From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v2 2/8] irqchip: Supply new driver for STi based devices Date: Thu, 27 Nov 2014 09:55:44 +0000 Message-ID: <20141127095544.GF4628@x1> References: <1416932705-16880-1-git-send-email-lee.jones@linaro.org> <35179358.tOpRGufXmc@wuerfel> <20141127092901.GE4628@x1> <2111250.BPZOtBCtcF@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <2111250.BPZOtBCtcF@wuerfel> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnd Bergmann Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, kernel-F5mvAk5X5gdBDgjK7y7TUQ@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, 27 Nov 2014, Arnd Bergmann wrote: > On Thursday 27 November 2014 09:29:01 Lee Jones wrote: > > On Thu, 27 Nov 2014, Arnd Bergmann wrote: > > > On Thursday 27 November 2014 09:02:55 Lee Jones wrote: > > > > On Tue, 25 Nov 2014, Arnd Bergmann wrote: > > > >=20 > > > > > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote: > > > > >=20 > > > > > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kcon= fig > > > > > > index b21f12f..e502f15 100644 > > > > > > --- a/drivers/irqchip/Kconfig > > > > > > +++ b/drivers/irqchip/Kconfig > > > > > > @@ -93,6 +93,13 @@ config RENESAS_IRQC > > > > > > bool > > > > > > select IRQ_DOMAIN > > > > > > =20 > > > > > > +config ST_IRQCHIP > > > > > > + bool > > > > > > + select REGMAP > > > > > > + select MFD_SYSCON > > > > > > + help > > > > > > + Enables SysCfg Controlled IRQs on STi based platforms= =2E > > > > > > + > > > > >=20 > > > > > I'm confused by the purpose of this code. It's apparently a d= river > > > > > in drivers/irqchip, the Kconfig symbol contains the string IR= QCHIP, > > > > > yet it doesn't actually register an irq_chip. > > > > >=20 > > > > > Also, the name is a bit too generic, ST has lots of different= irqchips, > > > > > and this apparently isn't even one of them=20 > > > >=20 > > > > Hmm... now you're going to ask me to remember who I had the > > > > conversation with that alluded to this as the best location for= this > > > > driver. Unfortunately, I cannot. Can you think of a better pl= ace to > > > > put it then? > > >=20 > > > I suspect it's in the right place but should actually be an irqch= ip > > > driver. I'm having trouble understanding what this code actually = does, > > > can you you explain the functionality in more detail so we can fi= gure > > > out what to do with it? > >=20 > > In the simplest terms it's an IRQ unmasker. A9 Core IRQs are disab= led > > on boot; PMU, CTI (CoreSight), PL310_L2 and EXT. In order for you = to > > make use of them they need to be unmasked in SYSCFG. >=20 > So you just apply static configuration once, or are there reasons why= you > would mask the interrupts again later? >=20 > If it's all static, why doesn't the boot loader unmask all interrupts= before > starting the kernel? We'd like to configure them at boot-time, via DT. --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html