On Sun, Sep 15, 2019 at 02:53:47PM +0100, Jonathan Cameron wrote: > On Mon, 9 Sep 2019 15:16:04 +0300 > Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> wrote: > > > Hi, > > > > Here's a simple RFC for Intel's Quadrature Encoder. Let me make it clear > > that I don't mean we should the following patch as is, rather I'd like > > to open the discussion to, perhaps, extending Industrial Automation > > Framework with support for Quadrature Encoders. > > > > Let me know if you think IIO would be correct place for such devices, > > then I can start reworking the driver to provide an IIO-compliant > > interface. > > > > I'm thinking we would need standard sysfs files for configuring the QEP > > into single-shot QEP mode or buffered Capture mode, configure thresholds > > and other details. > > Hi Felipe, > > Fairly recently, similar concerns that IIO didn't really suite these > devices lead William to create a specific 'counters' subsystem. > +CC William. > > It may not address all of your requirements yet, but I would imagine it > is a better fit than IIO would ever be. We have moved all the older > counter drivers out of IIO and across to this new subsystem. > > Thanks, > > Jonathan Felipe, Take a look at the Generic Counter interface, it may be what you need: https://www.kernel.org/doc/html/latest/driver-api/generic-counter.html There are some existing quadrature encoder counter devices using this interface already; look at the files under drivers/counter for reference. This interface is still relatively new, so if you have any problems just shoot me an email and I'll be happy to help. :-) William Breathitt Gray > > > > > > Cheers > > > > Felipe Balbi (1): > > misc: introduce intel QEP > > > > drivers/misc/Kconfig | 7 + > > drivers/misc/Makefile | 1 + > > drivers/misc/intel-qep.c | 813 +++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 821 insertions(+) > > create mode 100644 drivers/misc/intel-qep.c > > >
