iio:proximity:sx9310: Add frequency in read_avail

Instead of using IIO_DEV_ATTR_SAMP_FREQ_AVAIL sysfs attribute,
add a _FREQ case in read_avail() to display the frequency table.
No change to |sampling_frequency_available| was observed.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220101203817.290512-2-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/proximity/sx9310.c

@@ -196,6 +196,8 @@ static const struct iio_event_spec sx9310_events[] = {
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 		.info_mask_separate_available =				 \
 			BIT(IIO_CHAN_INFO_HARDWAREGAIN),		 \
+		.info_mask_shared_by_all_available =			 \
+			BIT(IIO_CHAN_INFO_SAMP_FREQ),			 \
 		.indexed = 1,						 \
 		.channel = idx,						 \
 		.extend_name = name,					 \
@@ -251,22 +253,6 @@ static const unsigned int sx9310_scan_period_table[] = {
 	400, 600, 800, 1000, 2000, 3000, 4000, 5000,
 };
 
-static ssize_t sx9310_show_samp_freq_avail(struct device *dev,
-					   struct device_attribute *attr,
-					   char *buf)
-{
-	size_t len = 0;
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
-		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%d ",
-				 sx9310_samp_freq_table[i].val,
-				 sx9310_samp_freq_table[i].val2);
-	buf[len - 1] = '\n';
-	return len;
-}
-static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sx9310_show_samp_freq_avail);
-
 static const struct regmap_range sx9310_writable_reg_ranges[] = {
 	regmap_reg_range(SX9310_REG_IRQ_MSK, SX9310_REG_IRQ_FUNC),
 	regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
@@ -562,6 +548,11 @@ static int sx9310_read_avail(struct iio_dev *indio_dev,
 		*length = ARRAY_SIZE(sx9310_gain_vals);
 		*vals = sx9310_gain_vals;
 		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		*length = ARRAY_SIZE(sx9310_samp_freq_table) * 2;
+		*vals = (int *)sx9310_samp_freq_table;
+		return IIO_AVAIL_LIST;
 	}
 
 	return -EINVAL;
@@ -1031,17 +1022,7 @@ static int sx9310_write_event_config(struct iio_dev *indio_dev,
 	return ret;
 }
 
-static struct attribute *sx9310_attributes[] = {
-	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
-	NULL
-};
-
-static const struct attribute_group sx9310_attribute_group = {
-	.attrs = sx9310_attributes,
-};
-
 static const struct iio_info sx9310_info = {
-	.attrs = &sx9310_attribute_group,
 	.read_raw = sx9310_read_raw,
 	.read_avail = sx9310_read_avail,
 	.read_event_value = sx9310_read_event_val,