All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chanho Park <chanho61.park@samsung.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Hector Martin <marcan@marcan.st>,
	Jaewon Kim <jaewon02.kim@samsung.com>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Chanho Park <chanho61.park@samsung.com>
Subject: [PATCH] tty: serial: samsung_tty: loopback mode support
Date: Mon, 27 Jun 2022 12:23:53 +0900	[thread overview]
Message-ID: <20220627032353.8868-1-chanho61.park@samsung.com> (raw)
In-Reply-To: CGME20220627032556epcas2p26c2cd2786888a5018607bf651bc5dec0@epcas2p2.samsung.com

Internal loopback mode can be supported by setting
S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
s3c2410 and later SoCs. We can test it by linux-serial-test program[1]
with -k option. It will set TIOCM_LOOP mode during test.

-k, --loopback     Use internal hardware loop back

[1]: https://github.com/cbrake/linux-serial-test
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 drivers/tty/serial/samsung_tty.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index d5ca904def34..d7d035cd95c0 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1002,16 +1002,22 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
 {
 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
+	unsigned int ucon = rd_reg(port, S3C2410_UCON);
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
 
 	if (umstat & S3C2410_UMSTAT_CTS)
-		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
-	else
-		return TIOCM_CAR | TIOCM_DSR;
+		mctrl |= TIOCM_CTS;
+
+	if (ucon & S3C2443_UCON_LOOPBACK)
+		mctrl |= TIOCM_LOOP;
+
+	return mctrl;
 }
 
 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
+	unsigned int ucon = rd_reg(port, S3C2410_UCON);
 
 	if (mctrl & TIOCM_RTS)
 		umcon |= S3C2410_UMCOM_RTS_LOW;
@@ -1019,6 +1025,13 @@ static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
 
 	wr_regl(port, S3C2410_UMCON, umcon);
+
+	if (mctrl & TIOCM_LOOP)
+		ucon |= S3C2443_UCON_LOOPBACK;
+	else
+		ucon &= ~S3C2443_UCON_LOOPBACK;
+
+	wr_regl(port, S3C2410_UCON, ucon);
 }
 
 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
-- 
2.36.1


WARNING: multiple messages have this Message-ID (diff)
From: Chanho Park <chanho61.park@samsung.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Hector Martin <marcan@marcan.st>,
	Jaewon Kim <jaewon02.kim@samsung.com>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Chanho Park <chanho61.park@samsung.com>
Subject: [PATCH] tty: serial: samsung_tty: loopback mode support
Date: Mon, 27 Jun 2022 12:23:53 +0900	[thread overview]
Message-ID: <20220627032353.8868-1-chanho61.park@samsung.com> (raw)
In-Reply-To: CGME20220627032556epcas2p26c2cd2786888a5018607bf651bc5dec0@epcas2p2.samsung.com

Internal loopback mode can be supported by setting
S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
s3c2410 and later SoCs. We can test it by linux-serial-test program[1]
with -k option. It will set TIOCM_LOOP mode during test.

-k, --loopback     Use internal hardware loop back

[1]: https://github.com/cbrake/linux-serial-test
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 drivers/tty/serial/samsung_tty.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index d5ca904def34..d7d035cd95c0 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1002,16 +1002,22 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
 {
 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
+	unsigned int ucon = rd_reg(port, S3C2410_UCON);
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
 
 	if (umstat & S3C2410_UMSTAT_CTS)
-		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
-	else
-		return TIOCM_CAR | TIOCM_DSR;
+		mctrl |= TIOCM_CTS;
+
+	if (ucon & S3C2443_UCON_LOOPBACK)
+		mctrl |= TIOCM_LOOP;
+
+	return mctrl;
 }
 
 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
+	unsigned int ucon = rd_reg(port, S3C2410_UCON);
 
 	if (mctrl & TIOCM_RTS)
 		umcon |= S3C2410_UMCOM_RTS_LOW;
@@ -1019,6 +1025,13 @@ static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
 
 	wr_regl(port, S3C2410_UMCON, umcon);
+
+	if (mctrl & TIOCM_LOOP)
+		ucon |= S3C2443_UCON_LOOPBACK;
+	else
+		ucon &= ~S3C2443_UCON_LOOPBACK;
+
+	wr_regl(port, S3C2410_UCON, ucon);
 }
 
 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
-- 
2.36.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

       reply	other threads:[~2022-06-27  3:26 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20220627032556epcas2p26c2cd2786888a5018607bf651bc5dec0@epcas2p2.samsung.com>
2022-06-27  3:23 ` Chanho Park [this message]
2022-06-27  3:23   ` [PATCH] tty: serial: samsung_tty: loopback mode support Chanho Park
2022-06-27 11:28   ` Krzysztof Kozlowski
2022-06-27 11:28     ` Krzysztof Kozlowski
2022-06-27 11:46   ` Ilpo Järvinen
2022-06-27 11:46     ` Ilpo Järvinen
2022-06-28 11:55     ` Chanho Park
2022-06-28 11:55       ` Chanho Park
2022-06-27 12:39   ` Greg Kroah-Hartman
2022-06-27 12:39     ` Greg Kroah-Hartman
2022-06-28  4:49     ` Chanho Park
2022-06-28  4:49       ` Chanho Park

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220627032353.8868-1-chanho61.park@samsung.com \
    --to=chanho61.park@samsung.com \
    --cc=alim.akhtar@samsung.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jaewon02.kim@samsung.com \
    --cc=jirislaby@kernel.org \
    --cc=krzysztof.kozlowski@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-samsung-soc@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=marcan@marcan.st \
    --cc=vincent.whitchurch@axis.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.