From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Tue, 28 Sep 2010 16:35:01 +0300 Subject: [PATCH 1/7] pwm: Add pwm core driver In-Reply-To: <20100928130610.GB20749@sortiz-mobl> 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> Message-ID: <20100928133501.GB8575@legolas.emea.dhcp.ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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