linux-kernel - [PATCH 2/2] sc16is7xx: add reading CTS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1469653123-21867-3-git-send-email-epsilonrt@gmail.com>
Date:	Wed, 27 Jul 2016 22:58:43 +0200
From:	Pascal JEAN <epsilonrt@...il.com>
To:	gregkh@...uxfoundation.org
Cc:	jslaby@...e.com, linux-serial@...r.kernel.org,
	linux-kernel@...r.kernel.org, Pascal JEAN <epsilonrt@...il.com>
Subject: [PATCH 2/2] sc16is7xx: add reading CTS

Signed-off-by: Pascal JEAN <epsilonrt@...il.com>
---
 drivers/tty/serial/sc16is7xx.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 3e65079..8833a18 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -818,10 +818,19 @@ static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
 
 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
 {
-	/* DCD and DSR are not wired and CTS/RTS is handled automatically
-	 * so just indicate all inputs asserted
-	 */
-	return TIOCM_DSR | TIOCM_CAR | TIOCM_RI | TIOCM_CTS;
+	/* DCD, DSR and RI are not wired so just indicate asserted */
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_RI;
+
+	if (port->status & UPSTAT_CTS_ENABLE)
+		/* CTS handled automatically, indicates that it is always
+		 * asserted, this is required for proper management of
+		 * the upper layer
+		 */
+		mctrl |= TIOCM_CTS;
+	else {
+		/* CTS is not managed automatically, returns its actual state
+		 * the upper layer
+		 */
+		u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
+
+		mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
+	}
+	return mctrl;
 }
 
 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
-- 
2.7.4