From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 1/3] dt: cpufreq: brcm: New binding document for brcm-avs-cpufreq Date: Tue, 16 Aug 2016 08:16:39 -0500 Message-ID: <20160816131639.GA938@rob-hp-laptop> References: <1471044331-2480-1-git-send-email-mmayer@broadcom.com> <1471044331-2480-2-git-send-email-mmayer@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-oi0-f67.google.com ([209.85.218.67]:35492 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753421AbcHPNQo (ORCPT ); Tue, 16 Aug 2016 09:16:44 -0400 Content-Disposition: inline In-Reply-To: <1471044331-2480-2-git-send-email-mmayer@broadcom.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Markus Mayer Cc: Mark Rutland , "Rafael J . Wysocki" , Viresh Kumar , Broadcom Kernel List , Device Tree List , Power Management List , Linux Kernel Mailing List On Fri, Aug 12, 2016 at 04:25:29PM -0700, Markus Mayer wrote: > Add the binding document for the new brcm-avs-cpufreq driver. > > Signed-off-by: Markus Mayer > --- > .../bindings/cpufreq/brcm-avs-cpufreq.txt | 84 ++++++++++++++++++++++ > MAINTAINERS | 7 ++ > 2 files changed, 91 insertions(+) > create mode 100644 Documentation/devicetree/bindings/cpufreq/brcm-avs-cpufreq.txt > > diff --git a/Documentation/devicetree/bindings/cpufreq/brcm-avs-cpufreq.txt b/Documentation/devicetree/bindings/cpufreq/brcm-avs-cpufreq.txt > new file mode 100644 > index 0000000..707ebe5 > --- /dev/null > +++ b/Documentation/devicetree/bindings/cpufreq/brcm-avs-cpufreq.txt > @@ -0,0 +1,84 @@ > +Broadcom AVS CPUfreq driver > +=========================== > + > +This driver provides voltage and frequency scaling on Broadcom SoCs using Bindings describe h/w (or firmware interfaces) not drivers. CPUFreq is a Linux term. Please re-word. > +the AVS firmware with DVFS support. The AVS firmware is running on its own > +co-processor. The driver supports both uniprocessor (UP) and symmetric > +multiprocessor (SMP) systems which share clock and voltage across all CPUs. > + > +Actual voltage and frequency scaling is done solely by the AVS firmware. > +This driver does not change frequency or voltage itself. It provides a > +standard CPUfreq interface to the rest of the kernel and to userland. It > +interfaces with the AVS firmware to effect the requested changes and to > +report back the current system status in a way that is expected by existing > +tools. > + > +This driver requires two DT nodes. One node (brcm,avs-cpu-data-mem) > +references the mailbox register used to communicate with the AVS CPU. The > +second node (brcm,avs-cpu-l2-intr) is required to trigger an interrupt on > +the AVS CPU. The interrupt tells the AVS CPU that it needs to process a > +command sent to it by this driver. Interrupting the AVS CPU is mandatory for > +commands to be processed. The mailbox and interrupt to the AVS CPU are only for DVFS?