- add mapping for the low pass filter cut-off frequency.
- make valid values visible for both the cut-off frequency and the scale.
Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>
---
drivers/iio/accel/bma220_core.c | 60 ++++++++++++++++++++++++++++++++-
1 file changed, 59 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_core.c
index 86347cf8ab1e..e60acd62cf96 100644
--- a/drivers/iio/accel/bma220_core.c
+++ b/drivers/iio/accel/bma220_core.c
@@ -4,6 +4,15 @@
*
* Copyright (c) 2016,2020 Intel Corporation.
* Copyright (c) 2025 Petre Rodan <petre.rodan@subdimension.ro>
+ *
+ *
+ * Device register to IIO ABI mapping:
+ *
+ * Register | IIO ABI (sysfs) | valid values
+ * --------------------------+--------------------------------+---------------
+ * scale (range) | in_accel_scale | see _available
+ * cut-off freq (filt_config)| in_accel_filter_low_pass_... | see _available
+ * ---------------------------------------------------------------------------
*/
#include <linux/bits.h>
@@ -135,13 +144,23 @@
#define BMA220_DEVICE_NAME "bma220"
+#define BMA220_COF_1000HZ 0x0
+#define BMA220_COF_500HZ 0x1
+#define BMA220_COF_250HZ 0x2
+#define BMA220_COF_125HZ 0x3
+#define BMA220_COF_64HZ 0x4
+#define BMA220_COF_32HZ 0x5
+
#define BMA220_ACCEL_CHANNEL(index, reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
- .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
+ .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE) |\
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
@@ -172,6 +191,7 @@ struct bma220_data {
struct device *dev;
struct regmap *regmap;
struct mutex lock;
+ u8 lpf_3db_freq_idx;
u8 range_idx;
struct iio_trigger *trig;
struct {
@@ -188,6 +208,18 @@ static const struct iio_chan_spec bma220_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(3),
};
+/*
+ * Available cut-off frequencies of the low pass filter in Hz.
+ */
+static const int bma220_lpf_3db_freq_hz_table[][2] = {
+ [BMA220_COF_1000HZ] = {1000, 0},
+ [BMA220_COF_500HZ] = {500, 0},
+ [BMA220_COF_250HZ] = {250, 0},
+ [BMA220_COF_125HZ] = {125, 0},
+ [BMA220_COF_64HZ] = {64, 0},
+ [BMA220_COF_32HZ] = {32, 0},
+};
+
static const unsigned long bma220_accel_scan_masks[] = {
BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
0
@@ -309,6 +341,11 @@ static int bma220_read_raw(struct iio_dev *indio_dev,
*val = bma220_scale_table[index][0];
*val2 = bma220_scale_table[index][1];
return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ index = data->lpf_3db_freq_idx;
+ *val = bma220_lpf_3db_freq_hz_table[index][0];
+ *val2 = bma220_lpf_3db_freq_hz_table[index][1];
+ return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
@@ -353,6 +390,22 @@ static int bma220_write_raw(struct iio_dev *indio_dev,
"failed to set measurement range\n");
data->range_idx = index;
+ return 0;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ index = bma220_find_match(bma220_lpf_3db_freq_hz_table,
+ ARRAY_SIZE(bma220_lpf_3db_freq_hz_table),
+ val, val2);
+ if (index < 0)
+ return -EINVAL;
+
+ ret = regmap_update_bits(data->regmap, BMA220_REG_FILTER,
+ BMA220_FILTER_MASK,
+ FIELD_PREP(BMA220_FILTER_MASK, index));
+ if (ret < 0)
+ dev_err(data->dev,
+ "failed to set low pass filter\n");
+ data->lpf_3db_freq_idx = index;
+
return 0;
}
@@ -370,6 +423,11 @@ static int bma220_read_avail(struct iio_dev *indio_dev,
*type = IIO_VAL_INT_PLUS_MICRO;
*length = ARRAY_SIZE(bma220_scale_table) * 2;
return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *vals = (const int *)bma220_lpf_3db_freq_hz_table;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ *length = ARRAY_SIZE(bma220_lpf_3db_freq_hz_table) * 2;
+ return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
--
2.49.1On 9/1/25 2:47 PM, Petre Rodan wrote:
> - add mapping for the low pass filter cut-off frequency.
> - make valid values visible for both the cut-off frequency and the scale.
>
> Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>
> ---
> drivers/iio/accel/bma220_core.c | 60 ++++++++++++++++++++++++++++++++-
> 1 file changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_core.c
> index 86347cf8ab1e..e60acd62cf96 100644
> --- a/drivers/iio/accel/bma220_core.c
> +++ b/drivers/iio/accel/bma220_core.c
> @@ -4,6 +4,15 @@
> *
> * Copyright (c) 2016,2020 Intel Corporation.
> * Copyright (c) 2025 Petre Rodan <petre.rodan@subdimension.ro>
> + *
> + *
> + * Device register to IIO ABI mapping:
> + *
> + * Register | IIO ABI (sysfs) | valid values
> + * --------------------------+--------------------------------+---------------
> + * scale (range) | in_accel_scale | see _available
> + * cut-off freq (filt_config)| in_accel_filter_low_pass_... | see _available
> + * ---------------------------------------------------------------------------
> */
>
> #include <linux/bits.h>
> @@ -135,13 +144,23 @@
>
> #define BMA220_DEVICE_NAME "bma220"
>
> +#define BMA220_COF_1000HZ 0x0
> +#define BMA220_COF_500HZ 0x1
> +#define BMA220_COF_250HZ 0x2
> +#define BMA220_COF_125HZ 0x3
> +#define BMA220_COF_64HZ 0x4
> +#define BMA220_COF_32HZ 0x5
> +
> #define BMA220_ACCEL_CHANNEL(index, reg, axis) { \
> .type = IIO_ACCEL, \
> .address = reg, \
> .modified = 1, \
> .channel2 = IIO_MOD_##axis, \
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
> + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
> + .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE) |\
> + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
> .scan_index = index, \
> .scan_type = { \
> .sign = 's', \
> @@ -172,6 +191,7 @@ struct bma220_data {
> struct device *dev;
> struct regmap *regmap;
> struct mutex lock;
> + u8 lpf_3db_freq_idx;
> u8 range_idx;
> struct iio_trigger *trig;
> struct {
> @@ -188,6 +208,18 @@ static const struct iio_chan_spec bma220_channels[] = {
> IIO_CHAN_SOFT_TIMESTAMP(3),
> };
>
> +/*
> + * Available cut-off frequencies of the low pass filter in Hz.
> + */
> +static const int bma220_lpf_3db_freq_hz_table[][2] = {
> + [BMA220_COF_1000HZ] = {1000, 0},
> + [BMA220_COF_500HZ] = {500, 0},
> + [BMA220_COF_250HZ] = {250, 0},
> + [BMA220_COF_125HZ] = {125, 0},
> + [BMA220_COF_64HZ] = {64, 0},
> + [BMA220_COF_32HZ] = {32, 0},
If all of these are integer values, why do we need 2-D table?
> +};
> +
> static const unsigned long bma220_accel_scan_masks[] = {
> BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
> 0
> @@ -309,6 +341,11 @@ static int bma220_read_raw(struct iio_dev *indio_dev,
> *val = bma220_scale_table[index][0];
> *val2 = bma220_scale_table[index][1];
> return IIO_VAL_INT_PLUS_MICRO;
> + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> + index = data->lpf_3db_freq_idx;
> + *val = bma220_lpf_3db_freq_hz_table[index][0];
> + *val2 = bma220_lpf_3db_freq_hz_table[index][1];
> + return IIO_VAL_INT_PLUS_MICRO;
Why not IIO_VAL_INT?
> }
>
> return -EINVAL;
> @@ -353,6 +390,22 @@ static int bma220_write_raw(struct iio_dev *indio_dev,
> "failed to set measurement range\n");
> data->range_idx = index;
>
> + return 0;
> + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> + index = bma220_find_match(bma220_lpf_3db_freq_hz_table,
> + ARRAY_SIZE(bma220_lpf_3db_freq_hz_table),
> + val, val2);
> + if (index < 0)
> + return -EINVAL;
> +
> + ret = regmap_update_bits(data->regmap, BMA220_REG_FILTER,
> + BMA220_FILTER_MASK,
> + FIELD_PREP(BMA220_FILTER_MASK, index));
> + if (ret < 0)
> + dev_err(data->dev,
> + "failed to set low pass filter\n");
Should `return ret;` here rather than logging error.
> + data->lpf_3db_freq_idx = index;
> +
> return 0;
> }
>
> @@ -370,6 +423,11 @@ static int bma220_read_avail(struct iio_dev *indio_dev,
> *type = IIO_VAL_INT_PLUS_MICRO;
> *length = ARRAY_SIZE(bma220_scale_table) * 2;
> return IIO_AVAIL_LIST;
> + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> + *vals = (const int *)bma220_lpf_3db_freq_hz_table;
> + *type = IIO_VAL_INT_PLUS_MICRO;
> + *length = ARRAY_SIZE(bma220_lpf_3db_freq_hz_table) * 2;
> + return IIO_AVAIL_LIST;
> default:
> return -EINVAL;
> }
> --
> 2.49.1
>
On Fri, 5 Sep 2025 14:59:27 -0500
David Lechner <dlechner@baylibre.com> wrote:
> On 9/1/25 2:47 PM, Petre Rodan wrote:
> > - add mapping for the low pass filter cut-off frequency.
> > - make valid values visible for both the cut-off frequency and the scale.
> >
> > Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>
> > +/*
> > + * Available cut-off frequencies of the low pass filter in Hz.
> > + */
> > +static const int bma220_lpf_3db_freq_hz_table[][2] = {
> > + [BMA220_COF_1000HZ] = {1000, 0},
> > + [BMA220_COF_500HZ] = {500, 0},
> > + [BMA220_COF_250HZ] = {250, 0},
> > + [BMA220_COF_125HZ] = {125, 0},
> > + [BMA220_COF_64HZ] = {64, 0},
> > + [BMA220_COF_32HZ] = {32, 0},
>
> If all of these are integer values, why do we need 2-D table?
Style wise, for IIO we are going for
{ 32, 0 },
That is extra spaces.
Mind you that's irrelevant if it's a 1D array ;)
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