media: pvrusb2: clean up unneeded complexity in pvrusb2 class logic

The pvrusb2 driver struct class logic was dynamically creating a class
that should have just been static as it did not do anything special and
was only a wrapper around a stock "struct class" implementation.  Clean
this all up by making a static struct class and modifying the code to
correctly reference it.

By doing so, lots of unneeded lines of code were removed, and #ifdef
logic was cleaned up so that the .c files are not cluttered up with
extra complexity following the proper kernel coding style.

Cc: Mike Isely <isely@pobox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/20230329060132.2688621-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/usb/pvrusb2/pvrusb2-main.c

@@ -16,9 +16,7 @@
 #include "pvrusb2-context.h"
 #include "pvrusb2-debug.h"
 #include "pvrusb2-v4l2.h"
-#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
 #include "pvrusb2-sysfs.h"
-#endif /* CONFIG_VIDEO_PVRUSB2_SYSFS */
 
 #define DRIVER_AUTHOR "Mike Isely <isely@pobox.com>"
 #define DRIVER_DESC "Hauppauge WinTV-PVR-USB2 MPEG2 Encoder/Tuner"
@@ -36,10 +34,6 @@ int pvrusb2_debug = DEFAULT_DEBUG_MASK;
 module_param_named(debug,pvrusb2_debug,int,S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug trace mask");
 
-#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
-static struct pvr2_sysfs_class *class_ptr = NULL;
-#endif /* CONFIG_VIDEO_PVRUSB2_SYSFS */
-
 static void pvr_setup_attach(struct pvr2_context *pvr)
 {
 	/* Create association with v4l layer */
@@ -48,9 +42,7 @@ static void pvr_setup_attach(struct pvr2_context *pvr)
 	/* Create association with dvb layer */
 	pvr2_dvb_create(pvr);
 #endif
-#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
-	pvr2_sysfs_create(pvr,class_ptr);
-#endif /* CONFIG_VIDEO_PVRUSB2_SYSFS */
+	pvr2_sysfs_create(pvr);
 }
 
 static int pvr_probe(struct usb_interface *intf,
@@ -115,9 +107,7 @@ static int __init pvr_init(void)
 		return ret;
 	}
 
-#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
-	class_ptr = pvr2_sysfs_class_create();
-#endif /* CONFIG_VIDEO_PVRUSB2_SYSFS */
+	pvr2_sysfs_class_create();
 
 	ret = usb_register(&pvr_driver);
 
@@ -141,9 +131,7 @@ static void __exit pvr_exit(void)
 
 	pvr2_context_global_done();
 
-#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
-	pvr2_sysfs_class_destroy(class_ptr);
-#endif /* CONFIG_VIDEO_PVRUSB2_SYSFS */
+	pvr2_sysfs_class_destroy();
 
 	pvr2_trace(PVR2_TRACE_INIT,"pvr_exit complete");
 }

drivers/media/usb/pvrusb2/pvrusb2-sysfs.c

@@ -66,10 +66,6 @@ struct pvr2_sysfs_ctl_item {
 	char name[80];
 };
 
-struct pvr2_sysfs_class {
-	struct class class;
-};
-
 static ssize_t show_name(struct device *class_dev,
 			 struct device_attribute *attr,
 			 char *buf)
@@ -487,15 +483,6 @@ static void pvr2_sysfs_tear_down_controls(struct pvr2_sysfs *sfp)
 }
 
 
-static void pvr2_sysfs_class_release(struct class *class)
-{
-	struct pvr2_sysfs_class *clp;
-	clp = container_of(class,struct pvr2_sysfs_class,class);
-	pvr2_sysfs_trace("Destroying pvr2_sysfs_class id=%p",clp);
-	kfree(clp);
-}
-
-
 static void pvr2_sysfs_release(struct device *class_dev)
 {
 	pvr2_sysfs_trace("Releasing class_dev id=%p",class_dev);
@@ -503,6 +490,12 @@ static void pvr2_sysfs_release(struct device *class_dev)
 }
 
 
+static struct class pvr2_class = {
+	.name		= "pvrusb2",
+	.dev_release	= pvr2_sysfs_release,
+};
+
+
 static void class_dev_destroy(struct pvr2_sysfs *sfp)
 {
 	struct device *dev;
@@ -614,8 +607,7 @@ static ssize_t unit_number_show(struct device *class_dev,
 }
 
 
-static void class_dev_create(struct pvr2_sysfs *sfp,
-			     struct pvr2_sysfs_class *class_ptr)
+static void class_dev_create(struct pvr2_sysfs *sfp)
 {
 	struct usb_device *usb_dev;
 	struct device *class_dev;
@@ -628,7 +620,7 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 
 	pvr2_sysfs_trace("Creating class_dev id=%p",class_dev);
 
-	class_dev->class = &class_ptr->class;
+	class_dev->class = &pvr2_class;
 
 	dev_set_name(class_dev, "%s",
 		     pvr2_hdw_get_device_identifier(sfp->channel.hdw));
@@ -753,47 +745,30 @@ static void pvr2_sysfs_internal_check(struct pvr2_channel *chp)
 }
 
 
-struct pvr2_sysfs *pvr2_sysfs_create(struct pvr2_context *mp,
-				     struct pvr2_sysfs_class *class_ptr)
+void pvr2_sysfs_create(struct pvr2_context *mp)
 {
 	struct pvr2_sysfs *sfp;
 	sfp = kzalloc(sizeof(*sfp),GFP_KERNEL);
-	if (!sfp) return sfp;
+	if (!sfp)
+		return;
 	pvr2_trace(PVR2_TRACE_STRUCT,"Creating pvr2_sysfs id=%p",sfp);
 	pvr2_channel_init(&sfp->channel,mp);
 	sfp->channel.check_func = pvr2_sysfs_internal_check;
 
-	class_dev_create(sfp,class_ptr);
-	return sfp;
+	class_dev_create(sfp);
 }
 
 
-
-struct pvr2_sysfs_class *pvr2_sysfs_class_create(void)
+void pvr2_sysfs_class_create(void)
 {
-	struct pvr2_sysfs_class *clp;
-	clp = kzalloc(sizeof(*clp),GFP_KERNEL);
-	if (!clp) return clp;
-	pvr2_sysfs_trace("Creating and registering pvr2_sysfs_class id=%p",
-			 clp);
-	clp->class.name = "pvrusb2";
-	clp->class.class_release = pvr2_sysfs_class_release;
-	clp->class.dev_release = pvr2_sysfs_release;
-	if (class_register(&clp->class)) {
-		pvr2_sysfs_trace(
-			"Registration failed for pvr2_sysfs_class id=%p",clp);
-		kfree(clp);
-		clp = NULL;
-	}
-	return clp;
+	if (class_register(&pvr2_class))
+		pvr2_sysfs_trace("Registration failed for pvr2_sysfs_class");
 }
 
 
-void pvr2_sysfs_class_destroy(struct pvr2_sysfs_class *clp)
+void pvr2_sysfs_class_destroy(void)
 {
-	pvr2_sysfs_trace("Unregistering pvr2_sysfs_class id=%p", clp);
-	if (clp)
-		class_unregister(&clp->class);
+	class_unregister(&pvr2_class);
 }
 
 

drivers/media/usb/pvrusb2/pvrusb2-sysfs.h

@@ -10,13 +10,15 @@
 #include <linux/sysfs.h>
 #include "pvrusb2-context.h"
 
-struct pvr2_sysfs;
-struct pvr2_sysfs_class;
+#ifdef CONFIG_VIDEO_PVRUSB2_SYSFS
+void pvr2_sysfs_class_create(void);
+void pvr2_sysfs_class_destroy(void);
+void pvr2_sysfs_create(struct pvr2_context *mp);
+#else
+static inline void pvr2_sysfs_class_create(void) { }
+static inline void pvr2_sysfs_class_destroy(void) { }
+static inline void pvr2_sysfs_create(struct pvr2_context *mp) { }
+#endif
 
-struct pvr2_sysfs_class *pvr2_sysfs_class_create(void);
-void pvr2_sysfs_class_destroy(struct pvr2_sysfs_class *);
-
-struct pvr2_sysfs *pvr2_sysfs_create(struct pvr2_context *,
-				     struct pvr2_sysfs_class *);
 
 #endif /* __PVRUSB2_SYSFS_H */