Commit c26c56c0 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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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: default avatarAlan Cox <>
Signed-off-by: default avatarLinus Torvalds <>
parent 6f967f78
......@@ -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 */
......@@ -173,6 +173,22 @@ struct serial_icounter_struct {
int reserved[9];
* Serial interface for controlling RS485 settings on chips with suitable
* support. Set with TIOCSRS485 and get with TIOCGRS485 if supported by your
* platform. The set function returns the new state, with any unsupported bits
* reverted appropriately.
struct serial_rs485 {
__u32 flags; /* RS485 feature flags */
#define SER_RS485_ENABLED (1 << 0)
#define SER_RS485_RTS_ON_SEND (1 << 1)
#define SER_RS485_RTS_AFTER_SEND (1 << 2)
__u32 delay_rts_before_send; /* Milliseconds */
__u32 padding[6]; /* Memory is cheap, new structs
are a royal PITA .. */
#ifdef __KERNEL__
#include <linux/compiler.h>
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