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Commit f907c9ea authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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serial: sh-sci: Add support for GPIO-controlled modem lines 



Enhance the Renesas SCI UART driver to add support for GPIO-controlled
modem lines (CTS, DSR, DCD, RNG, RTS, DTR), using the serial_mctrl_gpio
helpers.

GPIO-controlled modem lines can be used when dedicated modem lines are
not available. Invalid configurations specifying both GPIO RTS/CTS and
dedicated RTS/CTS are rejected.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 71e98e0e

drivers/tty/serial/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -736,6 +736,7 @@ config SERIAL_SH_SCI 
	tristate "SuperH SCI(F) serial port support"

	depends on SUPERH || ARCH_RENESAS || H8300 || COMPILE_TEST

	select SERIAL_CORE

	select SERIAL_MCTRL_GPIO if GPIOLIB



config SERIAL_SH_SCI_NR_UARTS

	int "Maximum number of SCI(F) serial ports"

drivers/tty/serial/sh-sci.c

+45 −1
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ 
#include <asm/sh_bios.h>

#endif



#include "serial_mctrl_gpio.h"

#include "sh-sci.h"



/* Offsets into the sci_port->irqs array */
@@ -111,6 +112,7 @@ struct sci_port { 
	unsigned int		error_clear;

	unsigned int		sampling_rate_mask;

	resource_size_t		reg_size;

	struct mctrl_gpios	*gpios;



	/* Break timer */

	struct timer_list	break_timer;
@@ -1817,6 +1819,8 @@ static unsigned int sci_tx_empty(struct uart_port *port) 
 */

static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)

{

	struct sci_port *s = to_sci_port(port);



	if (mctrl & TIOCM_LOOP) {

		const struct plat_sci_reg *reg;
@@ -1829,15 +1833,35 @@ static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) 
					serial_port_in(port, SCFCR) |

					SCFCR_LOOP);

	}



	mctrl_gpio_set(s->gpios, mctrl);

}



static unsigned int sci_get_mctrl(struct uart_port *port)

{

	struct sci_port *s = to_sci_port(port);

	struct mctrl_gpios *gpios = s->gpios;

	unsigned int mctrl = 0;



	mctrl_gpio_get(gpios, &mctrl);



	/*

	 * CTS/RTS is handled in hardware when supported, while nothing

	 * else is wired up. Keep it simple and simply assert CTS/DSR/CAR.

	 */

	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;

	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)))

		mctrl |= TIOCM_CTS;

	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))

		mctrl |= TIOCM_DSR;

	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))

		mctrl |= TIOCM_CAR;



	return mctrl;

}



static void sci_enable_ms(struct uart_port *port)

{

	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);

}



static void sci_break_ctl(struct uart_port *port, int break_state)
@@ -1899,6 +1923,8 @@ static void sci_shutdown(struct uart_port *port) 


	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);



	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);



	spin_lock_irqsave(&port->lock, flags);

	sci_stop_rx(port);

	sci_stop_tx(port);
@@ -2300,6 +2326,9 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, 
		sci_start_rx(port);



	sci_port_disable(s);



	if (UART_ENABLE_MS(port, termios->c_cflag))

		sci_enable_ms(port);

}



static void sci_pm(struct uart_port *port, unsigned int state,
@@ -2425,6 +2454,7 @@ static struct uart_ops sci_uart_ops = { 
	.start_tx	= sci_start_tx,

	.stop_tx	= sci_stop_tx,

	.stop_rx	= sci_stop_rx,

	.enable_ms	= sci_enable_ms,

	.break_ctl	= sci_break_ctl,

	.startup	= sci_startup,

	.shutdown	= sci_shutdown,
@@ -2912,6 +2942,20 @@ static int sci_probe_single(struct platform_device *dev, 
	if (ret)

		return ret;



	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);

	if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)

		return PTR_ERR(sciport->gpios);



	if (p->capabilities & SCIx_HAVE_RTSCTS) {

		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,

							UART_GPIO_CTS)) ||

		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,

							UART_GPIO_RTS))) {

			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");

			return -EINVAL;

		}

	}



	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);

	if (ret) {

		sci_cleanup_single(sciport);