Re: [PATCH 3/5] ARM: dove: create a proper PMU driver for power domains, PMU IRQs and resets - Russell King

From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Pawel Moll <pawel.moll@arm.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Rob Herring <robh+dt@kernel.org>,
	Tomasz Figa <tomasz.figa@gmail.com>
Subject: Re: [PATCH 3/5] ARM: dove: create a proper PMU driver for power domains, PMU IRQs and resets
Date: Mon, 28 Apr 2014 13:17:26 +0100	[thread overview]
Message-ID: <20140428121726.GK26756@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <CAPDyKFoboE4iKyom86+EwHHTQAGpgKxGq969yrjQVpqizk-SLA@mail.gmail.com>

On Mon, Apr 28, 2014 at 01:55:40PM +0200, Ulf Hansson wrote:
> On 27 April 2014 15:29, Russell King <rmk+kernel@arm.linux.org.uk> wrote:
> > The PMU device contains an interrupt controller, power control and
> > resets.  The interrupt controller is a little sub-standard in that
> > there is no race free way to clear down pending interrupts, so we try
> > to avoid problems by reducing the window as much as possible, and
> > clearing as infrequently as possible.
> >
> > The interrupt support is implemented using an IRQ domain, and the
> > parent interrupt referenced in the standard DT way.
> >
> > The power domains and reset support is closely related - there is a
> > defined sequence for powering down a domain which is tightly coupled
> > with asserting the reset.  Hence, it makes sense to group these two
> > together.
> >
> > This patch adds the core PMU driver: power domains must be defined in
> > the DT file in order to make use of them.  The reset controller can
> > be referenced in the standard way for reset controllers.
> 
> Hi Russell,
> 
> This patch would be simplified if this was based upon the not yet
> merged patchset from Tomasz Figa, "[PATCH v3 0/3] Generic Device Tree
> based power domain look-up".
> 
> For example you would likely not need to add some of the marvel
> specific DT bindings, and you wouldn’t need the bus_notifiers to add
> devices to the power domain. I guess I just though it could be useful
> input to consider while going forward, unless you already knew.

Does that apply to 3.14?

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