[PATCH v4 5/8] MFD: ti_am335x_tscadc: Add DT support

[Patil, Rachna]

Vaibhav,

<SNIP>
> > > > 
> > > > -	if (!pdata) {
> > > > +	if (!pdata && !pdev->dev.of_node) {
> > > > 		dev_err(&pdev->dev, "Could not find platform data\n");
> > > > 		return -EINVAL;
> > > > 	}
> > > > 
> > > > -	if (pdata->adc_init)
> > > > -		adc_channels = pdata->adc_init->adc_channels;
> > > > +	if (pdev->dev.platform_data) {
> > > > +		if (pdata->tsc_init)
> > > > +			tsc_wires = pdata->tsc_init->wires;
> > > > +
> > > > +		if (pdata->adc_init)
> > > > +			adc_channels = pdata->adc_init->adc_channels;
> > > > +	} else {
> > > > +		node = of_find_node_by_name(pdev->dev.of_node, "tsc");
> > > > +		of_property_read_u32(node, "ti,wires", &tsc_wires);
> > > > +
> > > > +		node = of_find_node_by_name(pdev->dev.of_node, "adc");
> > > > +		of_property_read_u32(node, "ti,adc-channels", &adc_channels);
> > > > +	}
> > > 
> > > Since AM335x is DT only, why is there a platform data codepath and why is it the first branch it tries? And I guess the next question is related to the first: why doesn't it work when used with DT? When I copy over the nodes from the evm.dts to my board I get "tsc tsc: Missing platform data" in dmesg.
> > 
> > This IP came up 1st on AM335x, but it is not platform dependent. The driver can be used on other platforms where-in DT is not supported.
> > According to the maintainers platform data takes precedence over DT. Hence the order.
> > 
> 
> Rachana,
> 
> I see no point adding support for platform_data when you know that none of older platforms are going to use this driver and all future platforms _must_ follow device-tree model.
> 
> So I agree that you should remove board file dependency from the driver.

Ok. I will remove support for platform data in the next version of patches.

> 
> 
> > I do not see "Missing platform data" error msg in the latest driver. I am not able to trace from where this got populated.
> > 
> 
> Can you share the branch which you have tested?

https://github.com/patilrachna/linux/tree/v3.8_rc3_MFD_TSCADC_DT-v2

Regards,
Rachna