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

[Jassi Brar]

On Fri, Oct 1, 2010 at 5:46 PM, Arun MURTHY <arun.murthy at stericsson.com> wrote:
>> On Fri, Oct 1, 2010 at 4:25 PM, Arun MURTHY
>> <arun.murthy at stericsson.com> wrote:
>> > You can have a look at the pwm_config_nosleep(),pwm_set_polarity(),
>> > pwm_synchronize(),pwm_unsynchronize(), pwm_set_handler() etc.
>> > These are not being used by the exsting pwm drivers except Atmel pwm.
>> How would your 'simple' driver handle Atmel then ?
>> What if future's SoCs start providing those 'advance' features like
>> Atmel's ?
>>
> The pwm core driver is the intersection of all pwm drivers and not union
> of all pwm driver. I refer this as simple pwm core driver / framework.
> Atmel pwm is of a separate classification.
> It includes GPIO also. Though, Atmel can use the pwm core driver framework
> for functionalities like pwm_enable, pwm_disable, pwm_config, etc and remaining
> functionalities specific to Atmel will be handled in Atlmel pwm driver and
> will not be exposed to the entire kernel.
> Its that the present day pwm device that has been made easy though, by providing
> the same functionality.
It's sad that Bill Gatliff didn't/couldn't take his work to conclusive end.
The work was apparently better
http://www.mail-archive.com/linux-embedded@vger.kernel.org/msg02599.html

Best of luck.