clk: Get the CLK by index without device

Getting a CLK by index with device is not straight forward
for some use-cases like handling clock operations for child
node in parent driver. So we need to process the child node
in parent probe via ofnode and process CLK operation for child
without udevice but with ofnode.

So add clk_get_by_index_nodev() and move the common code
in clk_get_by_index_tail() to use for clk_get_by_index()

Cc: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 75 insertions, 1 deletions

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 844b87cc33..d9236c5b51 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -54,6 +54,46 @@ static int clk_of_xlate_default(struct clk *clk,
 	return 0;
 }
 
+static int clk_get_by_index_tail(int ret, ofnode node,
+				 struct ofnode_phandle_args *args,
+				 const char *list_name, int index,
+				 struct clk *clk)
+{
+	struct udevice *dev_clk;
+	const struct clk_ops *ops;
+
+	assert(clk);
+	clk->dev = NULL;
+	if (ret)
+		goto err;
+
+	ret = uclass_get_device_by_ofnode(UCLASS_CLK, args->node, &dev_clk);
+	if (ret) {
+		debug("%s: uclass_get_device_by_of_offset failed: err=%d\n",
+		      __func__, ret);
+		return ret;
+	}
+
+	clk->dev = dev_clk;
+
+	ops = clk_dev_ops(dev_clk);
+
+	if (ops->of_xlate)
+		ret = ops->of_xlate(clk, args);
+	else
+		ret = clk_of_xlate_default(clk, args);
+	if (ret) {
+		debug("of_xlate() failed: %d\n", ret);
+		return ret;
+	}
+
+	return clk_request(dev_clk, clk);
+err:
+	debug("%s: Node '%s', property '%s', failed to request CLK index %d: %d\n",
+	      __func__, ofnode_get_name(node), list_name, index, ret);
+	return ret;
+}
+
 static int clk_get_by_indexed_prop(struct udevice *dev, const char *prop_name,
 				   int index, struct clk *clk)
 {
@@ -100,7 +140,26 @@ static int clk_get_by_indexed_prop(struct udevice *dev, const char *prop_name,
 
 int clk_get_by_index(struct udevice *dev, int index, struct clk *clk)
 {
-	return clk_get_by_indexed_prop(dev, "clocks", index, clk);
+	struct ofnode_phandle_args args;
+	int ret;
+
+	ret = dev_read_phandle_with_args(dev, "clocks", "#clock-cells", 0,
+					 index, &args);
+
+	return clk_get_by_index_tail(ret, dev_ofnode(dev), &args, "clocks",
+				     index > 0, clk);
+}
+
+int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk)
+{
+	struct ofnode_phandle_args args;
+	int ret;
+
+	ret = ofnode_parse_phandle_with_args(node, "clocks", "#clock-cells", 0,
+					     index > 0, &args);
+
+	return clk_get_by_index_tail(ret, node, &args, "clocks",
+				     index > 0, clk);
 }
 
 int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
diff --git a/include/clk.h b/include/clk.h
index 8e366163f9..d24e99713a 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -8,6 +8,7 @@
 #ifndef _CLK_H_
 #define _CLK_H_
 
+#include <dm/ofnode.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 
@@ -101,6 +102,20 @@ int clk_get_by_index_platdata(struct udevice *dev, int index,
 int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
 
 /**
+ * clock_get_by_index_nodev - Get/request a clock by integer index
+ * without a device.
+ *
+ * This is a version of clk_get_by_index() that does not use a device.
+ *
+ * @node:	The client ofnode.
+ * @index:	The index of the clock to request, within the client's list of
+ *		clocks.
+ * @clock	A pointer to a clock struct to initialize.
+ * @return 0 if OK, or a negative error code.
+ */
+int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
+
+/**
  * clock_get_bulk - Get/request all clocks of a device.
  *
  * This looks up and requests all clocks of the client device; each device is