Re: [PATCH v4 02/11] iio: accel: adxl313: introduce channel buffer

[Jonathan Cameron <jic23@kernel.org>]

On Sun,  1 Jun 2025 17:21:30 +0000
Lothar Rubusch <l.rubusch@gmail.com> wrote:

> Add a scan_mask and scan_index to the iio channel. The scan_index
> prepares the buffer usage. According to the datasheet, the ADXL313
> uses 13 bit in full resolution. Add signedness, storage bits and
> endianness.
> 
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>

I'd normally expect to see this in the same patch where it is first used.

There is little benefit in adding unused data on it's own - so combine this
with patch 6.  If there was something particularly unusual to discuss
and highlight for review, a separate patch might make sense, but I'm not
seeing that here.

Jonathan

> ---
>  drivers/iio/accel/adxl313_core.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c
> index 2f26da5857d4..06a771bb4726 100644
> --- a/drivers/iio/accel/adxl313_core.c
> +++ b/drivers/iio/accel/adxl313_core.c
> @@ -171,9 +171,10 @@ static const int adxl313_odr_freqs[][2] = {
>  	[9] = { 3200, 0 },
>  };
>  
> -#define ADXL313_ACCEL_CHANNEL(index, axis) {				\
> +#define ADXL313_ACCEL_CHANNEL(index, reg, axis) {			\
>  	.type = IIO_ACCEL,						\
> -	.address = index,						\
> +	.scan_index = (index),						\
> +	.address = (reg),						\
>  	.modified = 1,							\
>  	.channel2 = IIO_MOD_##axis,					\
>  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
> @@ -183,14 +184,26 @@ static const int adxl313_odr_freqs[][2] = {
>  	.info_mask_shared_by_type_available =				\
>  		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
>  	.scan_type = {							\
> +		.sign = 's',						\
>  		.realbits = 13,						\
> +		.storagebits = 16,					\
> +		.endianness = IIO_BE,					\
>  	},								\
>  }
>  
> +enum adxl313_chans {
> +	chan_x, chan_y, chan_z,
> +};
> +
>  static const struct iio_chan_spec adxl313_channels[] = {
> -	ADXL313_ACCEL_CHANNEL(0, X),
> -	ADXL313_ACCEL_CHANNEL(1, Y),
> -	ADXL313_ACCEL_CHANNEL(2, Z),
> +	ADXL313_ACCEL_CHANNEL(0, chan_x, X),
> +	ADXL313_ACCEL_CHANNEL(1, chan_y, Y),
> +	ADXL313_ACCEL_CHANNEL(2, chan_z, Z),
> +};
> +
> +static const unsigned long adxl313_scan_masks[] = {
> +	BIT(chan_x) | BIT(chan_y) | BIT(chan_z),
> +	0
>  };
>  
>  static int adxl313_set_odr(struct adxl313_data *data,
> @@ -419,6 +432,7 @@ int adxl313_core_probe(struct device *dev,
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->channels = adxl313_channels;
>  	indio_dev->num_channels = ARRAY_SIZE(adxl313_channels);
> +	indio_dev->available_scan_masks = adxl313_scan_masks;
>  
>  	ret = adxl313_setup(dev, data, setup);
>  	if (ret) {