[PATCH v8 09/11] iio: adc: ad7768-1: replace manual attribute declaration

[Jonathan Santos <Jonathan.Santos@analog.com>]

Use read_avail callback from struct iio_info to replace the manual
declaration of sampling_frequency_available attribute.

Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
---
v8 Changes:
* Addressed formatting issue.

v7 Changes:
* Iteractor changed to unsigned in the ad7768_fill_samp_freq_tbl()
  function.

v6 Changes:
* none.

v5 Changes:
* none.

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 906eb3ae588d..d962521b82a4 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -189,6 +189,7 @@ 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,
@@ -209,6 +210,7 @@ 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;
@@ -322,6 +324,15 @@ static int ad7768_send_sync_pulse(struct ad7768_state *st)
 	return 0;
 }
 
+static void ad7768_fill_samp_freq_tbl(struct ad7768_state *st)
+{
+	unsigned 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)
 {
@@ -579,28 +590,6 @@ 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)
@@ -646,6 +635,24 @@ 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)
@@ -668,15 +675,6 @@ 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)
 {
@@ -687,8 +685,8 @@ 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,
@@ -1139,6 +1137,7 @@ 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