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From: andrew@lunn.ch (Andrew Lunn)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] arm: mvebu: add RTC support for Armada 370 and Armada XP
Date: Tue, 11 Dec 2012 07:00:50 +0100	[thread overview]
Message-ID: <20121211060050.GC25466@lunn.ch> (raw)
In-Reply-To: <20121210233723.1f3656d0@skate>

On Mon, Dec 10, 2012 at 11:37:23PM +0100, Thomas Petazzoni wrote:
> Dear Grant Likely,
> 
> On Mon, 10 Dec 2012 21:47:55 +0000, Grant Likely wrote:
> 
> > > Maybe an explicit status = "okay" here?
> > 
> > Only necessary if it is typical for the device to get disabled. I don't
> > add status="okay" properties unless it is to enable a device previously
> > disabled with status="disabled"
> 
> Ok, thanks for clarifying what the best practice is. This device being
> internal to the SoC and having no dependency on external components, it
> is indeed always available.

Hi Thomas

This is not actually true. Its dependent on at least one external
component, a battery. The driver determines at load time if the clock
is ticking.

There are a few Kirkwood and XP designs which use an external i2c RTC,
because the battery recommended by Marvell is mechanically not so easy
to attached to the board, in a robust way.

So i expect some boards will disable this from there own .dts file.
However, defaulting to enabled would make sense.

   Andrew

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>
To: Thomas Petazzoni
	<thomas.petazzoni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Cc: Lior Amsalem <alior-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>,
	Ike Pan <ike.pan-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
	David Marlin <dmarlin-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Yehuda Yitschak <yehuday-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Jani Monoses
	<jani.monoses-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
	Tawfik Bayouk <tawfik-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Dan Frazier
	<dann.frazier-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
	Eran Ben-Avi <benavi-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Leif Lindholm <leif.lindholm-5wv7dgnIgG8@public.gmane.org>,
	Sebastian Hesselbarth
	<sebastian.hesselbarth-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Jason Cooper <jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org>,
	rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org,
	Alessandro Zummo
	<a.zummo-BfzFCNDTiLLj+vYz1yj4TQ@public.gmane.org>,
	Jon Masters <jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
	Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Chris Van Hoof <vanhoof-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
	Maen Suleiman <maen-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Nadav Haklai <nadavh-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Shadi Ammouri <shadi-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
Subject: Re: [PATCH 1/2] arm: mvebu: add RTC support for Armada 370 and Armada XP
Date: Tue, 11 Dec 2012 07:00:50 +0100	[thread overview]
Message-ID: <20121211060050.GC25466@lunn.ch> (raw)
In-Reply-To: <20121210233723.1f3656d0@skate>

On Mon, Dec 10, 2012 at 11:37:23PM +0100, Thomas Petazzoni wrote:
> Dear Grant Likely,
> 
> On Mon, 10 Dec 2012 21:47:55 +0000, Grant Likely wrote:
> 
> > > Maybe an explicit status = "okay" here?
> > 
> > Only necessary if it is typical for the device to get disabled. I don't
> > add status="okay" properties unless it is to enable a device previously
> > disabled with status="disabled"
> 
> Ok, thanks for clarifying what the best practice is. This device being
> internal to the SoC and having no dependency on external components, it
> is indeed always available.

Hi Thomas

This is not actually true. Its dependent on at least one external
component, a battery. The driver determines at load time if the clock
is ticking.

There are a few Kirkwood and XP designs which use an external i2c RTC,
because the battery recommended by Marvell is mechanically not so easy
to attached to the board, in a robust way.

So i expect some boards will disable this from there own .dts file.
However, defaulting to enabled would make sense.

   Andrew

  reply	other threads:[~2012-12-11  6:00 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-10 10:42 [PATCH 0/2] add RTC support for Armada 370 and Armada XP Gregory CLEMENT
2012-12-10 10:42 ` Gregory CLEMENT
2012-12-10 10:42 ` [PATCH 1/2] arm: mvebu: " Gregory CLEMENT
2012-12-10 10:42   ` Gregory CLEMENT
2012-12-10 15:28   ` Thomas Petazzoni
2012-12-10 15:28     ` Thomas Petazzoni
2012-12-10 21:47     ` Grant Likely
2012-12-10 21:47       ` Grant Likely
2012-12-10 22:37       ` Thomas Petazzoni
2012-12-10 22:37         ` Thomas Petazzoni
2012-12-11  6:00         ` Andrew Lunn [this message]
2012-12-11  6:00           ` Andrew Lunn
2012-12-11  8:18           ` Thomas Petazzoni
2012-12-11  8:18             ` Thomas Petazzoni
2012-12-10 10:42 ` [PATCH 2/2] rtc: rtc-mv: Add the device tree binding documentation Gregory CLEMENT
2012-12-10 10:42   ` Gregory CLEMENT
2012-12-10 13:39   ` Jason Cooper
2012-12-10 13:39     ` Jason Cooper
2012-12-10 21:49     ` Grant Likely
2012-12-10 21:49       ` Grant Likely
2012-12-10 10:59 ` [PATCH 0/2] add RTC support for Armada 370 and Armada XP Andrew Lunn
2012-12-10 10:59   ` Andrew Lunn
2012-12-10 14:01 ` Thomas Petazzoni
2012-12-10 14:01   ` Thomas Petazzoni
2012-12-10 14:17   ` Gregory CLEMENT
2012-12-10 14:17     ` Gregory CLEMENT

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