dm: clk: Define clk_get_parent() for clk operations
This commit adds the clk_get_parent() function, which is responsible
for getting the parent's struct clock pointer.
U-Boot's DM support for getting parent is different (the parent
relationship is in udevice) than the one in Common Clock Framework [CCF]
in Linux. To obtain the pointer to struct clk of parent the
pdev->uclass_priv field is read via dev_get_clk_ptr() wrapper.
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 79b3b04..4346c61 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -13,6 +13,7 @@
#include <dm/read.h>
#include <dt-structs.h>
#include <errno.h>
+#include <linux/clk-provider.h>
static inline const struct clk_ops *clk_dev_ops(struct udevice *dev)
{
@@ -379,6 +380,21 @@
return ops->get_rate(clk);
}
+struct clk *clk_get_parent(struct clk *clk)
+{
+ struct udevice *pdev;
+ struct clk *pclk;
+
+ debug("%s(clk=%p)\n", __func__, clk);
+
+ pdev = dev_get_parent(clk->dev);
+ pclk = dev_get_clk_ptr(pdev);
+ if (!pclk)
+ return ERR_PTR(-ENODEV);
+
+ return pclk;
+}
+
ulong clk_set_rate(struct clk *clk, ulong rate)
{
const struct clk_ops *ops = clk_dev_ops(clk->dev);
diff --git a/include/clk.h b/include/clk.h
index b10c001..e20641e 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -259,6 +259,15 @@
ulong clk_get_rate(struct clk *clk);
/**
+ * clk_get_parent() - Get current clock's parent.
+ *
+ * @clk: A clock struct that was previously successfully requested by
+ * clk_request/get_by_*().
+ * @return pointer to parent's struct clk, or error code passed as pointer
+ */
+struct clk *clk_get_parent(struct clk *clk);
+
+/**
* clk_set_rate() - Set current clock rate.
*
* @clk: A clock struct that was previously successfully requested by