From patchwork Thu Oct 19 11:28:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Eckert X-Patchwork-Id: 736837 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CAA0C41513 for ; Thu, 19 Oct 2023 11:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345362AbjJSL2V (ORCPT ); Thu, 19 Oct 2023 07:28:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345346AbjJSL2U (ORCPT ); Thu, 19 Oct 2023 07:28:20 -0400 Received: from mxout70.expurgate.net (mxout70.expurgate.net [91.198.224.70]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9A38112; Thu, 19 Oct 2023 04:28:17 -0700 (PDT) Received: from [127.0.0.1] (helo=localhost) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1qtRCJ-00493z-OI; Thu, 19 Oct 2023 13:28:15 +0200 Received: from [195.243.126.94] (helo=securemail.tdt.de) by relay.expurgate.net with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qtRCJ-0022g8-Ar; Thu, 19 Oct 2023 13:28:15 +0200 Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id 187EF24004B; Thu, 19 Oct 2023 13:28:15 +0200 (CEST) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id C2ABF240040; Thu, 19 Oct 2023 13:28:14 +0200 (CEST) Received: from localhost.localdomain (unknown [10.2.3.40]) by mail.dev.tdt.de (Postfix) with ESMTPSA id 7D0262062B; Thu, 19 Oct 2023 13:28:14 +0200 (CEST) From: Florian Eckert To: Eckert.Florian@googlemail.com, gregkh@linuxfoundation.org, jirislaby@kernel.org, pavel@ucw.cz, lee@kernel.org, kabel@kernel.org, u.kleine-koenig@pengutronix.de, ansuelsmth@gmail.com, m.brock@vanmierlo.com Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-leds@vger.kernel.org Subject: [PATCH v4 2/3] tty: add new helper function tty_get_tiocm Date: Thu, 19 Oct 2023 13:28:08 +0200 Message-ID: <20231019112809.881730-3-fe@dev.tdt.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231019112809.881730-1-fe@dev.tdt.de> References: <20231019112809.881730-1-fe@dev.tdt.de> MIME-Version: 1.0 X-purgate: clean X-purgate-type: clean X-purgate-ID: 151534::1697714895-F98EC49D-9EB96688/0/0 Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org The struct 'tty_struct' has a callback to read the status flags of the tty if the tty driver provides them. So fare, the data is transferred directly to userspace with the function 'tty_tiocmget'. This function cannot be used to evaluate the status line of the tty interface in the ledtrig-tty trigger. To make this possible, a new function must be added that does not immediately pass the data on to userspace. The new function 'tty_get_tiocm' only returns the status register. This information can then be processed further in the ledtrig-tty trigger. Signed-off-by: Florian Eckert --- drivers/tty/tty_io.c | 28 ++++++++++++++++++++++------ include/linux/tty.h | 1 + 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 3299a5d50727..a12f63854ac4 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2494,6 +2494,24 @@ static int send_break(struct tty_struct *tty, unsigned int duration) return retval; } +/** + * tty_get_tiocm - get tiocm status register + * @tty: tty device + * + * Obtain the modem status bits from the tty driver if the feature + * is supported. + */ +int tty_get_tiocm(struct tty_struct *tty) +{ + int retval = -ENOTTY; + + if (tty->ops->tiocmget) + retval = tty->ops->tiocmget(tty); + + return retval; +} +EXPORT_SYMBOL_GPL(tty_get_tiocm); + /** * tty_tiocmget - get modem status * @tty: tty device @@ -2506,14 +2524,12 @@ static int send_break(struct tty_struct *tty, unsigned int duration) */ static int tty_tiocmget(struct tty_struct *tty, int __user *p) { - int retval = -ENOTTY; + int retval; - if (tty->ops->tiocmget) { - retval = tty->ops->tiocmget(tty); + retval = tty_get_tiocm(tty); + if (retval >= 0) + retval = put_user(retval, p); - if (retval >= 0) - retval = put_user(retval, p); - } return retval; } diff --git a/include/linux/tty.h b/include/linux/tty.h index f002d0f25db7..8e4d0b3b12b7 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -421,6 +421,7 @@ int tty_unthrottle_safe(struct tty_struct *tty); int tty_do_resize(struct tty_struct *tty, struct winsize *ws); int tty_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount); +int tty_get_tiocm(struct tty_struct *tty); int is_current_pgrp_orphaned(void); void tty_hangup(struct tty_struct *tty); void tty_vhangup(struct tty_struct *tty);