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Commit 4ef03d32 authored by Yegor Yefremov's avatar Yegor Yefremov Committed by Greg Kroah-Hartman
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tty/serial/8250: use mctrl_gpio helpers 



This patch permits the usage for GPIOs to control
the CTS/RTS/DTR/DSR/DCD/RI signals.

Signed-off-by: default avatarYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 434be0ae

Documentation/devicetree/bindings/serial/8250.txt

+19 −0
Original line number Diff line number Diff line
@@ -42,6 +42,9 @@ Optional properties: 
- auto-flow-control: one way to enable automatic flow control support. The

  driver is allowed to detect support for the capability even without this

  property.

- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD

  line respectively. It will use specified GPIO instead of the peripheral

  function pin for the UART feature. If unsure, don't specify this property.



Note:

* fsl,ns16550:
@@ -63,3 +66,19 @@ Example: 
		interrupts = <10>;

		reg-shift = <2>;

	};



Example for OMAP UART using GPIO-based modem control signals:



	uart4: serial@49042000 {

		compatible = "ti,omap3-uart";

		reg = <0x49042000 0x400>;

		interrupts = <80>;

		ti,hwmods = "uart4";

		clock-frequency = <48000000>;

		cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;

		rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;

		dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;

		dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;

		dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;

		rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;

	};

drivers/tty/serial/8250/8250.h

+34 −1
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include <linux/serial_reg.h>

#include <linux/dmaengine.h>



#include "../serial_mctrl_gpio.h"



struct uart_8250_dma {

	int (*tx_dma)(struct uart_8250_port *p);

	int (*rx_dma)(struct uart_8250_port *p);
@@ -131,12 +133,43 @@ void serial8250_em485_destroy(struct uart_8250_port *p); 


static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)

{

	int mctrl_gpio = 0;



	serial_out(up, UART_MCR, value);



	if (value & UART_MCR_RTS)

		mctrl_gpio |= TIOCM_RTS;

	if (value & UART_MCR_DTR)

		mctrl_gpio |= TIOCM_DTR;



	mctrl_gpio_set(up->gpios, mctrl_gpio);

}



static inline int serial8250_in_MCR(struct uart_8250_port *up)

{

	return serial_in(up, UART_MCR);

	int mctrl, mctrl_gpio = 0;



	mctrl = serial_in(up, UART_MCR);



	/* save current MCR values */

	if (mctrl & UART_MCR_RTS)

		mctrl_gpio |= TIOCM_RTS;

	if (mctrl & UART_MCR_DTR)

		mctrl_gpio |= TIOCM_DTR;



	mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);



	if (mctrl_gpio & TIOCM_RTS)

		mctrl |= UART_MCR_RTS;

	else

		mctrl &= ~UART_MCR_RTS;



	if (mctrl_gpio & TIOCM_DTR)

		mctrl |= UART_MCR_DTR;

	else

		mctrl &= ~UART_MCR_DTR;



	return mctrl;

}



#if defined(__alpha__) && !defined(CONFIG_PCI)

drivers/tty/serial/8250/8250_core.c

+9 −0
Original line number Diff line number Diff line
@@ -974,6 +974,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up) 


	uart = serial8250_find_match_or_unused(&up->port);

	if (uart && uart->port.type != PORT_8250_CIR) {

		struct mctrl_gpios *gpios;



		if (uart->port.dev)

			uart_remove_one_port(&serial8250_reg, &uart->port);
@@ -1011,6 +1013,13 @@ int serial8250_register_8250_port(struct uart_8250_port *up) 
		if (up->port.flags & UPF_FIXED_TYPE)

			uart->port.type = up->port.type;



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

		if (IS_ERR(gpios)) {

			if (PTR_ERR(gpios) != -ENOSYS)

				return PTR_ERR(gpios);

		} else

			uart->gpios = gpios;



		serial8250_set_defaults(uart);



		/* Possibly override default I/O functions.  */

drivers/tty/serial/8250/8250_omap.c

+18 −13
Original line number Diff line number Diff line
@@ -134,9 +134,11 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) 


	serial8250_do_set_mctrl(port, mctrl);



	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,

						UART_GPIO_RTS))) {

		/*

	 * Turn off autoRTS if RTS is lowered and restore autoRTS setting

	 * if RTS is raised

		 * Turn off autoRTS if RTS is lowered and restore autoRTS

		 * setting if RTS is raised

		 */

		lcr = serial_in(up, UART_LCR);

		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
@@ -147,6 +149,7 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) 
		serial_out(up, UART_EFR, priv->efr);

		serial_out(up, UART_LCR, lcr);

	}

}



/*

 * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
@@ -446,7 +449,9 @@ static void omap_8250_set_termios(struct uart_port *port, 
	priv->efr = 0;

	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);



	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {

	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW

		&& IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,

							UART_GPIO_RTS))) {

		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */

		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;

		priv->efr |= UART_EFR_CTS;

drivers/tty/serial/8250/8250_port.c

+6 −1
Original line number Diff line number Diff line
@@ -1618,6 +1618,8 @@ static void serial8250_disable_ms(struct uart_port *port) 
	if (up->bugs & UART_BUG_NOMSR)

		return;



	mctrl_gpio_disable_ms(up->gpios);



	up->ier &= ~UART_IER_MSI;

	serial_port_out(port, UART_IER, up->ier);

}
@@ -1630,6 +1632,8 @@ static void serial8250_enable_ms(struct uart_port *port) 
	if (up->bugs & UART_BUG_NOMSR)

		return;



	mctrl_gpio_enable_ms(up->gpios);



	up->ier |= UART_IER_MSI;



	serial8250_rpm_get(up);
@@ -1913,7 +1917,8 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port) 
		ret |= TIOCM_DSR;

	if (status & UART_MSR_CTS)

		ret |= TIOCM_CTS;

	return ret;



	return mctrl_gpio_get(up->gpios, &ret);

}

EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);