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i2c: Let i2c_parent_is_i2c_adapter return the parent adapter

PATCH In review Jean Delvare 2 participants 2 messages Aug 23, 2010 1 message not in the archive

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Jean Delvare

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#0 lore raw

PATCH 2/2 i2c: Let i2c_parent_is_i2c_adapter return the parent adapter

This makes the calling site's code clearer IMHO.

Signed-off-by Jean Delvare <[email protected]>
Cc Michael Lawnick <[email protected]>

---
Michael, what do you think? Admittedly this makes the code (very) slightly larger, but think the improvement in code clarity justifies it.

 drivers/i2c/i2c-core.c |   30 ++++++++++++++++++------------
 drivers/i2c/i2c-dev.c  |   13 ++++++-------
 include/linux/i2c.h    |   11 ++++++++---
 3 files changed, 32 insertions(+), 22 deletions(-)
drivers/i2c/i2c-core.c +18 -12
@@ -428,14 +428,14 @@ static int __i2c_check_addr_busy(struct
 /* walk up mux tree */
 static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
 {
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
 	int result;
 
 	result = device_for_each_child(&adapter->dev, &addr,
 					__i2c_check_addr_busy);
 
-	if (!result && i2c_parent_is_i2c_adapter(adapter))
-		result = i2c_check_mux_parents(
-				    to_i2c_adapter(adapter->dev.parent), addr);
+	if (!result && parent)
+		result = i2c_check_mux_parents(parent, addr);
 
 	return result;
 }

@@ -456,11 +456,11 @@ static int i2c_check_mux_children(struct
 
 static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
 {
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
 	int result = 0;
 
-	if (i2c_parent_is_i2c_adapter(adapter))
-		result = i2c_check_mux_parents(
-				    to_i2c_adapter(adapter->dev.parent), addr);
+	if (parent)
+		result = i2c_check_mux_parents(parent, addr);
 
 	if (!result)
 		result = device_for_each_child(&adapter->dev, &addr,

@@ -475,8 +475,10 @@ static int i2c_check_addr_busy(struct i2
  */
 void i2c_lock_adapter(struct i2c_adapter *adapter)
 {
-	if (i2c_parent_is_i2c_adapter(adapter))
-		i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent));
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+	if (parent)
+		i2c_lock_adapter(parent);
 	else
 		rt_mutex_lock(&adapter->bus_lock);
 }

@@ -488,8 +490,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter);
  */
 static int i2c_trylock_adapter(struct i2c_adapter *adapter)
 {
-	if (i2c_parent_is_i2c_adapter(adapter))
-		return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent));
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+	if (parent)
+		return i2c_trylock_adapter(parent);
 	else
 		return rt_mutex_trylock(&adapter->bus_lock);
 }

@@ -500,8 +504,10 @@ static int i2c_trylock_adapter(struct i2
  */
 void i2c_unlock_adapter(struct i2c_adapter *adapter)
 {
-	if (i2c_parent_is_i2c_adapter(adapter))
-		i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent));
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+	if (parent)
+		i2c_unlock_adapter(parent);
 	else
 		rt_mutex_unlock(&adapter->bus_lock);
 }
drivers/i2c/i2c-dev.c +6 -7
@@ -192,13 +192,12 @@ static int i2cdev_check(struct device *d
 /* walk up mux tree */
 static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
 {
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
 	int result;
 
 	result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
-
-	if (!result && i2c_parent_is_i2c_adapter(adapter))
-		result = i2cdev_check_mux_parents(
-				    to_i2c_adapter(adapter->dev.parent), addr);
+	if (!result && parent)
+		result = i2cdev_check_mux_parents(parent, addr);
 
 	return result;
 }

@@ -222,11 +221,11 @@ static int i2cdev_check_mux_children(str
    driver bound to it, as NOT busy. */
 static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 {
+	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
 	int result = 0;
 
-	if (i2c_parent_is_i2c_adapter(adapter))
-		result = i2cdev_check_mux_parents(
-				    to_i2c_adapter(adapter->dev.parent), addr);
+	if (parent)
+		result = i2cdev_check_mux_parents(parent, addr);
 
 	if (!result)
 		result = device_for_each_child(&adapter->dev, &addr,
include/linux/i2c.h +8 -3
@@ -384,10 +384,15 @@ static inline void i2c_set_adapdata(stru
 	dev_set_drvdata(&dev->dev, data);
 }
 
-static inline int i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
+static inline struct i2c_adapter *
+i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 {
-	return adapter->dev.parent != NULL
-		&& adapter->dev.parent->type == &i2c_adapter_type;
+	struct device *parent = adapter->dev.parent;
+
+	if (parent != NULL && parent->type == &i2c_adapter_type)
+		return to_i2c_adapter(parent);
+	else
+		return NULL;
 }
 
 /* Adapter locking functions, exported for shared pin cases */
Signature · 1 line
Jean Delvare

A message that is not in the archive (sent off-list or not yet received): [email protected]

#2 lore raw

Jean Delvare said the following:

Quoted 7 lines

This makes the calling site's code clearer IMHO.

Signed-off-by Jean Delvare <[email protected]>
Cc Michael Lawnick <[email protected]>

---
Michael, what do you think? Admittedly this makes the code (very) slightly larger, but think the improvement in code clarity justifies it.

Well, at least it overcomes these awful 80 char break adjustments ...

ACK

Signature · 2 lines
KR
Michael