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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: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Geert Uytterhoeven 2016-06-03 12:00:04 +02:00 committed by Greg Kroah-Hartman
parent 71e98e0e2a
commit f907c9ea88
2 changed files with 46 additions and 1 deletions
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1
drivers/tty/serial/Kconfig
View File

@ -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"

46
drivers/tty/serial/sh-sci.c
View File

@ -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);