* @hr_timer: Hw timer resolution register info (addr + mask).
* @fifo_en: Hw timer FIFO enable register info (addr + mask).
* @decimator: Hw timer FIFO decimator register info (addr + mask).
+ * @freq_fine: Difference in % of ODR with respect to the typical.
*/
struct st_lsm6dsx_hw_ts_settings {
struct st_lsm6dsx_reg timer_en;
struct st_lsm6dsx_reg hr_timer;
struct st_lsm6dsx_reg fifo_en;
struct st_lsm6dsx_reg decimator;
+ u8 freq_fine;
};
/**
* @fifo_mode: FIFO operating mode supported by the device.
* @suspend_mask: Suspended sensor bitmask.
* @enable_mask: Enabled sensor bitmask.
+ * @ts_gain: Hw timestamp rate after internal calibration.
* @ts_sip: Total number of timestamp samples in a given pattern.
* @sip: Total number of samples (acc/gyro/ts) in a given pattern.
* @buff: Device read buffer.
enum st_lsm6dsx_fifo_mode fifo_mode;
u8 suspend_mask;
u8 enable_mask;
+ s64 ts_gain;
u8 ts_sip;
u8 sip;
#define ST_LSM6DSX_MAX_FIFO_ODR_VAL 0x08
-#define ST_LSM6DSX_TS_SENSITIVITY 25000UL /* 25us */
#define ST_LSM6DSX_TS_RESET_VAL 0xaa
struct st_lsm6dsx_decimator_entry {
*/
if (!reset_ts && ts >= 0xff0000)
reset_ts = true;
- ts *= ST_LSM6DSX_TS_SENSITIVITY;
+ ts *= hw->ts_gain;
offset += ST_LSM6DSX_SAMPLE_SIZE;
}
*/
if (!reset_ts && ts >= 0xffff0000)
reset_ts = true;
- ts *= ST_LSM6DSX_TS_SENSITIVITY;
+ ts *= hw->ts_gain;
} else {
st_lsm6dsx_push_tagged_data(hw, tag, iio_buff,
ts);
#define ST_LSM6DSX_REG_WHOAMI_ADDR 0x0f
+#define ST_LSM6DSX_TS_SENSITIVITY 25000UL /* 25us */
+
static const struct iio_chan_spec st_lsm6dsx_acc_channels[] = {
ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x28, IIO_MOD_X, 0),
ST_LSM6DSX_CHANNEL_ACC(IIO_ACCEL, 0x2a, IIO_MOD_Y, 1),
.addr = 0x0a,
.mask = GENMASK(7, 6),
},
+ .freq_fine = 0x63,
},
.shub_settings = {
.page_mux = {
.addr = 0x0a,
.mask = GENMASK(7, 6),
},
+ .freq_fine = 0x63,
},
.event_settings = {
.enable_reg = {
.addr = 0x0a,
.mask = GENMASK(7, 6),
},
+ .freq_fine = 0x63,
},
.shub_settings = {
.page_mux = {
if (err < 0)
return err;
}
+
+ /* calibrate timestamp sensitivity */
+ hw->ts_gain = ST_LSM6DSX_TS_SENSITIVITY;
+ if (ts_settings->freq_fine) {
+ err = regmap_read(hw->regmap, ts_settings->freq_fine, &val);
+ if (err < 0)
+ return err;
+
+ /*
+ * linearize the AN5192 formula:
+ * 1 / (1 + x) ~= 1 - x (Taylor’s Series)
+ * ttrim[s] = 1 / (40000 * (1 + 0.0015 * val))
+ * ttrim[ns] ~= 25000 - 37.5 * val
+ * ttrim[ns] ~= 25000 - (37500 * val) / 1000
+ */
+ hw->ts_gain -= ((s8)val * 37500) / 1000;
+ }
+
return 0;
}