On 08-09-20, 08:33, Pierre-Louis Bossart wrote:
> Thanks for the review Vinod,
>
> > This is good, thanks for adding it in changelog. Can you also add this
> > description to Documentation (that can come as an individual patch),
>
> ok
>
> > > +/*
> > > + * v1.2 device - SDCA address mapping
> > > + *
> > > + * Spec definition
> > > + * Bits Contents
> > > + * 31 0 (required by addressing range)
> > > + * 30:26 0b10000 (Control Prefix)
> >
> > So this is for 30:26
>
> I don't get the comment, sorry.
I should have added see below.
> >
> > > + * 25 0 (Reserved)
> > > + * 24:22 Function Number [2:0]
> > > + * 21 Entity[6]
> > > + * 20:19 Control Selector[5:4]
> > > + * 18 0 (Reserved)
> > > + * 17:15 Control Number[5:3]
> > > + * 14 Next
> > > + * 13 MBQ
> > > + * 12:7 Entity[5:0]
> > > + * 6:3 Control Selector[3:0]
> > > + * 2:0 Control Number[2:0]
> > > + */
> > > +
> > > +#define SDW_SDCA_CTL(fun, ent, ctl, ch) \
> > > + (BIT(30) | \
> >
> > Programmatically this is fine, but then since we are defining for the
> > description above, IMO it would actually make sense for this to be defined
> > as FIELD_PREP:
> >
> > FIELD_PREP(GENMASK(30, 26), 1)
> >
> > or better
> >
> > u32_encode_bits(GENMASK(30, 26), 1)
> >
> > > + FIELD_PREP(GENMASK(24, 22), FIELD_GET(GENMASK(2, 0), (fun))) | \
> >
> > Why not use u32_encode_bits(GENMASK(24, 22), (fun)) instead for this and
> > below?
>
> Because your comment for the v1 review was to use FIELD_PREP/FIELD_GET, and
> your other patches for bitfield access only use FIELD_PREP/FIELD_GET.
yes and looking at this, I feel u32_encode_bits(GENMASK(24, 22), (fun))
would look better than FIELD_PREP(GENMASK(24, 22), FIELD_GET(GENMASK(2, 0), (fun)))
Do you agree?
>
> I really don't care about which macro is used but it wouldn't hurt to have
> some level of consistency between different parts of the code? Why not use
> FIELD_PREP/GET everywhere?
>
> > > + FIELD_PREP(BIT(21), FIELD_GET(BIT(6), (ent))) | \
> > > + FIELD_PREP(GENMASK(20, 19), FIELD_GET(GENMASK(5, 4), (ctl))) | \
> > > + FIELD_PREP(GENMASK(17, 15), FIELD_GET(GENMASK(5, 3), (ch))) | \
> > > + FIELD_PREP(GENMASK(12, 7), FIELD_GET(GENMASK(5, 0), (ent))) | \
> > > + FIELD_PREP(GENMASK(6, 3), FIELD_GET(GENMASK(3, 0), (ctl))) | \
> > > + FIELD_PREP(GENMASK(2, 0), FIELD_GET(GENMASK(2, 0), (ch))))
> >
> > Also, can we rather have a nice function for this, that would look much
> > cleaner
>
> I am not sure what would be cleaner but fine.
Ok
> > And while at it, consider defining masks for various fields rather than
> > using numbers in GENMASK() above, that would look better, be more
> > readable and people can reuse it.
>
> Actually on this one I disagree. These fields are not intended to be used by
> anyone, the goal is precisely to hide them behind regmap, and the use of raw
> numbers makes it easier to cross-check the documentation and the code.
> Adding a separate set of definitions would not increase readability.
Which one would you prefer:
#define SDCA_FUN_MASK GENMASK(24, 22)
foo |= u32_encode_bits(SDCA_FUN_MASK, fun)
Or the one proposed...?
--
~Vinod
