From: Paul Osmialowski <paw...@king.net.pl>
These two functions are added to ease management of clocks obtained
from OF device nodes.
They are particulary useful while iterating over DT subnodes using e.g.
for_each_child_of_node(dev->of_node, child) in order do get resources
(i.e. clocks) for subdevices defined by these DT subnodes.
For example:
some_device {
compatible = "something"
#address-cells = <1>;
#size-cells = <1>;
ranges;
subdevice1: some_subdevice@some_address1 {
reg = <0xsome_address1 0xsome_size>
clocks = <&some_clock1>
}
subdevice2: some_subdevice@some_address2 {
reg = <0xsome_address2 0xsome_size>
clocks = <&some_clock2>
}
}
Normally, I'd have to use of_clk_get() on each subdevice node and then
worry about proper resource release myself.
IMHO using devres infrastructure for this is far better. This patch adds
missing functions needed to do it a better way.
Signed-off-by: Paul Osmialowski <paw...@king.net.pl>
---
Documentation/driver-model/devres.txt | 2 ++
drivers/clk/clk-devres.c | 46 +++++++++++++++++++++++++++++++++++
include/linux/clk.h | 46 +++++++++++++++++++++++++++++++++++
3 files changed, 94 insertions(+)
diff --git a/Documentation/driver-model/devres.txt
b/Documentation/driver-model/devres.txt
index 831a536..f3ad67a 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -235,6 +235,8 @@ certainly invest a bit more effort into libata core layer).
CLOCK
devm_clk_get()
+ devm_of_clk_get()
+ devm_of_clk_get_by_name()
devm_clk_put()
DMA
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 8f57154..197075a 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -34,6 +34,52 @@ struct clk *devm_clk_get(struct device *dev, const char *id)
}
EXPORT_SYMBOL(devm_clk_get);
+#ifdef CONFIG_OF
+
+struct clk *devm_of_clk_get(struct device *dev, struct device_node *np,
+ int index)
+{
+ struct clk **ptr, *clk;
+
+ ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ clk = of_clk_get(np, index);
+ if (!IS_ERR(clk)) {
+ *ptr = clk;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return clk;
+}
+EXPORT_SYMBOL(devm_of_clk_get);
+
+struct clk *devm_of_clk_get_by_name(struct device *dev, struct device_node *np,
+ const char *name)
+{
+ struct clk **ptr, *clk;
+
+ ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ clk = of_clk_get_by_name(np, name);
+ if (!IS_ERR(clk)) {
+ *ptr = clk;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return clk;
+}
+EXPORT_SYMBOL(devm_of_clk_get_by_name);
+
+#endif /* CONFIG_OF */
+
static int devm_clk_match(struct device *dev, void *res, void *data)
{
struct clk **c = res;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 0df4a51..8f31f9a 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -504,4 +504,50 @@ static inline struct clk *of_clk_get_by_name(struct
device_node *np,
}
#endif
+#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
+/**
+ * devm_of_clk_get - obtain a managed reference to a clock producer
+ * from device tree node (by index).
+ * @dev: device for clock "consumer"
+ * @np: device tree node
+ * @index: clock consumer index (within the node)
+ *
+ * devm_of_clk_get should not be called from within interrupt context.
+ *
+ * The clock will automatically be freed when the device is unbound
+ * from the bus.
+ */
+struct clk *devm_of_clk_get(struct device *dev, struct device_node *np,
+ int index);
+
+/**
+ * devm_of_clk_get_by_name - obtain a managed reference to a clock producer
+ * from device tree node (by name).
+ * @dev: device for clock "consumer"
+ * @np: device tree node
+ * @name: clock consumer name (within the node)
+ *
+ * devm_of_clk_get_by_name should not be called from within interrupt context.
+ *
+ * The clock will automatically be freed when the device is unbound
+ * from the bus.
+ */
+struct clk *devm_of_clk_get_by_name(struct device *dev, struct device_node *np,
+ const char *name);
+
+#else
+static inline struct clk *devm_of_clk_get(struct device *dev,
+ struct device_node *np,
+ int index)
+{
+ return ERR_PTR(-ENOENT);
+}
+static inline struct clk *devm_of_clk_get_by_name(struct device *dev,
+ struct device_node *np,
+ const char *name)
+{
+ return ERR_PTR(-ENOENT);
+}
+#endif
+
#endif
--
2.4.9
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