Commit 4a96895f 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.

Changed by Stefan:
Only call mctrl_gpio_init(), if the device has no ACPI companion device
to not break existing ACPI based systems. Also only use the mctrl_gpio_
functions when "gpios" is available.

Use MSR / MCR <-> TIOCM wrapper functions.

Signed-off-by: default avatarYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: default avatarStefan Roese <sr@denx.de>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: default avatarYegor Yefremov <yegorslists@googlemail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Giulio Benetti <giulio.benetti@micronovasrl.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d9948267

Documentation/devicetree/bindings/serial/8250.txt

+19 −0
Original line number Diff line number Diff line
@@ -53,6 +53,9 @@ Optional properties: 
  programmable TX FIFO thresholds.

- resets : phandle + reset specifier pairs

- overrun-throttle-ms : how long to pause uart rx when input overrun is encountered.

- {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:
@@ -74,3 +77,19 @@ 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

+17 −1
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#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);
@@ -214,11 +216,25 @@ static inline int serial8250_MSR_to_TIOCM(int msr) 
static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)

{

	serial_out(up, UART_MCR, value);



	if (up->gpios)

		mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));

}



static inline int serial8250_in_MCR(struct uart_8250_port *up)

{

	return serial_in(up, UART_MCR);

	int mctrl;



	mctrl = serial_in(up, UART_MCR);



	if (up->gpios) {

		unsigned int mctrl_gpio = 0;



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

		mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);

	}



	return mctrl;

}



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

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

+17 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
 *	      serial8250_register_8250_port() ports

 */



#include <linux/acpi.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/ioport.h>
@@ -982,6 +983,8 @@ 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);
@@ -1016,6 +1019,20 @@ int serial8250_register_8250_port(struct uart_8250_port *up) 
		if (up->port.flags & UPF_FIXED_TYPE)

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



		/*

		 * Only call mctrl_gpio_init(), if the device has no ACPI

		 * companion device

		 */

		if (!has_acpi_companion(uart->port.dev)) {

			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

+16 −13
Original line number Diff line number Diff line
@@ -141,9 +141,10 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) 


	serial8250_do_set_mctrl(port, mctrl);



	if (!up->gpios) {

		/*

	 * 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);
@@ -154,6 +155,7 @@ 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)
@@ -453,7 +455,8 @@ 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 &&

	    !up->gpios) {

		/* 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

+10 −1
Original line number Diff line number Diff line
@@ -1656,6 +1656,8 @@ 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);

}
@@ -1668,6 +1670,8 @@ 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);
@@ -1939,12 +1943,17 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port) 
{

	struct uart_8250_port *up = up_to_u8250p(port);

	unsigned int status;

	unsigned int val;



	serial8250_rpm_get(up);

	status = serial8250_modem_status(up);

	serial8250_rpm_put(up);



	return serial8250_MSR_to_TIOCM(status);

	val = serial8250_MSR_to_TIOCM(status);

	if (up->gpios)

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



	return val;

}

EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);

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