From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH V3 3/3] mfd: stmpe: Update DT support in stmpe driver Date: Tue, 27 Nov 2012 08:40:07 +0000 Message-ID: <20121127084007.GA7897@gmail.com> References: <57384ebc52c7d39d1bae31ba3baa6f820b4ac696.1353610436.git.viresh.kumar@linaro.org> <7a48ae364663ab3a336251fada9aee07ccd728b8.1353610437.git.viresh.kumar@linaro.org> <20121123094132.EFCB73E07BE@localhost> <20121126184015.784993E091F@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Viresh Kumar Cc: Grant Likely , sameo@linux.intel.com, devicetree-discuss@lists.ozlabs.org, spear-devel@list.st.com, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On Tue, 27 Nov 2012, Viresh Kumar wrote: > On 27 November 2012 08:10, Viresh Kumar wro= te: > > On 27 November 2012 00:10, Grant Likely = wrote: > >> It would actually be good to ask the interrupt controller driver w= hat > >> kind of interrupt signal it expects for a given interrupt line. Th= at > >> should also solve the problem and I think it would be more useful = to > >> other devices. Can you investigate whether or not > >> irqd_get_trigger_type() returns the information you need? > > > > That's a pretty cool function to use. :) > > > > Will check it out :) >=20 > I was thinking about this logic in my earlier mail, don't know what s= topped me > from thinking it is wrong. :( >=20 > Problem is with invert polarity, which the interrupt controller is no= t aware of. > For example, suppose interrupt controller needs Rising edge interrupt= , but > the board has inverted the line between stmpe and IC. So, we will get > Rising high from the routine you mentioned, but we need to generate > opposite of that to make it rising high. Surely that would be a hardware design error/quirk? Can you give an example where this has happened? > And so interrupt polarity field is still required. --=20 Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog