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From: Philipp Zabel <p.zabel@pengutronix.de>
To: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Russell King <linux@arm.linux.org.uk>,
	Jason Cooper <jason@lakedaemon.net>,
	devicetree@vger.kernel.org, linux-pci@vger.kernel.org,
	Sascha Hauer <s.hauer@pengutronix.de>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/9] PCI: mvebu: add support for reset on GPIO
Date: Tue, 13 Aug 2013 12:59:40 +0200	[thread overview]
Message-ID: <1376391580.4039.8.camel@pizza.hi.pengutronix.de> (raw)
In-Reply-To: <520A0D1D.4050609@gmail.com>

Hi Sebastian,

Am Dienstag, den 13.08.2013, 12:40 +0200 schrieb Sebastian Hesselbarth:
> On 08/13/13 12:03, Thierry Reding wrote:
> > On Tue, Aug 13, 2013 at 10:30:30AM +0200, Thomas Petazzoni wrote:
> >> Dear Thierry Reding,
> >>
> >> On Tue, 13 Aug 2013 10:09:56 +0200, Thierry Reding wrote:
> >>
> >>>> +- reset-gpios: optional gpio to PERST#
> >>>> +- reset-delay-ms: delay in ms to wait after reset de-assertion
> >>>
> >>> I remember some recent discussion about this, and we now have this reset
> >>> framework, so perhaps it makes more sense to use the reset binding for
> >>> this? Cc'ing Stephen (as part of the device tree bindings maintainers
> >>> team) who was involved in that recent reset bindings discussion.
> >>
> >> I also thought about this, but the reset framework seems to be designed
> >> for "reset controller" IPs, i.e special IPs that are controlling reset
> >> signals. Looking at Documentation/devicetree/bindings/reset/reset.txt,
> >> I'm not sure to see how this would apply to GPIO-controlled reset
> >> signals.
> >
> > See:
> >
> > 	http://www.mail-archive.com/devicetree-discuss@lists.ozlabs.org/msg36900.html
> >
> > which seems to have carried over to this at some point:
> >
> > 	http://www.spinics.net/lists/devicetree/msg00521.html
> >
> > Some of the messages in between I can't find in any archive, sorry.
> 
> Thierry, Sascha,
> 
> thanks for the input. Flipping through the above discussion, I guess
> using "reset-gpios" and "reset-delay-us" should be fine?
> 
> I can also remove the delay property for now, as I cannot find a final
> conclusion about the configurable delay.

Yes, I'm in favor of using 'reset-gpios'. If we can agree on this
binding, I'll add support to the reset framework core.

> In the driver, I will stick to bare gpiolib and wait for gpio-reset
> driver to become available. Currently, we don't have sophisticated
> reset handling in pci-mvebu anyway.

Sounds good to me.

regards
Philipp


  reply	other threads:[~2013-08-13 11:00 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-12 18:46 [PATCH 0/9] ARM: dove: DT PCIe support Sebastian Hesselbarth
2013-08-12 18:46 ` [PATCH 1/9] PCI: mvebu: move clock enable before register access Sebastian Hesselbarth
2013-08-13  7:11   ` Thomas Petazzoni
2013-08-13  9:22     ` Sebastian Hesselbarth
2013-08-13  7:58   ` Thierry Reding
2013-08-12 18:46 ` [PATCH 2/9] PCI: mvebu: increment nports only for registered ports Sebastian Hesselbarth
2013-08-13  7:15   ` Thomas Petazzoni
2013-08-13  9:23     ` Sebastian Hesselbarth
2013-08-12 18:46 ` [PATCH 3/9] PCI: mvebu: remove subsys_initcall Sebastian Hesselbarth
2013-08-13  7:19   ` Thomas Petazzoni
2013-08-13  8:06     ` Thierry Reding
2013-08-13  9:25       ` Sebastian Hesselbarth
2013-08-12 18:46 ` [PATCH 4/9] PCI: mvebu: add support for reset on GPIO Sebastian Hesselbarth
2013-08-13  0:56   ` Kumar Gala
2013-08-13  9:19     ` Sebastian Hesselbarth
2013-08-13  8:09   ` Thierry Reding
2013-08-13  8:30     ` Thomas Petazzoni
2013-08-13  9:59       ` Sascha Hauer
2013-08-13 10:03       ` Thierry Reding
2013-08-13 10:40         ` Sebastian Hesselbarth
2013-08-13 10:59           ` Philipp Zabel [this message]
2013-08-12 18:46 ` [PATCH 5/9] PCI: mvebu: add support for Marvell Dove SoCs Sebastian Hesselbarth
2013-08-12 20:54 ` [PATCH 0/9] ARM: dove: DT PCIe support Bjorn Helgaas

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