From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnaud.patard@rtp-net.org (Arnaud Patard (Rtp)) Date: Thu, 05 Jul 2012 18:30:00 +0200 Subject: [PATCH v2 01/12] ARM: Orion: DT support for IRQ and GPIO Controllers In-Reply-To: <4FF5B7F9.9020507@googlemail.com> (Sebastian Hesselbarth's message of "Thu, 05 Jul 2012 17:51:21 +0200") References: <1341325365-21393-1-git-send-email-andrew@lunn.ch> <20120705130819.GV17534@lunn.ch> <4FF5A15A.8070309@googlemail.com> <201207051454.24475.arnd@arndb.de> <4FF5B7F9.9020507@googlemail.com> Message-ID: <87hatmi31z.fsf@lebrac.rtp-net.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Sebastian Hesselbarth writes: > On 07/05/2012 04:54 PM, Arnd Bergmann wrote: >> This way you have multiple nodes with the same register >> and different names, which is not how it normally works. > > Ok. > >>> This would have the advantage that DT describes gpio-to-irq dependencies. >>> Moreover, nodes that reference gpios can do gpios =<&gpio 71 0>; instead of >>> gpios =<&gpio3 7 0>; >> >> Is that desired? >> >> The device tree representation should match what is in the data sheet >> normally. If they are in a single continuous number range, then we should >> probably have a single device node with multiple register ranges >> rather than one device node for each 32-bit register. Looking at >> arch/arm/plat-orion/gpio.c I think that is not actually the case though >> and having separate banks is more logical. > > Well, looking at the datasheet of Dove GPIOs are numbered [63:0] plus > GPOs [71:64]. This dt will be a lot shorter and maybe it is describing > the hardware as it is. (Not sure about the syntax for irqs, though) They're numbered as [63:0] and [71:64] but they're on 3 different banks. iirc, there may even be some differences with the way the banks are dealing interrupts, so I don't see any reason to not represent the 3 banks in DT. Arnaud