[PATCH 1/7] pwm: Add pwm core driver

[Felipe Balbi]

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"
>> <arun.murthy at stericsson.com>
>>
>>
>> >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