From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E848EC606B0 for ; Tue, 9 Jul 2019 06:46:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD9F9216C4 for ; Tue, 9 Jul 2019 06:46:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=geanix.com header.i=@geanix.com header.b="f8nqL4Qv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726486AbfGIGqr (ORCPT ); Tue, 9 Jul 2019 02:46:47 -0400 Received: from first.geanix.com ([116.203.34.67]:46434 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726324AbfGIGqo (ORCPT ); Tue, 9 Jul 2019 02:46:44 -0400 Received: from zen.localdomain (unknown [85.184.140.241]) by first.geanix.com (Postfix) with ESMTPSA id 18CA0A74F; Tue, 9 Jul 2019 06:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1562654713; bh=//FC8cP/LBlrTVTEX+Si3DQLq5jHCa1lNoWmCf1K6tU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f8nqL4Qvf0BtE5vqLb7BmyM6Jirv1I0Dhbb1il4D/3fsfqMS6i+oI8EsCRY8KhnRO cz4L+c6qzaHemRUFNW1IexOFYFPv4jtJvuIDdhAp6WGf3F0I1GYA6/FT3WlVujWoql Bd1rcM8sg1Og7unlUEZKQA132N1hdOBrppCXT8p4IeNUa7fHXtcEvhE8b4EpQSQvGW qnCvUdOa0/r9Rix/HVxw5bs19QEV1+gRjkgXgDMLub/80fe8CrLsptV0SdMgYdNgRK iGwHNHqKL5Uncw0RtxqN42lX95WUS3aODi4t5KSqCtyMB+NJrs345Ar7zGHdiNh6ND 6uHa05GL6Xu5Q== From: =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= To: Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= , =?UTF-8?q?Sean=20Nyekj=C3=A6r?= , Esben Haabendal Subject: [PATCHv2 4/4] tty: n_gsm: add ioctl to map serial device to mux'ed tty Date: Tue, 9 Jul 2019 08:46:33 +0200 Message-Id: <20190709064633.45411-4-martin@geanix.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190709064633.45411-1-martin@geanix.com> References: <20190709064633.45411-1-martin@geanix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Guessing the base tty for a gsm0710 multiplexed serial device is not currently possible, which makes it racy to use with multiple modems. Add a way to map the physical serial tty to its related mux devices using a ioctl. Signed-off-by: Martin Hundebøll --- Changes since v1: * use put_user() instead of copy_to_user() * add missing opening quote Documentation/serial/n_gsm.rst | 12 ++++++++++-- drivers/tty/n_gsm.c | 4 ++++ include/uapi/linux/gsmmux.h | 2 ++ 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst index 0ba731ab00b2..4a52499567f5 100644 --- a/Documentation/serial/n_gsm.rst +++ b/Documentation/serial/n_gsm.rst @@ -18,10 +18,12 @@ How to use it 2. switch the serial line to using the n_gsm line discipline by using TIOCSETD ioctl, 3. configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl, +4. obtain base gsmtty number for the used serial port, Major parts of the initialization program : (a good starting point is util-linux-ng/sys-utils/ldattach.c):: + #include #include #include #define DEFAULT_SPEED B115200 @@ -30,6 +32,7 @@ Major parts of the initialization program : int ldisc = N_GSM0710; struct gsm_config c; struct termios configuration; + int base; /* open the serial port connected to the modem */ fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY); @@ -58,19 +61,24 @@ Major parts of the initialization program : c.mtu = 127; /* set the new configuration */ ioctl(fd, GSMIOC_SETCONF, &c); + /* get base gsmtty device node */ + ioctl(fd, GSMIOC_GETBASE, &base); + /* the base node is used for mux control by the driver */ + printf("first muxed line: /dev/gsmtty%i\n", base + 1); + /* and wait for ever to keep the line discipline enabled */ daemon(0,0); pause(); -4. use these devices as plain serial ports. +5. use these devices as plain serial ports. for example, it's possible: - and to use gnokii to send / receive SMS on ttygsm1 - to use ppp to establish a datalink on ttygsm2 -5. first close all virtual ports before closing the physical port. +6. first close all virtual ports before closing the physical port. Note that after closing the physical port the modem is still in multiplexing mode. This may prevent a successful re-opening of the port later. To avoid diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index cba06063c44a..e7aea4ccbebd 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2612,6 +2612,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file, { struct gsm_config c; struct gsm_mux *gsm = tty->disc_data; + int base; switch (cmd) { case GSMIOC_GETCONF: @@ -2623,6 +2624,9 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file, if (copy_from_user(&c, (void *)arg, sizeof(c))) return -EFAULT; return gsm_config(gsm, &c); + case GSMIOC_GETBASE: + base = mux_num_to_base(gsm); + return put_user(base, (int __user *)arg); default: return n_tty_ioctl_helper(tty, file, cmd, arg); } diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h index 101d3c469acb..6eb63be3ed9e 100644 --- a/include/uapi/linux/gsmmux.h +++ b/include/uapi/linux/gsmmux.h @@ -37,5 +37,7 @@ struct gsm_netconfig { #define GSMIOC_ENABLE_NET _IOW('G', 2, struct gsm_netconfig) #define GSMIOC_DISABLE_NET _IO('G', 3) +/* get the base tty number for a configured gsmmux tty */ +#define GSMIOC_GETBASE _IOR('G', 4, int) #endif -- 2.22.0