Re: [PATCH v4 15/17] iio: adc: ad7768-1: replace manual attribute declaration

[Marcelo Schmitt <marcelo.schmitt1@gmail.com>]

On 03/06, Jonathan Santos wrote:
> Use read_avail callback from struct iio_info to replace the manual
> declaration of sampling_frequency_available attribute.
> 
> Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>

Reviewed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>

> ---
> v4 Changes:
> * Added ad7768_fill_samp_freq_tbl() helper function.
> * Sampling frequency table is precomputed at probe.
> 
> v3 Changes:
> * New patch in v3.
> ---
>  drivers/iio/adc/ad7768-1.c | 63 +++++++++++++++++++-------------------
>  1 file changed, 31 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
> index c48d3e0af985..0bdf2ae903c6 100644
> --- a/drivers/iio/adc/ad7768-1.c
> +++ b/drivers/iio/adc/ad7768-1.c
> @@ -187,6 +187,7 @@ static const struct iio_chan_spec ad7768_channels[] = {
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
>  		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>  		.indexed = 1,
>  		.channel = 0,
>  		.scan_index = 0,
> @@ -208,6 +209,7 @@ struct ad7768_state {
>  	unsigned int mclk_freq;
>  	unsigned int dec_rate;
>  	unsigned int samp_freq;
> +	unsigned int samp_freq_avail[ARRAY_SIZE(ad7768_clk_config)];
>  	struct completion completion;
>  	struct iio_trigger *trig;
>  	struct gpio_desc *gpio_sync_in;
> @@ -306,6 +308,15 @@ static int ad7768_send_sync_pulse(struct ad7768_state *st)
>  	return 0;
>  }
>  
> +static void ad7768_fill_samp_freq_tbl(struct ad7768_state *st)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++)
> +		st->samp_freq_avail[i] = DIV_ROUND_CLOSEST(st->mclk_freq,
> +							   ad7768_clk_config[i].clk_div);
> +}
> +
>  static int ad7768_set_mode(struct ad7768_state *st,
>  			   enum ad7768_conv_mode mode)
>  {
> @@ -566,28 +577,6 @@ static int ad7768_set_freq(struct ad7768_state *st,
>  	return 0;
>  }
>  
> -static ssize_t ad7768_sampling_freq_avail(struct device *dev,
> -					  struct device_attribute *attr,
> -					  char *buf)
> -{
> -	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> -	struct ad7768_state *st = iio_priv(indio_dev);
> -	unsigned int freq;
> -	int i, len = 0;
> -
> -	for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
> -		freq = DIV_ROUND_CLOSEST(st->mclk_freq,
> -					 ad7768_clk_config[i].clk_div);
> -		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", freq);
> -	}
> -
> -	buf[len - 1] = '\n';
> -
> -	return len;
> -}
> -
> -static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ad7768_sampling_freq_avail);
> -
>  static int ad7768_read_raw(struct iio_dev *indio_dev,
>  			   struct iio_chan_spec const *chan,
>  			   int *val, int *val2, long info)
> @@ -635,6 +624,24 @@ static int ad7768_read_raw(struct iio_dev *indio_dev,
>  	return -EINVAL;
>  }
>  
> +static int ad7768_read_avail(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     const int **vals, int *type, int *length,
> +			     long info)
> +{
> +	struct ad7768_state *st = iio_priv(indio_dev);
> +
> +	switch (info) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		*vals = (int *)st->samp_freq_avail;
> +		*length = ARRAY_SIZE(ad7768_clk_config);
> +		*type = IIO_VAL_INT;
> +		return IIO_AVAIL_LIST;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
>  static int ad7768_write_raw(struct iio_dev *indio_dev,
>  			    struct iio_chan_spec const *chan,
>  			    int val, int val2, long info)
> @@ -657,15 +664,6 @@ static int ad7768_read_label(struct iio_dev *indio_dev,
>  	return sprintf(label, "%s\n", st->labels[chan->channel]);
>  }
>  
> -static struct attribute *ad7768_attributes[] = {
> -	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
> -	NULL
> -};
> -
> -static const struct attribute_group ad7768_group = {
> -	.attrs = ad7768_attributes,
> -};
> -
>  static int ad7768_get_current_scan_type(const struct iio_dev *indio_dev,
>  					const struct iio_chan_spec *chan)
>  {
> @@ -676,8 +674,8 @@ static int ad7768_get_current_scan_type(const struct iio_dev *indio_dev,
>  }
>  
>  static const struct iio_info ad7768_info = {
> -	.attrs = &ad7768_group,
>  	.read_raw = &ad7768_read_raw,
> +	.read_avail = &ad7768_read_avail,
>  	.write_raw = &ad7768_write_raw,
>  	.read_label = ad7768_read_label,
>  	.get_current_scan_type = &ad7768_get_current_scan_type,
> @@ -1134,6 +1132,7 @@ static int ad7768_probe(struct spi_device *spi)
>  		return PTR_ERR(st->mclk);
>  
>  	st->mclk_freq = clk_get_rate(st->mclk);
> +	ad7768_fill_samp_freq_tbl(st);
>  
>  	indio_dev->channels = ad7768_channels;
>  	indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
> -- 
> 2.34.1
>