[PATCH v2 1/2] miscdevice: Add helper macro for misc device boilerplate

[PATCH v2 1/2] miscdevice: Add helper macro for misc device boilerplate

[PrasannaKumar Muralidharan]

Many modules call misc_register and misc_deregister in its module init
and exit methods without any additional code. This 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.

Change since v1:
Add device.h include in miscdevice.h as module_driver macro was not
available from other include files in some architectures.

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             |  8 ++++++++
 7 files changed, 15 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..722698a 100644
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -3,6 +3,7 @@
 #include <linux/major.h>
 #include <linux/list.h>
 #include <linux/types.h>
+#include <linux/device.h>
 
 /*
  *	These allocations are managed by device@lanana.org. If you use an
@@ -70,6 +71,13 @@ 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

[PATCH v2 2/2] miscdevice: Use module_misc_device() macro

[PrasannaKumar Muralidharan]

This patch removes module_init()/module_exit() from driver code by using
module_misc_device() macro. All modules in this patch has a print
statement which is removed when module_misc_device() macro is used.
If undesirable this patch can be dropped entirely, this is the only
purpose of making this as a separate patch.

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
---
 arch/um/drivers/harddog_kern.c | 25 +------------------------
 drivers/bluetooth/hci_vhci.c   | 16 +---------------
 drivers/char/bfin-otp.c        | 40 +---------------------------------------
 drivers/lightnvm/core.c        | 19 +------------------
 4 files changed, 4 insertions(+), 96 deletions(-)

diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index 2d0266d..3282787 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -175,27 +175,4 @@ static struct miscdevice harddog_miscdev = {
 	.name		= "watchdog",
 	.fops		= &harddog_fops,
 };
-
-static char banner[] __initdata = KERN_INFO "UML Watchdog Timer\n";
-
-static int __init harddog_init(void)
-{
-	int ret;
-
-	ret = misc_register(&harddog_miscdev);
-
-	if (ret)
-		return ret;
-
-	printk(banner);
-
-	return 0;
-}
-
-static void __exit harddog_exit(void)
-{
-	misc_deregister(&harddog_miscdev);
-}
-
-module_init(harddog_init);
-module_exit(harddog_exit);
+module_misc_device(harddog_miscdev);
diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index 3ff229b..c4a75a1 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -377,21 +377,7 @@ static struct miscdevice vhci_miscdev = {
 	.fops	= &vhci_fops,
 	.minor	= VHCI_MINOR,
 };
-
-static int __init vhci_init(void)
-{
-	BT_INFO("Virtual HCI driver ver %s", VERSION);
-
-	return misc_register(&vhci_miscdev);
-}
-
-static void __exit vhci_exit(void)
-{
-	misc_deregister(&vhci_miscdev);
-}
-
-module_init(vhci_init);
-module_exit(vhci_exit);
+module_misc_device(vhci_miscdev);
 
 module_param(amp, bool, 0644);
 MODULE_PARM_DESC(amp, "Create AMP controller device");
diff --git a/drivers/char/bfin-otp.c b/drivers/char/bfin-otp.c
index 44660f1..35d46da 100644
--- a/drivers/char/bfin-otp.c
+++ b/drivers/char/bfin-otp.c
@@ -230,45 +230,7 @@ static struct miscdevice bfin_otp_misc_device = {
 	.name     = DRIVER_NAME,
 	.fops     = &bfin_otp_fops,
 };
-
-/**
- *	bfin_otp_init - Initialize module
- *
- *	Registers the device and notifier handler. Actual device
- *	initialization is handled by bfin_otp_open().
- */
-static int __init bfin_otp_init(void)
-{
-	int ret;
-
-	stampit();
-
-	ret = misc_register(&bfin_otp_misc_device);
-	if (ret) {
-		pr_init(KERN_ERR PFX "unable to register a misc device\n");
-		return ret;
-	}
-
-	pr_init(KERN_INFO PFX "initialized\n");
-
-	return 0;
-}
-
-/**
- *	bfin_otp_exit - Deinitialize module
- *
- *	Unregisters the device and notifier handler. Actual device
- *	deinitialization is handled by bfin_otp_close().
- */
-static void __exit bfin_otp_exit(void)
-{
-	stampit();
-
-	misc_deregister(&bfin_otp_misc_device);
-}
-
-module_init(bfin_otp_init);
-module_exit(bfin_otp_exit);
+module_misc_device(bfin_otp_misc_device);
 
 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
 MODULE_DESCRIPTION("Blackfin OTP Memory Interface");
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 9ebd2cf..c784ddc 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1171,27 +1171,10 @@ static struct miscdevice _nvm_misc = {
 	.nodename	= "lightnvm/control",
 	.fops		= &_ctl_fops,
 };
+module_misc_device(_nvm_misc);
 
 MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
 
-static int __init nvm_mod_init(void)
-{
-	int ret;
-
-	ret = misc_register(&_nvm_misc);
-	if (ret)
-		pr_err("nvm: misc_register failed for control device");
-
-	return ret;
-}
-
-static void __exit nvm_mod_exit(void)
-{
-	misc_deregister(&_nvm_misc);
-}
-
 MODULE_AUTHOR("Matias Bjorling <m@bjorling.me>");
 MODULE_LICENSE("GPL v2");
 MODULE_VERSION("0.1");
-module_init(nvm_mod_init);
-module_exit(nvm_mod_exit);
-- 
2.5.0