greybus: uart-gb.c: dynamically allocate device numbers

diff --git a/drivers/staging/greybus/uart-gb.c b/drivers/staging/greybus/uart-gb.c
index 013936513eaccd49092766122cd510f46d96c3fd..f351046bd79ba099a07229b0ea027af1aff5d722 100644 (file)
--- a/drivers/staging/greybus/uart-gb.c
+++ b/drivers/staging/greybus/uart-gb.c
@@ -23,10 +23,13 @@
 #include <linux/tty_flip.h>
 #include <linux/serial.h>
 #include <linux/idr.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
 #include "greybus.h"
 
 #define GB_TTY_MAJOR   180     /* FIXME use a real number!!! */
 #define GB_NUM_MINORS  255     /* 255 is enough for anyone... */
+#define GB_NAME                "ttyGB"
 
 struct gb_tty {
        struct tty_port port;
@@ -467,16 +470,24 @@ static struct greybus_driver tty_gb_driver = {
 
 int __init gb_tty_init(void)
 {
-       int retval;
+       int retval = 0;
+       dev_t dev;
+
+       retval = alloc_chrdev_region(&dev, 0, GB_NUM_MINORS, GB_NAME);
+       if (retval)
+               return retval;
 
        gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0);
-       if (IS_ERR(gb_tty_driver))
-               return -ENOMEM;
+       if (IS_ERR(gb_tty_driver)) {
+               retval = -ENOMEM;
+               goto fail_unregister_dev;
+       }
 
+       gb_tty_driver->owner = THIS_MODULE;
        gb_tty_driver->driver_name = "gb";
-       gb_tty_driver->name = "ttyGB";
-       gb_tty_driver->major = GB_TTY_MAJOR;
-       gb_tty_driver->minor_start = 0;
+       gb_tty_driver->name = GB_NAME;
+       gb_tty_driver->major = MAJOR(dev);
+       gb_tty_driver->minor_start = MINOR(dev);
        gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
        gb_tty_driver->subtype = SERIAL_TYPE_NORMAL;
        gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
@@ -485,24 +496,32 @@ int __init gb_tty_init(void)
        tty_set_operations(gb_tty_driver, &gb_ops);
 
        retval = tty_register_driver(gb_tty_driver);
-       if (retval) {
-               put_tty_driver(gb_tty_driver);
-               return retval;
-       }
+       if (retval)
+               goto fail_put_gb_tty;
 
        retval = greybus_register(&tty_gb_driver);
-       if (retval) {
-               tty_unregister_driver(gb_tty_driver);
-               put_tty_driver(gb_tty_driver);
-       }
+       if (retval)
+               goto fail_unregister_gb_tty;
+
+       return 0;
+
+ fail_unregister_gb_tty:
+       tty_unregister_driver(gb_tty_driver);
+ fail_put_gb_tty:
+       put_tty_driver(gb_tty_driver);
+ fail_unregister_dev:
+       unregister_chrdev_region(dev, GB_NUM_MINORS);
        return retval;
 }
 
 void __exit gb_tty_exit(void)
 {
+       int major = MAJOR(gb_tty_driver->major);
+       int minor = gb_tty_driver->minor_start;
        greybus_deregister(&tty_gb_driver);
        tty_unregister_driver(gb_tty_driver);
        put_tty_driver(gb_tty_driver);
+       unregister_chrdev_region(MKDEV(major, minor), GB_NUM_MINORS);
 }
 
 #if 0