Re: [PATCH v9 12/27] pwm: jz4740: Use regmap from TCU driver

[Paul Cercueil]

Hi Uwe,

On Sat, Jan 5, 2019 at 4:42 PM, Uwe Kleine-König 
<u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> On Thu, Dec 27, 2018 at 07:13:04PM +0100, Paul Cercueil wrote:
> >  The ingenic-timer "TCU" driver provides us with a regmap, that we 
> > can
> >  use to safely access the TCU registers.
> >
> >  While this driver is devicetree-compatible, it is never (as of now)
> >  probed from devicetree, so this change does not introduce a ABI 
> > problem
> >  with current devicetree files.
>
> Does it change behaviour? If so, how?

No, it does not change the behaviour.

> >  @@ -113,26 +117,37 @@ static int jz4740_pwm_apply(struct pwm_chip 
> > *chip, struct pwm_device *pwm,
> >
> >   	jz4740_pwm_disable(chip, pwm);
> >
> >  -	jz4740_timer_set_count(pwm->hwpwm, 0);
> >  -	jz4740_timer_set_duty(pwm->hwpwm, duty);
> >  -	jz4740_timer_set_period(pwm->hwpwm, period);
> >  +	/* Set abrupt shutdown */
> >  +	regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
> >  +			   TCU_TCSR_PWM_SD, TCU_TCSR_PWM_SD);
>
> I think I already pointed that out before: abrupt mode is wrong. If
> .apply is called with a new set of parameters the currently running
> period with the old values is expected to complete before the new 
> values
> take effect.

You pointed it, indeed; but I won't change it until I can verify that 
the
behaviour is correct (which does not seem to be the case even if I leave
this bit cleared). Besides, this is the TCU patchset, fixes and patches
unrelated to the TCU don't belong here.

> Best regards
> Uwe

Kind regards,
-Paul