blob: 0dfc9514d7aaaf6058aa9b8a22017d4fe0bb7d90 [file] [log] [blame]
From 5be4dd303634af9cf393ecd3bd91ba97274ced29 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <>
Date: Mon, 30 Dec 2019 10:29:35 -0800
Subject: [PATCH] clk: Use parent node pointer during registration if necessary
commit 9011f92622e5ef2d075f45e5fa818776d4feb8c0 upstream.
Sometimes clk drivers are attached to devices which are children of a
parent device that is connected to a node in DT. This happens when
devices are MFD-ish and the parent device driver mostly registers child
devices to match against drivers placed in their respective subsystem
directories like drivers/clk, drivers/regulator, etc. When the clk
driver calls clk_register() with a device pointer, that struct device
pointer won't have a device_node associated with it because it was
created purely in software as a way to partition logic to a subsystem.
This causes problems for the way we find parent clks for the clks
registered by these child devices because we look at the registering
device's device_node pointer to lookup 'clocks' and 'clock-names'
properties. Let's use the parent device's device_node pointer if the
registering device doesn't have a device_node but the parent does. This
simplifies clk registration code by avoiding the need to assign some
device_node to the device registering the clk.
Cc: Bjorn Andersson <>
Reported-by: Niklas Cassel <>
Signed-off-by: Stephen Boyd <>
[ Fixup kernel-doc notation]
Reviewed-by: Niklas Cassel <>
Reviewed-by: Bjorn Andersson <>
Tested-by: Bjorn Andersson <>
Signed-off-by: Paul Gortmaker <>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index eb51f3df171d..37f1584e12c3 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3667,6 +3667,28 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
+ * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
+ * @dev: Device to get device node of
+ *
+ * Return: device node pointer of @dev, or the device node pointer of
+ * @dev->parent if dev doesn't have a device node, or NULL if neither
+ * @dev or @dev->parent have a device node.
+ */
+static struct device_node *dev_or_parent_of_node(struct device *dev)
+ struct device_node *np;
+ if (!dev)
+ return NULL;
+ np = dev_of_node(dev);
+ if (!np)
+ np = dev_of_node(dev->parent);
+ return np;
* clk_register - allocate a new clock, register it and return an opaque cookie
* @dev: device that is registering this clock
* @hw: link to hardware-specific clock data
@@ -3681,7 +3703,7 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
struct clk *clk_register(struct device *dev, struct clk_hw *hw)
- return __clk_register(dev, dev_of_node(dev), hw);
+ return __clk_register(dev, dev_or_parent_of_node(dev), hw);
@@ -3697,7 +3719,8 @@ EXPORT_SYMBOL_GPL(clk_register);
int clk_hw_register(struct device *dev, struct clk_hw *hw)
- return PTR_ERR_OR_ZERO(__clk_register(dev, dev_of_node(dev), hw));
+ return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
+ hw));