Introduce enums and functions to work with the sample frequency
adjustments. Let the sample frequency adjust via IIO and configure
a reasonable default.
Replace the old static sample frequency handling. The patch is in
preparation for activity/inactivity handling. During adjustment of
bw registers, measuring is disabled and afterwards enabled again.
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
drivers/iio/accel/adxl345.h | 2 +-
drivers/iio/accel/adxl345_core.c | 156 ++++++++++++++++++++++++-------
2 files changed, 124 insertions(+), 34 deletions(-)
diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
index 7d482dd595fa..6c1f96406136 100644
--- a/drivers/iio/accel/adxl345.h
+++ b/drivers/iio/accel/adxl345.h
@@ -69,7 +69,7 @@
* BW_RATE bits - Bandwidth and output data rate. The default value is
* 0x0A, which translates to a 100 Hz output data rate
*/
-#define ADXL345_BW_RATE GENMASK(3, 0)
+#define ADXL345_BW_RATE_MSK GENMASK(3, 0)
#define ADXL345_BW_LOW_POWER BIT(4)
#define ADXL345_BASE_RATE_NANO_HZ 97656250LL
diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 1a2bf0c630c9..4c5084497def 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -67,6 +67,45 @@ static const unsigned int adxl345_tap_time_reg[] = {
[ADXL345_TAP_TIME_DUR] = ADXL345_REG_DUR,
};
+enum adxl345_odr {
+ ADXL345_ODR_0P10HZ = 0,
+ ADXL345_ODR_0P20HZ,
+ ADXL345_ODR_0P39HZ,
+ ADXL345_ODR_0P78HZ,
+ ADXL345_ODR_1P56HZ,
+ ADXL345_ODR_3P13HZ,
+ ADXL345_ODR_6P25HZ,
+ ADXL345_ODR_12P50HZ,
+ ADXL345_ODR_25HZ,
+ ADXL345_ODR_50HZ,
+ ADXL345_ODR_100HZ,
+ ADXL345_ODR_200HZ,
+ ADXL345_ODR_400HZ,
+ ADXL345_ODR_800HZ,
+ ADXL345_ODR_1600HZ,
+ ADXL345_ODR_3200HZ,
+};
+
+/* Certain features recommend 12.5 Hz - 400 Hz ODR */
+static const int adxl345_odr_tbl[][2] = {
+ [ADXL345_ODR_0P10HZ] = { 0, 97000 },
+ [ADXL345_ODR_0P20HZ] = { 0, 195000 },
+ [ADXL345_ODR_0P39HZ] = { 0, 390000 },
+ [ADXL345_ODR_0P78HZ] = { 0, 781000 },
+ [ADXL345_ODR_1P56HZ] = { 1, 562000 },
+ [ADXL345_ODR_3P13HZ] = { 3, 125000 },
+ [ADXL345_ODR_6P25HZ] = { 6, 250000 },
+ [ADXL345_ODR_12P50HZ] = { 12, 500000 },
+ [ADXL345_ODR_25HZ] = { 25, 0 },
+ [ADXL345_ODR_50HZ] = { 50, 0 },
+ [ADXL345_ODR_100HZ] = { 100, 0 },
+ [ADXL345_ODR_200HZ] = { 200, 0 },
+ [ADXL345_ODR_400HZ] = { 400, 0 },
+ [ADXL345_ODR_800HZ] = { 800, 0 },
+ [ADXL345_ODR_1600HZ] = { 1600, 0 },
+ [ADXL345_ODR_3200HZ] = { 3200, 0 },
+};
+
struct adxl345_state {
const struct adxl345_chip_info *info;
struct regmap *regmap;
@@ -119,6 +158,7 @@ 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), \
.scan_index = (index), \
.scan_type = { \
.sign = 's', \
@@ -446,14 +486,59 @@ static int adxl345_set_ff_time(struct adxl345_state *st, u32 val_int,
return regmap_write(st->regmap, ADXL345_REG_TIME_FF, min(regval, 0xff));
}
+static int adxl345_find_odr(struct adxl345_state *st, int val,
+ int val2, enum adxl345_odr *odr)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(adxl345_odr_tbl); i++) {
+ if (val == adxl345_odr_tbl[i][0] &&
+ val2 == adxl345_odr_tbl[i][1]) {
+ *odr = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int adxl345_set_odr(struct adxl345_state *st, enum adxl345_odr odr)
+{
+ int ret;
+
+ ret = regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
+ ADXL345_BW_RATE_MSK,
+ FIELD_PREP(ADXL345_BW_RATE_MSK, odr));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+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_SAMP_FREQ:
+ *vals = (int *)adxl345_odr_tbl;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ *length = ARRAY_SIZE(adxl345_odr_tbl) * 2;
+ return IIO_AVAIL_LIST;
+ }
+
+ return -EINVAL;
+}
+
static int adxl345_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct adxl345_state *st = iio_priv(indio_dev);
__le16 accel;
- long long samp_freq_nhz;
unsigned int regval;
+ enum adxl345_odr odr;
int ret;
switch (mask) {
@@ -491,12 +576,10 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
ret = regmap_read(st->regmap, ADXL345_REG_BW_RATE, ®val);
if (ret)
return ret;
-
- samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
- (regval & ADXL345_BW_RATE);
- *val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);
-
- return IIO_VAL_INT_PLUS_NANO;
+ odr = FIELD_GET(ADXL345_BW_RATE_MSK, regval);
+ *val = adxl345_odr_tbl[odr][0];
+ *val2 = adxl345_odr_tbl[odr][1];
+ return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
@@ -507,7 +590,12 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct adxl345_state *st = iio_priv(indio_dev);
- s64 n;
+ enum adxl345_odr odr;
+ int ret;
+
+ ret = adxl345_set_measure_en(st, false);
+ if (ret)
+ return ret;
switch (mask) {
case IIO_CHAN_INFO_CALIBBIAS:
@@ -515,20 +603,26 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
* 8-bit resolution at +/- 2g, that is 4x accel data scale
* factor
*/
- return regmap_write(st->regmap,
- ADXL345_REG_OFS_AXIS(chan->address),
- val / 4);
+ ret = regmap_write(st->regmap,
+ ADXL345_REG_OFS_AXIS(chan->address),
+ val / 4);
+ if (ret)
+ return ret;
+ break;
case IIO_CHAN_INFO_SAMP_FREQ:
- n = div_s64(val * NANOHZ_PER_HZ + val2,
- ADXL345_BASE_RATE_NANO_HZ);
+ ret = adxl345_find_odr(st, val, val2, &odr);
+ if (ret)
+ return ret;
- return regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
- ADXL345_BW_RATE,
- clamp_val(ilog2(n), 0,
- ADXL345_BW_RATE));
+ ret = adxl345_set_odr(st, odr);
+ if (ret)
+ return ret;
+ break;
+ default:
+ return -EINVAL;
}
- return -EINVAL;
+ return adxl345_set_measure_en(st, true);
}
static int adxl345_read_event_config(struct iio_dev *indio_dev,
@@ -754,7 +848,7 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_CALIBBIAS:
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
- return IIO_VAL_INT_PLUS_NANO;
+ return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
@@ -767,19 +861,6 @@ static void adxl345_powerdown(void *ptr)
adxl345_set_measure_en(st, false);
}
-static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
-"0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
-);
-
-static struct attribute *adxl345_attrs[] = {
- &iio_const_attr_sampling_frequency_available.dev_attr.attr,
- NULL
-};
-
-static const struct attribute_group adxl345_attrs_group = {
- .attrs = adxl345_attrs,
-};
-
static int adxl345_set_fifo(struct adxl345_state *st)
{
unsigned int intio;
@@ -1040,9 +1121,9 @@ static irqreturn_t adxl345_irq_handler(int irq, void *p)
}
static const struct iio_info adxl345_info = {
- .attrs = &adxl345_attrs_group,
.read_raw = adxl345_read_raw,
.write_raw = adxl345_write_raw,
+ .read_avail = adxl345_read_avail,
.write_raw_get_fmt = adxl345_write_raw_get_fmt,
.read_event_config = adxl345_read_event_config,
.write_event_config = adxl345_write_event_config,
@@ -1112,6 +1193,15 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
indio_dev->available_scan_masks = adxl345_scan_masks;
+ /*
+ * Using I2C at 100kHz would limit the maximum ODR to 200Hz, operation
+ * at an output rate above the recommended maximum may result in
+ * undesired behavior.
+ */
+ ret = adxl345_set_odr(st, ADXL345_ODR_200HZ);
+ if (ret)
+ return ret;
+
/* Reset interrupts at start up */
ret = regmap_write(st->regmap, ADXL345_REG_INT_ENABLE, 0x00);
if (ret)
--
2.39.5