iio: accel: bma220: add LPF cut-off frequency mapping

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>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_core.c
index 08c4dec67d5e183f3a97351bc982bf33a23ae1d1..0ceffc41266475e1d1e360aeeca4806e5bafce4e 100644 (file)
--- a/drivers/iio/accel/bma220_core.c
+++ b/drivers/iio/accel/bma220_core.c
@@ -94,13 +94,23 @@
 
 #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',                                            \
@@ -124,6 +134,7 @@ static const int bma220_scale_table[][2] = {
 struct bma220_data {
        struct regmap *regmap;
        struct mutex lock;
+       u8 lpf_3dB_freq_idx;
        u8 range_idx;
        struct iio_trigger *trig;
        struct {
@@ -140,6 +151,16 @@ 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[] = {
+       [BMA220_COF_1000Hz] = 1000,
+       [BMA220_COF_500Hz] = 500,
+       [BMA220_COF_250Hz] = 250,
+       [BMA220_COF_125Hz] = 125,
+       [BMA220_COF_64Hz] = 64,
+       [BMA220_COF_32Hz] = 32,
+};
+
 static const unsigned long bma220_accel_scan_masks[] = {
        BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
        0
@@ -254,6 +275,10 @@ 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];
+               return IIO_VAL_INT;
        }
 
        return -EINVAL;
@@ -272,6 +297,18 @@ static int bma220_find_match_2dt(const int (*tbl)[2], const int n,
        return -EINVAL;
 }
 
+static int bma220_find_match(const int *arr, const int n, const int val)
+{
+       int i;
+
+       for (i = 0; i < n; i++) {
+               if (arr[i] == val)
+                       return i;
+       }
+
+       return -EINVAL;
+}
+
 static int bma220_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
@@ -297,6 +334,21 @@ static int bma220_write_raw(struct iio_dev *indio_dev,
                        return ret;
                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);
+               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)
+                       return ret;
+               data->lpf_3dB_freq_idx = index;
+
                return 0;
        }
 
@@ -314,6 +366,11 @@ 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;
+               *length = ARRAY_SIZE(bma220_lpf_3dB_freq_Hz_table);
+               return IIO_AVAIL_LIST;
        default:
                return -EINVAL;
        }