Re: [PATCH] iio: freq: admv1014: Fix warning about dubious x & !y and improve readability

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 19 Mar 2022 18:14:01 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> The warning comes from __BF_FIELD_CHECK()
> specifically
> 
> BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?		\
> 		 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
> 		 _pfx "value too large for the field"); \
> 
> The code was using !(enum value) which is not particularly easy to follow
> so replace that with explicit matching and use of ? 0 : 1; or ? 1 : 0;
> to improve readability.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Antoniu Miclaus <antoniu.miclaus@analog.com>

Antoniu, or anyone else who has time, can you sanity check this one?
I'd like to clean up the warning asap but don't really trust myself
enough to not have done something stupid ;)

Jonathan

> ---
>  drivers/iio/frequency/admv1014.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/frequency/admv1014.c b/drivers/iio/frequency/admv1014.c
> index a7994f8e6b9b..802835efbec7 100644
> --- a/drivers/iio/frequency/admv1014.c
> +++ b/drivers/iio/frequency/admv1014.c
> @@ -700,8 +700,10 @@ static int admv1014_init(struct admv1014_state *st)
>  			 ADMV1014_DET_EN_MSK;
>  
>  	enable_reg = FIELD_PREP(ADMV1014_P1DB_COMPENSATION_MSK, st->p1db_comp ? 3 : 0) |
> -		     FIELD_PREP(ADMV1014_IF_AMP_PD_MSK, !(st->input_mode)) |
> -		     FIELD_PREP(ADMV1014_BB_AMP_PD_MSK, st->input_mode) |
> +		     FIELD_PREP(ADMV1014_IF_AMP_PD_MSK,
> +				(st->input_mode == ADMV1014_IQ_MODE) ? 0 : 1) |
> +		     FIELD_PREP(ADMV1014_BB_AMP_PD_MSK,
> +				(st->input_mode == ADMV1014_IQ_MODE) ? 1 : 0) |
>  		     FIELD_PREP(ADMV1014_DET_EN_MSK, st->det_en);
>  
>  	return __admv1014_spi_update_bits(st, ADMV1014_REG_ENABLE, enable_reg_msk, enable_reg);