dm: clk: Add support for decoding clocks from the device tree
Add a method which can locate a clock for a device, given its index. This
uses the normal device tree bindings to return the clock device and the
first argument which is normally used as a peripheral ID in U-Boot.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 19f6f07..8a4c568 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -12,6 +12,8 @@
#include <dm/lists.h>
#include <dm/root.h>
+DECLARE_GLOBAL_DATA_PTR;
+
ulong clk_get_rate(struct udevice *dev)
{
struct clk_ops *ops = clk_get_ops(dev);
@@ -62,6 +64,32 @@
return ops->set_periph_rate(dev, periph, rate);
}
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+int clk_get_by_index(struct udevice *dev, int index, struct udevice **clk_devp)
+{
+ struct fdtdec_phandle_args args;
+ int ret;
+
+ assert(*clk_devp);
+ ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
+ "clocks", "#clock-cells", 0, index,
+ &args);
+ if (ret) {
+ debug("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = uclass_get_device_by_of_offset(UCLASS_CLK, args.node, clk_devp);
+ if (ret) {
+ debug("%s: uclass_get_device_by_of_offset failed: err=%d\n",
+ __func__, ret);
+ return ret;
+ }
+ return args.args_count > 0 ? args.args[0] : 0;
+}
+#endif
+
UCLASS_DRIVER(clk) = {
.id = UCLASS_CLK,
.name = "clk",