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Commit 5dbbd19f authored by Martin Fuzzey's avatar Martin Fuzzey Committed by Jonathan Cameron
Browse files

iio: mma8452: Add support for transient event debouncing 



Allow the debouce counter for transient events to be configured
using the sysfs attribute events/in_accel_thresh_rising_period

Signed-off-by: default avatarMartin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 28e34278

drivers/iio/accel/mma8452.c

+65 −11
Original line number Diff line number Diff line
@@ -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);

	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;



	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;



	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;



	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,
@@ -456,7 +509,8 @@ static const struct iio_event_spec mma8452_transient_event[] = { 
		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_RISING,

		.mask_separate = BIT(IIO_EV_INFO_ENABLE),

		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE)

		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |

					BIT(IIO_EV_INFO_PERIOD)

	},

};