From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: Interrupt handling documentation From: Michael Ellerman To: Laurent Pinchart In-Reply-To: <200803111158.48540.laurentp@cse-semaphore.com> References: <200803111158.48540.laurentp@cse-semaphore.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-u2Pjugs8wLBB6Nf8IlN4" Date: Wed, 12 Mar 2008 11:51:28 +1100 Message-Id: <1205283088.7544.8.camel@concordia.ozlabs.ibm.com> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-u2Pjugs8wLBB6Nf8IlN4 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2008-03-11 at 11:58 +0100, Laurent Pinchart wrote: > Hi everybody, >=20 > is there any documentation describing interrupt handling for the powerpc=20 > architecture ? I'm writing a driver for a cascaded interrupt controller a= nd=20 > the only source of information I found was the code. I don't think there's much documentation. You might want to look at arch/powerpc/platforms/cell/axon_msi.c, it's a reasonably simple example of how to setup an irq_host and so on - well I think so :D > I'm particularly interested in information about irq hosts (allocation an= d=20 > initialisation, especially the map and unmap callbacks) and irq chaining.= =20 > Different drivers seem to implement cascaded irqs differently (for instan= ce=20 > arch/powerpc/sysdev/uic.c uses setup_irq to register the cascaded irq=20 > handler, while arch/powerpc/platforms/82xx/pq2ads-pci-pic.c uses=20 > set_irq_chained_handler) so I'm a bit lost here. uic.c uses set_irq_chained_handler() now, so that probably answers that question. I don't think it makes all that much difference if you set it up by hand, but set_irq_chained_handler() is the neat way to do it. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-u2Pjugs8wLBB6Nf8IlN4 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBH1ykQdSjSd0sB4dIRAnzgAKDEjqEQ1rkgYs2iIpumdTzZBKepaQCeMymC xlF7FvMKpF6I6kMNbZfzAPQ= =ZkC0 -----END PGP SIGNATURE----- --=-u2Pjugs8wLBB6Nf8IlN4--