From: Stephen Boyd <sboyd@xxxxxxxxxx> [ Upstream commit 9011f92622e5ef2d075f45e5fa818776d4feb8c0 ] 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 <bjorn.andersson@xxxxxxxxxx> Reported-by: Niklas Cassel <niklas.cassel@xxxxxxxxxx> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20191230190455.141339-1-sboyd@xxxxxxxxxx [sboyd@xxxxxxxxxx: Fixup kernel-doc notation] Reviewed-by: Niklas Cassel <nks@xxxxxxxxxxx> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Tested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/clk/clk.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 53585cfc4b9ba..66f056ac4c156 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3736,6 +3736,28 @@ fail_out: return ERR_PTR(ret); } +/** + * 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 @@ -3751,7 +3773,7 @@ fail_out: */ 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); } EXPORT_SYMBOL_GPL(clk_register); @@ -3767,7 +3789,8 @@ 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)); } EXPORT_SYMBOL_GPL(clk_hw_register); -- 2.20.1
