Re: [PATCH V4 5/7] iio: mma8452: Add support for transient event debouncing

[Jonathan Cameron <jic23@kernel.org>]

On 13/05/15 11:26, Martin Fuzzey wrote:
> Allow the debouce counter for transient events to be configured
> using the sysfs attribute events/in_accel_thresh_rising_period
> 
> Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Looks good.

Applied.
> ---
>  drivers/iio/accel/mma8452.c |   76 +++++++++++++++++++++++++++++++++++++------
>  1 file changed, 65 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index 2e8f72d..196dc42 100644
> --- a/drivers/iio/accel/mma8452.c
> +++ b/drivers/iio/accel/mma8452.c
> @@ -38,6 +38,7 @@
>  #define MMA8452_TRANSIENT_SRC_ZTRANSE		BIT(5)
>  #define MMA8452_TRANSIENT_THS 0x1f
>  #define MMA8452_TRANSIENT_THS_MASK	0x7f
> +#define MMA8452_TRANSIENT_COUNT 0x20
>  #define MMA8452_OFF_X 0x2f
>  #define MMA8452_OFF_Y 0x30
>  #define MMA8452_OFF_Z 0x31
> @@ -124,6 +125,12 @@ static int mma8452_get_int_plus_micros_index(const int (*vals)[2], int n,
>  	return -EINVAL;
>  }
>  
> +static int mma8452_get_odr_index(struct mma8452_data *data)
> +{
> +	return (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >>
> +			MMA8452_CTRL_DR_SHIFT;
> +}
> +
>  static const int mma8452_samp_freq[8][2] = {
>  	{800, 0}, {400, 0}, {200, 0}, {100, 0}, {50, 0}, {12, 500000},
>  	{6, 250000}, {1, 560000}
> @@ -139,6 +146,18 @@ static const int mma8452_scales[3][2] = {
>  	{0, 9577}, {0, 19154}, {0, 38307}
>  };
>  
> +/* Datasheet table 35  (step time vs sample frequency) */
> +static const int mma8452_transient_time_step_us[8] = {
> +	1250,
> +	2500,
> +	5000,
> +	10000,
> +	20000,
> +	20000,
> +	20000,
> +	20000
> +};
> +
>  static ssize_t mma8452_show_samp_freq_avail(struct device *dev,
>  				struct device_attribute *attr, char *buf)
>  {
> @@ -198,8 +217,7 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
>  		*val2 = mma8452_scales[i][1];
>  		return IIO_VAL_INT_PLUS_MICRO;
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> -		i = (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >>
> -			MMA8452_CTRL_DR_SHIFT;
> +		i = mma8452_get_odr_index(data);
>  		*val = mma8452_samp_freq[i][0];
>  		*val2 = mma8452_samp_freq[i][1];
>  		return IIO_VAL_INT_PLUS_MICRO;
> @@ -297,15 +315,33 @@ static int mma8452_read_thresh(struct iio_dev *indio_dev,
>  			       int *val, int *val2)
>  {
>  	struct mma8452_data *data = iio_priv(indio_dev);
> -	int ret;
> +	int ret, us;
>  
> -	ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_THS);
> -	if (ret < 0)
> -		return ret;
> +	switch (info) {
> +	case IIO_EV_INFO_VALUE:
> +		ret = i2c_smbus_read_byte_data(data->client,
> +					       MMA8452_TRANSIENT_THS);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = ret & MMA8452_TRANSIENT_THS_MASK;
> +		return IIO_VAL_INT;
>  
> -	*val = ret & MMA8452_TRANSIENT_THS_MASK;
> +	case IIO_EV_INFO_PERIOD:
> +		ret = i2c_smbus_read_byte_data(data->client,
> +					       MMA8452_TRANSIENT_COUNT);
> +		if (ret < 0)
> +			return ret;
> +
> +		us = ret * mma8452_transient_time_step_us[
> +				mma8452_get_odr_index(data)];
> +		*val = us / USEC_PER_SEC;
> +		*val2 = us % USEC_PER_SEC;
> +		return IIO_VAL_INT_PLUS_MICRO;
>  
> -	return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
>  }
>  
>  static int mma8452_write_thresh(struct iio_dev *indio_dev,
> @@ -316,9 +352,26 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,
>  				int val, int val2)
>  {
>  	struct mma8452_data *data = iio_priv(indio_dev);
> +	int steps;
>  
> -	return mma8452_change_config(data, MMA8452_TRANSIENT_THS,
> -				     val & MMA8452_TRANSIENT_THS_MASK);
> +	switch (info) {
> +	case IIO_EV_INFO_VALUE:
> +		return mma8452_change_config(data, MMA8452_TRANSIENT_THS,
> +					     val & MMA8452_TRANSIENT_THS_MASK);
> +
> +	case IIO_EV_INFO_PERIOD:
> +		steps = (val * USEC_PER_SEC + val2) /
> +				mma8452_transient_time_step_us[
> +					mma8452_get_odr_index(data)];
> +
> +		if (steps > 0xff)
> +			return -EINVAL;
> +
> +		return mma8452_change_config(data, MMA8452_TRANSIENT_COUNT,
> +					     steps);
> +	default:
> +		return -EINVAL;
> +	}
>  }
>  
>  static int mma8452_read_event_config(struct iio_dev *indio_dev,
> @@ -457,7 +510,8 @@ static const struct iio_event_spec mma8452_transient_event[] = {
>  		.dir = IIO_EV_DIR_RISING,
>  		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
>  		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
> -					BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB),
> +					BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB) |
> +					BIT(IIO_EV_INFO_PERIOD),
>  	},
>  };
>  
>