On Tue, Jan 27, 2015 at 11:49:49AM +0200, Priit Laes wrote: > > On Tue, 2015-01-27 at 10:18 +0100, Maxime Ripard wrote: > > Hi, > > > > On Mon, Jan 26, 2015 at 06:58:32PM +0200, Priit Laes wrote: > > > --- > > > > Like Hans was pointing out, commit log and signed-off-by please > > > > > .../ABI/testing/sysfs-driver-input-sun4i-lradc | 4 ++ > > > drivers/input/keyboard/sun4i-lradc-keys.c | 49 > > > +++++++++++++++++----- > > > 2 files changed, 43 insertions(+), 10 deletions(-) > > > create mode 100644 Documentation/ABI/testing/sysfs-driver-input- > > > sun4i-lradc > > > > > > diff --git a/Documentation/ABI/testing/sysfs-driver-input-sun4i- > > > lradc b/Documentation/ABI/testing/sysfs-driver-input-sun4i-lradc > > > new file mode 100644 > > > index 0000000..e4e6448 > > > --- /dev/null > > > +++ b/Documentation/ABI/testing/sysfs-driver-input-sun4i-lradc > > > @@ -0,0 +1,4 @@ > > > +What: /sys/class/input/input(x)/device/voltage > > > +Date: February 2015 > > > +Contact: Priit Laes <plaes@xxxxxxxxx> > > > +Description: ADC output voltage in microvolts or 0 if device is > > > not opened. > > > > Why is it returning 0 when "device is not opened" ? What does that > > even mean? You can't read that file without opening it. > > It means that something has to open the /dev/input/inputX device which > sets up the ADC before the voltage can be read from the sysfs file. I'd consider this a bug. Why someone has to use an unrelated interface for another interface to work correctly? > > [...] > > > > > > As I told you already, if you're going to expose this an ADC in the > > end, the proper solution is to use the IIO framework, not adding a > > custom sysfs file. > > My intention was to expose just a simple debug output, so one can > press the buttons and read the voltages for devicetree keymap. > > If anyone can suggest a simpler approach than current sysfs based one, > I would do it. But full blown iio driver is currently out of scope. > Also, Carlo's (ccaione) initially submitted (?) driver for lradc > utilized iio subsystem. For stuff like this debugfs (AKA dumping ground) is better suited as it does not establish ABI. i 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
