serial: mcf: Add support RS485 in ColdFire serial driver (496c9077) · Commits · e / devices / android_kernel_teracube_2e

drivers/tty/serial/mcf.c

+71 −0

Original line number	Original line	Diff line number	Diff line
	@@ -23,6 +23,7 @@
	#include <linux/serial.h>		#include <linux/serial.h>
	#include <linux/serial_core.h>		#include <linux/serial_core.h>
	#include <linux/io.h>		#include <linux/io.h>
			#include <linux/uaccess.h>
	#include <asm/coldfire.h>		#include <asm/coldfire.h>
	#include <asm/mcfsim.h>		#include <asm/mcfsim.h>
	#include <asm/mcfuart.h>		#include <asm/mcfuart.h>
	@@ -55,6 +56,7 @@ struct mcf_uart {
	struct uart_port port;		struct uart_port port;
	unsigned int sigs; /* Local copy of line sigs */		unsigned int sigs; /* Local copy of line sigs */
	unsigned char imr; /* Local IMR mirror */		unsigned char imr; /* Local IMR mirror */
			struct serial_rs485 rs485; /* RS485 settings */
	};		};

	/****************************************************************************/		/****************************************************************************/
	@@ -101,6 +103,12 @@ static void mcf_start_tx(struct uart_port *port)
	{		{
	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);		struct mcf_uart *pp = container_of(port, struct mcf_uart, port);

			if (pp->rs485.flags & SER_RS485_ENABLED) {
			/* Enable Transmitter */
			writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
			/* Manually assert RTS */
			writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
			}
	pp->imr \|= MCFUART_UIR_TXREADY;		pp->imr \|= MCFUART_UIR_TXREADY;
	writeb(pp->imr, port->membase + MCFUART_UIMR);		writeb(pp->imr, port->membase + MCFUART_UIMR);
	}		}
	@@ -196,6 +204,7 @@ static void mcf_shutdown(struct uart_port *port)
	static void mcf_set_termios(struct uart_port port, struct ktermios termios,		static void mcf_set_termios(struct uart_port port, struct ktermios termios,
	struct ktermios *old)		struct ktermios *old)
	{		{
			struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
	unsigned long flags;		unsigned long flags;
	unsigned int baud, baudclk;		unsigned int baud, baudclk;
	#if defined(CONFIG_M5272)		#if defined(CONFIG_M5272)
	@@ -248,6 +257,11 @@ static void mcf_set_termios(struct uart_port port, struct ktermios termios,
	mr2 \|= MCFUART_MR2_TXCTS;		mr2 \|= MCFUART_MR2_TXCTS;
	}		}

			if (pp->rs485.flags & SER_RS485_ENABLED) {
			dev_dbg(port->dev, "Setting UART to RS485\n");
			mr2 \|= MCFUART_MR2_TXRTS;
			}

	spin_lock_irqsave(&port->lock, flags);		spin_lock_irqsave(&port->lock, flags);
	uart_update_timeout(port, termios->c_cflag, baud);		uart_update_timeout(port, termios->c_cflag, baud);
	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);		writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
	@@ -342,6 +356,10 @@ static void mcf_tx_chars(struct mcf_uart *pp)
	if (xmit->head == xmit->tail) {		if (xmit->head == xmit->tail) {
	pp->imr &= ~MCFUART_UIR_TXREADY;		pp->imr &= ~MCFUART_UIR_TXREADY;
	writeb(pp->imr, port->membase + MCFUART_UIMR);		writeb(pp->imr, port->membase + MCFUART_UIMR);
			/* Disable TX to negate RTS automatically */
			if (pp->rs485.flags & SER_RS485_ENABLED)
			writeb(MCFUART_UCR_TXDISABLE,
			port->membase + MCFUART_UCR);
	}		}
	}		}

	@@ -418,6 +436,58 @@ static int mcf_verify_port(struct uart_port port, struct serial_struct ser)

	/****************************************************************************/		/****************************************************************************/

			/* Enable or disable the RS485 support */
			static void mcf_config_rs485(struct uart_port port, struct serial_rs485 rs485)
			{
			struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
			unsigned long flags;
			unsigned char mr1, mr2;

			spin_lock_irqsave(&port->lock, flags);
			/* Get mode registers */
			mr1 = readb(port->membase + MCFUART_UMR);
			mr2 = readb(port->membase + MCFUART_UMR);
			if (rs485->flags & SER_RS485_ENABLED) {
			dev_dbg(port->dev, "Setting UART to RS485\n");
			/* Automatically negate RTS after TX completes */
			mr2 \|= MCFUART_MR2_TXRTS;
			} else {
			dev_dbg(port->dev, "Setting UART to RS232\n");
			mr2 &= ~MCFUART_MR2_TXRTS;
			}
			writeb(mr1, port->membase + MCFUART_UMR);
			writeb(mr2, port->membase + MCFUART_UMR);
			pp->rs485 = *rs485;
			spin_unlock_irqrestore(&port->lock, flags);
			}

			static int mcf_ioctl(struct uart_port *port, unsigned int cmd,
			unsigned long arg)
			{
			switch (cmd) {
			case TIOCSRS485: {
			struct serial_rs485 rs485;
			if (copy_from_user(&rs485, (struct serial_rs485 *)arg,
			sizeof(struct serial_rs485)))
			return -EFAULT;
			mcf_config_rs485(port, &rs485);
			break;
			}
			case TIOCGRS485: {
			struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
			if (copy_to_user((struct serial_rs485 *)arg, &pp->rs485,
			sizeof(struct serial_rs485)))
			return -EFAULT;
			break;
			}
			default:
			return -ENOIOCTLCMD;
			}
			return 0;
			}

			/****************************************************************************/

	/*		/*
	* Define the basic serial functions we support.		* Define the basic serial functions we support.
	*/		*/
	@@ -438,6 +508,7 @@ static const struct uart_ops mcf_uart_ops = {
	.release_port = mcf_release_port,		.release_port = mcf_release_port,
	.config_port = mcf_config_port,		.config_port = mcf_config_port,
	.verify_port = mcf_verify_port,		.verify_port = mcf_verify_port,
			.ioctl = mcf_ioctl,
	};		};

	static struct mcf_uart mcf_ports[4];		static struct mcf_uart mcf_ports[4];