Re: [PATCH v3 7/8] iio: adc: ti-ads112c14: implement gain on internal short SYS_MON channel

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `read_avail` callback incorrectly casts a native `s64` array to `const int *` for the IIO core, which corrupts scale values on big-endian architectures.
--

--- Patch [7]: [PATCH v3 7/8] iio: adc: ti-ads112c14: implement gain on internal short SYS_MON channel ---
commit 6c0e6ddc837dab31f5440831baff3fcb1a43f658
Author: David Lechner (TI) <dlechner@baylibre.com>

iio: adc: ti-ads112c14: implement gain on internal short SYS_MON channel

This commit implements support for the programmable gain amplifier on the
internal short SYS_MON channel. The scale_available table is populated
during probe to allow the PGA to be set to the same gain as external
channels.

> diff --git a/drivers/iio/adc/ti-ads112c14.c b/drivers/iio/adc/ti-ads112c14.c
> index 4d2e7d37be829..2ce4411a0d86f 100644
> --- a/drivers/iio/adc/ti-ads112c14.c
> +++ b/drivers/iio/adc/ti-ads112c14.c
[ ... ]
> @@ -402,6 +430,69 @@ static int ads112c14_read_raw(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int ads112c14_read_avail(struct iio_dev *indio_dev,
> +				const struct iio_chan_spec *chan, const int **vals,
> +				int *type, int *length, long mask)
> +{
> +	struct ads112c14_data *data = iio_priv(indio_dev);
> +
> +	if (chan->channel == ADS112C14_SYS_MON_CHANNEL_SHORT) {
> +		*vals = (const int *)data->sys_mon_chan_short_scale_available;
> +		*length = 2 * ARRAY_SIZE(data->sys_mon_chan_short_scale_available);
> +		*type = IIO_VAL_DECIMAL64_PICO;

[Severity: Medium]
Does casting a native s64 array to a const int pointer corrupt the scale
values on big-endian architectures?

When the IIO core processes these values as 32-bit pairs, vals[0] becomes
the most significant 32 bits and vals[1] the least significant on big-endian
systems. If the core later composes this via iio_val_s64_compose(vals[0],
vals[1]), the halves will be swapped, resulting in a mangled 64-bit scale
value.

Should the driver explicitly decompose the 64-bit values into an integer
array before handing them to the IIO core to avoid endianness issues?

> +		return IIO_AVAIL_LIST;
> +	}
> +
> +	return -EINVAL;
> +}
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260710-iio-adc-ti-ads122c14-v3-0-746d52cbf1d0@baylibre.com?part=7