[PATCH] TTY: return class device pointer from tty_register_device()

Let tty_register_device() return a pointer to the class device it creates.
This allows registrants to add their own sysfs files under the class
device node.

Signed-off-by: Hansjoerg Lipp <hjlipp@web.de>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 10 insertions, 5 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a88b94a82b..8b2a599698 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2961,12 +2961,14 @@ static struct class *tty_class;
  *      This field is optional, if there is no known struct device for this
  *      tty device it can be set to NULL safely.
  *
+ * Returns a pointer to the class device (or ERR_PTR(-EFOO) on error).
+ *
  * This call is required to be made to register an individual tty device if
  * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set.  If that
  * bit is not set, this function should not be called.
  */
-void tty_register_device(struct tty_driver *driver, unsigned index,
-                         struct device *device)
+struct class_device *tty_register_device(struct tty_driver *driver,
+                                         unsigned index, struct device *device)
 {
         char name[64];
         dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
@@ -2974,7 +2976,7 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
         if (index >= driver->num) {
                 printk(KERN_ERR "Attempt to register invalid tty line number "
                        " (%d).\n", index);
-                return;
+                return ERR_PTR(-EINVAL);
         }
 
         devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
@@ -2984,7 +2986,8 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
                 pty_line_name(driver, index, name);
         else
                 tty_line_name(driver, index, name);
-        class_device_create(tty_class, NULL, dev, device, "%s", name);
+
+        return class_device_create(tty_class, NULL, dev, device, "%s", name);
 }
 
 /**
diff --git a/include/linux/tty.h b/include/linux/tty.h
index e898eeb941..cb35ca50a0 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -290,7 +290,9 @@ extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
 extern int tty_unregister_ldisc(int disc);
 extern int tty_register_driver(struct tty_driver *driver);
 extern int tty_unregister_driver(struct tty_driver *driver);
-extern void tty_register_device(struct tty_driver *driver, unsigned index, struct device *dev);
+extern struct class_device *tty_register_device(struct tty_driver *driver,
+                                                unsigned index,
+                                                struct device *dev);
 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
                              int buflen);