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Commit 1e79841a authored by Martin Fuzzey's avatar Martin Fuzzey Committed by Jonathan Cameron
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iio: mma8452: Add highpass filter configuration.



Allow the cutoff frequency of the high pass filter to be configured.

Signed-off-by: default avatarMartin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 5dbbd19f
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+136 −4
Original line number Diff line number Diff line
@@ -29,9 +29,12 @@
#define MMA8452_INT_SRC 0x0c
#define MMA8452_WHO_AM_I 0x0d
#define MMA8452_DATA_CFG 0x0e
#define MMA8452_HP_FILTER_CUTOFF 0x0f
#define MMA8452_HP_FILTER_CUTOFF_SEL_MASK	(BIT(0) | BIT(1))
#define MMA8452_TRANSIENT_CFG 0x1d
#define MMA8452_TRANSIENT_CFG_ELE		BIT(4)
#define MMA8452_TRANSIENT_CFG_CHAN(chan)	BIT(chan + 1)
#define MMA8452_TRANSIENT_CFG_HPF_BYP		BIT(0)
#define MMA8452_TRANSIENT_SRC 0x1e
#define MMA8452_TRANSIENT_SRC_XTRANSE		BIT(1)
#define MMA8452_TRANSIENT_SRC_YTRANSE		BIT(3)
@@ -61,6 +64,7 @@
#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_TRANS	BIT(5)

@@ -158,6 +162,18 @@ static const int mma8452_transient_time_step_us[8] = {
	20000
};

/* Datasheet table 18 (normal mode) */
static const int mma8452_hp_filter_cutoff[8][4][2] = {
	{ {16, 0}, {8, 0}, {4, 0}, {2, 0} },		/* 800 Hz sample */
	{ {16, 0}, {8, 0}, {4, 0}, {2, 0} },		/* 400 Hz sample */
	{ {8, 0}, {4, 0}, {2, 0}, {1, 0} },		/* 200 Hz sample */
	{ {4, 0}, {2, 0}, {1, 0}, {0, 500000} },	/* 100 Hz sample */
	{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} },	/* 50 Hz sample */
	{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} },	/* 12.5 Hz sample */
	{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} },	/* 6.25 Hz sample */
	{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} }	/* 1.56 Hz sample */
};

static ssize_t mma8452_show_samp_freq_avail(struct device *dev,
				struct device_attribute *attr, char *buf)
{
@@ -172,9 +188,23 @@ static ssize_t mma8452_show_scale_avail(struct device *dev,
		ARRAY_SIZE(mma8452_scales));
}

static ssize_t mma8452_show_hp_cutoff_avail(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);
	int i = mma8452_get_odr_index(data);

	return mma8452_show_int_plus_micros(buf, mma8452_hp_filter_cutoff[i],
		ARRAY_SIZE(mma8452_hp_filter_cutoff[0]));
}

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 int mma8452_get_samp_freq_index(struct mma8452_data *data,
	int val, int val2)
@@ -190,6 +220,31 @@ static int mma8452_get_scale_index(struct mma8452_data *data,
		ARRAY_SIZE(mma8452_scales), val, val2);
}

static int mma8452_get_hp_filter_index(struct mma8452_data *data,
				       int val, int val2)
{
	int i = mma8452_get_odr_index(data);

	return mma8452_get_int_plus_micros_index(mma8452_hp_filter_cutoff[i],
		ARRAY_SIZE(mma8452_scales[0]), val, val2);
}

static int mma8452_read_hp_filter(struct mma8452_data *data, int *hz, int *uHz)
{
	int i, ret;

	ret = i2c_smbus_read_byte_data(data->client, MMA8452_HP_FILTER_CUTOFF);
	if (ret < 0)
		return ret;

	i = mma8452_get_odr_index(data);
	ret &= MMA8452_HP_FILTER_CUTOFF_SEL_MASK;
	*hz = mma8452_hp_filter_cutoff[i][ret][0];
	*uHz = mma8452_hp_filter_cutoff[i][ret][1];

	return 0;
}

static int mma8452_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
@@ -228,6 +283,16 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
			return ret;
		*val = sign_extend32(ret, 7);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
		if (data->data_cfg & MMA8452_DATA_CFG_HPF_MASK) {
			ret = mma8452_read_hp_filter(data, val, val2);
			if (ret < 0)
				return ret;
		} else {
			*val = 0;
			*val2 = 0;
		}
		return IIO_VAL_INT_PLUS_MICRO;
	}
	return -EINVAL;
}
@@ -269,12 +334,31 @@ static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val)
	return ret;
}

static int mma8452_set_hp_filter_frequency(struct mma8452_data *data,
					   int val, int val2)
{
	int i, reg;

	i = mma8452_get_hp_filter_index(data, val, val2);
	if (i < 0)
		return -EINVAL;

	reg = i2c_smbus_read_byte_data(data->client,
				       MMA8452_HP_FILTER_CUTOFF);
	if (reg < 0)
		return reg;
	reg &= ~MMA8452_HP_FILTER_CUTOFF_SEL_MASK;
	reg |= i;

	return mma8452_change_config(data, MMA8452_HP_FILTER_CUTOFF, reg);
}

static int mma8452_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct mma8452_data *data = iio_priv(indio_dev);
	int i;
	int i, ret;

	if (iio_buffer_enabled(indio_dev))
		return -EBUSY;
@@ -302,6 +386,19 @@ static int mma8452_write_raw(struct iio_dev *indio_dev,
			return -EINVAL;
		return mma8452_change_config(data, MMA8452_OFF_X +
			chan->scan_index, val);

	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
		if (val == 0 && val2 == 0) {
			data->data_cfg &= ~MMA8452_DATA_CFG_HPF_MASK;
		} else {
			data->data_cfg |= MMA8452_DATA_CFG_HPF_MASK;
			ret = mma8452_set_hp_filter_frequency(data, val, val2);
			if (ret < 0)
				return ret;
		}
		return mma8452_change_config(data, MMA8452_DATA_CFG,
						data->data_cfg);

	default:
		return -EINVAL;
	}
@@ -339,6 +436,22 @@ static int mma8452_read_thresh(struct iio_dev *indio_dev,
		*val2 = us % USEC_PER_SEC;
		return IIO_VAL_INT_PLUS_MICRO;

	case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
		ret = i2c_smbus_read_byte_data(data->client,
					       MMA8452_TRANSIENT_CFG);
		if (ret < 0)
			return ret;

		if (ret & MMA8452_TRANSIENT_CFG_HPF_BYP) {
			*val = 0;
			*val2 = 0;
		} else {
			ret = mma8452_read_hp_filter(data, val, val2);
			if (ret < 0)
				return ret;
		}
		return IIO_VAL_INT_PLUS_MICRO;

	default:
		return -EINVAL;
	}
@@ -352,7 +465,7 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,
				int val, int val2)
{
	struct mma8452_data *data = iio_priv(indio_dev);
	int steps;
	int ret, reg, steps;

	switch (info) {
	case IIO_EV_INFO_VALUE:
@@ -369,6 +482,22 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,

		return mma8452_change_config(data, MMA8452_TRANSIENT_COUNT,
					     steps);
	case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
		reg = i2c_smbus_read_byte_data(data->client,
					       MMA8452_TRANSIENT_CFG);
		if (reg < 0)
			return reg;

		if (val == 0 && val2 == 0) {
			reg |= MMA8452_TRANSIENT_CFG_HPF_BYP;
		} else {
			reg &= ~MMA8452_TRANSIENT_CFG_HPF_BYP;
			ret = mma8452_set_hp_filter_frequency(data, val, val2);
			if (ret < 0)
				return ret;
		}
		return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, reg);

	default:
		return -EINVAL;
	}
@@ -510,7 +639,8 @@ 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_PERIOD)
					BIT(IIO_EV_INFO_PERIOD) |
					BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB)
	},
};

@@ -537,7 +667,8 @@ static struct attribute_group mma8452_event_attribute_group = {
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
		BIT(IIO_CHAN_INFO_CALIBBIAS), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
		BIT(IIO_CHAN_INFO_SCALE), \
		BIT(IIO_CHAN_INFO_SCALE) | \
		BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \
	.scan_index = idx, \
	.scan_type = { \
		.sign = 's', \
@@ -560,6 +691,7 @@ static const struct iio_chan_spec mma8452_channels[] = {
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,
	NULL
};