rockchip: rk3128: add clock driver

Add rk3128 clock driver and cru structure definition.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/arch/arm/mach-rockchip/rk3128/clk_rk3128.c b/arch/arm/mach-rockchip/rk3128/clk_rk3128.c
new file mode 100644
index 0000000..7ca5fd3
--- /dev/null
+++ b/arch/arm/mach-rockchip/rk3128/clk_rk3128.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <syscon.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/cru_rk3128.h>
+
+int rockchip_get_clk(struct udevice **devp)
+{
+	return uclass_get_device_by_driver(UCLASS_CLK,
+			DM_GET_DRIVER(rockchip_rk3128_cru), devp);
+}
+
+void *rockchip_get_cru(void)
+{
+	struct rk3128_clk_priv *priv;
+	struct udevice *dev;
+	int ret;
+
+	ret = rockchip_get_clk(&dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	priv = dev_get_priv(dev);
+
+	return priv->cru;
+}