From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH 1/4 v2] i2c/gpio: add DT support Date: Mon, 20 Feb 2012 15:03:22 +0000 Message-ID: <20120220150322.GD26840@n2100.arm.linux.org.uk> References: <1328754308-7365-1-git-send-email-plagnioj@jcrosoft.com> <4F3945B1.9070900@samsung.com> <20120220095813.GB11307@game.jcrosoft.org> <20120220100843.GE22562@n2100.arm.linux.org.uk> <20120220102231.GC11307@game.jcrosoft.org> <20120220125054.GF22562@n2100.arm.linux.org.uk> <20120220143557.02787bad@endymion.delvare> <20120220135106.GA26840@n2100.arm.linux.org.uk> <20120220145137.GG11307@game.jcrosoft.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20120220145137.GG11307-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean-Christophe PLAGNIOL-VILLARD Cc: Jean Delvare , Karol Lewandowski , Grant Likely , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, Feb 20, 2012 at 03:51:37PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 13:51 Mon 20 Feb , Russell King - ARM Linux wrote: > > On Mon, Feb 20, 2012 at 02:35:57PM +0100, Jean Delvare wrote: > > > On Mon, 20 Feb 2012 12:50:54 +0000, Russell King - ARM Linux wrote: > > > > What is linux specific is specifying the _delay_ rather than specifying > > > > the bus frequency. So as soon as you're trying to justify not adding > > > > the units because they may be linux specific, you've already lost that > > > > argument by using a delay rather than a bus frequency. You can't have > > > > it both ways. > > > > > > While I am not much into DT and did not follow this thread too > > > carefully... I seem to understand that the dispute is mainly on > > > frequency vs. udelay specification for the bus speed, Jean-Christophe > > > arguing that hardware-specific delays are added when changing e.g. a > > > GPIO pin output value and thus the frequency can't be guaranteed. Do I > > > get this right? > > > > This sub-thread is more about the units of the properties rather > > than the properties themselves. > > > > What's being proposed is to have two properties, one named 'udelay' > > which takes microseconds, and one named 'timeout' which takes > > milliseconds. > > > > I'm saying that's a completely absurd proposal, as the proposal is > > for two opaque numeric properties with different units. At least > > make the units the same, or as Karol said, incorporate the units > > into the property names. > > > > At least we can then create new properties in the future of we need > > to change the units, rather than thinking up a different name for > > 'timeout'. > > please read the binding > > we have 2 properties > > - udelay: delay between GPIO operations (may depend on each platform) > - timeout: timeout to get data (ms) > > please do not mixed them together > > udelay is related to bus frequency > > timeout is implelentation detail, that allow to parameter the timeout og i2c > bit algo when reading the scl on slow device FOR FUCKING SAKE. MILLISECONDS FOR SOME STUFF VS MICROSECONDS FOR OTHER STUFF IS BAD NEWS. FIX THIS AND I WILL WITHDRAW MY NACK. CONTINUE BEING OBSTRUCTIVE OVER THIS AND MY NACK STANDS. I HOPE USING BIG LETTERS HELPS TO GET MY POINT THROUGH.