iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt

PATCH Superseded Eddie James 3 participants 6 messages Sep 12, 2022 – Sep 14, 2022

Subsystems (3)

Stable branch IIO Infineon DPS310 Driver

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Eddie James

author maintainer

2022-09-12 21:28 UTC #0 lore raw

v7 cover iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt

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. Include a patch to move the startup procedure into a function.

Changes since v6:
- Use helper instead of the lengthy regmap_read_poll_timeout twice
- Just return dps310_startup in dps310_reset_reinit

Changes since v5:
- Completely rework the second patch to reset and reinit in any timeout condition, if there haven't been previous timeouts that failed to recover the chip.

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 after timeout

 drivers/iio/pressure/dps310.c | 266 +++++++++++++++++++++-------------
 1 file changed, 167 insertions(+), 99 deletions(-)

Signature · 1 line

2.31.1

Eddie James

author maintainer

2022-09-12 21:28 UTC #1 lore raw

PATCH v7 1/2 iio: pressure: dps310: Refactor startup procedure

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 Joel Stanley <[email protected]>

---
 drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
 1 file changed, 99 insertions(+), 89 deletions(-)

drivers/iio/pressure/dps310.c +99 ~~-89~~

index 36fb7ae0d0a9..c706a8b423b5 100644
@@ -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, &reg);
+	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, &reg);
-	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);

Signature · 1 line

2.31.1

kernel test robot

build bot

2022-09-12 21:30 UTC #2 lore raw

Re: [PATCH v7 1/2] iio: pressure: dps310: Refactor startup procedure

FYI: kernel test robot notices the stable kernel rule is not satisfied.

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

Rule: 'Cc: [email protected]' or 'commit <sha1> upstream.'
Subject: [PATCH v7 1/2] iio: pressure: dps310: Refactor startup procedure

Link https://lore.kernel.org/stable/20220912212743.37365-2-eajames%40linux.ibm.com open here

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html

Signature · 2 lines

0-DAY CI Kernel Test Service
https://01.org/lkp

Eddie James

author maintainer

2022-09-12 21:28 UTC #3 lore raw

PATCH v7 2/2 iio: pressure: dps310: Reset chip after timeout

In reply to Eddie James

Fixes ba6ec48e76bc ("iio: Add driver for Infineon DPS310")

Cc <[email protected]> # iio: pressure: dps310: Refactor startup procedure

Cc <[email protected]>

Signed-off-by Eddie James <[email protected]>

---
 drivers/iio/pressure/dps310.c | 78 ++++++++++++++++++++++++++++++-----
 1 file changed, 68 insertions(+), 10 deletions(-)

drivers/iio/pressure/dps310.c +68 ~~-10~~

index c706a8b423b5..82c9a05123e2 100644
@@ -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 +394,73 @@ 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 ready;
+	int sleep = DPS310_POLL_SLEEP_US(timeout);
+
+	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) {
+			int rc2;
+
+			/* Reset and reinitialize the chip. */
+			rc2 = dps310_reset_reinit(data);
+			if (rc2) {
+				data->timeout_recovery_failed = true;
+			} else {
+				/* Try again to get sensor ready status. */
+				rc2 = dps310_ready_status(data, ready_bit, timeout);
+				if (rc2)
+					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 +472,7 @@ 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 +509,6 @@ 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 +518,8 @@ 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 +814,7 @@ 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 = {

Signature · 1 line

2.31.1

Andy Shevchenko

2022-09-14 10:58 UTC #4 lore raw

Re: [PATCH v7 2/2] iio: pressure: dps310: Reset chip after timeout

Quoted 6 lines · Eddie James

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.

...

drivers/iio/pressure/dps310.c static int dps310_get_temp_k(struct dps310_data *data) · line 424

Quoted 4 lines

drivers/iio/pressure/dps310.c +4 -0

+static int dps310_ready_status(struct dps310_data *data, int ready_bit, int timeout)
+{
+       int ready;
+       int sleep = DPS310_POLL_SLEEP_US(timeout);

Longer line first?

Quoted 3 lines

drivers/iio/pressure/dps310.c +3 -0

+       return regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, ready & ready_bit,
+                                       sleep, timeout);
+}

...

drivers/iio/pressure/dps310.c static int dps310_get_temp_k(struct dps310_data *data) · line 441

Quoted 12 lines

drivers/iio/pressure/dps310.c +12 -0

+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) {
+                       int rc2;
+
+                       /* Reset and reinitialize the chip. */
+                       rc2 = dps310_reset_reinit(data);
+                       if (rc2) {

With below in mind this might become

  if (dps310_reset_init(...))
    ... = true;

drivers/iio/pressure/dps310.c static int dps310_get_temp_k(struct dps310_data *data) · line 447

Quoted 7 lines

drivers/iio/pressure/dps310.c +6 -0

+                               data->timeout_recovery_failed = true;
+                       } else {
+                               /* Try again to get sensor ready status. */
 
+                               rc2 = dps310_ready_status(data, ready_bit, timeout);
+                               if (rc2)
+                                       data->timeout_recovery_failed = true;

Shouldn't you re-use rc here again?

Quoted 7 lines

drivers/iio/pressure/dps310.c +7 -0

+                               else
+                                       return 0;
+                       }
+               }
+
+               return rc;
+       }

Signature · 2 lines

With Best Regards,
Andy Shevchenko

Andy Shevchenko

Reviewed-by on the v7 series

2022-09-14 10:58 UTC #5 lore raw

In reply to Eddie James

Quoted 7 lines · Eddie James

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. Include a patch to move the startup procedure into a function.

Good enough, although having a couple of nit-picks.

Reviewed-by Andy Shevchenko <[email protected]>

Quoted 35 lines

Changes since v6:
- Use helper instead of the lengthy regmap_read_poll_timeout twice
- Just return dps310_startup in dps310_reset_reinit
Changes since v5:
- Completely rework the second patch to reset and reinit in any timeout condition, if there haven't been previous timeouts that failed to recover the chip.
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 after timeout
 drivers/iio/pressure/dps310.c | 266 +++++++++++++++++++++-------------
 1 file changed, 167 insertions(+), 99 deletions(-)
--
2.31.1

Signature · 2 lines

With Best Regards,
Andy Shevchenko