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authorStefan Popa <stefan.popa@analog.com>2018-08-20 17:54:55 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2018-08-25 09:19:33 +0100
commit7ec040af6ce11285c8bd3ec59a1a570db742e9aa (patch)
tree49041c947d8390abad5c2159d8c578cdc63b982b /drivers/iio
parent5e605a4df6f18dc4e2e529f5f2e01f76441cece5 (diff)
downloadlinux-7ec040af6ce11285c8bd3ec59a1a570db742e9aa.tar.bz2
iio:adxl372: Add filter bandwidth support
This patch adds the option for the user to select the filter bandwidth. The user can also read the available bandwidths which are always adjusted to be at most half of the sampling frequency. Furthermore, the currently selected bandwidth can be read via the read_raw function, while the write_raw sets a new bandwidth value. Signed-off-by: Stefan Popa <stefan.popa@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/accel/adxl372.c38
1 files changed, 36 insertions, 2 deletions
diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
index 6281e4a11632..fdaaa58ce68f 100644
--- a/drivers/iio/accel/adxl372.c
+++ b/drivers/iio/accel/adxl372.c
@@ -202,6 +202,10 @@ static const int adxl372_samp_freq_tbl[5] = {
400, 800, 1600, 3200, 6400,
};
+static const int adxl372_bw_freq_tbl[5] = {
+ 200, 400, 800, 1600, 3200,
+};
+
struct adxl372_axis_lookup {
unsigned int bits;
enum adxl372_fifo_format fifo_format;
@@ -224,7 +228,8 @@ static const struct adxl372_axis_lookup adxl372_axis_lookup_table[] = {
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
- BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
@@ -648,6 +653,9 @@ static int adxl372_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SAMP_FREQ:
*val = adxl372_samp_freq_tbl[st->odr];
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *val = adxl372_bw_freq_tbl[st->bw];
+ return IIO_VAL_INT;
}
return -EINVAL;
@@ -658,7 +666,7 @@ static int adxl372_write_raw(struct iio_dev *indio_dev,
int val, int val2, long info)
{
struct adxl372_state *st = iio_priv(indio_dev);
- int odr_index, ret;
+ int odr_index, bw_index, ret;
switch (info) {
case IIO_CHAN_INFO_SAMP_FREQ:
@@ -690,11 +698,34 @@ static int adxl372_write_raw(struct iio_dev *indio_dev,
ret = adxl372_set_bandwidth(st, odr_index);
return ret;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ bw_index = adxl372_find_closest_match(adxl372_bw_freq_tbl,
+ ARRAY_SIZE(adxl372_bw_freq_tbl),
+ val);
+ return adxl372_set_bandwidth(st, bw_index);
default:
return -EINVAL;
}
}
+static ssize_t adxl372_show_filter_freq_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct adxl372_state *st = iio_priv(indio_dev);
+ int i;
+ size_t len = 0;
+
+ for (i = 0; i <= st->odr; i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "%d ", adxl372_bw_freq_tbl[i]);
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
static ssize_t adxl372_get_fifo_enabled(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -838,9 +869,12 @@ static const struct iio_trigger_ops adxl372_trigger_ops = {
};
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("400 800 1600 3200 6400");
+static IIO_DEVICE_ATTR(in_accel_filter_low_pass_3db_frequency_available,
+ 0444, adxl372_show_filter_freq_avail, NULL, 0);
static struct attribute *adxl372_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ &iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
NULL,
};