tty: Remove more special casing and out of place code

[linux-2.6-omap-h63xx.git] / drivers / char / pty.c

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index ec09c1cd4fe9b6196d732715ba8b345f98fac7ae..328e8ac1230667d5b8b015dfa65c541279311505 100644 (file)
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -23,6 +23,7 @@
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/sysctl.h>
+#include <linux/device.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -332,6 +333,8 @@ int pty_limit = NR_UNIX98_PTY_DEFAULT;
 static int pty_limit_min = 0;
 static int pty_limit_max = NR_UNIX98_PTY_MAX;
 
+static struct cdev ptmx_cdev;
+
 static struct ctl_table pty_table[] = {
        {
                .ctl_name       = PTY_MAX,
@@ -408,6 +411,70 @@ static const struct tty_operations ptm_unix98_ops = {
        .shutdown = pty_shutdown
 };
 
+
+/**
+ *     ptmx_open               -       open a unix 98 pty master
+ *     @inode: inode of device file
+ *     @filp: file pointer to tty
+ *
+ *     Allocate a unix98 pty master device from the ptmx driver.
+ *
+ *     Locking: tty_mutex protects the init_dev work. tty->count should
+ *             protect the rest.
+ *             allocated_ptys_lock handles the list of free pty numbers
+ */
+
+static int __ptmx_open(struct inode *inode, struct file *filp)
+{
+       struct tty_struct *tty;
+       int retval;
+       int index;
+
+       nonseekable_open(inode, filp);
+
+       /* find a device that is not in use. */
+       index = devpts_new_index();
+       if (index < 0)
+               return index;
+
+       mutex_lock(&tty_mutex);
+       retval = tty_init_dev(ptm_driver, index, &tty, 1);
+       mutex_unlock(&tty_mutex);
+
+       if (retval)
+               goto out;
+
+       set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+       filp->private_data = tty;
+       file_move(filp, &tty->tty_files);
+
+       retval = devpts_pty_new(tty->link);
+       if (retval)
+               goto out1;
+
+       retval = ptm_driver->ops->open(tty, filp);
+       if (!retval)
+               return 0;
+out1:
+       tty_release_dev(filp);
+       return retval;
+out:
+       devpts_kill_index(index);
+       return retval;
+}
+
+static int ptmx_open(struct inode *inode, struct file *filp)
+{
+       int ret;
+
+       lock_kernel();
+       ret = __ptmx_open(inode, filp);
+       unlock_kernel();
+       return ret;
+}
+
+static struct file_operations ptmx_fops;
+
 static void __init unix98_pty_init(void)
 {
        ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
@@ -459,7 +526,18 @@ static void __init unix98_pty_init(void)
 
        pty_table[1].data = &ptm_driver->refcount;
        register_sysctl_table(pty_root_table);
+
+       /* Now create the /dev/ptmx special device */
+       tty_default_fops(&ptmx_fops);
+       ptmx_fops.open = ptmx_open;
+
+       cdev_init(&ptmx_cdev, &ptmx_fops);
+       if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+           register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+               panic("Couldn't register /dev/ptmx driver\n");
+       device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
 }
+
 #else
 static inline void unix98_pty_init(void) { }
 #endif