| Message ID | 20220524201729.39503-3-eajames@linux.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt | expand |
On Tue, 24 May 2022 at 20:17, Eddie James <eajames@linux.ibm.com> wrote: > > Corruption of the MEAS_CFG register has been observed soon after > system boot. In order to recover this scenario, check MEAS_CFG if > measurement isn't ready, and if it's incorrect, reset the DPS310 > and execute the startup procedure. > > Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> > --- > drivers/iio/pressure/dps310.c | 88 +++++++++++++++++++++++++++++------ > 1 file changed, 73 insertions(+), 15 deletions(-) > > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > index f79b274bb38d..fbceaa2cd71c 100644 > --- a/drivers/iio/pressure/dps310.c > +++ b/drivers/iio/pressure/dps310.c > @@ -397,6 +397,44 @@ static int dps310_get_temp_k(struct dps310_data *data) > return scale_factors[ilog2(rc)]; > } > > +/* > + * Called with lock held. Returns a negative value on error, a positive value > + * when the device is not ready, and zero when the device is ready. > + */ > +static int dps310_check_reset_meas_cfg(struct dps310_data *data, int ready_bit) > +{ > + int meas_cfg; > + int rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &meas_cfg); > + > + if (rc < 0) > + return rc; > + > + /* Device is ready, proceed to measurement */ > + if (meas_cfg & ready_bit) > + return 0; > + > + /* Device is OK, just not ready */ > + if (meas_cfg & (DPS310_PRS_EN | DPS310_TEMP_EN | DPS310_BACKGROUND)) > + return 1; > + > + /* DPS310 register state corrupt, better start from scratch */ > + rc = regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); > + if (rc < 0) > + return rc; > + > + /* Wait for device chip access: 2.5ms in specification */ > + usleep_range(2500, 12000); > + > + /* Reinitialize the chip */ > + rc = dps310_startup(data); > + if (rc) > + return rc; > + > + dev_info(&data->client->dev, > + "recovered from corrupted MEAS_CFG=%02x\n", meas_cfg); > + return 1; > +} > + > static int dps310_read_pres_raw(struct dps310_data *data) > { > int rc; > @@ -409,16 +447,26 @@ static int dps310_read_pres_raw(struct dps310_data *data) > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > > - rate = dps310_get_pres_samp_freq(data); > - timeout = DPS310_POLL_TIMEOUT_US(rate); > - > - /* Poll for sensor readiness; base the timeout upon the sample rate. */ > - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > - ready & DPS310_PRS_RDY, > - DPS310_POLL_SLEEP_US(timeout), timeout); > - if (rc) > + rc = dps310_check_reset_meas_cfg(data, DPS310_PRS_RDY); > + if (rc < 0) > goto done; > > + if (rc > 0) { > + rate = dps310_get_pres_samp_freq(data); > + timeout = DPS310_POLL_TIMEOUT_US(rate); > + > + /* > + * Poll for sensor readiness; base the timeout upon the sample > + * rate. > + */ > + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, > + ready, ready & DPS310_PRS_RDY, > + DPS310_POLL_SLEEP_US(timeout), > + timeout); > + if (rc) > + goto done; > + } > + > rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)); > if (rc < 0) > goto done; > @@ -458,16 +506,26 @@ static int dps310_read_temp_raw(struct dps310_data *data) > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > > - rate = dps310_get_temp_samp_freq(data); > - timeout = DPS310_POLL_TIMEOUT_US(rate); > - > - /* Poll for sensor readiness; base the timeout upon the sample rate. */ > - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > - ready & DPS310_TMP_RDY, > - DPS310_POLL_SLEEP_US(timeout), timeout); > + rc = dps310_check_reset_meas_cfg(data, DPS310_TMP_RDY); > if (rc < 0) > goto done; > > + if (rc > 0) { > + rate = dps310_get_temp_samp_freq(data); > + timeout = DPS310_POLL_TIMEOUT_US(rate); > + > + /* > + * Poll for sensor readiness; base the timeout upon the sample > + * rate. > + */ > + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, > + ready, ready & DPS310_TMP_RDY, > + DPS310_POLL_SLEEP_US(timeout), > + timeout); > + if (rc < 0) > + goto done; > + } > + > rc = dps310_read_temp_ready(data); > > done: > -- > 2.27.0 >
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c index f79b274bb38d..fbceaa2cd71c 100644 --- a/drivers/iio/pressure/dps310.c +++ b/drivers/iio/pressure/dps310.c @@ -397,6 +397,44 @@ static int dps310_get_temp_k(struct dps310_data *data) return scale_factors[ilog2(rc)]; } +/* + * Called with lock held. Returns a negative value on error, a positive value + * when the device is not ready, and zero when the device is ready. + */ +static int dps310_check_reset_meas_cfg(struct dps310_data *data, int ready_bit) +{ + int meas_cfg; + int rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &meas_cfg); + + if (rc < 0) + return rc; + + /* Device is ready, proceed to measurement */ + if (meas_cfg & ready_bit) + return 0; + + /* Device is OK, just not ready */ + if (meas_cfg & (DPS310_PRS_EN | DPS310_TEMP_EN | DPS310_BACKGROUND)) + return 1; + + /* DPS310 register state corrupt, better start from scratch */ + rc = regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); + if (rc < 0) + return rc; + + /* Wait for device chip access: 2.5ms in specification */ + usleep_range(2500, 12000); + + /* Reinitialize the chip */ + rc = dps310_startup(data); + if (rc) + return rc; + + dev_info(&data->client->dev, + "recovered from corrupted MEAS_CFG=%02x\n", meas_cfg); + return 1; +} + static int dps310_read_pres_raw(struct dps310_data *data) { int rc; @@ -409,16 +447,26 @@ static int dps310_read_pres_raw(struct dps310_data *data) if (mutex_lock_interruptible(&data->lock)) return -EINTR; - rate = dps310_get_pres_samp_freq(data); - timeout = DPS310_POLL_TIMEOUT_US(rate); - - /* Poll for sensor readiness; base the timeout upon the sample rate. */ - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, - ready & DPS310_PRS_RDY, - DPS310_POLL_SLEEP_US(timeout), timeout); - if (rc) + rc = dps310_check_reset_meas_cfg(data, DPS310_PRS_RDY); + if (rc < 0) goto done; + if (rc > 0) { + rate = dps310_get_pres_samp_freq(data); + timeout = DPS310_POLL_TIMEOUT_US(rate); + + /* + * Poll for sensor readiness; base the timeout upon the sample + * rate. + */ + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, + ready, ready & DPS310_PRS_RDY, + DPS310_POLL_SLEEP_US(timeout), + timeout); + if (rc) + goto done; + } + rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)); if (rc < 0) goto done; @@ -458,16 +506,26 @@ static int dps310_read_temp_raw(struct dps310_data *data) if (mutex_lock_interruptible(&data->lock)) return -EINTR; - rate = dps310_get_temp_samp_freq(data); - timeout = DPS310_POLL_TIMEOUT_US(rate); - - /* Poll for sensor readiness; base the timeout upon the sample rate. */ - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, - ready & DPS310_TMP_RDY, - DPS310_POLL_SLEEP_US(timeout), timeout); + rc = dps310_check_reset_meas_cfg(data, DPS310_TMP_RDY); if (rc < 0) goto done; + if (rc > 0) { + rate = dps310_get_temp_samp_freq(data); + timeout = DPS310_POLL_TIMEOUT_US(rate); + + /* + * Poll for sensor readiness; base the timeout upon the sample + * rate. + */ + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, + ready, ready & DPS310_TMP_RDY, + DPS310_POLL_SLEEP_US(timeout), + timeout); + if (rc < 0) + goto done; + } + rc = dps310_read_temp_ready(data); done:
Corruption of the MEAS_CFG register has been observed soon after system boot. In order to recover this scenario, check MEAS_CFG if measurement isn't ready, and if it's incorrect, reset the DPS310 and execute the startup procedure. Signed-off-by: Eddie James <eajames@linux.ibm.com> --- drivers/iio/pressure/dps310.c | 88 +++++++++++++++++++++++++++++------ 1 file changed, 73 insertions(+), 15 deletions(-)