Re: [PATCH 1/2] iio: vcnl4000: Export near level property for proximity sensor

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 17 Feb 2020 14:44:47 +0100
Guido Günther <agx@sigxcpu.org> wrote:

> When an object can be considered close to the sensor is hardware
> dependent. Allowing to configure the property via device tree
> allows to configure this device specific value.
> 
> This is useful for e.g. iio-sensor-proxy to indicate to userspace
> if an object is close to the sensor.
> 
> Signed-off-by: Guido Günther <agx@sigxcpu.org>

I'd like this to sit for a while on the mailing list and hopefully get
some input from others.

However, it needs documentation and I think this should be in the
generic docs, or at least proximity specific ones.

Documentation/ABI/testing/sysfs-bus-iio-proximity would be the obvious
place.

Thanks,

Jonathan

> ---
>  drivers/iio/light/vcnl4000.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> index 38fcd9a26046..7111118e0fda 100644
> --- a/drivers/iio/light/vcnl4000.c
> +++ b/drivers/iio/light/vcnl4000.c
> @@ -83,6 +83,7 @@ struct vcnl4000_data {
>  	struct mutex vcnl4000_lock;
>  	struct vcnl4200_channel vcnl4200_al;
>  	struct vcnl4200_channel vcnl4200_ps;
> +	uint32_t near_level;
>  };
>  
>  struct vcnl4000_chip_spec {
> @@ -342,6 +343,26 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
>  	},
>  };
>  
> +
> +static ssize_t vcnl4000_read_near_level(struct iio_dev *indio_dev,
> +					uintptr_t priv,
> +					const struct iio_chan_spec *chan,
> +					char *buf)
> +{
> +	struct vcnl4000_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%u\n", data->near_level);
> +}
> +
> +static const struct iio_chan_spec_ext_info vcnl4000_ext_info[] = {
> +	{
> +		.name = "near_level",
> +		.shared = IIO_SEPARATE,
> +		.read = vcnl4000_read_near_level,
> +	},
> +	{ /* sentinel */ }
> +};
> +
>  static const struct iio_chan_spec vcnl4000_channels[] = {
>  	{
>  		.type = IIO_LIGHT,
> @@ -350,6 +371,7 @@ static const struct iio_chan_spec vcnl4000_channels[] = {
>  	}, {
>  		.type = IIO_PROXIMITY,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.ext_info = vcnl4000_ext_info,
>  	}
>  };
>  
> @@ -439,6 +461,10 @@ static int vcnl4000_probe(struct i2c_client *client,
>  	dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
>  		data->chip_spec->prod, data->rev);
>  
> +	if (device_property_read_u32(&client->dev, "near-level",
> +				     &data->near_level) < 0)
> +		data->near_level = 0;
> +
>  	indio_dev->dev.parent = &client->dev;
>  	indio_dev->info = &vcnl4000_info;
>  	indio_dev->channels = vcnl4000_channels;