> On Sat, 13 Jan 2018 18:57:56 +0100 > Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx> wrote: > >> Introduce hw timestamp support instead of compute sample timestamps >> according to interrupt rate and configured watermark. LSM6DSx based >> devices are able to queue in hw FIFO the time reference of data >> sampling >> >> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx> > > I am curious, how good is the clock? Do you see significant jumps when > the timer reset happens and you rebase on the cpu timestamp? At the moment I do not have an answer to that question but I can carry out some tests :) > > The patch looks good to me, but I'd like to let it sit on the list > a little longer given its more or less a new feature to IIO. > Sure, fine for me Regards, Lorenzo > Jonathan >> --- >> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 29 +++-- >> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 161 ++++++++++++++++--------- >> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 104 +++++++++++++++- >> 3 files changed, 224 insertions(+), 70 deletions(-) >> >> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h >> index 8fdd723afa05..a3cc7cd97026 100644 >> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h >> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h >> @@ -27,7 +27,7 @@ enum st_lsm6dsx_hw_id { >> ST_LSM6DSX_MAX_ID, >> }; >> >> -#define ST_LSM6DSX_BUFF_SIZE 256 >> +#define ST_LSM6DSX_BUFF_SIZE 400 >> #define ST_LSM6DSX_CHAN_SIZE 2 >> #define ST_LSM6DSX_SAMPLE_SIZE 6 >> #define ST_LSM6DSX_MAX_WORD_LEN ((32 / ST_LSM6DSX_SAMPLE_SIZE) * \ >> @@ -57,6 +57,20 @@ struct st_lsm6dsx_fifo_ops { >> u8 th_wl; >> }; >> >> +/** >> + * struct st_lsm6dsx_hw_ts_settings - ST IMU hw timer settings >> + * @timer_en: Hw timer enable register info (addr + mask). >> + * @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). >> + */ >> +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; >> +}; >> + >> /** >> * struct st_lsm6dsx_settings - ST IMU sensor settings >> * @wai: Sensor WhoAmI default value. >> @@ -64,6 +78,7 @@ struct st_lsm6dsx_fifo_ops { >> * @id: List of hw id supported by the driver configuration. >> * @decimator: List of decimator register info (addr + mask). >> * @fifo_ops: Sensor hw FIFO parameters. >> + * @ts_settings: Hw timer related settings. >> */ >> struct st_lsm6dsx_settings { >> u8 wai; >> @@ -71,6 +86,7 @@ struct st_lsm6dsx_settings { >> enum st_lsm6dsx_hw_id id[ST_LSM6DSX_MAX_ID]; >> struct st_lsm6dsx_reg decimator[ST_LSM6DSX_MAX_ID]; >> struct st_lsm6dsx_fifo_ops fifo_ops; >> + struct st_lsm6dsx_hw_ts_settings ts_settings; >> }; >> >> enum st_lsm6dsx_sensor_id { >> @@ -94,8 +110,7 @@ enum st_lsm6dsx_fifo_mode { >> * @watermark: Sensor watermark level. >> * @sip: Number of samples in a given pattern. >> * @decimator: FIFO decimation factor. >> - * @delta_ts: Delta time between two consecutive interrupts. >> - * @ts: Latest timestamp from the interrupt handler. >> + * @ts_ref: Sensor timestamp reference for hw one. >> */ >> struct st_lsm6dsx_sensor { >> char name[32]; >> @@ -108,9 +123,7 @@ struct st_lsm6dsx_sensor { >> u16 watermark; >> u8 sip; >> u8 decimator; >> - >> - s64 delta_ts; >> - s64 ts; >> + s64 ts_ref; >> }; >> >> /** >> @@ -122,7 +135,8 @@ struct st_lsm6dsx_sensor { >> * @conf_lock: Mutex to prevent concurrent FIFO configuration update. >> * @fifo_mode: FIFO operating mode supported by the device. >> * @enable_mask: Enabled sensor bitmask. >> - * @sip: Total number of samples (acc/gyro) in a given pattern. >> + * @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. >> * @iio_devs: Pointers to acc/gyro iio_dev instances. >> * @settings: Pointer to the specific sensor settings in use. >> @@ -137,6 +151,7 @@ struct st_lsm6dsx_hw { >> >> enum st_lsm6dsx_fifo_mode fifo_mode; >> u8 enable_mask; >> + u8 ts_sip; >> u8 sip; >> >> u8 *buff; >> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c >> index 1d6aa9b1a4cf..1045e025e92b 100644 >> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c >> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c >> @@ -46,9 +46,13 @@ >> #define ST_LSM6DSX_FIFO_ODR_MASK GENMASK(6, 3) >> #define ST_LSM6DSX_FIFO_EMPTY_MASK BIT(12) >> #define ST_LSM6DSX_REG_FIFO_OUTL_ADDR 0x3e >> +#define ST_LSM6DSX_REG_TS_RESET_ADDR 0x42 >> >> #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 { >> u8 decimator; >> u8 val; >> @@ -98,9 +102,10 @@ static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw, >> >> static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw) >> { >> + u16 max_odr, min_odr, sip = 0, ts_sip = 0; >> + const struct st_lsm6dsx_reg *ts_dec_reg; >> struct st_lsm6dsx_sensor *sensor; >> - u16 max_odr, min_odr, sip = 0; >> - int err, i; >> + int err = 0, i; >> u8 data; >> >> st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr); >> @@ -119,6 +124,7 @@ static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw) >> sensor->decimator = 0; >> data = 0; >> } >> + ts_sip = max_t(u16, ts_sip, sensor->sip); >> >> dec_reg = &hw->settings->decimator[sensor->id]; >> if (dec_reg->addr) { >> @@ -131,9 +137,23 @@ static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw) >> } >> sip += sensor->sip; >> } >> - hw->sip = sip; >> + hw->sip = sip + ts_sip; >> + hw->ts_sip = ts_sip; >> >> - return 0; >> + /* >> + * update hw ts decimator if necessary. Decimator for hw timestamp >> + * is always 1 or 0 in order to have a ts sample for each data >> + * sample in FIFO >> + */ >> + ts_dec_reg = &hw->settings->ts_settings.decimator; >> + if (ts_dec_reg->addr) { >> + int val, ts_dec = !!hw->ts_sip; >> + >> + val = ST_LSM6DSX_SHIFT_VAL(ts_dec, ts_dec_reg->mask); >> + err = regmap_update_bits(hw->regmap, ts_dec_reg->addr, >> + ts_dec_reg->mask, val); >> + } >> + return err; >> } >> >> int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw, >> @@ -208,6 +228,28 @@ int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark) >> &wdata, sizeof(wdata)); >> } >> >> +static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw) >> +{ >> + struct st_lsm6dsx_sensor *sensor; >> + int i, err; >> + >> + /* reset hw ts counter */ >> + err = regmap_write(hw->regmap, ST_LSM6DSX_REG_TS_RESET_ADDR, >> + ST_LSM6DSX_TS_RESET_VAL); >> + if (err < 0) >> + return err; >> + >> + for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) { >> + sensor = iio_priv(hw->iio_devs[i]); >> + /* >> + * store enable buffer timestamp as reference for >> + * hw timestamp >> + */ >> + sensor->ts_ref = iio_get_time_ns(hw->iio_devs[i]); >> + } >> + return 0; >> +} >> + >> /* >> * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN in order to avoid >> * a kmalloc for each bus access >> @@ -231,6 +273,8 @@ static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 *data, >> return 0; >> } >> >> +#define ST_LSM6DSX_IIO_BUFF_SIZE (ALIGN(ST_LSM6DSX_SAMPLE_SIZE, \ >> + sizeof(s64)) + sizeof(s64)) >> /** >> * st_lsm6dsx_read_fifo() - LSM6DS3-LSM6DS3H-LSM6DSL-LSM6DSM read FIFO routine >> * @hw: Pointer to instance of struct st_lsm6dsx_hw. >> @@ -243,11 +287,13 @@ static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) >> { >> u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE; >> u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask; >> - int err, acc_sip, gyro_sip, read_len, samples, offset; >> + int err, acc_sip, gyro_sip, ts_sip, read_len, offset; >> struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor; >> - s64 acc_ts, acc_delta_ts, gyro_ts, gyro_delta_ts; >> - u8 iio_buff[ALIGN(ST_LSM6DSX_SAMPLE_SIZE, sizeof(s64)) + sizeof(s64)]; >> + u8 gyro_buff[ST_LSM6DSX_IIO_BUFF_SIZE]; >> + u8 acc_buff[ST_LSM6DSX_IIO_BUFF_SIZE]; >> + bool reset_ts = false; >> __le16 fifo_status; >> + s64 ts = 0; >> >> err = regmap_bulk_read(hw->regmap, >> hw->settings->fifo_ops.fifo_diff.addr, >> @@ -260,23 +306,10 @@ static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) >> >> fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) * >> ST_LSM6DSX_CHAN_SIZE; >> - samples = fifo_len / ST_LSM6DSX_SAMPLE_SIZE; >> fifo_len = (fifo_len / pattern_len) * pattern_len; >> >> - /* >> - * compute delta timestamp between two consecutive samples >> - * in order to estimate queueing time of data generated >> - * by the sensor >> - */ >> acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]); >> - acc_ts = acc_sensor->ts - acc_sensor->delta_ts; >> - acc_delta_ts = div_s64(acc_sensor->delta_ts * acc_sensor->decimator, >> - samples); >> - >> gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]); >> - gyro_ts = gyro_sensor->ts - gyro_sensor->delta_ts; >> - gyro_delta_ts = div_s64(gyro_sensor->delta_ts * gyro_sensor->decimator, >> - samples); >> >> for (read_len = 0; read_len < fifo_len; read_len += pattern_len) { >> err = st_lsm6dsx_read_block(hw, hw->buff, pattern_len); >> @@ -287,7 +320,7 @@ static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) >> * Data are written to the FIFO with a specific pattern >> * depending on the configured ODRs. The first sequence of data >> * stored in FIFO contains the data of all enabled sensors >> - * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated >> + * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated >> * depending on the value of the decimation factor set for each >> * sensor. >> * >> @@ -296,35 +329,65 @@ static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw) >> * - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz >> * Since the gyroscope ODR is twice the accelerometer one, the >> * following pattern is repeated every 9 samples: >> - * - Gx, Gy, Gz, Ax, Ay, Az, Gx, Gy, Gz >> + * - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, .. >> */ >> gyro_sip = gyro_sensor->sip; >> acc_sip = acc_sensor->sip; >> + ts_sip = hw->ts_sip; >> offset = 0; >> >> while (acc_sip > 0 || gyro_sip > 0) { >> - if (gyro_sip-- > 0) { >> - memcpy(iio_buff, &hw->buff[offset], >> + if (gyro_sip > 0) { >> + memcpy(gyro_buff, &hw->buff[offset], >> ST_LSM6DSX_SAMPLE_SIZE); >> - iio_push_to_buffers_with_timestamp( >> - hw->iio_devs[ST_LSM6DSX_ID_GYRO], >> - iio_buff, gyro_ts); >> offset += ST_LSM6DSX_SAMPLE_SIZE; >> - gyro_ts += gyro_delta_ts; >> } >> - >> - if (acc_sip-- > 0) { >> - memcpy(iio_buff, &hw->buff[offset], >> + if (acc_sip > 0) { >> + memcpy(acc_buff, &hw->buff[offset], >> ST_LSM6DSX_SAMPLE_SIZE); >> - iio_push_to_buffers_with_timestamp( >> - hw->iio_devs[ST_LSM6DSX_ID_ACC], >> - iio_buff, acc_ts); >> offset += ST_LSM6DSX_SAMPLE_SIZE; >> - acc_ts += acc_delta_ts; >> } >> + >> + if (ts_sip-- > 0) { >> + u8 data[ST_LSM6DSX_SAMPLE_SIZE]; >> + >> + memcpy(data, &hw->buff[offset], sizeof(data)); >> + /* >> + * hw timestamp is 3B long and it is stored >> + * in FIFO using 6B as 4th FIFO data set >> + * according to this schema: >> + * B0 = ts[15:8], B1 = ts[23:16], B3 = ts[7:0] >> + */ >> + ts = data[1] << 16 | data[0] << 8 | data[3]; >> + /* >> + * check if hw timestamp engine is going to >> + * reset (the sensor generates an interrupt >> + * to signal the hw timestamp will reset in >> + * 1.638s) >> + */ >> + if (!reset_ts && ts >= 0xff0000) >> + reset_ts = true; >> + ts *= ST_LSM6DSX_TS_SENSITIVITY; >> + >> + offset += ST_LSM6DSX_SAMPLE_SIZE; >> + } >> + >> + if (gyro_sip-- > 0) >> + iio_push_to_buffers_with_timestamp( >> + hw->iio_devs[ST_LSM6DSX_ID_GYRO], >> + gyro_buff, gyro_sensor->ts_ref + ts); >> + if (acc_sip-- > 0) >> + iio_push_to_buffers_with_timestamp( >> + hw->iio_devs[ST_LSM6DSX_ID_ACC], >> + acc_buff, acc_sensor->ts_ref + ts); >> } >> } >> >> + if (unlikely(reset_ts)) { >> + err = st_lsm6dsx_reset_hw_ts(hw); >> + if (err < 0) >> + return err; >> + } >> return read_len; >> } >> >> @@ -379,15 +442,12 @@ static int st_lsm6dsx_update_fifo(struct iio_dev *iio_dev, bool enable) >> goto out; >> >> if (hw->enable_mask) { >> - err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT); >> + /* reset hw ts counter */ >> + err = st_lsm6dsx_reset_hw_ts(hw); >> if (err < 0) >> goto out; >> >> - /* >> - * store enable buffer timestamp as reference to compute >> - * first delta timestamp >> - */ >> - sensor->ts = iio_get_time_ns(iio_dev); >> + err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT); >> } >> >> out: >> @@ -399,25 +459,8 @@ static int st_lsm6dsx_update_fifo(struct iio_dev *iio_dev, bool enable) >> static irqreturn_t st_lsm6dsx_handler_irq(int irq, void *private) >> { >> struct st_lsm6dsx_hw *hw = private; >> - struct st_lsm6dsx_sensor *sensor; >> - int i; >> - >> - if (!hw->sip) >> - return IRQ_NONE; >> - >> - for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) { >> - sensor = iio_priv(hw->iio_devs[i]); >> - >> - if (sensor->sip > 0) { >> - s64 timestamp; >> - >> - timestamp = iio_get_time_ns(hw->iio_devs[i]); >> - sensor->delta_ts = timestamp - sensor->ts; >> - sensor->ts = timestamp; >> - } >> - } >> >> - return IRQ_WAKE_THREAD; >> + return hw->sip > 0 ? IRQ_WAKE_THREAD : IRQ_NONE; >> } >> >> static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private) >> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c >> index c2fa3239b9c6..8656d72ef4ee 100644 >> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c >> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c >> @@ -181,6 +181,24 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { >> }, >> .th_wl = 3, /* 1LSB = 2B */ >> }, >> + .ts_settings = { >> + .timer_en = { >> + .addr = 0x58, >> + .mask = BIT(7), >> + }, >> + .hr_timer = { >> + .addr = 0x5c, >> + .mask = BIT(4), >> + }, >> + .fifo_en = { >> + .addr = 0x07, >> + .mask = BIT(7), >> + }, >> + .decimator = { >> + .addr = 0x09, >> + .mask = GENMASK(5, 3), >> + }, >> + }, >> }, >> { >> .wai = 0x69, >> @@ -209,6 +227,24 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { >> }, >> .th_wl = 3, /* 1LSB = 2B */ >> }, >> + .ts_settings = { >> + .timer_en = { >> + .addr = 0x58, >> + .mask = BIT(7), >> + }, >> + .hr_timer = { >> + .addr = 0x5c, >> + .mask = BIT(4), >> + }, >> + .fifo_en = { >> + .addr = 0x07, >> + .mask = BIT(7), >> + }, >> + .decimator = { >> + .addr = 0x09, >> + .mask = GENMASK(5, 3), >> + }, >> + }, >> }, >> { >> .wai = 0x6a, >> @@ -238,6 +274,24 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = { >> }, >> .th_wl = 3, /* 1LSB = 2B */ >> }, >> + .ts_settings = { >> + .timer_en = { >> + .addr = 0x19, >> + .mask = BIT(5), >> + }, >> + .hr_timer = { >> + .addr = 0x5c, >> + .mask = BIT(4), >> + }, >> + .fifo_en = { >> + .addr = 0x07, >> + .mask = BIT(7), >> + }, >> + .decimator = { >> + .addr = 0x09, >> + .mask = GENMASK(5, 3), >> + }, >> + }, >> }, >> }; >> >> @@ -630,6 +684,44 @@ static int st_lsm6dsx_get_drdy_reg(struct st_lsm6dsx_hw *hw, u8 *drdy_reg) >> return err; >> } >> >> +static int st_lsm6dsx_init_hw_timer(struct st_lsm6dsx_hw *hw) >> +{ >> + const struct st_lsm6dsx_hw_ts_settings *ts_settings; >> + int err, val; >> + >> + ts_settings = &hw->settings->ts_settings; >> + /* enable hw timestamp generation if necessary */ >> + if (ts_settings->timer_en.addr) { >> + val = ST_LSM6DSX_SHIFT_VAL(1, ts_settings->timer_en.mask); >> + err = regmap_update_bits(hw->regmap, >> + ts_settings->timer_en.addr, >> + ts_settings->timer_en.mask, val); >> + if (err < 0) >> + return err; >> + } >> + >> + /* enable high resolution for hw ts timer if necessary */ >> + if (ts_settings->hr_timer.addr) { >> + val = ST_LSM6DSX_SHIFT_VAL(1, ts_settings->hr_timer.mask); >> + err = regmap_update_bits(hw->regmap, >> + ts_settings->hr_timer.addr, >> + ts_settings->hr_timer.mask, val); >> + if (err < 0) >> + return err; >> + } >> + >> + /* enable ts queueing in FIFO if necessary */ >> + if (ts_settings->fifo_en.addr) { >> + val = ST_LSM6DSX_SHIFT_VAL(1, ts_settings->fifo_en.mask); >> + err = regmap_update_bits(hw->regmap, >> + ts_settings->fifo_en.addr, >> + ts_settings->fifo_en.mask, val); >> + if (err < 0) >> + return err; >> + } >> + return 0; >> +} >> + >> static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw) >> { >> u8 drdy_int_reg; >> @@ -654,10 +746,14 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw) >> if (err < 0) >> return err; >> >> - return regmap_update_bits(hw->regmap, drdy_int_reg, >> - ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, >> - FIELD_PREP(ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, >> - 1)); >> + err = regmap_update_bits(hw->regmap, drdy_int_reg, >> + ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, >> + FIELD_PREP(ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, >> + 1)); >> + if (err < 0) >> + return err; >> + >> + return st_lsm6dsx_init_hw_timer(hw); >> } >> >> static struct iio_dev *st_lsm6dsx_alloc_iiodev(struct st_lsm6dsx_hw *hw, > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html