/* Endpoint TX buffer allocation callback for nocopy sending.  */
static int get_tx_buffer(const struct device *instance, void *token, void **data, uint32_t *user_len, k_timeout_t wait)
/* Endpoint TX buffer allocation callback for nocopy sending.  */
static int get_tx_buffer(const struct device *instance, void *token, void **data, uint32_t *user_len, k_timeout_t wait)
{
	struct backend_data *dev_data = instance->data;
	int r;
	r = alloc_tx_buffer(dev_data, user_len, (uint8_t **)data, wait);
	if (r < 0) {
		return r;
	}
	return 0;
}