linuxconsole-dev

joystick whitout axis

[Juan P. S. <jp...@ma...>]

hi,

is it posible to make a driver for a joystick that only has buttons (a 
mat)? I tried with the 2.4 kernel series and didn't succeed, is it 
designed taht way or was I doing something wrong. The quick solution was 
to initialize 2 axis for the joystick that weren't used.

Re: joystick whitout axis

[Brad H. <bh...@bi...>]

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On Fri, 6 Jun 2003 05:21 am, Juan Pablo Sousa wrote:
> hi,
>
> is it posible to make a driver for a joystick that only has buttons (a
> mat)? I tried with the 2.4 kernel series and didn't succeed, is it
> designed taht way or was I doing something wrong. The quick solution was
> to initialize 2 axis for the joystick that weren't used.
I take it that you want to provide a low level driver that talks to the inp=
ut=20
layer, and outputs via the normal joydev driver to userspace. If so, then=20
there is no way. You must have at least one absolute axis - see below for=20
what the criteria is for a device to be associated with the joydev output:

See below for the description of what the=20
static struct input_device_id joydev_ids[] =3D {
        {
                .flags =3D INPUT_DEVICE_ID_MATCH_EVBIT |=20
INPUT_DEVICE_ID_MATCH_ABSBIT,
                .evbit =3D { BIT(EV_ABS) },
                .absbit =3D { BIT(ABS_X) },
        },
        {
                .flags =3D INPUT_DEVICE_ID_MATCH_EVBIT |=20
INPUT_DEVICE_ID_MATCH_ABSBIT,
                .evbit =3D { BIT(EV_ABS) },
                .absbit =3D { BIT(ABS_WHEEL) },
        },
        {
                .flags =3D INPUT_DEVICE_ID_MATCH_EVBIT |=20
INPUT_DEVICE_ID_MATCH_ABSBIT,
                .evbit =3D { BIT(EV_ABS) },
                .absbit =3D { BIT(ABS_THROTTLE) },
        },
        { },    /* Terminating entry */
};

If the device doesn't have an absolute axis, would it be easier to use the=
=20
input layer and event output? What do you need in userspace?

Brad
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Re: joystick whitout axis

[Juan P. <jp...@ma...>]

> If the device doesn't have an absolute axis, would it be easier to use the 
> input layer and event output? What do you need in userspace?
> 
> Brad

In userspace there's no problem with the joystick having a dummy axis, I use it that way at the moment.
The driver is for connecting a nintendo's powerpad via the parallel port, and use it as a joystick with 12 buttons and no axis, as I said there's no problem with having an axis that's never used.
BTW do you want me to send you the driver for inclusion in the kernel?

Re: joystick whitout axis

[Brad H. <bh...@bi...>]

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On Sat, 7 Jun 2003 01:21 am, Juan Pablo wrote:
> > If the device doesn't have an absolute axis, would it be easier to use
> > the input layer and event output? What do you need in userspace?
> >
> > Brad
>
> In userspace there's no problem with the joystick having a dummy axis, I
> use it that way at the moment. The driver is for connecting a nintendo's
> powerpad via the parallel port, and use it as a joystick with 12 buttons
> and no axis, as I said there's no problem with having an axis that's never
> used. BTW do you want me to send you the driver for inclusion in the
> kernel?
Don't send it to me. It needs to go to Vojtech.

Brad
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