I read the booting_without_of.txt document and the Interrupt Mapping docucument from http://playground.sun.com/1275. But I don't understand all parameters. Can somebody help me to create my device tree about interrupt part ?
I have an interrupt controller at the adresse 0x20006000. The irq_id range is 1 to 63. I would like to try UART interrupt, which have ids : 0x18 (tranmission fifo empty, 0x19 (reception fifo full), 0x1a (reception error), 0x1b (break emission). What other informations are needed ? Nothing is cascaded. Thanks 2008/9/4, Benjamin Herrenschmidt <[EMAIL PROTECTED]>: > > On Wed, 2008-09-03 at 23:02 +0200, Sébastien Chrétien wrote: > > > irq_of_parse_and_map is equivalent to ioremap in the MMU case ? > > > On the powerpc architecture, we use virtualized IRQ numbers in order to > deal with the wide range of interrupt controllers around and multiple > of them cascaded. > > The base function to "map" a physical interrupt to a virtual interrupt > is irq_create_mapping(). It takes an irq_host argument which represent > the IRQ "domain" (typically irq controller) off which the interrupt you > are trying to map hangs. > > If you pass NULL, it will use the "default" controller, which doesn't > always exist, it depends on the platform. Usually, platforms set that > to the toplevel PIC. > > However, normally, that function shouldn't be used directly. Instead, > you should create a representation of your device in the device-tree > along with the appropriate interrupt mapping, and then use the > irq_of_parse_and_map() function to obtain a mapped virtual irq based > on the device-tree information. This will take care of finding the > right irq_host but will also properly setup the polarity of the > interrupt etc... > > Now, as to how you should represent the interrupt in the device-tree, > this should be explained in Documentation/booting-without-of.txt > > Cheers, > Ben. > >
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