Hi Geert

+	common->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(common->clk)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		return PTR_ERR(common->clk);
+	}
+
+	ret = clk_prepare(common->clk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to prepare clock\n");
+		return ret;
+	}
+
+	clk_enable(common->clk);
+
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);

You can use "dev" instead of "&pdev->dev" :)

And this patch seems strange for me.
pm_runtime_xxx() is doing same things.
If it didn't work, wrong place is not driver, clock side ?