Re: [PATCH v4 6/8] iio: adc: ad7606: Introduce num_adc_channels

[Nuno Sá]

On Wed, 2024-10-09 at 09:19 +0000, Guillaume Stols wrote:
> This variable determines how many hardware channels has the chip,
> oppositely to the num_channels that can contain more channels, e.g a
> timestamp channel in our case. Introducing this variable avoids
> decreasing the former num_channels variable when reading the ADC's
> channels, and clarifies a bit the code.
> 
> Signed-off-by: Guillaume Stols <gstols@xxxxxxxxxxxx>
> ---

Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx>

>  drivers/iio/adc/ad7606.c | 10 +++++++++-
>  drivers/iio/adc/ad7606.h |  2 ++
>  2 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> index dfbdea8c28ba..ec902b268388 100644
> --- a/drivers/iio/adc/ad7606.c
> +++ b/drivers/iio/adc/ad7606.c
> @@ -150,6 +150,7 @@ static int ad7606_16bit_chan_scale_setup(struct ad7606_state
> *st,
>  const struct ad7606_chip_info ad7605_4_info = {
>  	.channels = ad7605_channels,
>  	.name = "ad7605-4",
> +	.num_adc_channels = 4,
>  	.num_channels = 5,
>  	.scale_setup_cb = ad7606_16bit_chan_scale_setup,
>  };
> @@ -158,6 +159,7 @@ EXPORT_SYMBOL_NS_GPL(ad7605_4_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606_8_info = {
>  	.channels = ad7606_channels_16bit,
>  	.name = "ad7606-8",
> +	.num_adc_channels = 8,
>  	.num_channels = 9,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -168,6 +170,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606_8_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606_6_info = {
>  	.channels = ad7606_channels_16bit,
>  	.name = "ad7606-6",
> +	.num_adc_channels = 6,
>  	.num_channels = 7,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -178,6 +181,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606_6_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606_4_info = {
>  	.channels = ad7606_channels_16bit,
>  	.name = "ad7606-4",
> +	.num_adc_channels = 4,
>  	.num_channels = 5,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -188,6 +192,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606_4_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606b_info = {
>  	.channels = ad7606_channels_16bit,
>  	.name = "ad7606b",
> +	.num_adc_channels = 8,
>  	.num_channels = 9,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -198,6 +203,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606b_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606c_16_info = {
>  	.channels = ad7606_channels_16bit,
>  	.name = "ad7606c16",
> +	.num_adc_channels = 8,
>  	.num_channels = 9,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -208,6 +214,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606c_16_info, IIO_AD7606);
>  const struct ad7606_chip_info ad7606c_18_info = {
>  	.channels = ad7606_channels_18bit,
>  	.name = "ad7606c18",
> +	.num_adc_channels = 8,
>  	.num_channels = 9,
>  	.oversampling_avail = ad7606_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> @@ -219,6 +226,7 @@ const struct ad7606_chip_info ad7616_info = {
>  	.channels = ad7616_channels,
>  	.init_delay_ms = 15,
>  	.name = "ad7616",
> +	.num_adc_channels = 16,
>  	.num_channels = 17,
>  	.oversampling_avail = ad7616_oversampling_avail,
>  	.oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
> @@ -528,7 +536,7 @@ static int ad7606_set_sampling_freq(struct ad7606_state *st,
> unsigned long freq)
>  
>  static int ad7606_read_samples(struct ad7606_state *st)
>  {
> -	unsigned int num = st->chip_info->num_channels - 1;
> +	unsigned int num = st->chip_info->num_adc_channels;
>  
>  	return st->bops->read_block(st->dev, num, &st->data);
>  }
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> index d401d3ab37e0..b26a11b2eba1 100644
> --- a/drivers/iio/adc/ad7606.h
> +++ b/drivers/iio/adc/ad7606.h
> @@ -71,6 +71,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
>   * @channels:		channel specification
>   * @name		device name
>   * @num_channels:	number of channels
> + * @num_adc_channels	the number of channels the ADC actually inputs.
>   * @scale_setup_cb:	callback to setup the scales for each channel
>   * @oversampling_avail	pointer to the array which stores the available
>   *			oversampling ratios.
> @@ -82,6 +83,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
>  struct ad7606_chip_info {
>  	const struct iio_chan_spec	*channels;
>  	const char			*name;
> +	unsigned int			num_adc_channels;
>  	unsigned int			num_channels;
>  	ad7606_scale_setup_cb_t		scale_setup_cb;
>  	const unsigned int		*oversampling_avail;
>