From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub =?UTF-8?B?S2ljacWEc2tp?= Subject: Re: spi: bcm2835: driver for "auxiliar" spi1/spi2 Date: Thu, 25 Jun 2015 19:42:19 +0200 Message-ID: <20150625194219.4846221d@north> References: <5582933E.1050500@martin.sperl.org> <55829B18.4030609@tronnes.org> <20150618105848.GE14071@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Noralf =?UTF-8?B?VHLDuG5uZXM=?= , Martin Sperl , "linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Stephen Warren To: Mark Brown Return-path: In-Reply-To: <20150618105848.GE14071-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Thu, 18 Jun 2015 11:58:48 +0100, Mark Brown wrote: > On Thu, Jun 18, 2015 at 12:19:04PM +0200, Noralf Tr=C3=B8nnes wrote: >=20 > > There is also an aux mini uart that shares interrupt with spi1/2. > > The AUXIRQ register determines the interrupt source. How should thi= s > > sharing be done? This uart is really only useful on the Compute Mod= ule > > since it's pins overlap the pl011 uart pins on the other boards. > > This is how the mini uart is used/setup downstream: > > https://github.com/raspberrypi/linux/pull/1008 >=20 > Linux supports shared interrupts perfectly fine, though it sounds lik= e > this is actually a cascaded interrupt (the demux is another interrupt > controller) which we also support just fine. Mark, could you give us a hint how to best go about this shared IRQ? I failed to find any generic interrupt controller. I imagine there should be some fake irqchip we can instantiate from DT giving it a irq line and a memory address and it should provide us with 32(bit) demuxed irqs based on status of bits in specified memory location. Does this sound reasonable? Does such fake irqchip driver exist? -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html