[PATCH 1/2] drivercore: Add helper macro for misc device boilerplate

[PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>]

For modules that call misc_register and misc_deregister in its module
init and exit methods without any additional code ends up being
boilerplate. This patch adds helper macro module_misc_device(), that
replaces module_init()/ module_exit() with template functions.

This patch also converts drivers to use new macro.

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
---
 arch/arm/common/bL_switcher_dummy_if.c | 14 +-------------
 arch/blackfin/mach-bf561/coreb.c       | 13 +------------
 drivers/hid/uhid.c                     | 13 +------------
 drivers/input/misc/uinput.c            | 15 ++-------------
 drivers/s390/char/sclp_ctl.c           | 19 +------------------
 drivers/vhost/test.c                   | 13 +------------
 include/linux/miscdevice.h             |  7 +++++++
 7 files changed, 14 insertions(+), 80 deletions(-)

diff --git a/arch/arm/common/bL_switcher_dummy_if.c b/arch/arm/common/bL_switcher_dummy_if.c
index 3f47f12..6053f64 100644
--- a/arch/arm/common/bL_switcher_dummy_if.c
+++ b/arch/arm/common/bL_switcher_dummy_if.c
@@ -56,16 +56,4 @@ static struct miscdevice bL_switcher_device = {
 	"b.L_switcher",
 	&bL_switcher_fops
 };
-
-static int __init bL_switcher_dummy_if_init(void)
-{
-	return misc_register(&bL_switcher_device);
-}
-
-static void __exit bL_switcher_dummy_if_exit(void)
-{
-	misc_deregister(&bL_switcher_device);
-}
-
-module_init(bL_switcher_dummy_if_init);
-module_exit(bL_switcher_dummy_if_exit);
+module_misc_device(bL_switcher_device);
diff --git a/arch/blackfin/mach-bf561/coreb.c b/arch/blackfin/mach-bf561/coreb.c
index 78ecb50..8a2543c 100644
--- a/arch/blackfin/mach-bf561/coreb.c
+++ b/arch/blackfin/mach-bf561/coreb.c
@@ -59,18 +59,7 @@ static struct miscdevice coreb_dev = {
 	.name  = "coreb",
 	.fops  = &coreb_fops,
 };
-
-static int __init bf561_coreb_init(void)
-{
-	return misc_register(&coreb_dev);
-}
-module_init(bf561_coreb_init);
-
-static void __exit bf561_coreb_exit(void)
-{
-	misc_deregister(&coreb_dev);
-}
-module_exit(bf561_coreb_exit);
+module_misc_device(coreb_dev);
 
 MODULE_AUTHOR("Bas Vermeulen <bvermeul@blackstar.xs4all.nl>");
 MODULE_DESCRIPTION("BF561 Core B Support");
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 99ec3ff..7f8ff39 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -779,19 +779,8 @@ static struct miscdevice uhid_misc = {
 	.minor		= UHID_MINOR,
 	.name		= UHID_NAME,
 };
+module_misc_device(uhid_misc);
 
-static int __init uhid_init(void)
-{
-	return misc_register(&uhid_misc);
-}
-
-static void __exit uhid_exit(void)
-{
-	misc_deregister(&uhid_misc);
-}
-
-module_init(uhid_init);
-module_exit(uhid_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
 MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem");
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 65ebbd1..92595b9 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -1013,23 +1013,12 @@ static struct miscdevice uinput_misc = {
 	.minor		= UINPUT_MINOR,
 	.name		= UINPUT_NAME,
 };
+module_misc_device(uinput_misc);
+
 MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
 MODULE_ALIAS("devname:" UINPUT_NAME);
 
-static int __init uinput_init(void)
-{
-	return misc_register(&uinput_misc);
-}
-
-static void __exit uinput_exit(void)
-{
-	misc_deregister(&uinput_misc);
-}
-
 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 MODULE_DESCRIPTION("User level driver support for input subsystem");
 MODULE_LICENSE("GPL");
 MODULE_VERSION("0.3");
-
-module_init(uinput_init);
-module_exit(uinput_exit);
diff --git a/drivers/s390/char/sclp_ctl.c b/drivers/s390/char/sclp_ctl.c
index ea607a4..554eaa1 100644
--- a/drivers/s390/char/sclp_ctl.c
+++ b/drivers/s390/char/sclp_ctl.c
@@ -126,21 +126,4 @@ static struct miscdevice sclp_ctl_device = {
 	.name = "sclp",
 	.fops = &sclp_ctl_fops,
 };
-
-/*
- * Register sclp_ctl misc device
- */
-static int __init sclp_ctl_init(void)
-{
-	return misc_register(&sclp_ctl_device);
-}
-module_init(sclp_ctl_init);
-
-/*
- * Deregister sclp_ctl misc device
- */
-static void __exit sclp_ctl_exit(void)
-{
-	misc_deregister(&sclp_ctl_device);
-}
-module_exit(sclp_ctl_exit);
+module_misc_device(sclp_ctl_device);
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index 97fb2f8..3cc98c0 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -322,18 +322,7 @@ static struct miscdevice vhost_test_misc = {
 	"vhost-test",
 	&vhost_test_fops,
 };
-
-static int vhost_test_init(void)
-{
-	return misc_register(&vhost_test_misc);
-}
-module_init(vhost_test_init);
-
-static void vhost_test_exit(void)
-{
-	misc_deregister(&vhost_test_misc);
-}
-module_exit(vhost_test_exit);
+module_misc_device(vhost_test_misc);
 
 MODULE_VERSION("0.0.1");
 MODULE_LICENSE("GPL v2");
diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
index 5430374..9f32990 100644
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -70,6 +70,13 @@ struct miscdevice  {
 extern int misc_register(struct miscdevice *misc);
 extern void misc_deregister(struct miscdevice *misc);
 
+/*
+ * Helper macro for drivers that don't do anything special in module init / exit
+ * call. This helps in eleminating of boilerplate code.
+ */
+#define module_misc_device(__misc_device) \
+	module_driver(__misc_device, misc_register, misc_deregister)
+
 #define MODULE_ALIAS_MISCDEV(minor)				\
 	MODULE_ALIAS("char-major-" __stringify(MISC_MAJOR)	\
 	"-" __stringify(minor))
-- 
2.5.0