The DPS310 chip has been observed to get "stuck" such that pressure and temperature measurements are never indicated as "ready" in the MEAS_CFG register. The only solution is to reset the device and try again. In order to avoid continual failures, use a boolean flag to only try the reset after timeout once if errors persist.
Fixes: ba6ec48e76bc ("iio: Add driver for Infineon DPS310") Cc: stable@vger.kernel.org Signed-off-by: Eddie James eajames@linux.ibm.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com --- drivers/iio/pressure/dps310.c | 74 ++++++++++++++++++++++++++++++----- 1 file changed, 64 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c index c706a8b423b5..984a3f511a1a 100644 --- a/drivers/iio/pressure/dps310.c +++ b/drivers/iio/pressure/dps310.c @@ -89,6 +89,7 @@ struct dps310_data { s32 c00, c10, c20, c30, c01, c11, c21; s32 pressure_raw; s32 temp_raw; + bool timeout_recovery_failed; };
static const struct iio_chan_spec dps310_channels[] = { @@ -393,11 +394,69 @@ static int dps310_get_temp_k(struct dps310_data *data) return scale_factors[ilog2(rc)]; }
+static int dps310_reset_wait(struct dps310_data *data) +{ + int rc; + + 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); + return 0; +} + +static int dps310_reset_reinit(struct dps310_data *data) +{ + int rc; + + rc = dps310_reset_wait(data); + if (rc) + return rc; + + return dps310_startup(data); +} + +static int dps310_ready_status(struct dps310_data *data, int ready_bit, int timeout) +{ + int sleep = DPS310_POLL_SLEEP_US(timeout); + int ready; + + return regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, ready & ready_bit, + sleep, timeout); +} + +static int dps310_ready(struct dps310_data *data, int ready_bit, int timeout) +{ + int rc; + + rc = dps310_ready_status(data, ready_bit, timeout); + if (rc) { + if (rc == -ETIMEDOUT && !data->timeout_recovery_failed) { + /* Reset and reinitialize the chip. */ + if (dps310_reset_reinit(data)) { + data->timeout_recovery_failed = true; + } else { + /* Try again to get sensor ready status. */ + if (dps310_ready_status(data, ready_bit, timeout)) + data->timeout_recovery_failed = true; + else + return 0; + } + } + + return rc; + } + + data->timeout_recovery_failed = false; + return 0; +} + static int dps310_read_pres_raw(struct dps310_data *data) { int rc; int rate; - int ready; int timeout; s32 raw; u8 val[3]; @@ -409,9 +468,7 @@ static int dps310_read_pres_raw(struct dps310_data *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); + rc = dps310_ready(data, DPS310_PRS_RDY, timeout); if (rc) goto done;
@@ -448,7 +505,6 @@ static int dps310_read_temp_raw(struct dps310_data *data) { int rc; int rate; - int ready; int timeout;
if (mutex_lock_interruptible(&data->lock)) @@ -458,10 +514,8 @@ static int dps310_read_temp_raw(struct dps310_data *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) + rc = dps310_ready(data, DPS310_TMP_RDY, timeout); + if (rc) goto done;
rc = dps310_read_temp_ready(data); @@ -756,7 +810,7 @@ static void dps310_reset(void *action_data) { struct dps310_data *data = action_data;
- regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); + dps310_reset_wait(data); }
static const struct regmap_config dps310_regmap_config = {