[PATCH libinput] Add a function to retrieve the udev_device handle from a libinput device

[Hans de Goede]

Hi,

On 12/01/2014 04:45 AM, Peter Hutterer wrote:
> The libinput device abstracts a number of things but sometimes the underlying
> device is important. The udev device provides the necessary handle to access
> that underlying device and various sysfs properties that may be necessary.
>
> A function returning the device node would've done the same thing but is more
> prone to race conditions than the udev_device.
>
> https://bugs.freedesktop.org/show_bug.cgi?id=85573
>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>

Looks good.

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

Regards,

Hans

> ---
>   src/evdev.c    |  6 ++++++
>   src/evdev.h    |  3 +++
>   src/libinput.c |  6 ++++++
>   src/libinput.h | 18 ++++++++++++++++++
>   test/device.c  | 13 +++++++++++++
>   5 files changed, 46 insertions(+)
>
> diff --git a/src/evdev.c b/src/evdev.c
> index 5d178fa..dc31840 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -1610,6 +1610,12 @@ evdev_device_get_id_vendor(struct evdev_device *device)
>   	return libevdev_get_id_vendor(device->evdev);
>   }
>
> +struct udev_device *
> +evdev_device_get_udev_device(struct evdev_device *device)
> +{
> +	return udev_device_ref(device->udev_device);
> +}
> +
>   void
>   evdev_device_set_default_calibration(struct evdev_device *device,
>   				     const float calibration[6])
> diff --git a/src/evdev.h b/src/evdev.h
> index e4144ec..033d455 100644
> --- a/src/evdev.h
> +++ b/src/evdev.h
> @@ -234,6 +234,9 @@ evdev_device_get_id_product(struct evdev_device *device);
>   unsigned int
>   evdev_device_get_id_vendor(struct evdev_device *device);
>
> +struct udev_device *
> +evdev_device_get_udev_device(struct evdev_device *device);
> +
>   void
>   evdev_device_set_default_calibration(struct evdev_device *device,
>   				     const float calibration[6]);
> diff --git a/src/libinput.c b/src/libinput.c
> index c318eee..96b255a 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -1226,6 +1226,12 @@ libinput_device_set_seat_logical_name(struct libinput_device *device,
>   							       name);
>   }
>
> +LIBINPUT_EXPORT struct udev_device *
> +libinput_device_get_udev_device(struct libinput_device *device)
> +{
> +	return evdev_device_get_udev_device((struct evdev_device *)device);
> +}
> +
>   LIBINPUT_EXPORT void
>   libinput_device_led_update(struct libinput_device *device,
>   			   enum libinput_led leds)
> diff --git a/src/libinput.h b/src/libinput.h
> index 26d94ff..d567df4 100644
> --- a/src/libinput.h
> +++ b/src/libinput.h
> @@ -1397,6 +1397,24 @@ libinput_device_set_seat_logical_name(struct libinput_device *device,
>   				      const char *name);
>
>   /**
> + * Return a udev handle to the device that is this libinput device, if any.
> + * The returned handle has a refcount of at least 1, the caller must call
> + * udev_device_unref() once to release the associated resources.
> + *
> + * Some devices may not have a udev device, or the udev device may be
> + * unobtainable. This function returns NULL if no udev device was available.
> + *
> + * Calling this function multiple times for the same device may not
> + * return the same udev handle each time.
> + *
> + * @param device A previously obtained device
> + * @return A udev handle to the device with a refcount of >= 1 or NULL.
> + * @retval NULL This device is not represented by a udev device
> + */
> +struct udev_device *
> +libinput_device_get_udev_device(struct libinput_device *device);
> +
> +/**
>    * @ingroup device
>    *
>    * Update the LEDs on the device, if any. If the device does not have
> diff --git a/test/device.c b/test/device.c
> index 6843824..84984f4 100644
> --- a/test/device.c
> +++ b/test/device.c
> @@ -618,6 +618,17 @@ START_TEST(device_ids)
>   }
>   END_TEST
>
> +START_TEST(device_get_udev_handle)
> +{
> +	struct litest_device *dev = litest_current_device();
> +	struct udev_device *udev_device;
> +
> +	udev_device = libinput_device_get_udev_device(dev->libinput_device);
> +	ck_assert_notnull(udev_device);
> +	udev_device_unref(udev_device);
> +}
> +END_TEST
> +
>   int main (int argc, char **argv)
>   {
>   	litest_add("device:sendevents", device_sendevents_config, LITEST_ANY, LITEST_TOUCHPAD);
> @@ -640,5 +651,7 @@ int main (int argc, char **argv)
>   	litest_add("device:sendevents", device_disable_topsoftbutton, LITEST_TOPBUTTONPAD, LITEST_ANY);
>   	litest_add("device:id", device_ids, LITEST_ANY, LITEST_ANY);
>
> +	litest_add("device:udev", device_get_udev_handle, LITEST_ANY, LITEST_ANY);
> +
>   	return litest_run(argc, argv);
>   }
>