On Mon, Jun 25, 2012 at 10:51:13AM +0200, Henrik Rydberg wrote: > > > +The touch screens have a "factory mode" that allows access to the raw sensor > > +data. However, the above mentioned settings are not available in this mode. > > +In particular this limits the use of the raw data for tuning the parameters > > +to a specific setup. Also the scan rate of the touch screen changes compared > > +to the regular operation mode. > > + > > +To access the raw data switch to factory mode: > > + echo 1 > /sys/class/input/eventX/device/device/mode > > + > > +then read out the "raw_data" file. It contains X*Y big endian 16 bit values > > +where X and Y are the number of sensor fields of the touch glass. These values > > +are model specific and get be determined by dividing maximum x and y > > +coordinate by 64. > > + > > +Note that reading raw_data gives a I/O error when the device is not in factory > > +mode. The same happens when reading/writing to the parameter files when the > > +device is not in regular operation mode. > > Raw data is nice (and an alternative driver could output only such > data), but extending the input interface by adding adhoc sysfs files > is far from optimal. Several devices of this kind have appeared > recently, so it is clear that the input interface is lacking. I would > prefer if the raw data be moved to debugfs, awaiting a more stable > solution. Dmitry, any opinion on this? Firstly the question to Simon - what was the intent of providing access to raw data? Was it mainly for debugging or was it truly additional interface? If it is debug-only then debugfs is a very good idea. Regarding extending input interface - let's talk about what is missing. You mentioned memory-mapped access, but I am not sure if it should be implemented within current input structure or if it should be a completely separate interface. If we implement it we should also make sure we stabdardize the data stream and not simply dump raw device data, as this would be a sep backwards. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
