From mboxrd@z Thu Jan 1 00:00:00 1970 From: anders.berg@lsi.com (Anders Berg) Date: Mon, 28 Apr 2014 11:41:04 +0200 Subject: [PATCH v2 3/6] ARM: dts: Device tree for AXM55xx. In-Reply-To: References: <2386bd1367aa44741979461358a72dec89608597.1398335771.git.anders.berg@lsi.com> <20140424174741.GA23444@swsaberg01> <20140425094343.GA3160@swsaberg01> Message-ID: <20140428094104.GA21191@swsaberg01> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Apr 25, 2014 at 01:50:25PM +0200, Linus Walleij wrote: > On Fri, Apr 25, 2014 at 11:43 AM, Anders Berg wrote: > > On Fri, Apr 25, 2014 at 11:16:18AM +0200, Linus Walleij wrote: > >> On Thu, Apr 24, 2014 at 7:47 PM, Anders Berg wrote: > >> > On Thu, Apr 24, 2014 at 03:24:14PM +0200, Linus Walleij wrote: > >> > >> >> One interrupt per CPU core? > >> >> > >> >> The drivers for these blocks will really just grab the first IRQ and > >> >> then I guess they > >> >> will only be able to execute on CPU0. > >> >> > >> >> It's definately correct to list all the IRQs here, but how do you envision > >> >> the drivers making use of them in the long run? > >> > > >> > It's one interrupt line per input pin (so with the current driver only the first pin > >> > is usable as interrupt source). > >> > >> Hm I'm not sure I understand what a "pin" is in this concept ... > >> being maintainer of the pin control subsystem and all that really > >> triggers my interest. > >> > > > > Ok, maybe should replace "pin" with "GPIO" in my previous comment. > > > > So, a clarification. In one of the PL061 blocks (named gpio0 in the dts) there > > is a separate interrupt per GPIO (I assume the motivation here is to enable to > > control irq affinity per GPIO), where as the other block has a more standard > > configuration with a single interrupt for all 8 GPIOs in that block. > > OK! I get it. Thus this is not a stock PL061, but a version modified to > generate a separate IRQ line per GPIO line. > I believe it's an unmodified PL061. Looking at the TRM, the PL061 interface signals include a GPIOMIS[7:0] in addition to the GPIOINTR. So I guess by hooking up the GPIOMIS[7:0] signals to the interrupt controller, you can get this one-irq-per-gpio setup. > This means that you can only get a proper, working IRQ from the > first line on gpio0 right? All other IRQs will be ignored. Right. /Anders