openwrt/target/linux/sibyte-2.6/patches/000-DUART.patch

diff -Nur linux-2.6.21.1/drivers/char/Kconfig linux-2.6.21.1-owrt/drivers/char/Kconfig
--- linux-2.6.21.1/drivers/char/Kconfig	2007-04-27 23:49:26.000000000 +0200
+++ linux-2.6.21.1-owrt/drivers/char/Kconfig	2007-05-24 22:28:54.000000000 +0200
@@ -386,6 +386,14 @@
 	  If you have an Alchemy AU1000 processor (MIPS based) and you want
 	  to use a console on a serial port, say Y.  Otherwise, say N.
 
+config SIBYTE_SB1250_DUART
+	bool "Support for BCM1xxx onchip DUART"
+	depends on MIPS && SIBYTE_SB1xxx_SOC=y
+
+config SIBYTE_SB1250_DUART_CONSOLE
+	bool "Console on BCM1xxx DUART"
+	depends on SIBYTE_SB1250_DUART
+
 config SERIAL_DEC
 	bool "DECstation serial support"
 	depends on MACH_DECSTATION
diff -Nur linux-2.6.21.1/drivers/char/Makefile linux-2.6.21.1-owrt/drivers/char/Makefile
--- linux-2.6.21.1/drivers/char/Makefile	2007-04-27 23:49:26.000000000 +0200
+++ linux-2.6.21.1-owrt/drivers/char/Makefile	2007-05-24 22:32:31.000000000 +0200
@@ -32,6 +32,7 @@
 obj-$(CONFIG_ATARI_DSP56K)	+= dsp56k.o
 obj-$(CONFIG_MOXA_SMARTIO)	+= mxser.o
 obj-$(CONFIG_MOXA_SMARTIO_NEW)	+= mxser_new.o
+obj-$(CONFIG_SIBYTE_SB1250_DUART) += sb1250_duart.o
 obj-$(CONFIG_COMPUTONE)		+= ip2/
 obj-$(CONFIG_RISCOM8)		+= riscom8.o
 obj-$(CONFIG_ISI)		+= isicom.o
diff -Nur linux-2.6.21.1/drivers/char/sb1250_duart.c linux-2.6.21.1-owrt/drivers/char/sb1250_duart.c
--- linux-2.6.21.1/drivers/char/sb1250_duart.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1-owrt/drivers/char/sb1250_duart.c	2007-05-24 22:10:12.000000000 +0200
@@ -0,0 +1,979 @@
+/*
+ * Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * Driver support for the on-chip sb1250 dual-channel serial port,
+ * running in asynchronous mode.  Also, support for doing a serial console
+ * on one of those ports
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/serial.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/kdev_t.h>
+#include <linux/major.h>
+#include <linux/termios.h>
+#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/tty_flip.h>
+#include <linux/timer.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/delay.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/sibyte/swarm.h>
+#include <asm/sibyte/sb1250.h>
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_int.h>
+#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+#else
+#error invalid SiByte UART configuation
+#endif
+#include <asm/sibyte/sb1250_uart.h>
+#include <asm/war.h>
+
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#define UNIT_CHANREG(n,reg)	A_BCM1480_DUART_CHANREG((n),(reg))
+#define UNIT_IMRREG(n)		A_BCM1480_DUART_IMRREG(n)
+#define UNIT_INT(n)		(K_BCM1480_INT_UART_0 + (n))
+#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
+#define UNIT_CHANREG(n,reg)	A_DUART_CHANREG((n),(reg))
+#define UNIT_IMRREG(n)		A_DUART_IMRREG(n)
+#define UNIT_INT(n)		(K_INT_UART_0 + (n))
+#else
+#error invalid SiByte UART configuation
+#endif
+
+/* Toggle spewing of debugging output */
+#undef DEBUG
+
+#define DEFAULT_CFLAGS          (CS8 | B115200)
+
+#define TX_INTEN          1
+#define DUART_INITIALIZED 2
+
+#define DUART_MAX_LINE 4
+char sb1250_duart_present[DUART_MAX_LINE];
+EXPORT_SYMBOL(sb1250_duart_present);
+
+/*
+ * In bug 1956, we get glitches that can mess up uart registers.  This
+ * "read-mode-reg after any register access" is an accepted workaround.
+ */
+#if SIBYTE_1956_WAR
+# define SB1_SER1956_WAR {							\
+	u32 ignore;										\
+	ignore = csr_in32(uart_states[line].mode_1);	\
+	ignore = csr_in32(uart_states[line].mode_2);	\
+	}
+#else
+# define SB1_SER1956_WAR
+#endif
+
+/*
+ * Still not sure what the termios structures set up here are for,
+ *  but we have to supply pointers to them to register the tty driver
+ */
+static struct tty_driver *sb1250_duart_driver; //, sb1250_duart_callout_driver;
+
+/*
+ * This lock protects both the open flags for all the uart states as
+ * well as the reference count for the module
+ */
+static DEFINE_SPINLOCK(open_lock);
+
+typedef struct {
+	unsigned char		outp_buf[SERIAL_XMIT_SIZE];
+	unsigned int		outp_head;
+	unsigned int		outp_tail;
+	unsigned int		outp_count;
+	spinlock_t		outp_lock;
+	unsigned int		open;
+	unsigned int		line;
+	unsigned int		last_cflags;
+	unsigned long		flags;
+	struct tty_struct	*tty;
+
+	/* CSR addresses */
+	unsigned int		*status;
+	unsigned int		*imr;
+	unsigned int		*tx_hold;
+	unsigned int		*rx_hold;
+	unsigned int		*mode_1;
+	unsigned int		*mode_2;
+	unsigned int		*clk_sel;
+	unsigned int		*cmd;
+} uart_state_t;
+
+static uart_state_t uart_states[DUART_MAX_LINE];
+
+/*
+ * Inline functions local to this module
+ */
+
+static inline u32 READ_SERCSR(volatile u32 *addr, int line)
+{
+	u32 val = csr_in32(addr);
+	SB1_SER1956_WAR;
+	return val;
+}
+
+static inline void WRITE_SERCSR(u32 val, volatile u32 *addr, int line)
+{
+	csr_out32(val, addr);
+	SB1_SER1956_WAR;
+}
+
+static void init_duart_port(uart_state_t *port, int line)
+{
+	if (!(port->flags & DUART_INITIALIZED)) {
+		port->line = line;
+		port->status = IOADDR(UNIT_CHANREG(line, R_DUART_STATUS));
+		port->imr = IOADDR(UNIT_IMRREG(line));
+		port->tx_hold = IOADDR(UNIT_CHANREG(line, R_DUART_TX_HOLD));
+		port->rx_hold = IOADDR(UNIT_CHANREG(line, R_DUART_RX_HOLD));
+		port->mode_1 = IOADDR(UNIT_CHANREG(line, R_DUART_MODE_REG_1));
+		port->mode_2 = IOADDR(UNIT_CHANREG(line, R_DUART_MODE_REG_2));
+		port->clk_sel = IOADDR(UNIT_CHANREG(line, R_DUART_CLK_SEL));
+		port->cmd = IOADDR(UNIT_CHANREG(line, R_DUART_CMD));
+		port->last_cflags = DEFAULT_CFLAGS;
+		spin_lock_init(&port->outp_lock);
+		port->flags |= DUART_INITIALIZED;
+	}
+}
+
+/*
+ * Mask out the passed interrupt lines at the duart level.  This should be
+ * called while holding the associated outp_lock.
+ */
+static inline void duart_mask_ints(unsigned int line, unsigned int mask)
+{
+	uart_state_t *port = uart_states + line;
+	u64 tmp = READ_SERCSR(port->imr, line);
+	WRITE_SERCSR(tmp & ~mask, port->imr, line);
+}
+
+
+/* Unmask the passed interrupt lines at the duart level */
+static inline void duart_unmask_ints(unsigned int line, unsigned int mask)
+{
+	uart_state_t *port = uart_states + line;
+	u64 tmp = READ_SERCSR(port->imr, line);
+	WRITE_SERCSR(tmp | mask, port->imr, line);
+}
+
+static inline void transmit_char_pio(uart_state_t *us)
+{
+	struct tty_struct *tty = us->tty;
+	int blocked = 0;
+
+	if (spin_trylock(&us->outp_lock)) {
+		for (;;) {
+			if (!(READ_SERCSR(us->status, us->line) & M_DUART_TX_RDY))
+				break;
+			if (us->outp_count <= 0 || tty->stopped || tty->hw_stopped) {
+				break;
+			} else {
+				WRITE_SERCSR(us->outp_buf[us->outp_head],
+					     us->tx_hold, us->line);
+				us->outp_head = (us->outp_head + 1) & (SERIAL_XMIT_SIZE-1);
+				if (--us->outp_count <= 0)
+					break;
+			}
+			udelay(10);
+		}
+		spin_unlock(&us->outp_lock);
+	} else {
+		blocked = 1;
+	}
+
+	if (!us->outp_count || tty->stopped ||
+	    tty->hw_stopped || blocked) {
+		us->flags &= ~TX_INTEN;
+		duart_mask_ints(us->line, M_DUART_IMR_TX);
+	}
+
+	if (us->open &&
+	    (us->outp_count < (SERIAL_XMIT_SIZE/2))) {
+		/*
+		 * We told the discipline at one point that we had no
+		 * space, so it went to sleep.  Wake it up when we hit
+		 * half empty
+		 */
+		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+		    tty->ldisc.write_wakeup)
+			tty->ldisc.write_wakeup(tty);
+		wake_up_interruptible(&tty->write_wait);
+	}
+}
+
+/*
+ * Generic interrupt handler for both channels.  dev_id is a pointer
+ * to the proper uart_states structure, so from that we can derive
+ * which port interrupted
+ */
+
+static irqreturn_t duart_int(int irq, void *dev_id)
+{
+	uart_state_t *us = (uart_state_t *)dev_id;
+	struct tty_struct *tty = us->tty;
+	unsigned int status = READ_SERCSR(us->status, us->line);
+
+	pr_debug("DUART INT\n");
+
+	if (status & M_DUART_RX_RDY) {
+		int counter = 2048;
+		unsigned int ch;
+
+		if (status & M_DUART_OVRUN_ERR)
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		if (status & M_DUART_PARITY_ERR) {
+			printk("Parity error!\n");
+		} else if (status & M_DUART_FRM_ERR) {
+			printk("Frame error!\n");
+		}
+
+		while (counter > 0) {
+			if (!(READ_SERCSR(us->status, us->line) & M_DUART_RX_RDY))
+				break;
+			ch = READ_SERCSR(us->rx_hold, us->line);
+			tty_insert_flip_char(tty, ch, 0);
+			udelay(1);
+			counter--;
+		}
+		tty_flip_buffer_push(tty);
+	}
+
+	if (status & M_DUART_TX_RDY) {
+		transmit_char_pio(us);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ *  Actual driver functions
+ */
+
+/* Return the number of characters we can accomodate in a write at this instant */
+static int duart_write_room(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	int retval;
+
+	retval = SERIAL_XMIT_SIZE - us->outp_count;
+
+	pr_debug("duart_write_room called, returning %i\n", retval);
+
+	return retval;
+}
+
+/* memcpy the data from src to destination, but take extra care if the
+   data is coming from user space */
+static inline int copy_buf(char *dest, const char *src, int size, int from_user)
+{
+	if (from_user) {
+		(void) copy_from_user(dest, src, size);
+	} else {
+		memcpy(dest, src, size);
+	}
+	return size;
+}
+
+/*
+ * Buffer up to count characters from buf to be written.  If we don't have
+ * other characters buffered, enable the tx interrupt to start sending
+ */
+static int duart_write(struct tty_struct *tty, const unsigned char *buf,
+		       int count)
+{
+	uart_state_t *us;
+	int c, t, total = 0;
+	unsigned long flags;
+
+	if (!tty) return 0;
+
+	us = tty->driver_data;
+	if (!us) return 0;
+
+	pr_debug("duart_write called for %i chars by %i (%s)\n", count,
+			current->pid, current->comm);
+
+	spin_lock_irqsave(&us->outp_lock, flags);
+
+	for (;;) {
+		c = count;
+
+		t = SERIAL_XMIT_SIZE - us->outp_tail;
+		if (t < c) c = t;
+
+		t = SERIAL_XMIT_SIZE - 1 - us->outp_count;
+		if (t < c) c = t;
+
+		if (c <= 0) break;
+
+		memcpy(us->outp_buf + us->outp_tail, buf, c);
+
+		us->outp_count += c;
+		us->outp_tail = (us->outp_tail + c) & (SERIAL_XMIT_SIZE - 1);
+		buf += c;
+		count -= c;
+		total += c;
+	}
+
+	spin_unlock_irqrestore(&us->outp_lock, flags);
+
+	if (us->outp_count && !tty->stopped &&
+	    !tty->hw_stopped && !(us->flags & TX_INTEN)) {
+		us->flags |= TX_INTEN;
+		duart_unmask_ints(us->line, M_DUART_IMR_TX);
+	}
+
+	return total;
+}
+
+
+/* Buffer one character to be written.  If there's not room for it, just drop
+   it on the floor.  This is used for echo, among other things */
+static void duart_put_char(struct tty_struct *tty, u_char ch)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("duart_put_char called.  Char is %x (%c)\n", (int)ch, ch);
+
+	spin_lock_irqsave(&us->outp_lock, flags);
+
+	if (us->outp_count == SERIAL_XMIT_SIZE) {
+		spin_unlock_irqrestore(&us->outp_lock, flags);
+		return;
+	}
+
+	us->outp_buf[us->outp_tail] = ch;
+	us->outp_tail = (us->outp_tail + 1) &(SERIAL_XMIT_SIZE-1);
+	us->outp_count++;
+
+	spin_unlock_irqrestore(&us->outp_lock, flags);
+}
+
+static void duart_flush_chars(struct tty_struct * tty)
+{
+	uart_state_t *port;
+
+	if (!tty)
+		return;
+
+	port = tty->driver_data;
+
+	if (!port)
+		return;
+
+	if (port->outp_count <= 0 || tty->stopped || tty->hw_stopped) {
+		return;
+	}
+
+	port->flags |= TX_INTEN;
+	duart_unmask_ints(port->line, M_DUART_IMR_TX);
+}
+
+/* Return the number of characters in the output buffer that have yet to be
+   written */
+static int duart_chars_in_buffer(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	int retval;
+
+	retval = us->outp_count;
+
+	pr_debug("duart_chars_in_buffer returning %i\n", retval);
+
+	return retval;
+}
+
+/* Kill everything we haven't yet shoved into the FIFO.  Turn off the
+   transmit interrupt since we've nothing more to transmit */
+static void duart_flush_buffer(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("duart_flush_buffer called\n");
+	spin_lock_irqsave(&us->outp_lock, flags);
+	us->outp_head = us->outp_tail = us->outp_count = 0;
+	spin_unlock_irqrestore(&us->outp_lock, flags);
+
+	wake_up_interruptible(&us->tty->write_wait);
+	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+	    tty->ldisc.write_wakeup)
+		tty->ldisc.write_wakeup(tty);
+}
+
+
+/* See sb1250 user manual for details on these registers */
+static inline void duart_set_cflag(unsigned int line, unsigned int cflag)
+{
+	unsigned int mode_reg1 = 0, mode_reg2 = 0;
+	unsigned int clk_divisor;
+	uart_state_t *port = uart_states + line;
+
+	switch (cflag & CSIZE) {
+	case CS7:
+		mode_reg1 |= V_DUART_BITS_PER_CHAR_7;
+
+	default:
+		/* We don't handle CS5 or CS6...is there a way we're supposed to
+		 * flag this?  right now we just force them to CS8 */
+		mode_reg1 |= 0x0;
+		break;
+	}
+	if (cflag & CSTOPB) {
+	        mode_reg2 |= M_DUART_STOP_BIT_LEN_2;
+	}
+	if (!(cflag & PARENB)) {
+	        mode_reg1 |= V_DUART_PARITY_MODE_NONE;
+	}
+	if (cflag & PARODD) {
+		mode_reg1 |= M_DUART_PARITY_TYPE_ODD;
+	}
+
+	/* Formula for this is (5000000/baud)-1, but we saturate
+	   at 12 bits, which means we can't actually do anything less
+	   that 1200 baud */
+	switch (cflag & CBAUD) {
+	case B200:
+	case B300:
+	case B1200:	clk_divisor = 4095;		break;
+	case B1800:	clk_divisor = 2776;		break;
+	case B2400:	clk_divisor = 2082;		break;
+	case B4800:	clk_divisor = 1040;		break;
+	case B9600:	clk_divisor = 519;		break;
+	case B19200:	clk_divisor = 259;		break;
+	case B38400:	clk_divisor = 129;		break;
+	default:
+	case B57600:	clk_divisor = 85;		break;
+	case B115200:	clk_divisor = 42;		break;
+	}
+	WRITE_SERCSR(mode_reg1, port->mode_1, port->line);
+	WRITE_SERCSR(mode_reg2, port->mode_2, port->line);
+	WRITE_SERCSR(clk_divisor, port->clk_sel, port->line);
+	port->last_cflags = cflag;
+}
+
+
+/* Handle notification of a termios change.  */
+static void duart_set_termios(struct tty_struct *tty, struct termios *old)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+
+	pr_debug("duart_set_termios called by %i (%s)\n", current->pid,
+		current->comm);
+	if (old && tty->termios->c_cflag == old->c_cflag)
+		return;
+	duart_set_cflag(us->line, tty->termios->c_cflag);
+}
+
+static int get_serial_info(uart_state_t *us, struct serial_struct * retinfo)
+{
+	struct serial_struct tmp;
+
+	memset(&tmp, 0, sizeof(tmp));
+
+	tmp.type = PORT_SB1250;
+	tmp.line = us->line;
+	tmp.port = UNIT_CHANREG(tmp.line,0);
+	tmp.irq = UNIT_INT(tmp.line);
+	tmp.xmit_fifo_size = 16; /* fixed by hw */
+	tmp.baud_base = 5000000;
+	tmp.io_type = SERIAL_IO_MEM;
+
+	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int duart_ioctl(struct tty_struct *tty, struct file * file,
+		       unsigned int cmd, unsigned long arg)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+
+/*	if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
+	return -ENODEV;*/
+	switch (cmd) {
+	case TIOCMGET:
+		printk("Ignoring TIOCMGET\n");
+		break;
+	case TIOCMBIS:
+		printk("Ignoring TIOCMBIS\n");
+		break;
+	case TIOCMBIC:
+		printk("Ignoring TIOCMBIC\n");
+		break;
+	case TIOCMSET:
+		printk("Ignoring TIOCMSET\n");
+		break;
+	case TIOCGSERIAL:
+		return get_serial_info(us,(struct serial_struct *) arg);
+	case TIOCSSERIAL:
+		printk("Ignoring TIOCSSERIAL\n");
+		break;
+	case TIOCSERCONFIG:
+		printk("Ignoring TIOCSERCONFIG\n");
+		break;
+	case TIOCSERGETLSR: /* Get line status register */
+		printk("Ignoring TIOCSERGETLSR\n");
+		break;
+	case TIOCSERGSTRUCT:
+		printk("Ignoring TIOCSERGSTRUCT\n");
+		break;
+	case TIOCMIWAIT:
+		printk("Ignoring TIOCMIWAIT\n");
+		break;
+	case TIOCGICOUNT:
+		printk("Ignoring TIOCGICOUNT\n");
+		break;
+	case TIOCSERGWILD:
+		printk("Ignoring TIOCSERGWILD\n");
+		break;
+	case TIOCSERSWILD:
+		printk("Ignoring TIOCSERSWILD\n");
+		break;
+	default:
+		break;
+	}
+//	printk("Ignoring IOCTL %x from pid %i (%s)\n", cmd, current->pid, current->comm);
+	return -ENOIOCTLCMD;
+}
+
+/* XXXKW locking? */
+static void duart_start(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+
+	pr_debug("duart_start called\n");
+
+	if (us->outp_count && !(us->flags & TX_INTEN)) {
+		us->flags |= TX_INTEN;
+		duart_unmask_ints(us->line, M_DUART_IMR_TX);
+	}
+}
+
+/* XXXKW locking? */
+static void duart_stop(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+
+	pr_debug("duart_stop called\n");
+
+	if (us->outp_count && (us->flags & TX_INTEN)) {
+		us->flags &= ~TX_INTEN;
+		duart_mask_ints(us->line, M_DUART_IMR_TX);
+	}
+}
+
+/* Not sure on the semantics of this; are we supposed to wait until the stuff
+ * already in the hardware FIFO drains, or are we supposed to wait until
+ * we've drained the output buffer, too?  I'm assuming the former, 'cause thats
+ * what the other drivers seem to assume
+ */
+
+static void duart_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	unsigned long orig_jiffies;
+
+	orig_jiffies = jiffies;
+	pr_debug("duart_wait_until_sent(%d)+\n", timeout);
+	while (!(READ_SERCSR(us->status, us->line) & M_DUART_TX_EMT)) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(1);
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+			break;
+	}
+	pr_debug("duart_wait_until_sent()-\n");
+}
+
+/*
+ * duart_hangup() --- called by tty_hangup() when a hangup is signaled.
+ */
+static void duart_hangup(struct tty_struct *tty)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+
+	duart_flush_buffer(tty);
+	us->open = 0;
+	us->tty = 0;
+}
+
+/*
+ * Open a tty line.  Note that this can be called multiple times, so ->open can
+ * be >1.  Only set up the tty struct if this is a "new" open, e.g. ->open was
+ * zero
+ */
+static int duart_open(struct tty_struct *tty, struct file *filp)
+{
+	uart_state_t *us;
+	unsigned int line = tty->index;
+	unsigned long flags;
+
+	if ((line >= tty->driver->num) || !sb1250_duart_present[line])
+		return -ENODEV;
+
+	pr_debug("duart_open called by %i (%s), tty is %p, rw is %p, ww is %p\n",
+	       current->pid, current->comm, tty, (void *)&tty->read_wait,
+	       (void *)&tty->write_wait);
+
+	us = uart_states + line;
+	tty->driver_data = us;
+
+	spin_lock_irqsave(&open_lock, flags);
+	if (!us->open) {
+		us->tty = tty;
+		us->tty->termios->c_cflag = us->last_cflags;
+	}
+	us->open++;
+	us->flags &= ~TX_INTEN;
+	duart_unmask_ints(line, M_DUART_IMR_RX);
+	spin_unlock_irqrestore(&open_lock, flags);
+
+	return 0;
+}
+
+
+/*
+ * Close a reference count out.  If reference count hits zero, null the
+ * tty, kill the interrupts.  The tty_io driver is responsible for making
+ * sure we've cleared out our internal buffers before calling close()
+ */
+static void duart_close(struct tty_struct *tty, struct file *filp)
+{
+	uart_state_t *us = (uart_state_t *) tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("duart_close called by %i (%s)\n", current->pid, current->comm);
+
+	if (!us || !us->open)
+		return;
+
+	spin_lock_irqsave(&open_lock, flags);
+	if (tty_hung_up_p(filp)) {
+		spin_unlock_irqrestore(&open_lock, flags);
+		return;
+	}
+
+	if (--us->open < 0) {
+		us->open = 0;
+		printk(KERN_ERR "duart: bad open count: %d\n", us->open);
+	}
+	if (us->open) {
+		spin_unlock_irqrestore(&open_lock, flags);
+		return;
+	}
+
+	spin_unlock_irqrestore(&open_lock, flags);
+
+	tty->closing = 1;
+
+	/* Stop accepting input */
+	duart_mask_ints(us->line, M_DUART_IMR_RX);
+	/* Wait for FIFO to drain */
+	while (!(READ_SERCSR(us->status, us->line) & M_DUART_TX_EMT))
+		;
+
+	if (tty->driver->flush_buffer)
+		tty->driver->flush_buffer(tty);
+	if (tty->ldisc.flush_buffer)
+		tty->ldisc.flush_buffer(tty);
+	tty->closing = 0;
+}
+
+
+static struct tty_operations duart_ops = {
+        .open   = duart_open,
+        .close = duart_close,
+        .write = duart_write,
+        .put_char = duart_put_char,
+        .flush_chars = duart_flush_chars,
+        .write_room = duart_write_room,
+        .chars_in_buffer = duart_chars_in_buffer,
+        .flush_buffer = duart_flush_buffer,
+        .ioctl = duart_ioctl,
+//        .throttle = duart_throttle,
+//        .unthrottle = duart_unthrottle,
+        .set_termios = duart_set_termios,
+        .stop = duart_stop,
+        .start = duart_start,
+        .hangup = duart_hangup,
+	.wait_until_sent = duart_wait_until_sent,
+};
+
+/* Initialize the sb1250_duart_present array based on SOC type.  */
+static void __init sb1250_duart_init_present_lines(void)
+{
+	int i, max_lines;
+
+	/* Set the number of available units based on the SOC type.  */
+	switch (soc_type) {
+	case K_SYS_SOC_TYPE_BCM1x55:
+	case K_SYS_SOC_TYPE_BCM1x80:
+		max_lines = 4;
+		break;
+	default:
+		/* Assume at least two serial ports at the normal address.  */
+		max_lines = 2;
+		break;
+	}
+	if (max_lines > DUART_MAX_LINE)
+		max_lines = DUART_MAX_LINE;
+
+	for (i = 0; i < max_lines; i++)
+		sb1250_duart_present[i] = 1;
+}
+
+/* Set up the driver and register it, register the UART interrupts.  This
+   is called from tty_init, or as a part of the module init */
+static int __init sb1250_duart_init(void)
+{
+	int i;
+
+	sb1250_duart_init_present_lines();
+
+	sb1250_duart_driver = alloc_tty_driver(DUART_MAX_LINE);
+	if (!sb1250_duart_driver)
+		return -ENOMEM;
+
+	sb1250_duart_driver->owner = THIS_MODULE;
+	sb1250_duart_driver->name = "duart";
+	sb1250_duart_driver->major = TTY_MAJOR;
+	sb1250_duart_driver->minor_start = SB1250_DUART_MINOR_BASE;
+	sb1250_duart_driver->type            = TTY_DRIVER_TYPE_SERIAL;
+	sb1250_duart_driver->subtype         = SERIAL_TYPE_NORMAL;
+	sb1250_duart_driver->init_termios    = tty_std_termios;
+	sb1250_duart_driver->flags           = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(sb1250_duart_driver, &duart_ops);
+
+	for (i = 0; i < DUART_MAX_LINE; i++) {
+		uart_state_t *port = uart_states + i;
+
+		if (!sb1250_duart_present[i])
+			continue;
+
+		init_duart_port(port, i);
+		duart_mask_ints(i, M_DUART_IMR_ALL);
+		if (request_irq(UNIT_INT(i), duart_int, 0, "uart", port)) {
+			panic("Couldn't get uart0 interrupt line");
+		}
+		/*
+		 * this generic write to a register does not implement the 1956
+		 * WAR and sometimes output gets corrupted afterwards,
+		 * especially if the port was in use as a console.
+		 */
+		__raw_writel(M_DUART_RX_EN|M_DUART_TX_EN, port->cmd);
+
+		/*
+		 * we should really check to see if it's registered as a console
+		 * before trashing those settings
+		 */
+		duart_set_cflag(i, port->last_cflags);
+	}
+
+	/* Interrupts are now active, our ISR can be called. */
+
+	if (tty_register_driver(sb1250_duart_driver)) {
+		printk(KERN_ERR "Couldn't register sb1250 duart serial driver\n");
+		put_tty_driver(sb1250_duart_driver);
+		return 1;
+	}
+	return 0;
+}
+
+/* Unload the driver.  Unregister stuff, get ready to go away */
+static void __exit sb1250_duart_fini(void)
+{
+	unsigned long flags;
+	int i;
+
+	local_irq_save(flags);
+	tty_unregister_driver(sb1250_duart_driver);
+	put_tty_driver(sb1250_duart_driver);
+
+	for (i = 0; i < DUART_MAX_LINE; i++) {
+		if (!sb1250_duart_present[i])
+			continue;
+		free_irq(UNIT_INT(i), &uart_states[i]);
+		disable_irq(UNIT_INT(i));
+	}
+	local_irq_restore(flags);
+}
+
+module_init(sb1250_duart_init);
+module_exit(sb1250_duart_fini);
+MODULE_DESCRIPTION("SB1250 Duart serial driver");
+MODULE_AUTHOR("Broadcom Corp.");
+
+#ifdef CONFIG_SIBYTE_SB1250_DUART_CONSOLE
+
+/*
+ * Serial console stuff.  Very basic, polling driver for doing serial
+ * console output.  The console_sem is held by the caller, so we
+ * shouldn't be interrupted for more console activity.
+ * XXXKW What about getting interrupted by uart driver activity?
+ */
+
+void serial_outc(unsigned char c, int line)
+{
+	uart_state_t *port = uart_states + line;
+	while (!(READ_SERCSR(port->status, line) & M_DUART_TX_RDY)) ;
+	WRITE_SERCSR(c, port->tx_hold, line);
+	while (!(READ_SERCSR(port->status, port->line) & M_DUART_TX_EMT)) ;
+}
+
+static void ser_console_write(struct console *cons, const char *s,
+	unsigned int count)
+{
+	int line = cons->index;
+	uart_state_t *port = uart_states + line;
+	u32 imr;
+
+	imr = READ_SERCSR(port->imr, line);
+	WRITE_SERCSR(0, port->imr, line);
+	while (count--) {
+		if (*s == '\n')
+			serial_outc('\r', line);
+		serial_outc(*s++, line);
+	}
+	WRITE_SERCSR(imr, port->imr, line);
+}
+
+static struct tty_driver *ser_console_device(struct console *c, int *index)
+{
+	*index = c->index;
+	return sb1250_duart_driver;
+}
+
+static int ser_console_setup(struct console *cons, char *str)
+{
+	int i;
+
+	sb1250_duart_init_present_lines();
+
+	for (i = 0; i < DUART_MAX_LINE; i++) {
+		uart_state_t *port = uart_states + i;
+		u32 cflags = DEFAULT_CFLAGS;
+
+		if (!sb1250_duart_present[i])
+			continue;
+
+		init_duart_port(port, i);
+		if (str) {
+			int speed;
+			char par = 'n';
+			int cbits = 8;
+
+			cflags = 0;
+
+			/*
+			 * format is in Documentation/serial_console.txt
+			 */
+			sscanf(str, "%d%c%d", &speed, &par, &cbits);
+
+			switch (speed) {
+			case 200:
+			case 300:
+			case 1200:
+				cflags |= B1200;
+				break;
+			case 1800:
+				cflags |= B1800;
+				break;
+			case 2400:
+				cflags |= B2400;
+				break;
+			case 4800:
+				cflags |= B4800;
+				break;
+			default:
+			case 9600:
+				cflags |= B9600;
+				break;
+			case 19200:
+				cflags |= B19200;
+				break;
+			case 38400:
+				cflags |= B38400;
+				break;
+			case 57600:
+				cflags |= B57600;
+				break;
+			case 115200:
+				cflags |= B115200;
+				break;
+			}
+			switch (par) {
+			case 'o':
+				cflags |= PARODD;
+			case 'e':
+				cflags |= PARENB;
+			}
+			switch (cbits) {
+			default:	// we only do 7 or 8
+			case 8:
+				cflags |= CS8;
+				break;
+			case 7:
+				cflags |= CS7;
+				break;
+			}
+		}
+		duart_set_cflag(i, cflags);
+		WRITE_SERCSR(M_DUART_RX_EN | M_DUART_TX_EN, port->cmd, i);
+	}
+
+	return 0;
+}
+
+static struct console sb1250_ser_cons = {
+	.name		= "duart",
+	.write		= ser_console_write,
+	.device		= ser_console_device,
+	.setup		= ser_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+static int __init sb1250_serial_console_init(void)
+{
+	//add_preferred_console("duart", 0, "57600n8");
+	register_console(&sb1250_ser_cons);
+	return 0;
+}
+
+console_initcall(sb1250_serial_console_init);
+
+#endif /* CONFIG_SIBYTE_SB1250_DUART_CONSOLE */
diff -Nur linux-2.6.21.1/include/linux/serial.h linux-2.6.21.1-owrt/include/linux/serial.h
--- linux-2.6.21.1/include/linux/serial.h	2007-04-27 23:49:26.000000000 +0200
+++ linux-2.6.21.1-owrt/include/linux/serial.h	2007-05-24 22:10:29.000000000 +0200
@@ -76,7 +76,8 @@
 #define PORT_16654	11
 #define PORT_16850	12
 #define PORT_RSA	13	/* RSA-DV II/S card */
-#define PORT_MAX	13
+#define PORT_SB1250	14
+#define PORT_MAX	14
 
 #define SERIAL_IO_PORT	0
 #define SERIAL_IO_HUB6	1