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. Include a patch to move the
startup procedure into a function.
Changes since v4:
- Just check for rc rather than rc < 0 in some cases
- Split declaration and init of rc
Changes since v3:
- Don't check regmap* return codes for < 0
- Fix comment spelling
Changes since v2:
- Add some comments
- Fix the clunky control flow
Changes since v1:
- Separate into two patches
- Rename 'dps310_verify_meas_cfg' to 'dps310_check_reset_meas_cfg'
Eddie James (2):
iio: pressure: dps310: Refactor startup procedure
iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
drivers/iio/pressure/dps310.c | 277 +++++++++++++++++++++-------------
1 file changed, 173 insertions(+), 104 deletions(-)
--
2.31.1
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 <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
---
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
Move the startup procedure into a function, and correct a missing
check on the return code for writing the PRS_CFG register.
Signed-off-by: Eddie James <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
---
drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
1 file changed, 99 insertions(+), 89 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index 36fb7ae0d0a9..c706a8b423b5 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
return 0;
}
+/*
+ * Some versions of the chip will read temperatures in the ~60C range when
+ * it's actually ~20C. This is the manufacturer recommended workaround
+ * to correct the issue. The registers used below are undocumented.
+ */
+static int dps310_temp_workaround(struct dps310_data *data)
+{
+ int rc;
+ int reg;
+
+ rc = regmap_read(data->regmap, 0x32, ®);
+ if (rc)
+ return rc;
+
+ /*
+ * If bit 1 is set then the device is okay, and the workaround does not
+ * need to be applied
+ */
+ if (reg & BIT(1))
+ return 0;
+
+ rc = regmap_write(data->regmap, 0x0e, 0xA5);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0f, 0x96);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x62, 0x02);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0e, 0x00);
+ if (rc)
+ return rc;
+
+ return regmap_write(data->regmap, 0x0f, 0x00);
+}
+
+static int dps310_startup(struct dps310_data *data)
+{
+ int rc;
+ int ready;
+
+ /*
+ * Set up pressure sensor in single sample, one measurement per second
+ * mode
+ */
+ rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
+ if (rc)
+ return rc;
+
+ /*
+ * Set up external (MEMS) temperature sensor in single sample, one
+ * measurement per second mode
+ */
+ rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
+ if (rc)
+ return rc;
+
+ /* Temp and pressure shifts are disabled when PRC <= 8 */
+ rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
+ DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
+ if (rc)
+ return rc;
+
+ /* MEAS_CFG doesn't update correctly unless first written with 0 */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, 0);
+ if (rc)
+ return rc;
+
+ /* Turn on temperature and pressure measurement in the background */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
+ DPS310_TEMP_EN | DPS310_BACKGROUND);
+ if (rc)
+ return rc;
+
+ /*
+ * Calibration coefficients required for reporting temperature.
+ * They are available 40ms after the device has started
+ */
+ rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
+ ready & DPS310_COEF_RDY, 10000, 40000);
+ if (rc)
+ return rc;
+
+ rc = dps310_get_coefs(data);
+ if (rc)
+ return rc;
+
+ return dps310_temp_workaround(data);
+}
+
static int dps310_get_pres_precision(struct dps310_data *data)
{
int rc;
@@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
.write_raw = dps310_write_raw,
};
-/*
- * Some verions of chip will read temperatures in the ~60C range when
- * its actually ~20C. This is the manufacturer recommended workaround
- * to correct the issue. The registers used below are undocumented.
- */
-static int dps310_temp_workaround(struct dps310_data *data)
-{
- int rc;
- int reg;
-
- rc = regmap_read(data->regmap, 0x32, ®);
- if (rc < 0)
- return rc;
-
- /*
- * If bit 1 is set then the device is okay, and the workaround does not
- * need to be applied
- */
- if (reg & BIT(1))
- return 0;
-
- rc = regmap_write(data->regmap, 0x0e, 0xA5);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0f, 0x96);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x62, 0x02);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0e, 0x00);
- if (rc < 0)
- return rc;
-
- return regmap_write(data->regmap, 0x0f, 0x00);
-}
-
static int dps310_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct dps310_data *data;
struct iio_dev *iio;
- int rc, ready;
+ int rc;
iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!iio)
@@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
if (rc)
return rc;
- /*
- * Set up pressure sensor in single sample, one measurement per second
- * mode
- */
- rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
-
- /*
- * Set up external (MEMS) temperature sensor in single sample, one
- * measurement per second mode
- */
- rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
- if (rc < 0)
- return rc;
-
- /* Temp and pressure shifts are disabled when PRC <= 8 */
- rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
- DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
- if (rc < 0)
- return rc;
-
- /* MEAS_CFG doesn't update correctly unless first written with 0 */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, 0);
- if (rc < 0)
- return rc;
-
- /* Turn on temperature and pressure measurement in the background */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
- DPS310_TEMP_EN | DPS310_BACKGROUND);
- if (rc < 0)
- return rc;
-
- /*
- * Calibration coefficients required for reporting temperature.
- * They are available 40ms after the device has started
- */
- rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
- ready & DPS310_COEF_RDY, 10000, 40000);
- if (rc < 0)
- return rc;
-
- rc = dps310_get_coefs(data);
- if (rc < 0)
- return rc;
-
- rc = dps310_temp_workaround(data);
- if (rc < 0)
+ rc = dps310_startup(data);
+ if (rc)
return rc;
rc = devm_iio_device_register(&client->dev, iio);
--
2.31.1
On Mon, Aug 15, 2022 at 5:57 PM Eddie James <[email protected]> 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.
...
> + * 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.
Can we have
#define DPS310_DEVICE_NOT_READY 1
(or anonymous enum) and return it instead of abstract 1 or any other
positive number?
...
> + 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;
> + }
But have you tried to make a helper that takes a pointer to the
respective function?
--
With Best Regards,
Andy Shevchenko
On Thu, 18 Aug 2022 23:16:55 +0300
Andy Shevchenko <[email protected]> wrote:
> On Mon, Aug 15, 2022 at 5:57 PM Eddie James <[email protected]> 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.
>
> ...
>
> > + * 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.
>
> Can we have
>
> #define DPS310_DEVICE_NOT_READY 1
>
> (or anonymous enum) and return it instead of abstract 1 or any other
> positive number?
Perhaps make it even clearer by returning the need to wait via another parameter
rather than this being (probably) the only place in driver with a postive rc.
bool reset_done;
rc = dps310_check_reset_meas_cfg(data, DPS310_TMP_RDY, &reset_done);
if (reset_done) {
}
>
> ...
>
> > + 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;
> > + }
>
> But have you tried to make a helper that takes a pointer to the
> respective function?
>
On 8/20/22 07:02, Jonathan Cameron wrote:
> On Thu, 18 Aug 2022 23:16:55 +0300
> Andy Shevchenko <[email protected]> wrote:
>
>> On Mon, Aug 15, 2022 at 5:57 PM Eddie James <[email protected]> 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.
>> ...
>>
>>> + * 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.
>> Can we have
>>
>> #define DPS310_DEVICE_NOT_READY 1
>>
>> (or anonymous enum) and return it instead of abstract 1 or any other
>> positive number?
> Perhaps make it even clearer by returning the need to wait via another parameter
> rather than this being (probably) the only place in driver with a postive rc.
>
> bool reset_done;
>
> rc = dps310_check_reset_meas_cfg(data, DPS310_TMP_RDY, &reset_done);
>
> if (reset_done) {
> }
Thanks for the feedback.
Unfortunately our issue is still presenting itself even with a correct
MEAS_CFG register. The sensor ready bit never gets set. So I'm going to
rework this patch to reset the device after a timeout.
Thanks,
Eddie
>
>> ...
>>
>>> + 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;
>>> + }
>> But have you tried to make a helper that takes a pointer to the
>> respective function?
>>