RE: [PATCH v14 3/3] Input: new da7280 haptic driver

[Roy Im]

On Sat, June 27, 2020 12:56 AM, Uwe Kleine-König wrote:
> On Fri, Jun 26, 2020 at 01:17:29PM +0000, Roy Im wrote:
> > > On Fri, June 26, 2020 3:19 PM, Uwe Kleine-König wrote:
> > > Hello,
> > > from the PWM POV I'm happy now. Just a few minor comments that I noticed while checking the PWM details.
> >
> > Many thanks for your comments.
> >
> > >
> > > On Thu, Jun 25, 2020 at 01:59:29AM +0900, Roy Im wrote:
> > > > +		val = haptics->ps_seq_id << DA7280_PS_SEQ_ID_SHIFT |
> > > > +			haptics->ps_seq_loop << DA7280_PS_SEQ_LOOP_SHIFT;
> > >
> > > If you write this as:
> > >
> > > 	val = FIELD_PREP(DA7280_PS_SEQ_ID_MASK, haptics->ps_seq_id) |
> > > 		FIELD_PREP(DA7280_PS_SEQ_LOOP_MASK, haptics->ps_seq_loop);
> > >
> > > you get some additional checks for free and can drop all defines for ..._SHIFT .
> >
> > It is not difficult to update that as you advise, but I think having
> > the shift there explicitly makes it more readable, so most of the
> > drivers from my team have the defines(shift) up to now. I guess this
> > is a kind of subjective thing.
> > Do you think it is still necessary? Then I will update as you said.
> 
> No, from my side it's not a hard requirement (and after all I'm not the one who will take your commit). I personally like it better
> with FIELD_PREP, but I can still sleep if you don't agree :-)
> 
> What I don't like about having both ..._SHIFT and ..._MASK is that there is some duplication as ..._SHIFT can be calculated
> from ..._MASK:
> 
> 	#define LALA_SHIFT (ffs(LALA_MASK) - 1)

OK, I got it and I will update.

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