of: device: Support loading a module with OF based modalias

In the case of ULPI devices, we want to be able to load the driver before registering the device so that we don't get stuck in a loop waiting for the phy module to appear and failing usb controller probe. Currently we request the ulpi module via the ulpi ids, but in the DT case we might need to request it with the OF based modalias instead. Add a common function that allows anyone to request a module with the OF based modalias. Acked-by: Rob Herring <[email protected]> Cc: <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> Signed-off-by: Peter Chen <[email protected]>
0day-ci · Jan 20, 2017 · 9c829c0 · 9c829c0
1 parent 3f991aa
commit 9c829c0
Show file tree

Hide file tree

Showing 2 changed files with 29 additions and 0 deletions.
diff --git a/drivers/of/device.c b/drivers/of/device.c
@@ -226,6 +226,29 @@ ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 	return tsize;
 }
 
+int of_device_request_module(struct device *dev)
+{
+	char *str;
+	ssize_t size;
+	int ret;
+
+	size = of_device_get_modalias(dev, NULL, 0);
+	if (size < 0)
+		return size;
+
+	str = kmalloc(size + 1, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	of_device_get_modalias(dev, str, size);
+	str[size] = '\0';
+	ret = request_module(str);
+	kfree(str);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_device_request_module);
+
 /**
  * of_device_uevent - Display OF related uevent information
  */

diff --git a/include/linux/of_device.h b/include/linux/of_device.h
@@ -37,6 +37,7 @@ 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 int of_device_request_module(struct device *dev);
 
 extern void of_device_uevent(struct device *dev, struct kobj_uevent_env *env);
 extern int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env);
@@ -78,6 +79,11 @@ static inline int of_device_get_modalias(struct device *dev,
 	return -ENODEV;
 }
 
+static inline int of_device_request_module(struct device *dev)
+{
+	return -ENODEV;
+}
+
 static inline int of_device_uevent_modalias(struct device *dev,
 				   struct kobj_uevent_env *env)
 {