In my opinion, DSR/DTR is another (wrong) way to do RTS/CTS flow control, so
I would have it implemented in setserial as a modifier to the CRTSCTS flag.
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 ?
JP Tosoni
> -----Original Message-----
> From: linux-serial-owner@xxxxxxxxxxxxxxx
> [mailto:linux-serial-owner@xxxxxxxxxxxxxxx]On Behalf Of
> Laurent Pinchart
> Sent: Thursday, August 07, 2008 10:32 AM
> To: Aristeu Rozanski
> Cc: linux-serial@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v1] 8250: add support for DTR/DSR hardware flow
> control
>
>
> Hi,
>
> On Wednesday 06 August 2008, Aristeu Rozanski wrote:
> > This patch adds support for DTR/DSR hardware flow control
> on 8250 driver on
> > x86 machines. It's done by adding a CDTRDSR flag to work
> just like CRTSCTS,
> > which is not done on other architectures on purpose (so
> each maintainer can
> > allocate it).
>
> It's funny, serial flow control hasn't been discussed for a
> long time, and you're the third person to start a flow
> control related thread on this mailing list in a few days.
>
> > This patch was tested with success with a serial printer
> configured with a
> > small buffer and DTR/DSR flow control.
> >
> > This is based on the work of Michael Westermann
> > (http://lkml.org/lkml/2007/8/31/133)
> >
> > Comments more than welcome.
>
> Please read the '[PATCH/RFC] 8250: Auto RS485 direction
> control' thread for background information. In a nutshell we
> need more than just CTS/RTS and DTR/DSR, and we don't have
> enough c_cflags bits. We will probably have to create a new ioctl.
>
> Best regards,
>
> --
> Laurent Pinchart
> CSE Semaphore Belgium
>
> Chaussee de Bruxelles, 732A
> B-1410 Waterloo
> Belgium
>
> T +32 (2) 387 42 59
> F +32 (2) 387 42 75
>
#ifndef __ARCH_CRIS_IOCTLS_H__
#define __ARCH_CRIS_IOCTLS_H__
/* verbatim copy of asm-i386/ioctls.h */
#include <asm/ioctl.h>
/* 0x54 is just a magic number to make these relatively unique ('T') */
#define TCGETS 0x5401
#define TCSETS 0x5402
#define TCSETSW 0x5403
#define TCSETSF 0x5404
#define TCGETA 0x5405
#define TCSETA 0x5406
#define TCSETAW 0x5407
#define TCSETAF 0x5408
#define TCSBRK 0x5409
#define TCXONC 0x540A
#define TCFLSH 0x540B
#define TIOCEXCL 0x540C
#define TIOCNXCL 0x540D
#define TIOCSCTTY 0x540E
#define TIOCGPGRP 0x540F
#define TIOCSPGRP 0x5410
#define TIOCOUTQ 0x5411
#define TIOCSTI 0x5412
#define TIOCGWINSZ 0x5413
#define TIOCSWINSZ 0x5414
#define TIOCMGET 0x5415
#define TIOCMBIS 0x5416
#define TIOCMBIC 0x5417
#define TIOCMSET 0x5418
#define TIOCGSOFTCAR 0x5419
#define TIOCSSOFTCAR 0x541A
#define FIONREAD 0x541B
#define TIOCINQ FIONREAD
#define TIOCLINUX 0x541C
#define TIOCCONS 0x541D
#define TIOCGSERIAL 0x541E
#define TIOCSSERIAL 0x541F
#define TIOCPKT 0x5420
#define FIONBIO 0x5421
#define TIOCNOTTY 0x5422
#define TIOCSETD 0x5423
#define TIOCGETD 0x5424
#define TCSBRKP 0x5425 /* Needed for POSIX tcsendbreak() */
#define TIOCSBRK 0x5427 /* BSD compatibility */
#define TIOCCBRK 0x5428 /* BSD compatibility */
#define TIOCGSID 0x5429 /* Return the session ID of FD */
#define TCGETS2 _IOR('T',0x2A, struct termios2)
#define TCSETS2 _IOW('T',0x2B, struct termios2)
#define TCSETSW2 _IOW('T',0x2C, struct termios2)
#define TCSETSF2 _IOW('T',0x2D, struct termios2)
#define TIOCGPTN _IOR('T',0x30, unsigned int) /* Get Pty Number (of pty-mux device) */
#define TIOCSPTLCK _IOW('T',0x31, int) /* Lock/unlock Pty */
#define FIONCLEX 0x5450 /* these numbers need to be adjusted. */
#define FIOCLEX 0x5451
#define FIOASYNC 0x5452
#define TIOCSERCONFIG 0x5453
#define TIOCSERGWILD 0x5454
#define TIOCSERSWILD 0x5455
#define TIOCGLCKTRMIOS 0x5456
#define TIOCSLCKTRMIOS 0x5457
#define TIOCSERGSTRUCT 0x5458 /* For debugging only */
#define TIOCSERGETLSR 0x5459 /* Get line status register */
#define TIOCSERGETMULTI 0x545A /* Get multiport config */
#define TIOCSERSETMULTI 0x545B /* Set multiport config */
#define TIOCMIWAIT 0x545C /* wait for a change on serial input line(s) */
#define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */
#define TIOCGHAYESESP 0x545E /* Get Hayes ESP configuration */
#define TIOCSHAYESESP 0x545F /* Set Hayes ESP configuration */
#define FIOQSIZE 0x5460
#define TIOCSERSETRS485 0x5461 /* enable rs-485 */
#define TIOCSERWRRS485 0x5462 /* write rs-485 */
/* Used for packet mode */
#define TIOCPKT_DATA 0
#define TIOCPKT_FLUSHREAD 1
#define TIOCPKT_FLUSHWRITE 2
#define TIOCPKT_STOP 4
#define TIOCPKT_START 8
#define TIOCPKT_NOSTOP 16
#define TIOCPKT_DOSTOP 32
#define TIOCSER_TEMT 0x01 /* Transmitter physically empty */
#endif
/* RS-485 structures */
/* RS-485 support */
/* Used with ioctl() TIOCSERSETRS485 */
struct rs485_control {
unsigned short rts_on_send;
unsigned short rts_after_sent;
unsigned long delay_rts_before_send;
unsigned short enabled;
#ifdef __KERNEL__
int disable_serial_loopback;
#endif
};
/* Used with ioctl() TIOCSERWRRS485 */
struct rs485_write {
unsigned short outc_size;
unsigned char *outc;
};
