[U-Boot] [PATCH v4 07/13] dm: clk: Define clk_get_parent() for clk operations

[Lukasz Majewski]

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->driver_data field is read.

Signed-off-by: Lukasz Majewski <lukma at denx.de>

---

Changes in v4: None
Changes in v3:
- New patch

 drivers/clk/clk-uclass.c | 15 +++++++++++++++
 include/clk.h            |  9 +++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 79b3b0494c..1a726dafaa 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -379,6 +379,21 @@ ulong clk_get_rate(struct clk *clk)
 	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 = (struct clk *)dev_get_driver_data(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 89dc64bfaf..0873b1e507 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -259,6 +259,15 @@ int clk_free(struct clk *clk);
 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
-- 
2.11.0