[PATCH v3 3/5] iio: adc: ad7192: Use standard attribute

[Alisa-Dariana Roman <alisadariana@gmail.com>]

Replace custom attribute filter_low_pass_3db_frequency_available with
standard attribute.

Store the available values in ad7192_state struct.

The function that used to compute those values replaced by
ad7192_update_filter_freq_avail().

Function ad7192_show_filter_avail() is no longer needed.

Note that the initial available values are hardcoded.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
---
 drivers/iio/adc/ad7192.c | 67 ++++++++++++++++++----------------------
 1 file changed, 30 insertions(+), 37 deletions(-)

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 5e8043865233..d8393ac048e7 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -187,6 +187,7 @@ struct ad7192_state {
 	u32				mode;
 	u32				conf;
 	u32				scale_avail[8][2];
+	u32				filter_freq_avail[4][2];
 	u32				oversampling_ratio_avail[4];
 	u8				gpocon;
 	u8				clock_sel;
@@ -470,6 +471,16 @@ static int ad7192_setup(struct ad7192_state *st)
 	st->oversampling_ratio_avail[2] = 8;
 	st->oversampling_ratio_avail[3] = 16;
 
+	st->filter_freq_avail[0][0] = 600;
+	st->filter_freq_avail[1][0] = 800;
+	st->filter_freq_avail[2][0] = 2300;
+	st->filter_freq_avail[3][0] = 2720;
+
+	st->filter_freq_avail[0][1] = 1000;
+	st->filter_freq_avail[1][1] = 1000;
+	st->filter_freq_avail[2][1] = 1000;
+	st->filter_freq_avail[3][1] = 1000;
+
 	return 0;
 }
 
@@ -583,48 +594,24 @@ static int ad7192_get_f_adc(struct ad7192_state *st)
 				 f_order * FIELD_GET(AD7192_MODE_RATE_MASK, st->mode));
 }
 
-static void ad7192_get_available_filter_freq(struct ad7192_state *st,
-						    int *freq)
+static void ad7192_update_filter_freq_avail(struct ad7192_state *st)
 {
 	unsigned int fadc;
 
 	/* Formulas for filter at page 25 of the datasheet */
 	fadc = ad7192_compute_f_adc(st, false, true);
-	freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
+	st->filter_freq_avail[0][0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
 
 	fadc = ad7192_compute_f_adc(st, true, true);
-	freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
+	st->filter_freq_avail[1][0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
 
 	fadc = ad7192_compute_f_adc(st, false, false);
-	freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
+	st->filter_freq_avail[2][0] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
 
 	fadc = ad7192_compute_f_adc(st, true, false);
-	freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
+	st->filter_freq_avail[3][0] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
 }
 
-static ssize_t ad7192_show_filter_avail(struct device *dev,
-					struct device_attribute *attr,
-					char *buf)
-{
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ad7192_state *st = iio_priv(indio_dev);
-	unsigned int freq_avail[4], i;
-	size_t len = 0;
-
-	ad7192_get_available_filter_freq(st, freq_avail);
-
-	for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
-		len += sysfs_emit_at(buf, len, "%d.%03d ", freq_avail[i] / 1000,
-				     freq_avail[i] % 1000);
-
-	buf[len - 1] = '\n';
-
-	return len;
-}
-
-static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
-		       0444, ad7192_show_filter_avail, NULL, 0);
-
 static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
 		       ad7192_show_bridge_switch, ad7192_set,
 		       AD7192_REG_GPOCON);
@@ -634,7 +621,6 @@ static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
 		       AD7192_REG_CONF);
 
 static struct attribute *ad7192_attributes[] = {
-	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
 	NULL
 };
@@ -644,7 +630,6 @@ static const struct attribute_group ad7192_attribute_group = {
 };
 
 static struct attribute *ad7195_attributes[] = {
-	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
 	NULL
@@ -662,17 +647,15 @@ static unsigned int ad7192_get_temp_scale(bool unipolar)
 static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
 				      int val, int val2)
 {
-	int freq_avail[4], i, ret, freq;
+	int i, ret, freq;
 	unsigned int diff_new, diff_old;
 	int idx = 0;
 
 	diff_old = U32_MAX;
 	freq = val * 1000 + val2;
 
-	ad7192_get_available_filter_freq(st, freq_avail);
-
-	for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
-		diff_new = abs(freq - freq_avail[i]);
+	for (i = 0; i < ARRAY_SIZE(st->filter_freq_avail); i++) {
+		diff_new = abs(freq - st->filter_freq_avail[i][0]);
 		if (diff_new < diff_old) {
 			diff_old = diff_new;
 			idx = i;
@@ -823,6 +806,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
 		st->mode &= ~AD7192_MODE_RATE_MASK;
 		st->mode |= FIELD_PREP(AD7192_MODE_RATE_MASK, div);
 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
+		ad7192_update_filter_freq_avail(st);
 		break;
 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 		ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
@@ -843,6 +827,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
 				break;
 			}
 		mutex_unlock(&st->lock);
+		ad7192_update_filter_freq_avail(st);
 		break;
 	default:
 		ret = -EINVAL;
@@ -885,6 +870,12 @@ static int ad7192_read_avail(struct iio_dev *indio_dev,
 		/* Values are stored in a 2D matrix  */
 		*length = ARRAY_SIZE(st->scale_avail) * 2;
 
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		*vals = (int *)st->filter_freq_avail;
+		*type = IIO_VAL_FRACTIONAL;
+		*length = ARRAY_SIZE(st->filter_freq_avail) * 2;
+
 		return IIO_AVAIL_LIST;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		*vals = (int *)st->oversampling_ratio_avail;
@@ -953,7 +944,9 @@ static const struct iio_info ad7195_info = {
 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
 			(_mask_all), \
 		.info_mask_shared_by_type_available = (_mask_type_av), \
-		.info_mask_shared_by_all_available = (_mask_all_av), \
+		.info_mask_shared_by_all_available = \
+			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
+			(_mask_all_av), \
 		.ext_info = (_ext_info), \
 		.scan_index = (_si), \
 		.scan_type = { \
-- 
2.34.1