Re: [PATCH v2 4/4] Exynos4 NURI: support for NTC thermistor

Mark Brown
2011-06-22T11:08:57Z

On Wed, Jun 22, 2011 at 02:00:37PM +0900, MyungJoo Ham wrote:
> On Tue, Jun 21, 2011 at 7:50 PM, Mark Brown

> >> +#include <linux/platform_data/ntc_thermistor.h>

> > This doesn't appear to be in mainline.

> Right, not just yet. I should've added comment about the patch just
> being applied to "next".

I was actually looking at -next rather than Linus' tree there...

> Should I surround them with "#ifdef CONFIG_NTC_THERMISTOR"?

I guess, or just wait until it gets merged.

> > Why not do this in an initcall or in the device registration?  This
> > looks like working around a limitation of the ntc_thermistor driver
> > which should be fixed as part of a mainline merge for that.

> Um... I think I can put this away to a common plat-samsung/dev-ntc.c
> as I've seen many S5PC110/S5PV210/Exynos4 devices using NTC attached
> to the CPU's ADC ports.

Yes, but it's not just the location of the code - I was mostly noticing
the fact that it was doing something that's clearly supposed to be a
probe() method in the main read function. It'd be better if there were
an explicit probe() and corresponding remove() interface.

I also note that this callback based stuff won't work terribly well with
device tree.

> However, I won't be able to put that part into the NTC driver because
> using S3C-ADC is plat-samsung specific method and NTC thermistor
> itself is a general thermistor device not specific to S3C. Maybe, I
> can do so after we've got a common ADC framework.

Yes, we really need to get that ADC stuff sorted soon :(