[PATCH v5 12/14] iio: adc: ad7768-1: replace manual attribute declaration

Jonathan Santos
2025-04-11T15:59:13Z

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>
---
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 aa60c55afd24..6bf3c332ad94 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,
@@ -210,6 +211,7 @@ 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;
@@ -314,6 +316,15 @@ 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)
{
@@ -569,28 +580,6 @@ 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)
@@ -636,6 +625,24 @@ 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)
@@ -658,15 +665,6 @@ 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)
{
@@ -677,8 +675,8 @@ 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,
@@ -1145,6 +1143,7 @@ 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