lkml.org 
[lkml]   [2022]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
    From

    On 8/12/22 17:03, Andy Shevchenko wrote:
    > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
    >> Move the startup procedure into a function, and correct a missing
    >> check on the return code for writing the PRS_CFG register.
    > Code looks good, one remark below.
    > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
    >
    >> 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;
    > This code already exists, but still want to ask, is it really
    > byte-registers here and not be16/le16 one? In such a case perhaps bulk
    > write can be used to reflect it better?


    The temperature and pressure regs are 24 bits big endian, and all the
    rest are 8 bits. I think the existing approach is best.


    Thanks Andy!


    >
    >> + 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);
    > Ditto.
    >
    >> +}
    >> +
    >> +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);
    >> --
    >> 2.31.1
    >>
    >

    \
     
     \ /
      Last update: 2022-08-15 15:44    [W:3.629 / U:0.540 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site