On Fri, 2018-03-02 at 11:57 +0100, Thierry Reding wrote: > On Thu, Mar 01, 2018 at 04:19:12PM +0800, sean.wang@xxxxxxxxxxxx wrote: > > From: Sean Wang <sean.wang@xxxxxxxxxxxx> > > > > Since the offset for both registers, PWMDWIDTH and PWMTHRES, used to > > control PWM4 or PWM5 are distinct from the other PWMs, whose wrong > > programming on PWM hardware causes waveform cannot be output as expected. > > Thus, the patch adds the extra condition for fixing up the weird case to > > let PWM4 or PWM5 able to work on MT7623. > > > > v1 -> v2: use pwm45_fixup naming instead of pwm45_quirk > > v2 -> v3: add more tags for Reviewed-by, Fixes, and Cc stable > > > > Cc: stable@xxxxxxxxxxxxxxx > > Fixes: caf065f8fd58 ("pwm: Add MediaTek PWM support") > > Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx> > > Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx> > > Cc: Zhi Mao <zhi.mao@xxxxxxxxxxxx> > > Cc: John Crispin <john@xxxxxxxxxxx> > > Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx> > > --- > > drivers/pwm/pwm-mediatek.c | 24 +++++++++++++++++++++--- > > 1 file changed, 21 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > [...] > > @@ -151,9 +156,18 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > return -EINVAL; > > } > > > > + if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) { > > + /* > > + * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES > > + * from the other PWMs on MT7623. > > + */ > > + reg_width = PWM45DWIDTH_FIXUP; > > + reg_thres = PWM45THRES_FIXUP; > > + } > > I don't understand this. According to the condition above the above > would also use the PWM[4,5] "fixup" register offsets with PWM[3]. Should > the condition be pwm->hwpwm > 3? > > Thierry PWM[4,5] are the naming specified in datasheet and kept it as is here and driver or userspace would use index 3 and 4 to have a reference to them respectively.