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Subject[PATCH 2/3] clk: Add devm_clk_{register,unregister}()
Date
Some clock drivers can be simplified if devres takes care of
unregistering any registered clocks along error paths. Introduce
devm_clk_register() so that clock drivers get unregistration for
free along with simplified error paths.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
drivers/clk/clk.c | 111 +++++++++++++++++++++++++++++++++++--------
include/linux/clk-provider.h | 2 +
2 files changed, 92 insertions(+), 21 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 56e4495e..6852809 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -17,6 +17,7 @@
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/of.h>
+#include <linux/device.h>

static DEFINE_SPINLOCK(enable_lock);
static DEFINE_MUTEX(prepare_lock);
@@ -1361,28 +1362,9 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
}
EXPORT_SYMBOL_GPL(__clk_register);

-/**
- * 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
- *
- * clk_register is the primary interface for populating the clock tree with new
- * clock nodes. It returns a pointer to the newly allocated struct clk which
- * cannot be dereferenced by driver code but may be used in conjuction with the
- * rest of the clock API. In the event of an error clk_register will return an
- * error code; drivers must test for an error code after calling clk_register.
- */
-struct clk *clk_register(struct device *dev, struct clk_hw *hw)
+static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
{
int i, ret;
- struct clk *clk;
-
- clk = kzalloc(sizeof(*clk), GFP_KERNEL);
- if (!clk) {
- pr_err("%s: could not allocate clk\n", __func__);
- ret = -ENOMEM;
- goto fail_out;
- }

clk->name = kstrdup(hw->init->name, GFP_KERNEL);
if (!clk->name) {
@@ -1420,7 +1402,7 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)

ret = __clk_init(dev, clk);
if (!ret)
- return clk;
+ return 0;

fail_parent_names_copy:
while (--i >= 0)
@@ -1429,6 +1411,36 @@ fail_parent_names_copy:
fail_parent_names:
kfree(clk->name);
fail_name:
+ return ret;
+}
+
+/**
+ * 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
+ *
+ * clk_register is the primary interface for populating the clock tree with new
+ * clock nodes. It returns a pointer to the newly allocated struct clk which
+ * cannot be dereferenced by driver code but may be used in conjuction with the
+ * rest of the clock API. In the event of an error clk_register will return an
+ * error code; drivers must test for an error code after calling clk_register.
+ */
+struct clk *clk_register(struct device *dev, struct clk_hw *hw)
+{
+ int ret;
+ struct clk *clk;
+
+ clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+ if (!clk) {
+ pr_err("%s: could not allocate clk\n", __func__);
+ ret = -ENOMEM;
+ goto fail_out;
+ }
+
+ ret = _clk_register(dev, hw, clk);
+ if (!ret)
+ return clk;
+
kfree(clk);
fail_out:
return ERR_PTR(ret);
@@ -1444,6 +1456,63 @@ EXPORT_SYMBOL_GPL(clk_register);
void clk_unregister(struct clk *clk) {}
EXPORT_SYMBOL_GPL(clk_unregister);

+static void devm_clk_release(struct device *dev, void *res)
+{
+ clk_unregister(res);
+}
+
+/**
+ * devm_clk_register - resource managed clk_register()
+ * @dev: device that is registering this clock
+ * @hw: link to hardware-specific clock data
+ *
+ * Managed clk_register(). Clocks returned from this function are
+ * automatically clk_unregister()ed on driver detach. See clk_register() for
+ * more information.
+ */
+struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL);
+ if (!clk)
+ return ERR_PTR(-ENOMEM);
+
+ ret = _clk_register(dev, hw, clk);
+ if (!ret) {
+ devres_add(dev, clk);
+ } else {
+ devres_free(clk);
+ clk = ERR_PTR(ret);
+ }
+
+ return clk;
+}
+EXPORT_SYMBOL_GPL(devm_clk_register);
+
+static int devm_clk_match(struct device *dev, void *res, void *data)
+{
+ struct clk *c = res;
+ if (WARN_ON(!c))
+ return 0;
+ return c == data;
+}
+
+/**
+ * devm_clk_unregister - resource managed clk_unregister()
+ * @clk: clock to unregister
+ *
+ * Deallocate a clock allocated with devm_clk_register(). Normally
+ * this function will not need to be called and the resource management
+ * code will ensure that the resource is freed.
+ */
+void devm_clk_unregister(struct device *dev, struct clk *clk)
+{
+ WARN_ON(devres_destroy(dev, devm_clk_release, devm_clk_match, clk));
+}
+EXPORT_SYMBOL(devm_clk_unregister);
+
/*** clk rate change notifiers ***/

/**
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index c127315..710c6cb 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -327,8 +327,10 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
* error code; drivers must test for an error code after calling clk_register.
*/
struct clk *clk_register(struct device *dev, struct clk_hw *hw);
+struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw);

void clk_unregister(struct clk *clk);
+void devm_clk_unregister(struct device *dev, struct clk *clk);

/* helper functions */
const char *__clk_get_name(struct clk *clk);
--
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