From patchwork Mon Nov 30 15:37:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 334979 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=-17.0 required=3.0 tests=BAYES_00, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 630EDC83014 for ; Mon, 30 Nov 2020 15:38:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 131A620725 for ; Mon, 30 Nov 2020 15:38:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728348AbgK3Pii (ORCPT ); Mon, 30 Nov 2020 10:38:38 -0500 Received: from mail-lf1-f66.google.com ([209.85.167.66]:46096 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727556AbgK3Pii (ORCPT ); Mon, 30 Nov 2020 10:38:38 -0500 Received: by mail-lf1-f66.google.com with SMTP id t6so22414180lfl.13; Mon, 30 Nov 2020 07:38:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wX/I1sXDrWB17nXmZ4/VUTNk1RGewCzBNozxf+IPcvs=; b=Lg6IdV5x2TAYVPD8+hlZ8Ggtc1TbruqJbN0tqzfcE37zwDguLpBdnxDC9zNyot9nVS AAR/IpD64zEt11Tr3LZbgD4Mx/oGbv20xbt/IKMXAIPu3IbMkxxGvXndXkxIGR9Ps95I JkvDdbiopj2pkM67JSljTRVkM5LZaWnpHG2Mv+KVJRE4WJmfmC0WU9FOaGQ6k5Ka5naQ 86JlKKO+sQX3aMmoOcUnRR7Dm8KPFBGD5Nfca7F2uCoJnfSg/frA1yYlKFBmdFfczPto dXslRNK7HLsFIZhrEKSR/XqVr3UZykWked94NdWl3g+AVOMkRBLiN08wJIANFbl2gxV5 dLnA== X-Gm-Message-State: AOAM532SntCEQe39izRNbFoGQfRIOWBw7dH77is7i3YC22+Pjz5e/DGz 8Ak17YwM/MwvPGSNGyMl6YE= X-Google-Smtp-Source: ABdhPJxvScOcMYD7Tt8YWHK2qbhuamWyLHg0NrITzgg3eak3+wQeEhys0HE0qxd5qn8dNo2FOY6fGg== X-Received: by 2002:ac2:53bc:: with SMTP id j28mr9680680lfh.39.1606750675410; Mon, 30 Nov 2020 07:37:55 -0800 (PST) Received: from xi.terra (c-beaee455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.174.190]) by smtp.gmail.com with ESMTPSA id 84sm2491995lfa.39.2020.11.30.07.37.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Nov 2020 07:37:52 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.93.0.4) (envelope-from ) id 1kjlFu-0002Oq-RT; Mon, 30 Nov 2020 16:38:22 +0100 From: Johan Hovold To: Greg Kroah-Hartman Cc: Jiri Slaby , "Mychaela N . Falconia" , linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 3/5] USB: serial: add sysfs attribute to suppress ready signalling on open Date: Mon, 30 Nov 2020 16:37:40 +0100 Message-Id: <20201130153742.9163-4-johan@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201130153742.9163-1-johan@kernel.org> References: <20201130153742.9163-1-johan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Add a nordy sysfs attribute to suppress raising the modem-control lines on open to signal DTE readiness. This can be use to prevent undesirable side-effects on open for applications where the DTR and RTS lines are used for non-standard purposes such as generating power-on and reset pulses. Signed-off-by: Johan Hovold --- drivers/usb/serial/bus.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c index eb0195cf37dd..37bbeab6666e 100644 --- a/drivers/usb/serial/bus.c +++ b/drivers/usb/serial/bus.c @@ -35,6 +35,40 @@ static int usb_serial_device_match(struct device *dev, return 0; } +static ssize_t nordy_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct usb_serial_port *port = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", tty_port_nordy(&port->port)); +} + +static ssize_t nordy_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct usb_serial_port *port = dev_get_drvdata(dev); + unsigned int val; + int ret; + + ret = kstrtouint(buf, 0, &val); + if (ret) + return ret; + + if (val > 1) + return -EINVAL; + + tty_port_set_nordy(&port->port, val); + + return count; +} +static DEVICE_ATTR_RW(nordy); + +static struct attribute *tty_attrs[] = { + &dev_attr_nordy.attr, + NULL +}; +ATTRIBUTE_GROUPS(tty); + static int usb_serial_device_probe(struct device *dev) { struct usb_serial_driver *driver; @@ -60,8 +94,8 @@ static int usb_serial_device_probe(struct device *dev) } minor = port->minor; - tty_dev = tty_port_register_device(&port->port, usb_serial_tty_driver, - minor, dev); + tty_dev = tty_port_register_device_attr(&port->port, + usb_serial_tty_driver, minor, dev, port, tty_groups); if (IS_ERR(tty_dev)) { retval = PTR_ERR(tty_dev); goto err_port_remove;