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@xxxxxxxxxxxxx>
Reviewed-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/iio/pressure/dps310.c | 89 +++++++++++++++++++++++++++++------
1 file changed, 74 insertions(+), 15 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index c706a8b423b5..bbeb2f3bcc8a 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -393,6 +393,45 @@ 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 rc;
+ int meas_cfg;
+
+ rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &meas_cfg);
+ if (rc)
+ 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)
+ 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;
@@ -405,16 +444,26 @@ 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;
@@ -454,16 +503,26 @@ 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)
+ goto done;
+ }
+
rc = dps310_read_temp_ready(data);
done:
--
2.31.1
