On Mon, May 01, 2017 at 02:21:02PM +0300, Andy Shevchenko wrote:
[...]
> Couple of minors below.
> Otherwise, FWIW:
> Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
>
Hello Andy,
> > +static int adxl345_data_ready(struct adxl345_data *data)
> > +{
> > + struct device *dev = regmap_get_device(data->regmap);
>
> > + int tries = 5;
>
> unsigned int tries = 5;
>
Ack.
> > + 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.
>
Before this function is called, the sensor is placed into measurement
mode. The delay is there to account for the "wake-up" time from standby
to measurement mode. So sleep first then attempt to read. In the first
version I was not yet aware of it until I look around in the datasheet
trying to justify how long to delay. I will clarify the comment to make
it more clear.
Thanks,
Eva
> > +
> > + 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
