Re: [PATCH RFC v2 4/4] iio: test: add kunit tests for channel info writes

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 13 Oct 2026 10:36:47 -0300
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:

> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
> 
> Add a KUnit test suite covering iio_write_channel_info(), the sysfs
> store handler that parses a channel info value according to the format
> reported by write_raw_get_fmt() and hands it to write_raw(). The
> function is made visible to KUnit through VISIBLE_IF_KUNIT and
> EXPORT_SYMBOL_IF_KUNIT, so it stays static in regular builds.
> 
> The suite uses an unregistered iio_dev allocated on a KUnit device,
> with stub write_raw_get_fmt() and write_raw() callbacks that select
> the format under test and capture the parsed values. Cases are grouped
> by format:
> 
>   - IIO_VAL_INT: decimal, hex and octal input, decimal fallback with
>     truncation and E notation, and 32-bit range checks.
>   - IIO_VAL_INT_PLUS_MICRO / IIO_VAL_INT_PLUS_NANO: sign handling,
>     truncation of extra digits, E notation and malformed input.
>   - IIO_VAL_INT_PLUS_MICRO_DB: optional "dB" / " dB" suffix.
>   - IIO_VAL_CHAR: single character input.
>   - IIO_VAL_INT_64 and IIO_VAL_DECIMAL64_*: 64-bit values split into
>     val/val2, including the S64_MAX / S64_MIN boundaries.
> 
> Further cases cover unsupported formats, the default micro precision
> used when write_raw_get_fmt() is absent, a missing write_raw(), and
> error propagation from write_raw().
> 
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
Very pleased to see these given our still somewhat complex
parsers!

Thanks for doing this.
Note I mostly defer to Andy for review of parsing code
as I've messed it up far too many times in the past ;)

Jonathan