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 eajames@linux.ibm.com Reviewed-by: Joel Stanley joel@jms.id.au --- 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, &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);

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 # iio: pressure: dps310: Refactor startup procedure Cc: stable@vger.kernel.org Signed-off-by: Eddie James eajames@linux.ibm.com --- drivers/iio/pressure/dps310.c | 78 ++++++++++++++++++++++++++++++----- 1 file changed, 68 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c index c706a8b423b5..82c9a05123e2 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 +394,73 @@ 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 = {