On Mon, May 8, 2017 at 10:49 AM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> This is an upstream port of an IIO driver for the TI ADC108S102 and
> ADC128S102. The former can be found on the Intel Galileo Gen2 and the
> Siemens SIMATIC IOT2000. For those boards, ACPI-based enumeration is
> included.
>
> Due to the lack of regulators under ACPI, we hard-code the voltage
> provided to the VA pin of the ADC to 5 V, the value used on Galileo and
> IOT2000. For DT usage, the regulator "vref-supply" provides this
> information. Note that DT usage has not been tested.
>
> Original author: Bogdan Pricop <bogdan.pricop@xxxxxxxxxx>
> Ported from Intel Galileo Gen2 BSP to Intel Yocto kernel:
> Todor Minchev <todor@xxxxxxxxxxxxx>.
>
> +static int adc108s102_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long m)
> +{
> + struct adc108s102_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = adc108s102_scan_direct(st, chan->address);
> +
> + iio_device_release_direct_mode(indio_dev);
> +
> + if (ret < 0)
> + return ret;
> +
> + *val = ADC108S102_RES_DATA(ret);
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_VOLTAGE) {
> + *val = st->va_millivolt;
> + *val2 = chan->scan_type.realbits;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + } else {
Redundant. and I would rather go with pattern
if (chan->type != IIO_VOLTAGE)
return -EINVAL;
...
return IIO_VAL_FRACTIONAL_LOG2;
_Or_ use
break;
here
> + return -EINVAL;
> + }
> + default:
> + return -EINVAL;
...and here.
> + }
...and
return -EINVAL;
in one place.
> +}
> + if (ACPI_COMPANION(&spi->dev)) {
> + st->va_millivolt = ADC108S102_VA_MV_ACPI_DEFAULT;
> + } else {
> + st->reg = devm_regulator_get(&spi->dev, "vref");
I'm still not satisfied with this. Why we just can't use _optional()
unconditionally?
If regulator framework is broken it should be fixed first then.
> + if (IS_ERR(st->reg))
> + return PTR_ERR(st->reg);
> +
> + ret = regulator_enable(st->reg);
> + if (ret < 0) {
> + dev_err(&spi->dev, "Cannot enable vref regulator\n");
> + return ret;
> + }
> +
> + ret = regulator_get_voltage(st->reg);
> + if (ret < 0) {
> + dev_err(&spi->dev, "vref get voltage failed\n");
> + return ret;
> + }
> +
> + st->va_millivolt = ret / 1000;
> + }
> + if (!IS_ERR(st->reg))
I'm wondering why regulator framework does need this check.
> + regulator_disable(st->reg);
--
With Best Regards,
Andy Shevchenko
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