On May 12 2016 or thereabouts, Benjamin Tissoires wrote:
> On May 12 2016 or thereabouts, Dmitry Torokhov wrote:
> > Hi Benjamin,
> >
> > On Thu, May 12, 2016 at 05:07:54PM +0200, Benjamin Tissoires wrote:
> > > This is a basic driver for the Surface 3. I am not so sure it will work
> > > with any firmwares as most values are encoded, but given that I only have
> > > access to my current device with its firmware and I don't have the
> > > datasheet, it should be OK for now.
> > >
> > > The Surface Pen is not supported (if it is supposed to be). I'll work on
> > > this when I get one.
> > >
> > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> > > ---
> > > drivers/input/touchscreen/Kconfig | 11 ++
> > > drivers/input/touchscreen/Makefile | 1 +
> > > drivers/input/touchscreen/ntrig_spi.c | 339 ++++++++++++++++++++++++++++++++++
> > > 3 files changed, 351 insertions(+)
> > > create mode 100644 drivers/input/touchscreen/ntrig_spi.c
> > >
> > > diff --git a/drivers/input/touchscreen/ntrig_spi.c b/drivers/input/touchscreen/ntrig_spi.c
> > > new file mode 100644
> > > index 0000000..0d61fc0
> > > --- /dev/null
> > > +++ b/drivers/input/touchscreen/ntrig_spi.c
[stripped]
> > > +
> > > + while (gpiod_get_value(data->gpiod_int)) {
> >
> > What if interrupt line is not described as GPIO?
>
> I do not have the spec, but I implied that it might be close to the
> official HID over I2C spec. In this spec, they said that the interrupt
> line will be kept high until there is no more data.
>
> I can try to work around this, but right now, the driver fails if the
> interrupt line is not a GPIO.
So if I check the value of the GPIO after the full read, it stays at 0
so the while loop can be removed.
[stripped]
> > > +
> > > + dev = &data->spi->dev;
> > > +
> > > + /* Get the interrupt GPIO pin number */
> > > + gpiod = devm_gpiod_get_index(dev, NULL, 2, GPIOD_IN);
> > > + if (IS_ERR(gpiod)) {
> > > + error = PTR_ERR(gpiod);
> > > + if (error != -EPROBE_DEFER)
> > > + dev_err(dev, "Failed to get int GPIO: %d\n", error);
> > > + return error;
> > > + }
> >
> > Can this made optional?
>
> I can work around an optional INT GPIO. But I don't know if Ntrig will
> provide this touchscreen to other devices than just the Surface.
I just checked if I remove this hunk. The touchscreen gets unresponsive.
I *think* we need to actually configure the GPIO as an IN to make it
work. I would have thought that it would have been translated
automatically by requesting the irq but it looks like not.
Also, given that the driver will be renamed into surface3_spi I think
it's safe to assume that the GPIO will be there and are mandatory.
Cheers,
Benjamin
--
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
