tty: Cris has a nice RS485 ioctl so we should steal it

JP Tosoni observed:

"About a RS485 ioctl: could you consider the attached files which are
 already in the Linux kernel (in include/asm-cris).  They define a
 TIOCSERSETRS485 (ioctl.h), and the data structure (rs485.h)
 with allows to specify timings. Sounds just like what we want ?"

and he's right: sort of. Rework the structure to use flag bits and make the
time delay a fixed sized field so we don't get 32/64bit problems. Add the ioctls
to x86 so that people know what to add to their platform of choice.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-x86/ioctls.h b/include/asm-x86/ioctls.h
index 336603512399..1a8ac45b28be 100644
--- a/include/asm-x86/ioctls.h
+++ b/include/asm-x86/ioctls.h
@@ -51,6 +51,8 @@
 #define TCSETS2         _IOW('T', 0x2B, struct termios2)
 #define TCSETSW2        _IOW('T', 0x2C, struct termios2)
 #define TCSETSF2        _IOW('T', 0x2D, struct termios2)
+#define TIOCGRS485      0x542E
+#define TIOCSRS485      0x542F
 #define TIOCGPTN        _IOR('T', 0x30, unsigned int)
                                 /* Get Pty Number (of pty-mux device) */
 #define TIOCSPTLCK      _IOW('T', 0x31, int)  /* Lock/unlock Pty */