in sirf.c [125:137]
static void sirf_close(struct gnss_device *gdev)
{
struct sirf_data *data = gnss_get_drvdata(gdev);
struct serdev_device *serdev = data->serdev;
sirf_serdev_close(data);
pm_runtime_put(&serdev->dev);
mutex_lock(&data->gdev_mutex);
data->open = false;
mutex_unlock(&data->gdev_mutex);
}