On Wed, Aug 01, 2012 at 11:50:35AM +0900, Alex Courbot wrote: > On 07/31/2012 07:19 PM, Thierry Reding wrote: > >* PGP Signed by an unknown key > > > >On Tue, Jul 31, 2012 at 06:51:03PM +0900, Alex Courbot wrote: > >>I would like to do that actually. The issue is that it did not work > >>go well with the legacy pwm_backlight behavior: a power sequence > >>needs to be constructed out of a PWM obtained through > >>pwm_request(int pwm_id, char *label) and this behavior cannot be > >>emulated using the new platform data interface (which only works > >>with pwm_get()). But if I remove this old behavior, then I could > >>make power_seq opaque. I don't think many drivers are using it. What > >>do you think? > > > >I don't see how that is relevant here, since this power-sequencing code > >is supposed to be generic and not tied to any specific implementation. > >Can you explain further? > > > >In any case you shouldn't be using pwm_request() in new code. > > Power sequences only rely on pwm_get, and never call pwm_request > since it is, as you stated, deprecated. However there are still > boards that use the old pwm_id member of the > pwm_backlight_platform_data. For these, we must call pwm_request > from the pwm_backlight driver in order to resolve the PWM (see > pwm_backlight_legacy_probe of the seconds patch). As the PWM is > being resolved by the backlight driver, and not within the power > sequences parser, the resolved data structure must be visible to > pwm_backlight so it can construct it. There are two ways to solve > this and keep the power sequences structure private: > > 1) Add a way to resolve a PWM by id using pwm_request in the power > sequences (we probably should not do that) No. But I think we don't need that either. If you use power sequences, then you shouldn't be using the pwm_id member. Both methods should be exclusive. > 2) Port the old platform pwm_request code to use pwm_add_table and > pwm_get instead. In the long term, every PWM user should move to pwm_add_table() and pwm_get(), but there are quite a lot of boards that need conversion. > Do I get points if I do 2)? :) Yes. =) I have a sample patch for PXA EZX, but as I said, many more boards need conversion. Thierry
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