[PATCH v6 02/10] rpmsg: create the rpmsg class in core instead of in rpmsg char

[Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>]

Migrate the creation of the rpmsg class from the rpmsg_char
to the core that the class is usable by all rpmsg services.

Suggested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
 drivers/rpmsg/rpmsg_char.c | 14 ++------------
 drivers/rpmsg/rpmsg_core.c | 26 ++++++++++++++++++++++++--
 include/linux/rpmsg.h      | 10 ++++++++++
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 941c5c54dd72..327ed739a3a7 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -28,7 +28,6 @@
 #define RPMSG_DEV_MAX	(MINORMASK + 1)
 
 static dev_t rpmsg_major;
-static struct class *rpmsg_class;
 
 static DEFINE_IDA(rpmsg_ctrl_ida);
 static DEFINE_IDA(rpmsg_ept_ida);
@@ -362,7 +361,7 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
 	init_waitqueue_head(&eptdev->readq);
 
 	device_initialize(dev);
-	dev->class = rpmsg_class;
+	dev->class = rpmsg_get_class();
 	dev->parent = parent;
 	dev->groups = rpmsg_eptdev_groups;
 	dev_set_drvdata(dev, eptdev);
@@ -482,7 +481,7 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
 	dev = &ctrldev->dev;
 	device_initialize(dev);
 	dev->parent = &rpdev->dev;
-	dev->class = rpmsg_class;
+	dev->class = rpmsg_get_class();
 
 	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
 	ctrldev->cdev.owner = THIS_MODULE;
@@ -558,17 +557,9 @@ static int rpmsg_chrdev_init(void)
 		return ret;
 	}
 
-	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
-	if (IS_ERR(rpmsg_class)) {
-		pr_err("failed to create rpmsg class\n");
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-		return PTR_ERR(rpmsg_class);
-	}
-
 	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
 	if (ret < 0) {
 		pr_err("rpmsgchr: failed to register rpmsg driver\n");
-		class_destroy(rpmsg_class);
 		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
 	}
 
@@ -579,7 +570,6 @@ postcore_initcall(rpmsg_chrdev_init);
 static void rpmsg_chrdev_exit(void)
 {
 	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
-	class_destroy(rpmsg_class);
 	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
 }
 module_exit(rpmsg_chrdev_exit);
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 9151836190ce..53162038254d 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -20,6 +20,8 @@
 
 #include "rpmsg_internal.h"
 
+static struct class *rpmsg_class;
+
 /**
  * rpmsg_create_channel() - create a new rpmsg channel
  * using its name and address info.
@@ -296,6 +298,19 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 }
 EXPORT_SYMBOL(rpmsg_poll);
 
+/**
+ * rpmsg_get_class() - get reference to the sysfs rpmsg class
+ *
+ * This function return the pointer to the "rpmsg" class created by the rpmsg core.
+ *
+ * Returns the struct class pointer
+ */
+struct class *rpmsg_get_class(void)
+{
+	return rpmsg_class;
+}
+EXPORT_SYMBOL(rpmsg_get_class);
+
 /**
  * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
  * @ept: the rpmsg endpoint
@@ -629,10 +644,17 @@ static int __init rpmsg_init(void)
 {
 	int ret;
 
+	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
+	if (IS_ERR(rpmsg_class)) {
+		pr_err("failed to create rpmsg class\n");
+		return PTR_ERR(rpmsg_class);
+	}
+
 	ret = bus_register(&rpmsg_bus);
-	if (ret)
+	if (ret) {
 		pr_err("failed to register rpmsg bus: %d\n", ret);
-
+		class_destroy(rpmsg_class);
+	}
 	return ret;
 }
 postcore_initcall(rpmsg_init);
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index a8dcf8a9ae88..6fe51549d931 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -186,6 +186,8 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 			poll_table *wait);
 
+struct class *rpmsg_get_class(void);
+
 #else
 
 static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
@@ -296,6 +298,14 @@ static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept,
 	return 0;
 }
 
+static inline struct class *rpmsg_get_class(void)
+{
+	/* This shouldn't be possible */
+	WARN_ON(1);
+
+	return NULL;
+}
+
 #endif /* IS_ENABLED(CONFIG_RPMSG) */
 
 /* use a macro to avoid include chaining to get THIS_MODULE */
-- 
2.17.1