[PATCH 1/3] iio: adc: sun4i-gpadc-iio: no temp sensor on R40

[Jonathan Cameron]

On Mon, 22 Nov 2021 10:11:32 +0100
Maxime Ripard <maxime at cerno.tech> wrote:

> On Fri, Nov 19, 2021 at 10:14:54PM +0300, Evgeny Boger wrote:
> > R40 SoC has touchscreen controller also serving as general-purpose ADC.
> > The hardware is very similar to A31, except that R40 has separate
> > calibrated thermal sensor IP (handled by sun8i_thermal).
> > 
> > Despite the temperature sensor in the RTP is never mentioned in
> > the R40 family user manuals, it appears to be working. However,
> > it's not very useful as it lacks calibration data and there is another
> > fully functioning temperature sensor anyway.
> > 
> > This patch disables the temperature sensor in RTP/GPADC IP on R40.
> > 
> > The reason for disabling the temperature sensor is that the IP
> > needs to be switched back and forth between RTP and GPADC modes for
> > temperature measurements. Not only this introduces delays, but it also
> > disturbs external circuitry by injecting current into ADC inputs.
> > 
> > Signed-off-by: Evgeny Boger <boger at wirenboard.com>  
> 
> Acked-by: Maxime Ripard <maxime at cerno.tech>

+Cc linux-iio at vger.kernel.org

I'm fine with this and assuming Lee is happy to pick it up + send
me an immutable branch in case anything crosses with it this cycle..

Acked-by: Jonathan Cameron <Jonathan.Cameron at huawei.com>

Thanks,

Jonathan

> 
> Maxime
>