From patchwork Mon Nov 27 11:03:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Eckert X-Patchwork-Id: 747911 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mxout70.expurgate.net (mxout70.expurgate.net [91.198.224.70]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F02D5135; Mon, 27 Nov 2023 03:03:24 -0800 (PST) Received: from [127.0.0.1] (helo=localhost) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1r7ZOY-006UlZ-Q9; Mon, 27 Nov 2023 12:03:18 +0100 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 1r7ZOY-006Uko-2Y; Mon, 27 Nov 2023 12:03:18 +0100 Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id B0B84240049; Mon, 27 Nov 2023 12:03:17 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id 24ED424004B; Mon, 27 Nov 2023 12:03:17 +0100 (CET) Received: from localhost.localdomain (unknown [10.2.3.40]) by mail.dev.tdt.de (Postfix) with ESMTPSA id 71FCB33D90; Mon, 27 Nov 2023 12:03:16 +0100 (CET) From: Florian Eckert To: Eckert.Florian@googlemail.com, pavel@ucw.cz, lee@kernel.org, kabel@kernel.org, gregkh@linuxfoundation.org, u.kleine-koenig@pengutronix.de Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [Patch v9 1/4] tty: add new helper function tty_get_tiocm Date: Mon, 27 Nov 2023 12:03:08 +0100 Message-ID: <20231127110311.3583957-2-fe@dev.tdt.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231127110311.3583957-1-fe@dev.tdt.de> References: <20231127110311.3583957-1-fe@dev.tdt.de> Precedence: bulk X-Mailing-List: linux-leds@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-purgate-ID: 151534::1701082998-FA0CB49D-132AF335/0/0 X-purgate-type: clean X-purgate: clean There is no in-kernel function to get the status register of a tty device like the TIOCMGET ioctl returns to userspace. Create a new function, tty_get_tiocm(), to obtain the status register that other portions of the kernel can call if they need this information, and move the existing internal tty_tiocmget() function to use this interface. Acked-by: Greg Kroah-Hartman 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 06414e43e0b5..e2e93404133e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2498,6 +2498,24 @@ 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 @@ -2510,14 +2528,12 @@ 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 4b6340ac2af2..d219a11e3fe0 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -419,6 +419,7 @@ bool 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);