Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752680AbYHRPnd (ORCPT ); Mon, 18 Aug 2008 11:43:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752585AbYHRPnZ (ORCPT ); Mon, 18 Aug 2008 11:43:25 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:55791 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751713AbYHRPnY (ORCPT ); Mon, 18 Aug 2008 11:43:24 -0400 Date: Mon, 18 Aug 2008 16:25:26 +0100 From: Alan Cox To: "Tosoni" Cc: "'Laurent Pinchart'" , "'Aristeu Rozanski'" , , Subject: Re: [PATCH v1] 8250: add support for DTR/DSR hardware flow control Message-ID: <20080818162526.1975dace@lxorguk.ukuu.org.uk> In-Reply-To: <000f01c8f88c$ad29d950$2e01a8c0@acksys.local> References: <200808071032.16709.laurentp@cse-semaphore.com> <000f01c8f88c$ad29d950$2e01a8c0@acksys.local> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3164 Lines: 86 On Thu, 7 Aug 2008 14:54:05 +0200 "Tosoni" wrote: > 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 ? I had a deeper look at this for RS485 and the answer is "sort of". I've reworked the structure to keep it the same size irrespective of 32/64bit systems, and to make stuff flags that can be, plus add some extra u32 words in case we need to (.. when we need to ;)) add stuff later. Comments, thoughts - will this do what people in the RS485 world need ? Alan -------------- tty: Cris has a nice RS485 ioctl so we should steal it From: Alan Cox 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 --- include/asm-x86/ioctls.h | 2 ++ include/linux/serial.h | 16 ++++++++++++++++ 2 files changed, 18 insertions(+), 0 deletions(-) diff --git a/include/asm-x86/ioctls.h b/include/asm-x86/ioctls.h index c0c338b..2cd4775 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 deb7143..1ea8d92 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/