[PATCH 1/2] evdev: Add support for device quirks and implement axes swapping

[Pekka Paalanen]

On Tue, 18 Sep 2012 16:44:57 +0100
Rob Bradford <rob at robster.org.uk> wrote:

> From: Rob Bradford <rob at linux.intel.com>
> 
> This quirk is designed for hardware that has the X and Y axes swapped for
> absolute events.
> ---
>  src/evdev.c | 68 ++++++++++++++++++++++++++++++++++++++++++++-----------------
>  src/evdev.h |  6 ++++++
>  2 files changed, 55 insertions(+), 19 deletions(-)
> 
> diff --git a/src/evdev.c b/src/evdev.c
> index 8848736..3f9d635 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -129,21 +129,41 @@ evdev_process_absolute_motion(struct evdev_device *device,
>  	const int screen_width = device->output->current->width;
>  	const int screen_height = device->output->current->height;
>  
> -	switch (e->code) {
> -	case ABS_X:
> -		device->abs.x =
> -			(e->value - device->abs.min_x) * screen_width /
> -			(device->abs.max_x - device->abs.min_x) +
> -			device->output->x;
> -		device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> -		break;
> -	case ABS_Y:
> -		device->abs.y =
> -			(e->value - device->abs.min_y) * screen_height /
> -			(device->abs.max_y - device->abs.min_y) +
> -			device->output->y;
> -		device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> -		break;
> +	if (device->quirks & EVDEV_QUIRK_SWAP_AXES) {
> +		switch (e->code) {
> +		case ABS_X:
> +			device->abs.y =
> +				(e->value - device->abs.min_y) * screen_height /
> +				(device->abs.max_y - device->abs.min_y) +
> +				device->output->y;
> +			device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> +			break;
> +		case ABS_Y:
> +			device->abs.x =
> +				(e->value - device->abs.min_x) * screen_width /
> +				(device->abs.max_x - device->abs.min_x) +
> +				device->output->x;
> +			device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> +			break;
> +		}
> +
> +	} else {
> +		switch (e->code) {
> +		case ABS_X:
> +			device->abs.x =
> +				(e->value - device->abs.min_x) * screen_width /
> +				(device->abs.max_x - device->abs.min_x) +
> +				device->output->x;
> +			device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> +			break;
> +		case ABS_Y:
> +			device->abs.y =
> +				(e->value - device->abs.min_y) * screen_height /
> +				(device->abs.max_y - device->abs.min_y) +
> +				device->output->y;
> +			device->pending_events |= EVDEV_ABSOLUTE_MOTION;
> +			break;
> +		}
>  	}
>  }
>  
> @@ -395,12 +415,22 @@ evdev_configure_device(struct evdev_device *device)
>  		if (TEST_BIT(abs_bits, ABS_MT_SLOT)) {
>  			ioctl(device->fd, EVIOCGABS(ABS_MT_POSITION_X),
>  			      &absinfo);
> -			device->abs.min_x = absinfo.minimum;
> -			device->abs.max_x = absinfo.maximum;
> +			if (device->quirks & EVDEV_QUIRK_SWAP_AXES) {
> +				device->abs.min_y = absinfo.minimum;
> +				device->abs.max_y = absinfo.maximum;
> +			} else {
> +				device->abs.min_x = absinfo.minimum;
> +				device->abs.max_x = absinfo.maximum;
> +			}
>  			ioctl(device->fd, EVIOCGABS(ABS_MT_POSITION_Y),
>  			      &absinfo);
> -			device->abs.min_y = absinfo.minimum;
> -			device->abs.max_y = absinfo.maximum;
> +			if (device->quirks & EVDEV_QUIRK_SWAP_AXES) {
> +				device->abs.min_x = absinfo.minimum;
> +				device->abs.max_x = absinfo.maximum;
> +			} else {
> +				device->abs.min_y = absinfo.minimum;
> +				device->abs.max_y = absinfo.maximum;
> +			}
>  			device->is_mt = 1;
>  			device->mt.slot = 0;
>  			device->caps |= EVDEV_TOUCH;

Hi Rob,

this seems to have quite much of code duplication. Would it not be any
easier to do the swap only at notify_*() calling time instead?
Or do you really need to limit it to these very specific evdev events?


Thanks,
pq