Re: [PATCH v2 4/4] iio: light: ltr501: Add support for the LTR-659PS-01 proximity sensor

[Jonathan Cameron <jic23@kernel.org>]

On Fri,  6 Nov 2026 11:19:43 +0200
Svyatoslav Ryhel <clamor95@gmail.com> wrote:

> Add support for the Lite-On LTR-659PS-01 proximity sensor. This device is
> nearly identical to the LTR-559ALS-01, but omits all elements related to
> ambient light sensing.
> 
> Add a no_als_support flag, similar to how no_irq_support is used, to
> isolate ALS register access for the LTR-659PS-01, since ALS registers are
> marked as reserved and interactions with them are discouraged.
> 
> The ltr501_trigger_handler relied on the scan index to identify channels.
> This approach is fragile regarding channel status flags and can break if
> the index is not strictly set. Switch to checking the channel type
> instead.
> 
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> ---
>  drivers/iio/light/ltr501.c | 73 +++++++++++++++++++++++++++++++-------
>  1 file changed, 61 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
> index d5ce6468a229b..e7762115df913 100644
> --- a/drivers/iio/light/ltr501.c
> +++ b/drivers/iio/light/ltr501.c
> @@ -151,6 +151,7 @@ struct ltr501_chip_info {
>  	u8 als_gain_mask;
>  	u8 als_gain_shift;
>  	bool no_irq_support;
> +	bool no_als_support;
>  	struct iio_chan_spec const *channels;
>  	const int no_channels;
>  };
> @@ -192,6 +193,11 @@ static bool ltr501_has_irq_support(const struct ltr501_chip_info *info)
>  	return !info->no_irq_support;
>  }
>  
> +static bool ltr501_has_als_support(const struct ltr501_chip_info *info)

Is the helper bring enough value?  The !info->no_als_support
where this is used seems clear enough to me.

> +{
> +	return !info->no_als_support;
> +}
> +
>  static int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
>  					   int len, int val, int val2)
>  {
> @@ -656,6 +662,29 @@ static const struct iio_chan_spec ltr301_channels[] = {
>  	IIO_CHAN_SOFT_TIMESTAMP(2),
>  };
>  
> +static const struct iio_chan_spec ltr659_channels[] = {
> +	{
> +		.type = IIO_PROXIMITY,
> +		.address = LTR501_PS_DATA,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +		.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
> +						BIT(IIO_CHAN_INFO_SAMP_FREQ),

The sampling frequency applies to both channels here. I'd just make that
info_mask_shared_by_all

> +		.scan_index = 0,
> +		.scan_type = {
> +			.sign = 'u',
> +			.realbits = 11,
> +			.storagebits = 16,
> +			.endianness = IIO_CPU,
> +		},
> +		.event_spec = ltr501_pxs_event_spec,
> +		.num_event_specs = ARRAY_SIZE(ltr501_pxs_event_spec),
> +		.ext_info = ltr501_ext_info,
> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(1),
> +};