of: Add function for generating a DT modalias with a newline

The modalias sysfs attr is lacking a newline for DT aliases on platform
devices. The macio and ibmebus correctly add the newline, but open code it.
Introduce a new function, of_device_modalias(), that fills the buffer with
the modalias including the newline and update users of the old
of_device_get_modalias function.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/powerpc/platforms/pseries/ibmebus.c

@@ -410,10 +410,7 @@ static ssize_t name_show(struct device *dev,
 static ssize_t modalias_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
-	buf[len] = '\n';
-	buf[len+1] = 0;
-	return len+1;
+	return of_device_modalias(dev, buf, PAGE_SIZE);
 }
 
 static struct device_attribute ibmebus_bus_device_attrs[] = {

drivers/base/platform.c

@@ -847,7 +847,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 	struct platform_device	*pdev = to_platform_device(dev);
 	int len;
 
-	len = of_device_get_modalias(dev, buf, PAGE_SIZE -1);
+	len = of_device_modalias(dev, buf, PAGE_SIZE);
 	if (len != -ENODEV)
 		return len;
 

drivers/macintosh/macio_sysfs.c

@@ -41,12 +41,7 @@ compatible_show (struct device *dev, struct device_attribute *attr, char *buf)
 static ssize_t modalias_show (struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
-	int len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
-
-	buf[len] = '\n';
-	buf[len+1] = 0;
-
-	return len+1;
+	return of_device_modalias(dev, buf, PAGE_SIZE);
 }
 
 static ssize_t devspec_show(struct device *dev,

drivers/of/device.c

@@ -176,7 +176,7 @@ const void *of_device_get_match_data(const struct device *dev)
 }
 EXPORT_SYMBOL(of_device_get_match_data);
 
-ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
+static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 {
 	const char *compat;
 	int cplen, i;
@@ -225,7 +225,6 @@ ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 
 	return repend;
 }
-EXPORT_SYMBOL_GPL(of_device_get_modalias);
 
 int of_device_request_module(struct device *dev)
 {
@@ -250,6 +249,21 @@ int of_device_request_module(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(of_device_request_module);
 
+/**
+ * of_device_modalias - Fill buffer with newline terminated modalias string
+ */
+ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
+{
+	ssize_t sl = of_device_get_modalias(dev, str, len - 2);
+	if (sl < 0)
+		return sl;
+
+	str[sl++] = '\n';
+	str[sl] = 0;
+	return sl;
+}
+EXPORT_SYMBOL_GPL(of_device_modalias);
+
 /**
  * of_device_uevent - Display OF related uevent information
  */

drivers/tty/serdev/core.c

@@ -191,10 +191,7 @@ static int serdev_drv_remove(struct device *dev)
 static ssize_t modalias_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
-	buf[len] = '\n';
-	buf[len+1] = 0;
-	return len+1;
+	return of_device_modalias(dev, buf, PAGE_SIZE);
 }
 
 static struct device_attribute serdev_device_attrs[] = {

drivers/usb/common/ulpi.c

@@ -107,7 +107,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 	int len;
 	struct ulpi *ulpi = to_ulpi_dev(dev);
 
-	len = of_device_get_modalias(dev, buf, PAGE_SIZE - 1);
+	len = of_device_modalias(dev, buf, PAGE_SIZE);
 	if (len != -ENODEV)
 		return len;
 

include/linux/of_device.h

@@ -34,8 +34,7 @@ extern void of_device_unregister(struct platform_device *ofdev);
 
 extern const void *of_device_get_match_data(const struct device *dev);
 
-extern ssize_t of_device_get_modalias(struct device *dev,
-					char *str, ssize_t len);
+extern ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len);
 extern int of_device_request_module(struct device *dev);
 
 extern void of_device_uevent(struct device *dev, struct kobj_uevent_env *env);
@@ -72,7 +71,7 @@ static inline const void *of_device_get_match_data(const struct device *dev)
 	return NULL;
 }
 
-static inline int of_device_get_modalias(struct device *dev,
+static inline int of_device_modalias(struct device *dev,
 				     char *str, ssize_t len)
 {
 	return -ENODEV;