From mboxrd@z Thu Jan 1 00:00:00 1970 From: atull Subject: Re: [PATCH v2 2/3] ARM: dts: socfpga: fpga bridges bindings docs Date: Wed, 29 Oct 2014 09:30:36 -0500 Message-ID: References: <1414108267-22058-1-git-send-email-atull@opensource.altera.com> <1414108267-22058-3-git-send-email-atull@opensource.altera.com> <20141024070042.GL10262@pengutronix.de> <20141029075701.GA10262@pengutronix.de> <20141029101632.GU18557@sirena.org.uk> <20141029103103.GD10262@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Return-path: In-Reply-To: <20141029103103.GD10262@pengutronix.de> Sender: linux-doc-owner@vger.kernel.org To: Steffen Trumtrar Cc: Mark Brown , jgunthorpe@obsidianresearch.com, hpa@zytor.com, monstr@monstr.eu, michal.simek@xilinx.com, rdunlap@infradead.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, pantelis.antoniou@konsulko.com, robh+dt@kernel.org, grant.likely@linaro.org, iws@ovro.caltech.edu, linux-doc@vger.kernel.org, pavel@denx.de, philip@balister.org, rubini@gnudd.com, jason@lakedaemon.net, kyle.teske@ni.com, nico@linaro.org, balbi@ti.com, m.chehab@samsung.com, davidb@codeaurora.org, rob@landley.net, davem@davemloft.net, cesarb@cesarb.net, sameo@linux.intel.com, akpm@linux-foundation.org, linus.walleij@linaro.org, mgerlach@opensource.altera.com, delicious.quinoa@gmail.com, dinguyen@opensource.altera.com, yvanderv@opensource.altera.com List-Id: devicetree@vger.kernel.org On Wed, 29 Oct 2014, Steffen Trumtrar wrote: > On Wed, Oct 29, 2014 at 10:16:32AM +0000, Mark Brown wrote: > > On Wed, Oct 29, 2014 at 08:57:01AM +0100, Steffen Trumtrar wrote: > > > > > So, that shouldn't be a problem though, as I already cooked up a driver for > > > the L3 with all the ranges specified. The only thing I need to figure out > > > before I will post it, is how to nicely handle the WO remap register. > > > I think regmap might be able to handle this itself, but am not sure yet. > > > > It's supposed to be able to, not sure if anyone really tests that or not > > though so it's possible bugs crept in. Most write only registers can > > physically be read so actually come out as volatile rather than write > > only even if functionally there is no reason to read. > > Ah, I think you might be actually right there. IIRC it IS possible to read > from that register, but you only get 0s. Yes, you can read and it will be all 0s. So read-modify-write is not something you would want to do for instance. Alan > So, I shot myself in the knee with specifying that register as write-only > in my driver. > > Thanks, > Steffen > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >