[PATCH v4 1/8] clk: clkdev/of_clk - add managed lookup and provider registrations

Matti Vaittinen
2018-11-13T11:56:17Z

With MFD devices the clk properties may be contained in MFD (parent) DT
node. Current devm_of_clk_add_hw_provider assumes the clk is bound to MFD
subdevice not to MFD device (parent). Add
devm_of_clk_add_hw_provider_parent to tackle this issue.

Also clkdev registration lacks of managed registration functions and it
seems few drivers do not drop clkdev lookups at exit. Add
devm_clk_hw_register_clkdev and devm_clk_release_clkdev to ease lookup
releasing at exit.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
Documentation/driver-model/devres.txt | 3 +
drivers/clk/clk.c | 28 ++++++--
drivers/clk/clkdev.c | 122 ++++++++++++++++++++++++++--------
include/linux/clk-provider.h | 11 +++
include/linux/clkdev.h | 4 ++
5 files changed, 136 insertions(+), 32 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 43681ca0837f..fac63760b01c 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -238,6 +238,9 @@ CLOCK
devm_clk_put()
devm_clk_hw_register()
devm_of_clk_add_hw_provider()
+ devm_of_clk_add_parent_hw_provider()
+ devm_clk_hw_register_clkdev()
+ devm_clk_release_clkdev()

DMA
dmaenginem_async_device_register()
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index af011974d4ec..9bb921eb90f6 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3893,12 +3893,12 @@ static void devm_of_clk_release_provider(struct device *dev, void *res)
of_clk_del_provider(*(struct device_node **)res);
}

-int devm_of_clk_add_hw_provider(struct device *dev,
+static int __devm_of_clk_add_hw_provider(struct device *dev,
struct clk_hw *(*get)(struct of_phandle_args *clkspec,
void *data),
- void *data)
+ struct device_node *of_node, void *data)
{
- struct device_node **ptr, *np;
+ struct device_node **ptr;
int ret;

ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
@@ -3906,10 +3906,9 @@ int devm_of_clk_add_hw_provider(struct device *dev,
if (!ptr)
return -ENOMEM;

- np = dev->of_node;
- ret = of_clk_add_hw_provider(np, get, data);
+ *ptr = of_node;
+ ret = of_clk_add_hw_provider(of_node, get, data);
if (!ret) {
- *ptr = np;
devres_add(dev, ptr);
} else {
devres_free(ptr);
@@ -3917,8 +3916,25 @@ int devm_of_clk_add_hw_provider(struct device *dev,

return ret;
}
+int devm_of_clk_add_hw_provider(struct device *dev,
+ struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+ void *data),
+ void *data)
+{
+ return __devm_of_clk_add_hw_provider(dev, get, dev->of_node, data);
+}
EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);

+int devm_of_clk_add_parent_hw_provider(struct device *dev,
+ struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+ void *data),
+ void *data)
+{
+ return __devm_of_clk_add_hw_provider(dev, get, dev->parent->of_node,
+ data);
+}
+EXPORT_SYMBOL_GPL(devm_of_clk_add_parent_hw_provider);
+
/**
* of_clk_del_provider() - Remove a previously registered clock provider
* @np: Device node pointer associated with clock provider
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 9ab3db8b3988..f6100b6e06fd 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -401,6 +401,25 @@ static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
return cl;
}

+static int do_clk_register_clkdev(struct clk_hw *hw,
+ struct clk_lookup **cl, const char *con_id, const char *dev_id)
+{
+
+ if (IS_ERR(hw))
+ return PTR_ERR(hw);
+ /*
+ * 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;
+}
+
/**
* clk_register_clkdev - register one clock lookup for a struct clk
* @clk: struct clk to associate with all clk_lookups
@@ -420,20 +439,10 @@ int clk_register_clkdev(struct clk *clk, const char *con_id,
{
struct clk_lookup *cl;

- if (IS_ERR(clk))
- return PTR_ERR(clk);
-
- /*
- * 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);
-
- return cl ? 0 : -ENOMEM;
+ if (!IS_ERR(clk))
+ return do_clk_register_clkdev(__clk_get_hw(clk), &cl, con_id,
+ dev_id);
+ return PTR_ERR(clk);
}
EXPORT_SYMBOL(clk_register_clkdev);

@@ -456,18 +465,79 @@ int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,
{
struct clk_lookup *cl;

- if (IS_ERR(hw))
- return PTR_ERR(hw);
+ return do_clk_register_clkdev(hw, &cl, con_id, dev_id);
+}
+EXPORT_SYMBOL(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);
+static void devm_clkdev_release(struct device *dev, void *res)
+{
+ clkdev_drop(*(struct clk_lookup **)res);
+}

- return cl ? 0 : -ENOMEM;
+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;
}
-EXPORT_SYMBOL(clk_hw_register_clkdev);
+
+/**
+ * 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.
+ * 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)
+{
+ int rval = -ENOMEM;
+ struct clk_lookup **cl;
+
+ cl = devres_alloc(devm_clkdev_release, sizeof(*cl), GFP_KERNEL);
+ if (cl) {
+ rval = do_clk_register_clkdev(hw, cl, con_id, dev_id);
+ if (!rval)
+ devres_add(dev, cl);
+ else
+ devres_free(cl);
+ }
+ return rval;
+}
+EXPORT_SYMBOL(devm_clk_hw_register_clkdev);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 60c51871b04b..a6663f084cf1 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -916,6 +916,10 @@ int devm_of_clk_add_hw_provider(struct device *dev,
struct clk_hw *(*get)(struct of_phandle_args *clkspec,
void *data),
void *data);
+int devm_of_clk_add_parent_hw_provider(struct device *dev,
+ struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+ void *data),
+ void *data);
void of_clk_del_provider(struct device_node *np);
void devm_of_clk_del_provider(struct device *dev);
struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
@@ -953,6 +957,13 @@ static inline int devm_of_clk_add_hw_provider(struct device *dev,
{
return 0;
}
+static inline int devm_of_clk_add_parent_hw_provider(struct device *dev,
+ struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+ void *data),
+ void *data)
+{
+ return 0;
+}
static inline void of_clk_del_provider(struct device_node *np) {}
static inline void devm_of_clk_del_provider(struct device *dev) {}
static inline struct clk *of_clk_src_simple_get(
diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h
index 4890ff033220..ccb32af5848b 100644
--- a/include/linux/clkdev.h
+++ b/include/linux/clkdev.h
@@ -52,4 +52,8 @@ 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_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