path: root/drivers/serial/samsung.c

/* linux/drivers/serial/samsuing.c
 *
 * Driver core for Samsung SoC onboard UARTs.
 *
 * Ben Dooks, Copyright (c) 2003-2005,2008 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

/* Hote on 2410 error handling
 *
 * The s3c2410 manual has a love/hate affair with the contents of the
 * UERSTAT register in the UART blocks, and keeps marking some of the
 * error bits as reserved. Having checked with the s3c2410x01,
 * it copes with BREAKs properly, so I am happy to ignore the RESERVED
 * feature from the latter versions of the manual.
 *
 * If it becomes aparrent that latter versions of the 2410 remove these
 * bits, then action will have to be taken to differentiate the versions
 * and change the policy on BREAK
 *
 * BJD, 04-Nov-2004
*/

#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/delay.h>
#include <linux/clk.h>

#include <asm/irq.h>

#include <mach/hardware.h>

#include <plat/regs-serial.h>
#include <mach/regs-gpio.h>

#include "samsung.h"

/* UART name and device definitions */

#define S3C24XX_SERIAL_NAME	"ttySAC"
#define S3C24XX_SERIAL_MAJOR	204
#define S3C24XX_SERIAL_MINOR	64

/* we can support 3 uarts, but not always use them */

#ifdef CONFIG_CPU_S3C2400
#define NR_PORTS (2)
#else
#define NR_PORTS (3)
#endif

/* port irq numbers */

#define TX_IRQ(port) ((port)->irq + 1)
#define RX_IRQ(port) ((port)->irq)

/* macros to change one thing to another */

#define tx_enabled(port) ((port)->unused[0])
#define rx_enabled(port) ((port)->unused[1])

/* flag to ignore all characters comming in */
#define RXSTAT_DUMMY_READ (0x10000000)

static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
{
	return container_of(port, struct s3c24xx_uart_port, port);
}

/* translate a port to the device name */

static inline const char *s3c24xx_serial_portname(struct uart_port *port)
{
	return to_platform_device(port->dev)->name;
}

static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
{
	return (rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE);
}

static void s3c24xx_serial_rx_enable(struct uart_port *port)
{
	unsigned long flags;
	unsigned int ucon, ufcon;
	int count = 10000;

	spin_lock_irqsave(&port->lock, flags);

	while (--count && !s3c24xx_serial_txempty_nofifo(port))
		udelay(100);

	ufcon = rd_regl(port, S3C2410_UFCON);
	ufcon |= S3C2410_UFCON_RESETRX;
	wr_regl(port, S3C2410_UFCON, ufcon);

	ucon = rd_regl(port, S3C2410_UCON);
	ucon |= S3C2410_UCON_RXIRQMODE;
	wr_regl(port, S3C2410_UCON, ucon);

	rx_enabled(port) = 1;
	spin_unlock_irqrestore(&port->lock, flags);
}

static<