[PATCH libinput 4/9] evdev: use LIBINPUT_ATTR_SIZE_HINT for resolutions

[Hans de Goede]

Hi,

On 01-07-15 08:08, Peter Hutterer wrote:
> Touchpads, notably Elantech, ALPS and bcm5974 don't provide x/y resolution
> until recent generations.
> Add a new property, LIBINPUT_ATTR_SIZE_HINT, that provides size information to
> libinput. Note that this property *does not* override true resolution values,
> it is only used when the resolution is missing. It is used merely as an
> approximate size hint.
>
> If the resolution for a specific device is known it should be added to the
> udev hwdb so it can be set globally. See the bcm5974 entries here:
> http://cgit.freedesktop.org/systemd/systemd/tree/hwdb/60-evdev.hwdb.
>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>

LGTM: Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans



> ---
>   doc/device-configuration-via-udev.dox | 14 +++++++++-----
>   src/evdev.c                           | 36 +++++++++++++++++++++++++++++++++--
>   2 files changed, 43 insertions(+), 7 deletions(-)
>
> diff --git a/doc/device-configuration-via-udev.dox b/doc/device-configuration-via-udev.dox
> index e38b93f..85c5c9c 100644
> --- a/doc/device-configuration-via-udev.dox
> +++ b/doc/device-configuration-via-udev.dox
> @@ -67,6 +67,10 @@ to normalize them.
>   <dd><b>This prefix is reserved as private API, do not use.</b>. See @ref
>   model_specific_configuration for details.
>   </dd>
> +<dt>LIBINPUT_ATTR_*</dt>
> +<dd><b>This prefix is reserved as private API, do not use.</b>. See @ref
> +model_specific_configuration for details.
> +</dd>
>   </dl>
>
>   Below is an example udev rule to assign "seat1" to a device from vendor
> @@ -103,13 +107,13 @@ ENV{ID_MODEL_ID}=="034b", ENV{ID_INPUT_TOUCHPAD}="", ENV{ID_INPUT_TABLET}="1"
>
>   @section model_specific_configuration Model-specific configuration
>
> -libinput reserves the property prefix <b>LIBINPUT_MODEL_</b> for
> -model-specific configuration. <b>This prefix is reserved as private API, do
> -not use.</b>
> +libinput reserves the property prefixes <b>LIBINPUT_MODEL_</b> and
> +<b>LIBINPUT_ATTR_*</b> for model-specific configuration. <b>These prefixes
> +are reserved as private API, do not use.</b>
>
> -The effect of this property may be to enable or disable certain
> +The effect of these properties may be to enable or disable certain
>   features on a specific device or set of devices, to change configuration
> -defaults or any other reason. The effects of setting this property, the
> +defaults or any other reason. The effects of setting these properties, the
>   format of the property and the value of the property are subject to change
>   at any time.
>
> diff --git a/src/evdev.c b/src/evdev.c
> index 5d9b9d0..26bcf41 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -1547,6 +1547,23 @@ evdev_read_model(struct evdev_device *device)
>   	return m->model;
>   }
>
> +static inline int
> +evdev_read_attr_size_prop(struct evdev_device *device,
> +			  size_t *size_x,
> +			  size_t *size_y)
> +{
> +	struct udev_device *udev;
> +	const char *size_prop;
> +
> +	udev = device->udev_device;
> +	size_prop = udev_device_get_property_value(udev,
> +						   "LIBINPUT_ATTR_SIZE_HINT");
> +	if (!size_prop)
> +		return false;
> +
> +	return parse_dimension_property(size_prop, size_x, size_y);
> +}
> +
>   /* Return 1 if the device is set to the fake resolution or 0 otherwise */
>   static inline int
>   evdev_fix_abs_resolution(struct evdev_device *device,
> @@ -1555,6 +1572,8 @@ evdev_fix_abs_resolution(struct evdev_device *device,
>   {
>   	struct libinput *libinput = device->base.seat->libinput;
>   	struct libevdev *evdev = device->evdev;
> +	const struct input_absinfo *absx, *absy;
> +	size_t widthmm = 0, heightmm = 0;
>   	int xres = EVDEV_FAKE_RESOLUTION,
>   	    yres = EVDEV_FAKE_RESOLUTION;
>
> @@ -1566,15 +1585,28 @@ evdev_fix_abs_resolution(struct evdev_device *device,
>   		return 0;
>   	}
>
> -	if (libevdev_get_abs_resolution(evdev, xcode) != 0)
> +	absx = libevdev_get_abs_info(evdev, xcode);
> +	absy = libevdev_get_abs_info(evdev, ycode);
> +
> +	if (absx->resolution != 0 || absy->resolution != 0)
>   		return 0;
>
> +	/* Note: we *do not* override resolutions if provided by the kernel.
> +	 * If a device needs this, add it to 60-evdev.hwdb. The libinput
> +	 * property is only for general size hints where we can make
> +	 * educated guesses but don't know better.
> +	 */
> +	if (evdev_read_attr_size_prop(device, &widthmm, &heightmm)) {
> +		xres = (absx->maximum - absx->minimum)/widthmm;
> +		yres = (absy->maximum - absy->minimum)/heightmm;
> +	}
> +
>   	/* libevdev_set_abs_resolution() changes the absinfo we already
>   	   have a pointer to, no need to fetch it again */
>   	libevdev_set_abs_resolution(evdev, xcode, xres);
>   	libevdev_set_abs_resolution(evdev, ycode, yres);
>
> -	return 1;
> +	return xres == EVDEV_FAKE_RESOLUTION;
>   }
>
>   static enum evdev_device_udev_tags
>