From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mitch Bradley Subject: Re: [PATCHv2] Input: omap4-keypad: Add pinctrl support Date: Tue, 23 Oct 2012 07:51:22 -1000 Message-ID: <5086D91A.5080109@firmworks.com> References: <1350911580-20307-1-git-send-email-sourav.poddar@ti.com> <20121022155028.GA13791@core.coreip.homeip.net> <508664CA.7000601@ti.com> <20121023100333.GA24418@arwen.pp.htv.fi> <5086CD91.9070101@firmworks.com> <20121023172035.GB32167@arwen.pp.htv.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from rs130.luxsci.com ([72.32.115.17]:35533 "EHLO rs130.luxsci.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754731Ab2JWRvg (ORCPT ); Tue, 23 Oct 2012 13:51:36 -0400 In-Reply-To: <20121023172035.GB32167@arwen.pp.htv.fi> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: balbi@ti.com Cc: Linus Walleij , devicetree-discuss@lists.ozlabs.org, Dmitry Torokhov , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Sourav Poddar , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Perhaps I misunderstood what you were suggesting. I thought that, when you said "explicitly manage all their resources", you meant that the driver should know the platform-specific details about clocks and power domains. That is one possible interpretation of the word "explicit". Now I see that you meant that the driver should explicitly call abstracted functions. On 10/23/2012 7:20 AM, Felipe Balbi wrote: > HI, > > On Tue, Oct 23, 2012 at 07:02:09AM -1000, Mitch Bradley wrote: >> On 10/23/2012 12:03 AM, Felipe Balbi wrote: >>> Hi, >>> >>> I much prefer having drivers explicitly manage all their resources, >>> which would mean that pinctrl calls need to be done on probe() and, if >>> necessary, during suspend()/resume(). >> >> >> Per-driver resource management is certainly convenient when you are >> dealing with a single system, but it becomes difficult to maintain for >> drivers that are shared among many platforms. > > why ? look at drivers/usb/dwc3/, we're using that on OMAP, exynos, PCIe > and a couple of different FPGA implementations inside TI. Not to mention > what other licensees of that IP core might have internally. > > So far no problesm with resources at all. > > We have frameworks exactly to hide the differences. > >> The industry trend for many years has been consolidation around a single >> programming model per class of device. For example, SDHCI, EHCI, ATA. >> This trend will only accelerate, as the cost of developing controller IP >> and associated drivers increases. Such drivers need to be as >> platform-agnostic as possible. > > that's why we have pinctrl framework to abstract the details about pin > muxing. > From mboxrd@z Thu Jan 1 00:00:00 1970 From: wmb@firmworks.com (Mitch Bradley) Date: Tue, 23 Oct 2012 07:51:22 -1000 Subject: [PATCHv2] Input: omap4-keypad: Add pinctrl support In-Reply-To: <20121023172035.GB32167@arwen.pp.htv.fi> References: <1350911580-20307-1-git-send-email-sourav.poddar@ti.com> <20121022155028.GA13791@core.coreip.homeip.net> <508664CA.7000601@ti.com> <20121023100333.GA24418@arwen.pp.htv.fi> <5086CD91.9070101@firmworks.com> <20121023172035.GB32167@arwen.pp.htv.fi> Message-ID: <5086D91A.5080109@firmworks.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Perhaps I misunderstood what you were suggesting. I thought that, when you said "explicitly manage all their resources", you meant that the driver should know the platform-specific details about clocks and power domains. That is one possible interpretation of the word "explicit". Now I see that you meant that the driver should explicitly call abstracted functions. On 10/23/2012 7:20 AM, Felipe Balbi wrote: > HI, > > On Tue, Oct 23, 2012 at 07:02:09AM -1000, Mitch Bradley wrote: >> On 10/23/2012 12:03 AM, Felipe Balbi wrote: >>> Hi, >>> >>> I much prefer having drivers explicitly manage all their resources, >>> which would mean that pinctrl calls need to be done on probe() and, if >>> necessary, during suspend()/resume(). >> >> >> Per-driver resource management is certainly convenient when you are >> dealing with a single system, but it becomes difficult to maintain for >> drivers that are shared among many platforms. > > why ? look at drivers/usb/dwc3/, we're using that on OMAP, exynos, PCIe > and a couple of different FPGA implementations inside TI. Not to mention > what other licensees of that IP core might have internally. > > So far no problesm with resources at all. > > We have frameworks exactly to hide the differences. > >> The industry trend for many years has been consolidation around a single >> programming model per class of device. For example, SDHCI, EHCI, ATA. >> This trend will only accelerate, as the cost of developing controller IP >> and associated drivers increases. Such drivers need to be as >> platform-agnostic as possible. > > that's why we have pinctrl framework to abstract the details about pin > muxing. >