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Commit d2b9775d authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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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: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4780c09f

drivers/tty/serial/sh-sci.c

+8 −15
Original line number Diff line number Diff line
@@ -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);

	}

}