On 06/27/2013 09:26 PM, Alexandre Belloni wrote: > Hi, > > On 27/06/2013 16:27, Guenter Roeck wrote: >> 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@xxxxxxxxxxxxxxxxxx> >>>>> --- >>>> 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. > > They are already registered as IIO_TEMP but only implement read_raw. Also, > > iio_hwmon_read_val() is using iio_read_channel_processed() and that will > basically only read one of the 2 channels. As I documented, you actually > need to read both channel 8 and channel 9 and then compute the value in > Kelvins. I'm not sure how you want me to do that in the current framework. What are these two channels actually measuring? Is the value of a single channel meaningful on it's own? If not it might make sense to update the IIO driver to just have one temperature channel. - Lars -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
