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iio: accel: adxl345: add g-range configuration

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Introduce a mechanism to be able to configure and work with the available
g-ranges keeping the precision of 13 digits.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250510224405.17910-3-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Lothar Rubusch
2025-06-09 07:45:35 +01:00
committed by Jonathan Cameron
parent 93ddd06492
commit b99dbe3a0f
1 changed files with 79 additions and 3 deletions
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drivers/iio/accel/adxl345_core.c
+79 -3
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@@ -83,6 +83,13 @@ enum adxl345_odr {
ADXL345_ODR_3200HZ,
};
enum adxl345_range {
ADXL345_2G_RANGE = 0,
ADXL345_4G_RANGE,
ADXL345_8G_RANGE,
ADXL345_16G_RANGE,
};
/* Certain features recommend 12.5 Hz - 400 Hz ODR */
static const int adxl345_odr_tbl[][2] = {
[ADXL345_ODR_0P10HZ] = { 0, 97000 },
@@ -103,6 +110,25 @@ static const int adxl345_odr_tbl[][2] = {
[ADXL345_ODR_3200HZ] = { 3200, 0 },
};
/*
* Full resolution frequency table:
* (g * 2 * 9.80665) / (2^(resolution) - 1)
*
* resolution := 13 (full)
* g := 2|4|8|16
*
* 2g at 13bit: 0.004789
* 4g at 13bit: 0.009578
* 8g at 13bit: 0.019156
* 16g at 16bit: 0.038312
*/
static const int adxl345_fullres_range_tbl[][2] = {
[ADXL345_2G_RANGE] = { 0, 4789 },
[ADXL345_4G_RANGE] = { 0, 9578 },
[ADXL345_8G_RANGE] = { 0, 19156 },
[ADXL345_16G_RANGE] = { 0, 38312 },
};
struct adxl345_state {
const struct adxl345_chip_info *info;
struct regmap *regmap;
@@ -146,7 +172,8 @@ static struct iio_event_spec adxl345_events[] = {
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.scan_index = (index), \
.scan_type = { \
.sign = 's', \
@@ -446,12 +473,40 @@ static int adxl345_set_odr(struct adxl345_state *st, enum adxl345_odr odr)
FIELD_PREP(ADXL345_BW_RATE_MSK, odr));
}
static int adxl345_find_range(struct adxl345_state *st, int val, int val2,
enum adxl345_range *range)
{
int i;
for (i = 0; i < ARRAY_SIZE(adxl345_fullres_range_tbl); i++) {
if (val == adxl345_fullres_range_tbl[i][0] &&
val2 == adxl345_fullres_range_tbl[i][1]) {
*range = i;
return 0;
}
}
return -EINVAL;
}
static int adxl345_set_range(struct adxl345_state *st, enum adxl345_range range)
{
return regmap_update_bits(st->regmap, ADXL345_REG_DATA_FORMAT,
ADXL345_DATA_FORMAT_RANGE,
FIELD_PREP(ADXL345_DATA_FORMAT_RANGE, range));
}
static int adxl345_read_avail(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type,
int *length, long mask)
{
switch (mask) {
case IIO_CHAN_INFO_SCALE:
*vals = (int *)adxl345_fullres_range_tbl;
*type = IIO_VAL_INT_PLUS_MICRO;
*length = ARRAY_SIZE(adxl345_fullres_range_tbl) * 2;
return IIO_AVAIL_LIST;
case IIO_CHAN_INFO_SAMP_FREQ:
*vals = (int *)adxl345_odr_tbl;
*type = IIO_VAL_INT_PLUS_MICRO;
@@ -470,6 +525,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
__le16 accel;
unsigned int regval;
enum adxl345_odr odr;
enum adxl345_range range;
int ret;
switch (mask) {
@@ -488,8 +544,12 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
*val = sign_extend32(le16_to_cpu(accel), 12);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = st->info->uscale;
ret = regmap_read(st->regmap, ADXL345_REG_DATA_FORMAT, &regval);
if (ret)
return ret;
range = FIELD_GET(ADXL345_DATA_FORMAT_RANGE, regval);
*val = adxl345_fullres_range_tbl[range][0];
*val2 = adxl345_fullres_range_tbl[range][1];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_CALIBBIAS:
ret = regmap_read(st->regmap,
@@ -521,6 +581,7 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct adxl345_state *st = iio_priv(indio_dev);
enum adxl345_range range;
enum adxl345_odr odr;
int ret;
@@ -549,6 +610,15 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
if (ret)
return ret;
break;
case IIO_CHAN_INFO_SCALE:
ret = adxl345_find_range(st, val, val2, &range);
if (ret)
return ret;
ret = adxl345_set_range(st, range);
if (ret)
return ret;
break;
default:
return -EINVAL;
}
@@ -741,6 +811,8 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_CALIBBIAS:
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
return IIO_VAL_INT_PLUS_MICRO;
default:
@@ -1083,6 +1155,10 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
if (ret)
return ret;
ret = adxl345_set_range(st, ADXL345_16G_RANGE);
if (ret)
return ret;
/* Reset interrupts at start up */
ret = regmap_write(st->regmap, ADXL345_REG_INT_ENABLE, 0x00);
if (ret)