Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

["Ivan T. Ivanov" <iivanov-NEYub+7Iv8PQT0dZR+AlfA@public.gmane.org>]

+iio maintainers

On Thu, 2014-10-02 at 12:29 +0300, Ivan T. Ivanov wrote:
> Hi Stan,
> 
> On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:
> 
> <snip>
> 
> > +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
> > +{
> > +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
> > +	const struct vadc_channels *vadc_chan;
> > +	struct vadc_channel_prop prop;
> > +	struct device_node *child;
> > +	int ret, index = 0;
> > +
> > +	for_each_available_child_of_node(node, child) {
> > +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
> > +		if (ret)
> > +			return ret;
> > +
> > +		vadc->chan_props[index] = prop;
> > +
> > +		vadc_chan = &vadc_chans[prop.channel];
> > +
> > +		iio_chan->channel = prop.channel;
> > +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
> > +		iio_chan->info_mask_separate = vadc_chan->info_mask;
> > +		iio_chan->type = vadc_chan->type;
> > +		iio_chan->indexed = 1;
> > +		iio_chan->scan_type.sign = 's';
> > +		iio_chan->scan_type.realbits = 15;
> > +		iio_chan->scan_type.storagebits = 16;
> > +		iio_chan->address = index++;
> > +
> > +		iio_chan++;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> 
> <snip>
> 
> > +static int vadc_probe(struct platform_device *pdev)
> > +{
> 
> <snip>
> 
> > +
> > +	indio_dev->dev.parent = dev;
> > +	indio_dev->dev.of_node = node;
> > +	indio_dev->name = pdev->name;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +	indio_dev->info = &vadc_info;
> > +	indio_dev->channels = vadc->iio_chans;
> > +	indio_dev->num_channels = vadc->nchannels;
> 
> This will not work as we thought. Registration will be fine and entries
> in sysfs are created as expected, but this is breaking numbering scheme
> for client drivers. For us the problem is that iio framework expect channels
> numbering to be linear and channel number should not be greater than
> channel count. For example even if die temperature channel is always 8, if
> I describe only 5 channels in DTS files (4 for reference points measurement)
> and 1 for die temperature, clients could not get OF reference to 
> temperature
> channel using io-channels = <&pm8941_vadc 8>;
> 
> Jonathan, please, could you advise us.
> 
> Regards,
> Ivan
> 
> > +
> > +	return devm_iio_device_register(dev, indio_dev);
> > +}
> > +
> >
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html