[PATCH v2 03/15] pwm: lpss: Add range limit check for the base_unit register value

[Uwe Kleine-König]

Hello Andy,

On Fri, Jun 12, 2020 at 02:57:32PM +0300, Andy Shevchenko wrote:
> On Fri, Jun 12, 2020 at 12:12:42AM +0200, Uwe Kleine-König wrote:
> > I didn't follow the complete discussion but note that the general rule
> > is:
> > 
> > 	round period down to the next possible implementable period
> > 	round duty_cycle down to the next possible implementable duty_cycle
> > 
> > so if a small enough period (and so a small duty_cycle) is requested it
> > is expected that duty_cycle will be zero.
> 
> ...which brings me an idea that PWM framework should expose API to get a
> capabilities, like DMA Engine has.
> 
> In such capabilities, in particular, caller can get ranges of the correct
> frequencies of the underneath hardware.

my idea is to introduce a function pwm_round_state() that has a similar
semantic to clk_round_rate(). But this is only one of several thoughts I
have for the pwm framework. And as there is (AFAIK) no user who would
benefit from pwm_round_state() this is further down on my todo list.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |
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