lkml.org 
[lkml]   [2022]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
    Date
    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 c706a8b423b5..3a1aeeea3cdd 100644
    --- a/drivers/iio/pressure/dps310.c
    +++ b/drivers/iio/pressure/dps310.c
    @@ -393,6 +393,44 @@ 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;
    @@ -405,16 +443,26 @@ 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 +502,26 @@ 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:
    --
    2.31.1
    \
     
     \ /
      Last update: 2022-08-09 23:14    [W:2.750 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site