such an
entry really exist in the .dts file which
you are using.

Since in your case
 np = of_find_compatible_node(NULL,NULL,
"xilinx,cpld-led");
returns NULL, its a  sign that the entry does not exist in the .dts file
your system is using.
thnaks,
Vishwas S



Hello out there,
I got a problem with the kernel function "of_find_compatible_node". I
use it with:   np = of_find_compatible_node(NULL,NULL,
"xilinx,cpld-led"); or with   np = of_find_compatible_node(NULL,NULL,
"cpld-led"); but none of this works, because I get a null-pointer back.
But it suppose to work? The target is a PPC-walnut-board.
Which is the mechanism behind this function, which namespace is parsed
in order to detect devices on the board? Can I parse the whole namespace
in order to list up all devices?

What else can I do to solve this problem?

Thank you in advance...

Regards /chris
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Subject: Problems with of_find_compatible_node

[chrishell]

Hello Vishwas,
thanks for your reply. But I don not have a /proc/device-tree at all. I
solved the problem by writing a appropriate node into the .dts-file and
recompile the whole kernel. I exchanged also "xilinx,cpld-led" with
"cpld-led". After that it worked.

Regards /Chris



> Hi Chris,
>               probably you can do cat /proc/device-tree o/p to see if such
> a node exist in the device tree file.
> also you can check
> arch/ppc/boot/dts/  directory and check the .dts file to check if such an
> entry really exist in the .dts file which
> you are using.
> 
> Since in your case
>  np = of_find_compatible_node(NULL,NULL,
> "xilinx,cpld-led");
> returns NULL, its a  sign that the entry does not exist in the .dts file
> your system is using.
> thnaks,
> Vishwas S
> 
> 
> 
> Hello out there,
> I got a problem with the kernel function "of_find_compatible_node". I
> use it with:   np = of_find_compatible_node(NULL,NULL,
> "xilinx,cpld-led"); or with   np = of_find_compatible_node(NULL,NULL,
> "cpld-led"); but none of this works, because I get a null-pointer back.
> But it suppose to work? The target is a PPC-walnut-board.
> Which is the mechanism behind this function, which namespace is parsed
> in order to detect devices on the board? Can I parse the whole namespace
> in order to list up all devices?
> 
> What else can I do to solve this problem?
> 
> Thank you in advance...
> 
> Regards /chris
> 
> 
> 
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


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