tty: Add termiox

We need a way to describe the various additional modes and flow control
features that random weird hardware shows up and software such as wine
wants to emulate as Windows supports them.

TCGETX/TCSETX and the termiox ioctl are a SYS5 extension that we might as
well adopt. This patches adds the structures and the basic ioctl interfaces
when the TCGETX etc defines are added for an architecture. Drivers wishing
to use this stuff need to add new methods.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 87 insertions, 0 deletions

diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index bf34e4597421..93bfa1d6cc92 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -579,6 +579,50 @@ static int get_termio(struct tty_struct *tty, struct termio __user *termio)
         return 0;
 }
 
+
+#ifdef TCGETX
+
+/**
+ *      set_termiox     -       set termiox fields if possible
+ *      @tty: terminal
+ *      @arg: termiox structure from user
+ *      @opt: option flags for ioctl type
+ *
+ *      Implement the device calling points for the SYS5 termiox ioctl
+ *      interface in Linux
+ */
+
+static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
+{
+        struct termiox tnew;
+        struct tty_ldisc *ld;
+
+        if (tty->termiox == NULL)
+                return -EINVAL;
+        if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
+                return -EFAULT;
+
+        ld = tty_ldisc_ref(tty);
+        if (ld != NULL) {
+                if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+                        ld->ops->flush_buffer(tty);
+                tty_ldisc_deref(ld);
+        }
+        if (opt & TERMIOS_WAIT) {
+                tty_wait_until_sent(tty, 0);
+                if (signal_pending(current))
+                        return -EINTR;
+        }
+
+        mutex_lock(&tty->termios_mutex);
+        if (tty->ops->set_termiox)
+                tty->ops->set_termiox(tty, &tnew);
+        mutex_unlock(&tty->termios_mutex);
+        return 0;
+}
+
+#endif
+
 static unsigned long inq_canon(struct tty_struct *tty)
 {
         int nr, head, tail;
@@ -936,6 +980,20 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
                         return -EFAULT;
                         return 0;
 #endif
+#ifdef TCGETX
+        case TCGETX:
+                if (real_tty->termiox == NULL)
+                        return -EINVAL;
+                if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
+                        return -EFAULT;
+                return 0;
+        case TCSETX:
+                return set_termiox(real_tty, p, 0);
+        case TCSETXW:
+                return set_termiox(real_tty, p, TERMIOS_WAIT);
+        case TCSETXF:
+                return set_termiox(real_tty, p, TERMIOS_FLUSH);
+#endif          
         case TIOCGSOFTCAR:
                 /* FIXME: for correctness we may need to take the termios
                    lock here - review */
diff --git a/include/asm-x86/ioctls.h b/include/asm-x86/ioctls.h
index 1a8ac45b28be..06752a649044 100644
--- a/include/asm-x86/ioctls.h
+++ b/include/asm-x86/ioctls.h
@@ -56,6 +56,10 @@
 #define TIOCGPTN        _IOR('T', 0x30, unsigned int)
                                 /* Get Pty Number (of pty-mux device) */
 #define TIOCSPTLCK      _IOW('T', 0x31, int)  /* Lock/unlock Pty */
+#define TCGETX          0x5432 /* SYS5 TCGETX compatibility */
+#define TCSETX          0x5433
+#define TCSETXF         0x5434
+#define TCSETXW         0x5435
 
 #define FIONCLEX        0x5450
 #define FIOCLEX         0x5451
diff --git a/include/linux/termios.h b/include/linux/termios.h
index 478662889f48..2acd0c1f8a2a 100644
--- a/include/linux/termios.h
+++ b/include/linux/termios.h
@@ -4,4 +4,19 @@
 #include <linux/types.h>
 #include <asm/termios.h>
 
+#define NFF     5
+
+struct termiox
+{
+        __u16   x_hflag;
+        __u16   x_cflag;
+        __u16   x_rflag[NFF];
+        __u16   x_sflag;
+};
+
+#define RTSXOFF         0x0001          /* RTS flow control on input */
+#define CTSXON          0x0002          /* CTS flow control on output */
+#define DTRXOFF         0x0004          /* DTR flow control on input */
+#define DSRXON          0x0008          /* DCD flow control on output */
+
 #endif
diff --git a/include/linux/tty.h b/include/linux/tty.h
index b6e6c26883ee..b64d10b66548 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -219,6 +219,7 @@ struct tty_struct {
         spinlock_t ctrl_lock;
         /* Termios values are protected by the termios mutex */
         struct ktermios *termios, *termios_locked;
+        struct termiox *termiox;        /* May be NULL for unsupported */
         char name[64];
         struct pid *pgrp;               /* Protected by ctrl lock */
         struct pid *session;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 16d27944c321..ac6e58e26b73 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -180,6 +180,14 @@
  *      not force errors here if they are not resizable objects (eg a serial
  *      line). See tty_do_resize() if you need to wrap the standard method
  *      in your own logic - the usual case.
+ *
+ * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
+ *
+ *      Called when the device receives a termiox based ioctl. Passes down
+ *      the requested data from user space. This method will not be invoked
+ *      unless the tty also has a valid tty->termiox pointer.
+ *
+ *      Optional: Called under the termios lock
  */
 
 #include <linux/fs.h>
@@ -220,6 +228,7 @@ struct tty_operations {
                         unsigned int set, unsigned int clear);
         int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty,
                                 struct winsize *ws);
+        int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
 #ifdef CONFIG_CONSOLE_POLL
         int (*poll_init)(struct tty_driver *driver, int line, char *options);
         int (*poll_get_char)(struct tty_driver *driver, int line);