DTS device tree node for dual port RAM

Grant Likely grant.likely at secretlab.ca
Mon Mar 16 15:57:34 EST 2009

On Thu, Mar 12, 2009 at 9:19 AM, EXTERNAL Lange Matthias (AA-DGW/ENG1)
<Matthias.Lange at beissbarth.com> wrote:
>> What hardware irq# are you using?  See this link for a description of
>> what the interrupts property should look like for external IRQs:
> I am using hardware irq# 0 which is wired to the critical input line. That's why I was defining the interrupts property to <0 0 0>. So my device tree node now looks like this

Okay, good.  I just wanted to make sure.

> dpram at 40000000 {
>        compatible = "beissbarth,orion-dpram";
>        interrupts = <0 0 0>;
>        interrupt-parent = <&mpc5200_pic>;
> };

This is unrelated to your question, but I'm wondering why you don't
have a reg property in your node.

> If I am understanding it correctly I now need to implement a OF platform driver in which I can use irq_of_parse_and_map() to get the virq for my device.

That is the easiest way, yes.  Actually, all you need to call
irq_of_parse_and_map() is a pointer to the device_node which can be
obtained by directly searching the tree.  However, writing an
of_platform driver is a better way to get the device_node in this


Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

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