Hi Guenter Roeck,
Thanks for the feedback.
> Subject: Re: [PATCH v3 2/3] hwmon: tmp513: Drop enum tmp51x_ids and
> variable id from struct tmp51x_data
>
> On Fri, Aug 25, 2023 at 09:53:44PM +0100, Biju Das wrote:
> > Drop variable id from struct tmp51x_data and enum tmp51x_ids as all
> > the hw differences can be handled by max_channels.
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > ---
> > v2->v3:
> > * Updated the macro TMP51X_TEMP_CONFIG_DEFAULT by adding bit
> definitions.
> > * Dropped unused macros TMP51{2,3}_TEMP_CONFIG_DEFAULT.
> > ---
>
> [ ... ]
>
> I had another look at those. First of all, using MASK and FIELD_PREP for
> single-bit fields doesn't add value. Just drop the _MASK from all those and
> just use BIT().
OK.
>
> > +#define TMP51X_TEMP_CONFIG_GPM_MASK BIT(2)
>
> GPM is bit 0 and 1, so this is wrong. This should probably be
> TMP51X_TEMP_CONFIG_GP which is bit 2. It is also a read-only value, so
> setting it is never warranted.
OK, will drop this.
>
> > +#define TMP51X_TEMP_CONFIG_RC_MASK BIT(10)
> > +#define TMP51X_TEMP_CONFIG_CONT_MASK BIT(15)
>
> Drop _MASK.
OK.
>
> > +
> > +#define TMP51X_TEMP_CONFIG_GPM FIELD_PREP(GENMASK(1, 0), 0)
>
> Technically, using a 2-bit field here is misleading, since bit 1 defines if
> the gpio bit is an input or output, and bit 0 defines the state of the pin
> if it is an output. This would have to change if and when gpio support is
> added to the driver, so it is best to not define anything GP related in the
> first place.
OK.
>
> > +#define TMP51X_TEMP_CONFIG_GP
> FIELD_PREP(TMP51X_TEMP_CONFIG_GPM_MASK, 0)
> > +#define TMP51X_TEMP_CONFIG_CONV_RATE FIELD_PREP(GENMASK(9, 7), 0x7)
> > +#define TMP51X_TEMP_CONFIG_RC
> FIELD_PREP(TMP51X_TEMP_CONFIG_RC_MASK, 1)
>
> Those are really the values to be put into the configuration register,
> which I find is just confusing. But define the register bits, set the bit
> if needed, and otherwise keep it alone.
OK.
>
> > +#define TMP51X_TEMP_CHANNEL_MASK(n) FIELD_PREP(GENMASK(14, 11),
> GENMASK(n, 0) > 1)
>
> This is wrong. Either s/>/>>/ or GENMASK((n) - 1, 0). I personally prefer
> the latter since I find it easier to understand.
Agreed, there is a mistake, your suggestion is good.
>
> > +#define TMP51X_TEMP_CONFIG_CONT
> FIELD_PREP(TMP51X_TEMP_CONFIG_CONT_MASK, 1)
> > +
> > +#define TMP51X_TEMP_CONFIG_DEFAULT(n) \
> > + (TMP51X_TEMP_CONFIG_GPM | TMP51X_TEMP_CONFIG_GP | \
> > + TMP51X_TEMP_CONFIG_CONV_RATE | TMP51X_TEMP_CONFIG_RC |
> \
> > + TMP51X_TEMP_CHANNEL_MASK(n) | TMP51X_TEMP_CONFIG_CONT)
> > +
>
> I would very much prefer something like
>
> #define TMP51X_TEMP_CONFIG_DEFAULT(n) (TMP51X_TEMP_CONFIG_CONT | \
> TMP51X_TEMP_CHANNEL_MASK(n) \
> TMP51X_TEMP_CONFIG_CONV_RATE | TMP51X_TEMP_CONFIG_RC)
>
> and drop the unnecessary complexity of defining single bit values with
> FIELD_PREP().
OK.
Cheers,
Biju
