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iio: magn: bmc150_magn: add oversampling ratio

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Export the oversampling ratio so that the user can change the
number of repetions for x/y/z axis.

The sampling frequency is limited by the oversampling ratio.
The available sampling frequencies might change depending
on the values of oversampling_ratio.

The specification can be downloaded from:
http://ae-bst.resource.bosch.com/media/products/dokumente/bmc150/BST-BMC150-DS000-04.pdf.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Irina Tirdea 2015-04-29 21:16:40 +03:00 committed by Jonathan Cameron
parent faaa44955d
commit 5990dc9703
1 changed files with 129 additions and 4 deletions
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133
drivers/iio/magnetometer/bmc150_magn.c
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@ -146,6 +146,7 @@ struct bmc150_magn_data {
s32 buffer[6];
struct iio_trigger *dready_trig;
bool dready_trigger_on;
int max_odr;
};
static const struct {
@ -323,6 +324,43 @@ static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val)
return -EINVAL;
}
static int bmc150_magn_set_max_odr(struct bmc150_magn_data *data, int rep_xy,
int rep_z, int odr)
{
int ret, reg_val, max_odr;
if (rep_xy <= 0) {
ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
&reg_val);
if (ret < 0)
return ret;
rep_xy = BMC150_MAGN_REGVAL_TO_REPXY(reg_val);
}
if (rep_z <= 0) {
ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
&reg_val);
if (ret < 0)
return ret;
rep_z = BMC150_MAGN_REGVAL_TO_REPZ(reg_val);
}
if (odr <= 0) {
ret = bmc150_magn_get_odr(data, &odr);
if (ret < 0)
return ret;
}
/* the maximum selectable read-out frequency from datasheet */
max_odr = 1000000 / (145 * rep_xy + 500 * rep_z + 980);
if (odr > max_odr) {
dev_err(&data->client->dev,
"Can't set oversampling with sampling freq %d\n",
odr);
return -EINVAL;
}
data->max_odr = max_odr;
return 0;
}
static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,
u16 rhall)
{
@ -422,7 +460,7 @@ static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct bmc150_magn_data *data = iio_priv(indio_dev);
int ret;
int ret, tmp;
s32 values[AXIS_XYZ_MAX];
switch (mask) {
@ -467,6 +505,26 @@ static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
if (ret < 0)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->channel2) {
case IIO_MOD_X:
case IIO_MOD_Y:
ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
&tmp);
if (ret < 0)
return ret;
*val = BMC150_MAGN_REGVAL_TO_REPXY(tmp);
return IIO_VAL_INT;
case IIO_MOD_Z:
ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
&tmp);
if (ret < 0)
return ret;
*val = BMC150_MAGN_REGVAL_TO_REPZ(tmp);
return IIO_VAL_INT;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
@ -481,10 +539,50 @@ static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
if (val > data->max_odr)
return -EINVAL;
mutex_lock(&data->mutex);
ret = bmc150_magn_set_odr(data, val);
mutex_unlock(&data->mutex);
return ret;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->channel2) {
case IIO_MOD_X:
case IIO_MOD_Y:
if (val < 1 || val > 511)
return -EINVAL;
mutex_lock(&data->mutex);
ret = bmc150_magn_set_max_odr(data, val, 0, 0);
if (ret < 0) {
mutex_unlock(&data->mutex);
return ret;
}
ret = regmap_update_bits(data->regmap,
BMC150_MAGN_REG_REP_XY,
0xFF,
BMC150_MAGN_REPXY_TO_REGVAL
(val));
mutex_unlock(&data->mutex);
return ret;
case IIO_MOD_Z:
if (val < 1 || val > 256)
return -EINVAL;
mutex_lock(&data->mutex);
ret = bmc150_magn_set_max_odr(data, 0, val, 0);
if (ret < 0) {
mutex_unlock(&data->mutex);
return ret;
}
ret = regmap_update_bits(data->regmap,
BMC150_MAGN_REG_REP_Z,
0xFF,
BMC150_MAGN_REPZ_TO_REGVAL
(val));
mutex_unlock(&data->mutex);
return ret;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
@ -501,10 +599,31 @@ static int bmc150_magn_validate_trigger(struct iio_dev *indio_dev,
return 0;
}
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("2 6 8 10 15 20 25 30");
static ssize_t bmc150_magn_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct bmc150_magn_data *data = iio_priv(indio_dev);
size_t len = 0;
u8 i;
for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
if (bmc150_magn_samp_freq_table[i].freq > data->max_odr)
break;
len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
bmc150_magn_samp_freq_table[i].freq);
}
/* replace last space with a newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(bmc150_magn_show_samp_freq_avail);
static struct attribute *bmc150_magn_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
@ -516,7 +635,8 @@ static const struct attribute_group bmc150_magn_attrs_group = {
.type = IIO_MAGN, \
.modified = 1, \
.channel2 = IIO_MOD_##_axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
BIT(IIO_CHAN_INFO_SCALE), \
.scan_index = AXIS_##_axis, \
@ -616,6 +736,11 @@ static int bmc150_magn_init(struct bmc150_magn_data *data)
goto err_poweroff;
}
ret = bmc150_magn_set_max_odr(data, preset.rep_xy, preset.rep_z,
preset.odr);
if (ret < 0)
goto err_poweroff;
ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
true);
if (ret < 0) {