linux-kernel - [PATCH v2 08/11] serial: sh-sci: Correct pin initialization on (H)SCIF

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Message-Id: <1461934714-18681-9-git-send-email-geert+renesas@glider.be>
Date:	Fri, 29 Apr 2016 14:58:31 +0200
From:	Geert Uytterhoeven <geert+renesas@...der.be>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jslaby@...e.com>,
	Peter Hurley <peter@...leysoftware.com>
Cc:	Magnus Damm <magnus.damm@...il.com>,
	Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>,
	Yoshinori Sato <ysato@...rs.sourceforge.jp>,
	linux-serial@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
	linux-sh@...r.kernel.org, linux-kernel@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH v2 08/11] serial: sh-sci: Correct pin initialization on (H)SCIF

Correct pin initialization on (H)SCIF:
  - RTS must be deasserted (it's active low),
  - SCK must be an input, as it may be used as the optional external
    clock input.

Initial pin configuration must always be done:
  - Regardless of the presence of dedicated RTS and CTS pins: if the
    register exists, the RTS/CTS bits exist, too,
  - Regardless of hardware flow control being enabled or not: RTS must
    be deasserted.

Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
v2:
  - New.
---
 drivers/tty/serial/sh-sci.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index ce7bd165929ea078..c46999f20917964e 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -712,21 +712,14 @@ static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 		return;
 	}
 
-	/*
-	 * For the generic path SCSPTR is necessary. Bail out if that's
-	 * unavailable, too.
-	 */
-	if (!sci_getreg(port, SCSPTR)->size)
-		return;
-
-	if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
-	    ((!(cflag & CRTSCTS)))) {
-		unsigned short status;
-
-		status = serial_port_in(port, SCSPTR);
-		status &= ~SCSPTR_CTSIO;
-		status |= SCSPTR_RTSIO;
-		serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */
+	if (sci_getreg(port, SCSPTR)->size) {
+		u16 status = serial_port_in(port, SCSPTR);
+
+		/* RTS# is output, driven 1 */
+		status |= SCSPTR_RTSIO | SCSPTR_RTSDT;
+		/* CTS# and SCK are inputs */
+		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
+		serial_port_out(port, SCSPTR, status);
 	}
 }
 
-- 
1.9.1