> The hardware contains a single configurable highpass filter which
> is normally used for transient detection (event).
>
> However it is also possible to enable this filter for normal channel
> reading. Add a new attribute in_accel_high_pass_filter_en to do this.
the patch moves around many lines of code, can likely be made much more
compact
> Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
> ---
> drivers/iio/accel/mma8452.c | 115 +++++++++++++++++++++++++++++--------------
> 1 file changed, 78 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index 66933b2..c56d34e 100644
> --- a/drivers/iio/accel/mma8452.c
> +++ b/drivers/iio/accel/mma8452.c
> @@ -62,6 +62,7 @@
> #define MMA8452_DATA_CFG_FS_2G 0
> #define MMA8452_DATA_CFG_FS_4G 1
> #define MMA8452_DATA_CFG_FS_8G 2
> +#define MMA8452_DATA_CFG_HPF_MASK BIT(4)
>
> #define MMA8452_INT_DRDY BIT(0)
> #define MMA8452_INT_FF_MT BIT(2)
> @@ -106,6 +107,43 @@ static int mma8452_read(struct mma8452_data *data, __be16 buf[3])
> MMA8452_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
> }
>
> +static int mma8452_standby(struct mma8452_data *data)
> +{
> + return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
> + data->ctrl_reg1 & ~MMA8452_CTRL_ACTIVE);
> +}
> +
> +static int mma8452_active(struct mma8452_data *data)
> +{
> + return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
> + data->ctrl_reg1);
> +}
> +
> +static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val)
> +{
> + int ret;
> +
> + mutex_lock(&data->lock);
> +
> + /* config can only be changed when in standby */
> + ret = mma8452_standby(data);
> + if (ret < 0)
> + goto fail;
> +
> + ret = i2c_smbus_write_byte_data(data->client, reg, val);
> + if (ret < 0)
> + goto fail;
> +
> + ret = mma8452_active(data);
> + if (ret < 0)
> + goto fail;
> +
> + ret = 0;
> +fail:
> + mutex_unlock(&data->lock);
> + return ret;
> +}
> +
> static ssize_t mma8452_show_int_plus_micros(char *buf,
> const int (*vals)[2], int n)
> {
> @@ -201,11 +239,50 @@ static ssize_t mma8452_show_hp_cutoff_avail(struct device *dev,
> ARRAY_SIZE(mma8452_hp_filter_cutoff[0]));
> }
>
> +static ssize_t mma8452_show_hp_cutoff_en(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct mma8452_data *data = iio_priv(indio_dev);
> +
> + return sprintf(buf, "%d\n",
> + data->data_cfg & MMA8452_DATA_CFG_HPF_MASK ? 1 : 0);
> +}
> +
> +static ssize_t mma8452_store_hp_cutoff_en(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct mma8452_data *data = iio_priv(indio_dev);
> + bool state;
> + int ret;
> +
> + ret = strtobool(buf, &state);
> + if (ret < 0)
> + return ret;
> +
> + if (state)
> + data->data_cfg |= MMA8452_DATA_CFG_HPF_MASK;
> + else
> + data->data_cfg &= ~MMA8452_DATA_CFG_HPF_MASK;
> +
> + ret = mma8452_change_config(data, MMA8452_DATA_CFG, data->data_cfg);
> + if (ret)
> + return ret;
> +
> + return len;
> +}
> +
> static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mma8452_show_samp_freq_avail);
> static IIO_DEVICE_ATTR(in_accel_scale_available, S_IRUGO,
> mma8452_show_scale_avail, NULL, 0);
> static IIO_DEVICE_ATTR(in_accel_filter_high_pass_3db_frequency_available,
> S_IRUGO, mma8452_show_hp_cutoff_avail, NULL, 0);
> +static IIO_DEVICE_ATTR(in_accel_filter_high_pass_en,
> + S_IRUGO | S_IWUSR,
> + mma8452_show_hp_cutoff_en,
> + mma8452_store_hp_cutoff_en, 0);
>
> static int mma8452_get_samp_freq_index(struct mma8452_data *data,
> int val, int val2)
> @@ -282,43 +359,6 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> -static int mma8452_standby(struct mma8452_data *data)
> -{
> - return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
> - data->ctrl_reg1 & ~MMA8452_CTRL_ACTIVE);
> -}
> -
> -static int mma8452_active(struct mma8452_data *data)
> -{
> - return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
> - data->ctrl_reg1);
> -}
> -
> -static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val)
> -{
> - int ret;
> -
> - mutex_lock(&data->lock);
> -
> - /* config can only be changed when in standby */
> - ret = mma8452_standby(data);
> - if (ret < 0)
> - goto fail;
> -
> - ret = i2c_smbus_write_byte_data(data->client, reg, val);
> - if (ret < 0)
> - goto fail;
> -
> - ret = mma8452_active(data);
> - if (ret < 0)
> - goto fail;
> -
> - ret = 0;
> -fail:
> - mutex_unlock(&data->lock);
> - return ret;
> -}
> -
> static int mma8452_write_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int val, int val2, long mask)
> @@ -636,6 +676,7 @@ static struct attribute *mma8452_attributes[] = {
> &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
> &iio_dev_attr_in_accel_scale_available.dev_attr.attr,
> &iio_dev_attr_in_accel_filter_high_pass_3db_frequency_available.dev_attr.attr,
> + &iio_dev_attr_in_accel_filter_high_pass_en.dev_attr.attr,
> NULL
> };
>
>
> --
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>
--
Peter Meerwald
+43-664-2444418 (mobile)
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