From c26c56c0f40e200e61d1390629c806f6adaffbcc Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@redhat.com>
Date: Mon, 13 Oct 2008 10:37:48 +0100
Subject: [PATCH] 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>
---
include/asm-x86/ioctls.h | 2 ++
include/linux/serial.h | 16 ++++++++++++++++
2 files changed, 18 insertions(+)
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 */
diff --git a/include/linux/serial.h b/include/linux/serial.h
index deb714314fb1..1ea8d9265bf6 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -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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