Re: [PATCH 3/4] hwmon: Add a simple driver to read the MXS SoC temperature

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Jun 27, 2013 at 11:17:32AM +0200, Maxime Ripard wrote:
> On Wed, Jun 26, 2013 at 07:39:27AM -0700, Guenter Roeck wrote:
> > On Wed, Jun 26, 2013 at 10:51:12AM +0200, Alexandre Belloni wrote:
> > > The low resolution ADC of the mxs is able to read an internal temperature
> > > sensor, expose that using hwmon.
> > > 
> > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> > > ---
> > 
> > Wouldn't it make more sense to use iio-hwmon and improve it if necessary ?
> 
> Actually, I wonder if we should not just put the hwmon driver
> capabilities directly into the mxs-lradc driver, just like it's already
> been done in this driver for the touchscreen support.
> 
> The probing of this hwmon driver doesn't really belong to the DT, it's
> not really realistic to probe it from the machine definition, and it
> really is the IP that is wired that way.
> 
Merging iio-hwmon functionality into an adc driver seems just as bad
(or even worse) as copying it into a new driver.

If the lradc driver knows that the ADC channels are temperature sensors, it
should register them with the iio subsystem as IIO_TEMP type. Then you should
be able to use iio_hwmon as is.

Guenter