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Subject[PATCH] clk: clkdev - add managed versions of lookup registrations
Add devm_clk_hw_register_clkdev, devm_clk_register_clkdev and
devm_clk_release_clkdev as a first styep to clean up drivers which are
leaking clkdev lookups at driver remove.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---

While searching for example on how clk drivers release clkdev at exit
I found that many of those don't. Simple grep for clkdev under
drivers/clk suggest that bunch of drivers which call clk_register_clkdev
or clk_hw_register_clkdev never call clkdev_drop. In order to help
cleaning this up I decided to add devm versions of clk_register_clkdev
and clk_hw_register_clkdev. I hope this would allow simply converting
bunch of calls to clk_register_clkdev and clk_hw_register_clkdev into
managed versions without building further clean up logic.

Please review this carefully. I have only performed some simple tests
with my BD71837 driver. And as I have only limited understanding on
clkdev lookups I may have done mistakes. Thanks!

drivers/clk/clkdev.c | 165 +++++++++++++++++++++++++++++++++++++++++--------
include/linux/clkdev.h | 8 +++
2 files changed, 147 insertions(+), 26 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 7513411140b6..4752a0004a6c 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -390,7 +390,7 @@ void clkdev_drop(struct clk_lookup *cl)
}
EXPORT_SYMBOL(clkdev_drop);

-static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
+static struct clk_lookup *do_clk_register_clkdev(struct clk_hw *hw,
const char *con_id,
const char *dev_id, ...)
{
@@ -404,6 +404,24 @@ static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
return cl;
}

+static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
+ const char *con_id, const char *dev_id)
+{
+ struct clk_lookup *cl;
+
+ /*
+ * Since dev_id can be NULL, and NULL is handled specially, we must
+ * pass it as either a NULL format string, or with "%s".
+ */
+ if (dev_id)
+ cl = do_clk_register_clkdev(hw, con_id, "%s",
+ dev_id);
+ else
+ cl = do_clk_register_clkdev(hw, con_id, NULL);
+
+ return cl;
+}
+
/**
* clk_register_clkdev - register one clock lookup for a struct clk
* @clk: struct clk to associate with all clk_lookups
@@ -421,22 +439,18 @@ static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
int clk_register_clkdev(struct clk *clk, const char *con_id,
const char *dev_id)
{
- struct clk_lookup *cl;
-
- if (IS_ERR(clk))
- return PTR_ERR(clk);
+ int rval = 0;

- /*
- * Since dev_id can be NULL, and NULL is handled specially, we must
- * pass it as either a NULL format string, or with "%s".
- */
- if (dev_id)
- cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, "%s",
- dev_id);
- else
- cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, NULL);
+ if (IS_ERR(clk)) {
+ rval = PTR_ERR(clk);
+ } else {
+ struct clk_lookup *cl;

- return cl ? 0 : -ENOMEM;
+ cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, dev_id);
+ if (!cl)
+ rval = -ENOMEM;
+ }
+ return rval;
}
EXPORT_SYMBOL(clk_register_clkdev);

@@ -456,21 +470,120 @@ EXPORT_SYMBOL(clk_register_clkdev);
*/
int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,
const char *dev_id)
+{
+ int rval = 0;
+
+ if (IS_ERR(hw)) {
+ rval = PTR_ERR(hw);
+ } else {
+ struct clk_lookup *cl;
+
+ cl = __clk_register_clkdev(hw, con_id, dev_id);
+ if (!cl)
+ rval = -ENOMEM;
+ }
+
+ return rval;
+}
+EXPORT_SYMBOL(clk_hw_register_clkdev);
+
+static void devm_clkdev_release(struct device *dev, void *res)
+{
+ clkdev_drop(*(struct clk_lookup **)res);
+}
+
+static int devm_clk_match_clkdev(struct device *dev, void *res, void *data)
+{
+ struct clk_lookup **l = res;
+
+ if (!l || !*l) {
+ WARN_ON(!l || !*l);
+ return 0;
+ }
+
+ return *l == data;
+}
+
+/**
+ * devm_clk_release_clkdev - Resource managed clkdev lookup release
+ * @dev: device this lookup is bound
+ * @con_id: connection ID string on device
+ * @dev_id: format string describing device name
+ *
+ * Drop the clkdev lookup created with devm_clk_hw_register_clkdev or
+ * with devm_clk_register_clkdev. Normally this function will not need to be
+ * called and the resource management code will ensure that the resource is
+ * freed.
+ */
+void devm_clk_release_clkdev(struct device *dev, const char *con_id,
+ const char *dev_id)
{
struct clk_lookup *cl;
+ int rval;
+
+ cl = clk_find(dev_id, con_id);
+ WARN_ON(!cl);
+ rval = devres_release(dev, devm_clkdev_release,
+ &devm_clk_match_clkdev, cl);
+ WARN_ON(rval);
+}
+EXPORT_SYMBOL(devm_clk_release_clkdev);
+
+/**
+ * devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw
+ * @dev: device this lookup is bound
+ * @hw: struct clk_hw to associate with all clk_lookups
+ * @con_id: connection ID string on device
+ * @dev_id: format string describing device name
+ *
+ * con_id or dev_id may be NULL as a wildcard, just as in the rest of
+ * clkdev.
+ *
+ * To make things easier for mass registration, we detect error clk_hws
+ * from a previous clk_hw_register_*() call, and return the error code for
+ * those. This is to permit this function to be called immediately
+ * after clk_hw_register_*().
+ */
+int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw,
+ const char *con_id, const char *dev_id)
+{
+ struct clk_lookup **cl = NULL;

if (IS_ERR(hw))
return PTR_ERR(hw);
+ cl = devres_alloc(devm_clkdev_release, sizeof(*cl), GFP_KERNEL);
+ if (cl) {
+ *cl = __clk_register_clkdev(hw, con_id, dev_id);
+ if (*cl)
+ devres_add(dev, cl);
+ else
+ devres_free(cl);
+ }
+ return (cl && *cl) ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(devm_clk_hw_register_clkdev);

- /*
- * Since dev_id can be NULL, and NULL is handled specially, we must
- * pass it as either a NULL format string, or with "%s".
- */
- if (dev_id)
- cl = __clk_register_clkdev(hw, con_id, "%s", dev_id);
- else
- cl = __clk_register_clkdev(hw, con_id, NULL);
-
- return cl ? 0 : -ENOMEM;
+/**
+ * devm_clk_register_clkdev - managed clk lookup registration for a struct clk
+ * @dev: device this lookup is bound
+ * @clk: struct clk to associate with all clk_lookups
+ * @con_id: connection ID string on device
+ * @dev_id: string describing device name
+ *
+ * con_id or dev_id may be NULL as a wildcard, just as in the rest of
+ * clkdev.
+ *
+ * To make things easier for mass registration, we detect error clks
+ * from a previous clk_register() call, and return the error code for
+ * those. This is to permit this function to be called immediately
+ * after clk_register().
+ */
+int devm_clk_register_clkdev(struct device *dev, struct clk *clk,
+ const char *con_id, const char *dev_id)
+{
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+ return devm_clk_hw_register_clkdev(dev, __clk_get_hw(clk), con_id,
+ dev_id);
}
-EXPORT_SYMBOL(clk_hw_register_clkdev);
+EXPORT_SYMBOL(devm_clk_register_clkdev);
diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h
index 4890ff033220..27ebeae8ae26 100644
--- a/include/linux/clkdev.h
+++ b/include/linux/clkdev.h
@@ -52,4 +52,12 @@ int clk_add_alias(const char *, const char *, const char *, struct device *);
int clk_register_clkdev(struct clk *, const char *, const char *);
int clk_hw_register_clkdev(struct clk_hw *, const char *, const char *);

+int devm_clk_register_clkdev(struct device *dev, struct clk *clk,
+ const char *con_id, const char *dev_id);
+int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw,
+ const char *con_id, const char *dev_id);
+void devm_clk_release_clkdev(struct device *dev, const char *con_id,
+ const char *dev_id);
+
+
#endif
--
2.14.3
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