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iio: mma8452: Add highpass filter configuration.

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

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Martin Fuzzey 2015-06-01 15:39:56 +02:00 committed by Jonathan Cameron
parent 5dbbd19f11
commit 1e79841a00
1 changed files with 136 additions and 4 deletions
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140
drivers/iio/accel/mma8452.c
View file

@ -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 @@ fail:
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
};