drivers: add a fallback for fetching the SVG name

In case the udev property is not present, we might want to query
the driver for the SVG name.
This is useful for driver-test as there is no udev device attached to
it, and for hidpp20 as we have auto-detection. We should then be able
to implement this in hidpp20 also so that the name gets automatically
created.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

src/driver-test.c

@@ -170,6 +170,13 @@ test_write_led(struct ratbag_led *led,
 	return 0;
 }
 
+static const char* test_get_svg_name(const struct ratbag_device *device)
+{
+	struct ratbag_test_device *d = ratbag_get_drv_data(device);
+
+	return d->svg;
+}
+
 static int
 test_fake_probe(struct ratbag_device *device)
 {
@@ -211,6 +218,7 @@ struct ratbag_driver test_driver = {
 	.probe = test_fake_probe,
 	.test_probe = test_probe,
 	.remove = test_remove,
+	.get_svg_name = test_get_svg_name,
 	.read_profile = test_read_profile,
 	.write_profile = test_write_profile,
 	.set_active_profile = test_set_active_profile,

src/libratbag-private.h

@@ -144,6 +144,15 @@ struct ratbag_driver {
 	 */
 	int (*commit)(struct ratbag_device *device);
 
+	/**
+	 * Callback called when the device doesn't have the udev property
+	 * RATBAG_SVG.
+	 *
+	 * The returned value must not be free by the caller, the driver
+	 * has to free it during .remove().
+	 */
+	const char *(*get_svg_name)(const struct ratbag_device *device);
+
 	/**
 	 * Callback called when a read profile is requested by the
 	 * caller of the library.
@@ -359,7 +368,7 @@ ratbag_set_drv_data(struct ratbag_device *device, void *drv_data)
 }
 
 static inline void *
-ratbag_get_drv_data(struct ratbag_device *device)
+ratbag_get_drv_data(const struct ratbag_device *device)
 {
 	return device->drv_data;
 }

src/libratbag-test.h

@@ -75,6 +75,7 @@ struct ratbag_test_device {
 	unsigned int num_resolutions;
 	unsigned int num_buttons;
 	unsigned int num_leds;
+	const char *svg;
 	struct ratbag_test_profile profiles[RATBAG_TEST_MAX_PROFILES];
 	void (*destroyed)(struct ratbag_device *device, void *data);
 	void *destroyed_data;

src/libratbag.c

@@ -484,7 +484,13 @@ ratbag_device_get_name(const struct ratbag_device* device)
 LIBRATBAG_EXPORT const char *
 ratbag_device_get_svg_name(const struct ratbag_device* device)
 {
-	return udev_prop_value(device->udev_device, "RATBAG_SVG");
+	const char *name;
+
+	name = udev_prop_value(device->udev_device, "RATBAG_SVG");
+	if (!name && device->driver->get_svg_name)
+		name = device->driver->get_svg_name(device);
+
+	return name;
 }
 
 const char *