Re: [PATCH] iio: adc: qcom-spmi-adc5: Add ADC5_AMUX_THM[24]_100K_PU to rev2 channel list

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 24 Aug 2018 15:14:39 -0700
Matthias Kaehlcke <mka@chromium.org> wrote:

> On Sun, Aug 19, 2018 at 05:54:52PM +0100, Jonathan Cameron wrote:
> > On Fri, 10 Aug 2018 12:47:02 -0700
> > Matthias Kaehlcke <mka@chromium.org> wrote:
> >   
> > > Add ADC5_AMUX_THM2_100K_PU and ADC5_AMUX_THM4_100K_PU to the list of
> > > rev2 ADC channels.
> > > 
> > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>  
> > This is fine and applied to the togreg branch of iio.git.
> > Pushed out as testing to let the autobuilders play with it.  
> 
> Thanks!
> 
> > However, I took a quick look and can't immediately see what prevents us
> > specifying channels in DT that don't have these definitions in the driver.  
> 
> Indeed, the DT could just specify an arbitrary value.
> 
> > Should we have a check for that as at least superficially it seems like
> > a bad idea!  
> 
> It seems there isn't a single contiguous range, but a very superficial
> check could at least verify that the value isn't larger than CHAN_MAX
> or check a few sub-ranges.

Given other entries will be zeroed, just check for something not being 0?

> 
> > > ---
> > >  drivers/iio/adc/qcom-spmi-adc5.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/drivers/iio/adc/qcom-spmi-adc5.c b/drivers/iio/adc/qcom-spmi-adc5.c
> > > index a4299417f3de..1f9298a5c83d 100644
> > > --- a/drivers/iio/adc/qcom-spmi-adc5.c
> > > +++ b/drivers/iio/adc/qcom-spmi-adc5.c
> > > @@ -491,8 +491,12 @@ static const struct adc5_channels adc5_chans_rev2[ADC5_MAX_CHANNEL] = {
> > >  					SCALE_HW_CALIB_PMIC_THERM)
> > >  	[ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 1,
> > >  					SCALE_HW_CALIB_THERM_100K_PULLUP)
> > > +	[ADC5_AMUX_THM2_100K_PU] = ADC5_CHAN_TEMP("amux_thm2_100k_pu", 1,
> > > +					SCALE_HW_CALIB_THERM_100K_PULLUP)
> > >  	[ADC5_AMUX_THM3_100K_PU] = ADC5_CHAN_TEMP("amux_thm3_100k_pu", 1,
> > >  					SCALE_HW_CALIB_THERM_100K_PULLUP)
> > > +	[ADC5_AMUX_THM4_100K_PU] = ADC5_CHAN_TEMP("amux_thm4_100k_pu", 1,
> > > +					SCALE_HW_CALIB_THERM_100K_PULLUP)
> > >  	[ADC5_AMUX_THM5_100K_PU] = ADC5_CHAN_TEMP("amux_thm5_100k_pu", 1,
> > >  					SCALE_HW_CALIB_THERM_100K_PULLUP)
> > >  	[ADC5_XO_THERM_100K_PU]	= ADC5_CHAN_TEMP("xo_therm_100k_pu", 1,  
> >