From mboxrd@z Thu Jan 1 00:00:00 1970 From: sameo@linux.intel.com (Samuel Ortiz) Date: Tue, 28 Sep 2010 15:06:11 +0200 Subject: [PATCH 1/7] pwm: Add pwm core driver In-Reply-To: <040c01cb5f0c$29bcb3b0$LocalHost@wipblrx0099946> 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> Message-ID: <20100928130610.GB20749@sortiz-mobl> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Cheers, Samuel. -- Intel Open Source Technology Centre http://oss.intel.com/