Re: [PATCH v7 3/6] iio: tools: Add support for floating-point numbers in buffer scan elements

[David Lechner]

On 3/4/26 2:06 AM, Francesco Lavra wrote:
> A subsequent commit will add floating-point support to the ABI; enhance
> the iio_generic_buffer tool to be able to parse this new data format.
> 
> Signed-off-by: Francesco Lavra <flavra@xxxxxxxxxxxx>
> ---
>  tools/iio/iio_generic_buffer.c | 56 +++++++++++++++++++++++++++++-----
>  tools/iio/iio_utils.c          |  8 ++---
>  tools/iio/iio_utils.h          |  4 +--
>  3 files changed, 55 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/iio/iio_generic_buffer.c b/tools/iio/iio_generic_buffer.c
> index bc82bb6a7a2a..39c13b9ad20b 100644
> --- a/tools/iio/iio_generic_buffer.c
> +++ b/tools/iio/iio_generic_buffer.c
> @@ -89,7 +89,7 @@ static void print1byte(uint8_t input, struct iio_channel_info *info)
>  	 */
>  	input >>= info->shift;
>  	input &= info->mask;
> -	if (info->is_signed) {
> +	if (info->format == 's') {
>  		int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
>  			     (8 - info->bits_used);
>  		printf("%05f ", ((float)val + info->offset) * info->scale);
> @@ -112,12 +112,26 @@ static void print2byte(uint16_t input, struct iio_channel_info *info)
>  	 */
>  	input >>= info->shift;
>  	input &= info->mask;
> -	if (info->is_signed) {
> +	switch (info->format) {
> +	case 's': {
>  		int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
>  			      (16 - info->bits_used);
>  		printf("%05f ", ((float)val + info->offset) * info->scale);
> -	} else {
> +		break;
> +	}
> +	case 'u':
>  		printf("%05f ", ((float)input + info->offset) * info->scale);
> +		break;
> +	case 'f': {
> +		union {
> +			uint16_t u;
> +			__fp16 f;

Do we need to check for compiler support here since this data type might not
be supported on all targets?

Also wondering if _Float16 would be better than __fp16.

> +		} converter;
> +
> +		converter.u = input;
> +		printf("%05f ", ((float)converter.f + info->offset) * info->scale);
> +		break;
> +	}
>  	}
>  }
>  

...

> @@ -46,7 +46,7 @@ struct iio_channel_info {
>  	unsigned shift;
>  	uint64_t mask;
>  	unsigned be;
> -	unsigned is_signed;
> +	unsigned format;

char would be more natural.

>  	unsigned location;
>  };
>