Re: [PATCH v2 2/4] staging: iio: adt7316: remove shift/offset macros

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 05 Mar 2026 23:16:59 -0800
Michael Harris <michaelharriscode@gmail.com> wrote:

> Remove shift/offset macros and instead use the corresponding mask with
> FIELD_GET(), FIELD_PREP(), or FIELD_FIT().
> 
> In cases where an appropriate mask didn't exist, it was created.
> 
> One of the shift/offset macros was used for a convoluted dynamic
> bitfield extraction. In its place, a helper function,
> adt7316_extract_ad_lsb(), was created so the shift/offset could be
> removed.
> 
> Signed-off-by: Michael Harris <michaelharriscode@gmail.com>

> ---
>  drivers/staging/iio/addac/adt7316.c | 59 ++++++++++++++++++++++---------------
>  1 file changed, 36 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/staging/iio/addac/adt7316.c b/drivers/staging/iio/addac/adt7316.c
> index 1412808c50c76a68b5771a25c46dd3308c5cbcdb..b8b66f4dd14bb59c3d29fdd569d84f0dd786db9e 100644
> --- a/drivers/staging/iio/addac/adt7316.c
> +++ b/drivers/staging/iio/addac/adt7316.c
> @@ -17,6 +17,7 @@
>  #include <linux/i2c.h>
>  #include <linux/rtc.h>
>  #include <linux/module.h>
> +#include <linux/bitfield.h>
>  
>  #include <linux/iio/iio.h>
>  #include <linux/iio/events.h>
> @@ -31,10 +32,11 @@
>  #define ADT7316_LSB_IN_TEMP_VDD		0x3
>  #define ADT7316_LSB_IN_TEMP_MASK	0x3
>  #define ADT7316_LSB_VDD_MASK		0xC

Convert all masks to GENMASK_U32() rather than just the ones where you
are removing a shift.  That will give us more consistent code and
makes sense as part of this patch.


> -#define ADT7316_LSB_VDD_OFFSET		2
>  #define ADT7316_LSB_EX_TEMP_AIN		0x4
> -#define ADT7316_LSB_EX_TEMP_MASK	0x3
> -#define ADT7516_LSB_AIN_SHIFT		2
> +#define ADT7316_LSB_EX_TEMP_AIN1_MASK	GENMASK_U32(1, 0)
Why GENMASK_U32()?  The registers seem to be 8 bit.
I'm not sure we care that much about the extra checks the sized
variant brings but if we do want to use it use the U8() variant.

Jonathan