From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755519Ab0I1NgW (ORCPT ); Tue, 28 Sep 2010 09:36:22 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:33553 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755435Ab0I1NgS (ORCPT ); Tue, 28 Sep 2010 09:36:18 -0400 Date: Tue, 28 Sep 2010 16:35:01 +0300 From: Felipe Balbi To: Samuel Ortiz Cc: "V, Hemanth" , Arun Murthy , "lars@metafoo.de" , Andrew Morton , "kernel@pengutronix.de" , "philipp.zabel@gmail.com" , "robert.jarzmik@free.fr" , "marek.vasut@gmail.com" , "eric.y.miao@gmail.com" , "rpurdie@rpsys.net" , "kgene.kim@samsung.com" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-mips@linux-mips.org" , "STEricsson_nomadik_linux@list.st.com" Subject: Re: [PATCH 1/7] pwm: Add pwm core driver Message-ID: <20100928133501.GB8575@legolas.emea.dhcp.ti.com> Reply-To: balbi@ti.com References: <1285670134-18063-1-git-send-email-arun.murthy@stericsson.com> <1285670134-18063-2-git-send-email-arun.murthy@stericsson.com> <040c01cb5f0c$29bcb3b0$LocalHost@wipblrx0099946> <20100928130610.GB20749@sortiz-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20100928130610.GB20749@sortiz-mobl> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 28, 2010 at 08:06:11AM -0500, Samuel Ortiz wrote: >On Tue, Sep 28, 2010 at 06:23:24PM +0530, Hemanth V wrote: >> ----- Original Message ----- From: "Arun Murthy" >> >> >> >> >The existing pwm based led and backlight driver makes use of the >> >pwm(include/linux/pwm.h). So all the board specific pwm drivers will >> >be exposing the same set of function name as in include/linux/pwm.h. >> >As a result build fails in case of multi soc environments where each soc >> >has a pwm device in it. >> >> This seems very specific to ST environment, >No it's not. It's an issue Arun has hit while enabling one of the ST MFD chip, >but he's tackling a generic issue. > >> looking at the driver list from >> ( [PATCH 4/7] pwm: Align existing pwm drivers with pwm-core ) it seems >> most multi SOC environments might support PWM in either one of the SOC. >> >> arch/arm/plat-mxc/pwm.c >> arch/arm/plat-pxa/pwm.c >> arch/arm/plat-samsung/pwm.c >> arch/mips/jz4740/pwm.c >> drivers/mfd/twl6030-pwm.c >> >> Unless people have examples of other SOCs which might use this, >> the better approach might be to go for a custom driver rather than changing >> the framework. >I wouldn't call the current pwm code a framework. It's a bunch of header >definitions that happens to work in the specific case of 1 pwm per >sub architecture. >What Arun is proposing is an actual framework. And it seems to be clean and >simple enough. FWIW, I agree with you Sam. Sooner or later, this will hit other SoCs. -- balbi