From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 2/2] ARM: bcm2835: Add devicetree for the Raspberry Pi 3. Date: Fri, 4 Mar 2016 18:59:24 +0000 Message-ID: <20160304185923.GC5033@leverpostej> References: <1457116769-8567-1-git-send-email-eric@anholt.net> <1457116769-8567-2-git-send-email-eric@anholt.net> <20160304184136.GB5033@leverpostej> <874mcm3wfs.fsf@eliezer.anholt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <874mcm3wfs.fsf-omZaPlIz5HhaEpDpdNBo/KxOck334EZe@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eric Anholt Cc: linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Stephen Warren , Lee Jones , Florian Fainelli , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Fri, Mar 04, 2016 at 10:55:03AM -0800, Eric Anholt wrote: > Mark Rutland writes: > > > On Fri, Mar 04, 2016 at 10:39:29AM -0800, Eric Anholt wrote: > >> For now this doesn't support the new hardware present on the Pi 3 (BT, > >> wifi, GPIO expander). Since the GPIO expander isn't supported, we > >> also don't have the LEDs like the other board files do. > >> > >> Signed-off-by: Eric Anholt > >> --- > >> arch/arm/boot/dts/Makefile | 3 +- > >> arch/arm/boot/dts/bcm2837-rpi-3-b.dts | 22 ++++++++++++ > >> arch/arm/boot/dts/bcm2837.dtsi | 68 +++++++++++++++++++++++++++++++++++ > >> 3 files changed, 92 insertions(+), 1 deletion(-) > >> create mode 100644 arch/arm/boot/dts/bcm2837-rpi-3-b.dts > >> create mode 100644 arch/arm/boot/dts/bcm2837.dtsi > > > >> + timer { > >> + compatible = "arm,armv7-timer"; > >> + interrupt-parent = <&local_intc>; > >> + interrupts = <0>, // PHYS_SECURE_PPI > >> + <1>, // PHYS_NONSECURE_PPI > >> + <3>, // VIRT_PPI > >> + <2>; // HYP_PPI > >> + always-on; > >> + }; > > > > Are the CPUs in an always-on power domain? Or is it jsut that the kernel > > doesn't perform power management of CPUs? > > > > The always-on proeprty is only intended for the former. > > The kernel doesn't get to do power management of CPUs. We only have > control of power domains through the firmware, and the firmware's > keeping the CPU domain on. So there is no way that the CPUs could request for the firmare to place them in a state where the timer would lose context (but other events coukd wake them up), even if they don't do that today? Mark -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html