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    SubjectRe: [PATCH v2 2/4] iio: accel: adxl345_core: Introduce set_mode and data_ready functions
    On Sat, Apr 29, 2017 at 10:48 AM, Eva Rachel Retuya <eraretuya@gmail.com> wrote:
    > Move code that enables measurement/standby mode into its own function
    > and call that function when appropriate. Previously, we set the sensor
    > to measurement in probe and back to standby during remove. Change it
    > here to only enter measurement mode when request for data is initiated.
    >
    > The DATA_READY bit is always set if the corresponding event occurs.
    > Introduce the data_ready function that monitors the INT_SOURCE register
    > of this bit. This is done to ensure consistent readings.

    Couple of minors below.
    Otherwise, FWIW:
    Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

    > +static int adxl345_data_ready(struct adxl345_data *data)
    > +{
    > + struct device *dev = regmap_get_device(data->regmap);

    > + int tries = 5;

    unsigned int tries = 5;

    > + u32 val;
    > + int ret;
    > +
    > + do {

    > + /*
    > + * 1/ODR + 1.1ms; 11.1ms at ODR of 0.10 Hz
    > + * Sensor currently operates at default ODR of 100 Hz
    > + */
    > + usleep_range(1100, 11100);

    From the above comment I can't get why we sleep first then attempt to
    read and not otherwise. Please, elaborate.

    > +
    > + ret = regmap_read(data->regmap, ADXL345_REG_INT_SOURCE, &val);
    > + if (ret < 0)
    > + return ret;
    > + if ((val & ADXL345_INT_DATA_READY) == ADXL345_INT_DATA_READY)
    > + return 0;
    > + } while (--tries);
    > + dev_err(dev, "Data is not yet ready, try again.\n");
    > +
    > + return -EAGAIN;
    > +}

    --
    With Best Regards,
    Andy Shevchenko

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