Hi Roderick,
Thanks for having a look. I'd understand if this is not a desirable direction,
I was not aware of this legacy-ish connotation of EV_LED (should have figured
it out with the hoops about the clear_bit thing) and it seemed convenient to
interact with the pad through a single /dev/input/xxx interface.
Let me know what you decide :)
Benoit
Le dim. 23 oct. 2022 à 06:00, Roderick Colenbrander
<thunderbird2k@xxxxxxxxx> a écrit :
>
> Hi Benoit,
>
> Thanks for your patch. I'm thinking out loud whether this is a
> direction we want to go in regards to EV_LED. I vaguely recall some
> discussions a while ago that EV_LED was really from a different era
> for legacy reasons (keyboard LEDs). Since the introduction of the LED
> framework that was really the way to go.
>
> Thanks,
> Roderick
>
> On Sat, Oct 22, 2022 at 3:08 PM Benoit Maurin <maurinbe@xxxxxxxxx> wrote:
> >
> > (EV_LED, LED_MISC, #VALUE) can now be used to control leds on the
> > xpad gamepad (was only possible through /sys/class/leds/xpad0/brightness)
> > with permissions of /dev/input/xxx
> >
> > To test the code (xpad can be compiled out-of-tree with some slight
> > tweaks):
> >
> > ```
> > import evdev
> > device = evdev.InputDevice('/dev/input/event15') # not js0
> > device.set_led(8, 2)
> > device.set_led(8, 0) # this won't be delivered
> > device.set_led(8, 16) # must do this instead
> > device.set_led(8, 15)
> > ```
> >
> > Signed-off-by: Benoit Maurin <maurinbe@xxxxxxxxx>
> > ---
> > drivers/input/joystick/xpad.c | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
> > index 2959d80f7..fcf4d2c8f 100644
> > --- a/drivers/input/joystick/xpad.c
> > +++ b/drivers/input/joystick/xpad.c
> > @@ -1646,6 +1646,7 @@ static int xpad_led_probe(struct usb_xpad *xpad)
> > goto err_free_mem;
> > }
> >
> > + input_set_capability(xpad->dev, EV_LED, LED_MISC);
> > snprintf(led->name, sizeof(led->name), "xpad%d", xpad->pad_nr);
> > led->xpad = xpad;
> >
> > @@ -1824,6 +1825,28 @@ static void xpad_deinit_input(struct usb_xpad *xpad)
> > }
> > }
> >
> > +static int xpad_event(struct input_dev *dev, unsigned int type,
> > + unsigned int code, int value)
> > +{
> > + struct usb_xpad *xpad = input_get_drvdata(dev);
> > +
> > + if (type != EV_LED || xpad->led == NULL)
> > + return 0;
> > + xpad_send_led_command(xpad, value);
> > + xpad->led->led_cdev.brightness = value;
> > + /* Bit clearing is necessary otherwise two events with
> > + * different non-null values will deliver only the first one.
> > + * To work around this, we clear the bit to indicate that the
> > + * current value is zero. The downside is that events with zero
> > + * value won't be delivered. It's not a big deal since a value of
> > + * 16 can be sent which is the same as 0
> > + * See xpad_send_led_command, command %= 16
> > + */
> > +
> > + clear_bit(code, xpad->dev->led);
> > + return 0;
> > +}
> > +
> > static int xpad_init_input(struct usb_xpad *xpad)
> > {
> > struct input_dev *input_dev;
> > @@ -1851,6 +1874,7 @@ static int xpad_init_input(struct usb_xpad *xpad)
> > input_dev->open = xpad_open;
> > input_dev->close = xpad_close;
> > }
> > + input_dev->event = xpad_event;
> >
> > if (!(xpad->mapping & MAP_STICKS_TO_NULL)) {
> > /* set up axes */
> > --
> > 2.38.1
> >
