On Thu, Jul 02, 2015 at 09:49:55AM +0200, Boris Brezillon wrote:

On Thu, 2 Jul 2015 08:44:45 +0200
Uwe Kleine-König [off-list ref] wrote:

quoted

On Wed, Jul 01, 2015 at 10:21:51AM +0200, Boris Brezillon wrote:

quoted

When requested by a user, the PWM is assigned a default period and polarity
extracted from the DT, the platform data or statically set by the driver.
Those default values are currently stored in the period and polarity
fields of the pwm_device struct, but they will be stored somewhere else
once we have introduced the architecture allowing for hardware state
retrieval.

The pwm_set_default_polarity and pwm_set_default_period should only be
used by PWM drivers or the PWM core infrastructure to specify the
default period and polarity values.

Would it make sense to put the prototypes of
pwm_set_default_p{olarity,eriod} into (say) drivers/pwm/pwm-private.h
then?

Yes, definitely. I was thinking about moving those functions/prototypes
into include/linux/pwm-provider.h, but I'm fine with
drivers/pwm/pwm-private.h too.

Thierry, any opinion ?

I'm not sure I see the need for this. If they are the default values and
drivers have no need to change them, then storing them in the regular
period and polarity fields seems just fine (they'll be propagated into
new state objects as they get created).

And if the driver has a need to change them, then why would it ever care
about the default values?

Thierry