mn10300: add the MN10300/AM33 architecture to the kernel

Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.

This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305.  The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.

[akpm@linux-foundation.org: nuke cvs control strings]
Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1480 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/mn10300-serial.c b/arch/mn10300/kernel/mn10300-serial.c
new file mode 100644
index 0000000..b9c268c
--- /dev/null
+++ b/arch/mn10300/kernel/mn10300-serial.c
@@ -0,0 +1,1480 @@
+/* MN10300 On-chip serial port UART driver
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+static const char serial_name[] = "MN10300 Serial driver";
+static const char serial_version[] = "mn10300_serial-1.0";
+static const char serial_revdate[] = "2007-11-06";
+
+#if defined(CONFIG_MN10300_TTYSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/circ_buf.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/bitops.h>
+#include <asm/serial-regs.h>
+#include <asm/unit/timex.h>
+#include "mn10300-serial.h"
+
+static inline __attribute__((format(printf, 1, 2)))
+void no_printk(const char *fmt, ...)
+{
+}
+
+#define kenter(FMT, ...) \
+	printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
+#define _enter(FMT, ...) \
+	no_printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+	printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
+#define _debug(FMT, ...) \
+	no_printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
+#define kproto(FMT, ...) \
+	printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
+#define _proto(FMT, ...) \
+	no_printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
+
+#define NR_UARTS 3
+
+#ifdef CONFIG_MN10300_TTYSM_CONSOLE
+static void mn10300_serial_console_write(struct console *co,
+					   const char *s, unsigned count);
+static int __init mn10300_serial_console_setup(struct console *co,
+						 char *options);
+
+static struct uart_driver mn10300_serial_driver;
+static struct console mn10300_serial_console = {
+	.name		= "ttySM",
+	.write		= mn10300_serial_console_write,
+	.device		= uart_console_device,
+	.setup		= mn10300_serial_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &mn10300_serial_driver,
+};
+#endif
+
+static struct uart_driver mn10300_serial_driver = {
+	.owner		= NULL,
+	.driver_name	= "mn10300-serial",
+	.dev_name	= "ttySM",
+	.major		= TTY_MAJOR,
+	.minor		= 128,
+	.nr		= NR_UARTS,
+#ifdef CONFIG_MN10300_TTYSM_CONSOLE
+	.cons		= &mn10300_serial_console,
+#endif
+};
+
+static unsigned int mn10300_serial_tx_empty(struct uart_port *);
+static void mn10300_serial_set_mctrl(struct uart_port *, unsigned int mctrl);
+static unsigned int mn10300_serial_get_mctrl(struct uart_port *);
+static void mn10300_serial_stop_tx(struct uart_port *);
+static void mn10300_serial_start_tx(struct uart_port *);
+static void mn10300_serial_send_xchar(struct uart_port *, char ch);
+static void mn10300_serial_stop_rx(struct uart_port *);
+static void mn10300_serial_enable_ms(struct uart_port *);
+static void mn10300_serial_break_ctl(struct uart_port *, int ctl);
+static int mn10300_serial_startup(struct uart_port *);
+static void mn10300_serial_shutdown(struct uart_port *);
+static void mn10300_serial_set_termios(struct uart_port *,
+					 struct ktermios *new,
+					 struct ktermios *old);
+static const char *mn10300_serial_type(struct uart_port *);
+static void mn10300_serial_release_port(struct uart_port *);
+static int mn10300_serial_request_port(struct uart_port *);
+static void mn10300_serial_config_port(struct uart_port *, int);
+static int mn10300_serial_verify_port(struct uart_port *,
+					struct serial_struct *);
+
+static const struct uart_ops mn10300_serial_ops = {
+	.tx_empty	= mn10300_serial_tx_empty,
+	.set_mctrl	= mn10300_serial_set_mctrl,
+	.get_mctrl	= mn10300_serial_get_mctrl,
+	.stop_tx	= mn10300_serial_stop_tx,
+	.start_tx	= mn10300_serial_start_tx,
+	.send_xchar	= mn10300_serial_send_xchar,
+	.stop_rx	= mn10300_serial_stop_rx,
+	.enable_ms	= mn10300_serial_enable_ms,
+	.break_ctl	= mn10300_serial_break_ctl,
+	.startup	= mn10300_serial_startup,
+	.shutdown	= mn10300_serial_shutdown,
+	.set_termios	= mn10300_serial_set_termios,
+	.type		= mn10300_serial_type,
+	.release_port	= mn10300_serial_release_port,
+	.request_port	= mn10300_serial_request_port,
+	.config_port	= mn10300_serial_config_port,
+	.verify_port	= mn10300_serial_verify_port,
+};
+
+static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id);
+
+/*
+ * the first on-chip serial port: ttySM0 (aka SIF0)
+ */
+#ifdef CONFIG_MN10300_TTYSM0
+struct mn10300_serial_port mn10300_serial_port_sif0 = {
+	.uart.ops	= &mn10300_serial_ops,
+	.uart.membase	= (void __iomem *) &SC0CTR,
+	.uart.mapbase	= (unsigned long) &SC0CTR,
+	.uart.iotype	= UPIO_MEM,
+	.uart.irq	= 0,
+	.uart.uartclk	= 0, /* MN10300_IOCLK, */
+	.uart.fifosize	= 1,
+	.uart.flags	= UPF_BOOT_AUTOCONF,
+	.uart.line	= 0,
+	.uart.type	= PORT_MN10300,
+	.uart.lock	=
+	__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif0.uart.lock),
+	.name		= "ttySM0",
+	._iobase	= &SC0CTR,
+	._control	= &SC0CTR,
+	._status	= (volatile u8 *) &SC0STR,
+	._intr		= &SC0ICR,
+	._rxb		= &SC0RXB,
+	._txb		= &SC0TXB,
+	.rx_name	= "ttySM0/Rx",
+	.tx_name	= "ttySM0/Tx",
+#ifdef CONFIG_MN10300_TTYSM0_TIMER8
+	.tm_name	= "ttySM0/Timer8",
+	._tmxmd		= &TM8MD,
+	._tmxbr		= &TM8BR,
+	._tmicr		= &TM8ICR,
+	.tm_irq		= TM8IRQ,
+	.div_timer	= MNSCx_DIV_TIMER_16BIT,
+#else /* CONFIG_MN10300_TTYSM0_TIMER2 */
+	.tm_name	= "ttySM0/Timer2",
+	._tmxmd		= &TM2MD,
+	._tmxbr		= (volatile u16 *) &TM2BR,
+	._tmicr		= &TM2ICR,
+	.tm_irq		= TM2IRQ,
+	.div_timer	= MNSCx_DIV_TIMER_8BIT,
+#endif
+	.rx_irq		= SC0RXIRQ,
+	.tx_irq		= SC0TXIRQ,
+	.rx_icr		= &GxICR(SC0RXIRQ),
+	.tx_icr		= &GxICR(SC0TXIRQ),
+	.clock_src	= MNSCx_CLOCK_SRC_IOCLK,
+	.options	= 0,
+#ifdef CONFIG_GDBSTUB_ON_TTYSM0
+	.gdbstub	= 1,
+#endif
+};
+#endif /* CONFIG_MN10300_TTYSM0 */
+
+/*
+ * the second on-chip serial port: ttySM1 (aka SIF1)
+ */
+#ifdef CONFIG_MN10300_TTYSM1
+struct mn10300_serial_port mn10300_serial_port_sif1 = {
+	.uart.ops	= &mn10300_serial_ops,
+	.uart.membase	= (void __iomem *) &SC1CTR,
+	.uart.mapbase	= (unsigned long) &SC1CTR,
+	.uart.iotype	= UPIO_MEM,
+	.uart.irq	= 0,
+	.uart.uartclk	= 0, /* MN10300_IOCLK, */
+	.uart.fifosize	= 1,
+	.uart.flags	= UPF_BOOT_AUTOCONF,
+	.uart.line	= 1,
+	.uart.type	= PORT_MN10300,
+	.uart.lock	=
+	__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif1.uart.lock),
+	.name		= "ttySM1",
+	._iobase	= &SC1CTR,
+	._control	= &SC1CTR,
+	._status	= (volatile u8 *) &SC1STR,
+	._intr		= &SC1ICR,
+	._rxb		= &SC1RXB,
+	._txb		= &SC1TXB,
+	.rx_name	= "ttySM1/Rx",
+	.tx_name	= "ttySM1/Tx",
+#ifdef CONFIG_MN10300_TTYSM1_TIMER9
+	.tm_name	= "ttySM1/Timer9",
+	._tmxmd		= &TM9MD,
+	._tmxbr		= &TM9BR,
+	._tmicr		= &TM9ICR,
+	.tm_irq		= TM9IRQ,
+	.div_timer	= MNSCx_DIV_TIMER_16BIT,
+#else /* CONFIG_MN10300_TTYSM1_TIMER3 */
+	.tm_name	= "ttySM1/Timer3",
+	._tmxmd		= &TM3MD,
+	._tmxbr		= (volatile u16 *) &TM3BR,
+	._tmicr		= &TM3ICR,
+	.tm_irq		= TM3IRQ,
+	.div_timer	= MNSCx_DIV_TIMER_8BIT,
+#endif
+	.rx_irq		= SC1RXIRQ,
+	.tx_irq		= SC1TXIRQ,
+	.rx_icr		= &GxICR(SC1RXIRQ),
+	.tx_icr		= &GxICR(SC1TXIRQ),
+	.clock_src	= MNSCx_CLOCK_SRC_IOCLK,
+	.options	= 0,
+#ifdef CONFIG_GDBSTUB_ON_TTYSM1
+	.gdbstub	= 1,
+#endif
+};
+#endif /* CONFIG_MN10300_TTYSM1 */
+
+/*
+ * the third on-chip serial port: ttySM2 (aka SIF2)
+ */
+#ifdef CONFIG_MN10300_TTYSM2
+struct mn10300_serial_port mn10300_serial_port_sif2 = {
+	.uart.ops	= &mn10300_serial_ops,
+	.uart.membase	= (void __iomem *) &SC2CTR,
+	.uart.mapbase	= (unsigned long) &SC2CTR,
+	.uart.iotype	= UPIO_MEM,
+	.uart.irq	= 0,
+	.uart.uartclk	= 0, /* MN10300_IOCLK, */
+	.uart.fifosize	= 1,
+	.uart.flags	= UPF_BOOT_AUTOCONF,
+	.uart.line	= 2,
+#ifdef CONFIG_MN10300_TTYSM2_CTS
+	.uart.type	= PORT_MN10300_CTS,
+#else
+	.uart.type	= PORT_MN10300,
+#endif
+	.uart.lock	=
+	__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif2.uart.lock),
+	.name		= "ttySM2",
+	.rx_name	= "ttySM2/Rx",
+	.tx_name	= "ttySM2/Tx",
+	.tm_name	= "ttySM2/Timer10",
+	._iobase	= &SC2CTR,
+	._control	= &SC2CTR,
+	._status	= &SC2STR,
+	._intr		= &SC2ICR,
+	._rxb		= &SC2RXB,
+	._txb		= &SC2TXB,
+	._tmxmd		= &TM10MD,
+	._tmxbr		= &TM10BR,
+	._tmicr		= &TM10ICR,
+	.tm_irq		= TM10IRQ,
+	.div_timer	= MNSCx_DIV_TIMER_16BIT,
+	.rx_irq		= SC2RXIRQ,
+	.tx_irq		= SC2TXIRQ,
+	.rx_icr		= &GxICR(SC2RXIRQ),
+	.tx_icr		= &GxICR(SC2TXIRQ),
+	.clock_src	= MNSCx_CLOCK_SRC_IOCLK,
+#ifdef CONFIG_MN10300_TTYSM2_CTS
+	.options	= MNSCx_OPT_CTS,
+#else
+	.options	= 0,
+#endif
+#ifdef CONFIG_GDBSTUB_ON_TTYSM2
+	.gdbstub	= 1,
+#endif
+};
+#endif /* CONFIG_MN10300_TTYSM2 */
+
+
+/*
+ * list of available serial ports
+ */
+struct mn10300_serial_port *mn10300_serial_ports[NR_UARTS + 1] = {
+#ifdef CONFIG_MN10300_TTYSM0
+	[0]	= &mn10300_serial_port_sif0,
+#endif
+#ifdef CONFIG_MN10300_TTYSM1
+	[1]	= &mn10300_serial_port_sif1,
+#endif
+#ifdef CONFIG_MN10300_TTYSM2
+	[2]	= &mn10300_serial_port_sif2,
+#endif
+	[NR_UARTS] = NULL,
+};
+
+
+/*
+ * we abuse the serial ports' baud timers' interrupt lines to get the ability
+ * to deliver interrupts to userspace as we use the ports' interrupt lines to
+ * do virtual DMA on account of the ports having no hardware FIFOs
+ *
+ * we can generate an interrupt manually in the assembly stubs by writing to
+ * the enable and detect bits in the interrupt control register, so all we need
+ * to do here is disable the interrupt line
+ *
+ * note that we can't just leave the line enabled as the baud rate timer *also*
+ * generates interrupts
+ */
+static void mn10300_serial_mask_ack(unsigned int irq)
+{
+	u16 tmp;
+	GxICR(irq) = GxICR_LEVEL_6;
+	tmp = GxICR(irq); /* flush write buffer */
+}
+
+static void mn10300_serial_nop(unsigned int irq)
+{
+}
+
+static struct irq_chip mn10300_serial_pic = {
+	.name		= "mnserial",
+	.ack		= mn10300_serial_mask_ack,
+	.mask		= mn10300_serial_mask_ack,
+	.mask_ack	= mn10300_serial_mask_ack,
+	.unmask		= mn10300_serial_nop,
+	.end		= mn10300_serial_nop,
+};
+
+
+/*
+ * serial virtual DMA interrupt jump table
+ */
+struct mn10300_serial_int mn10300_serial_int_tbl[NR_IRQS];
+
+static void mn10300_serial_dis_tx_intr(struct mn10300_serial_port *port)
+{
+	u16 x;
+	*port->tx_icr = GxICR_LEVEL_1 | GxICR_DETECT;
+	x = *port->tx_icr;
+}
+
+static void mn10300_serial_en_tx_intr(struct mn10300_serial_port *port)
+{
+	u16 x;
+	*port->tx_icr = GxICR_LEVEL_1 | GxICR_ENABLE;
+	x = *port->tx_icr;
+}
+
+static void mn10300_serial_dis_rx_intr(struct mn10300_serial_port *port)
+{
+	u16 x;
+	*port->rx_icr = GxICR_LEVEL_1 | GxICR_DETECT;
+	x = *port->rx_icr;
+}
+
+/*
+ * multi-bit equivalent of test_and_clear_bit()
+ */
+static int mask_test_and_clear(volatile u8 *ptr, u8 mask)
+{
+	u32 epsw;
+	asm volatile("	bclr	%1,(%2)		\n"
+		     "	mov	epsw,%0		\n"
+		     : "=d"(epsw) : "d"(mask), "a"(ptr));
+	return !(epsw & EPSW_FLAG_Z);
+}
+
+/*
+ * receive chars from the ring buffer for this serial port
+ * - must do break detection here (not done in the UART)
+ */
+static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
+{
+	struct uart_icount *icount = &port->uart.icount;
+	struct tty_struct *tty = port->uart.info->tty;
+	unsigned ix;
+	int count;
+	u8 st, ch, push, status, overrun;
+
+	_enter("%s", port->name);
+
+	push = 0;
+
+	count = CIRC_CNT(port->rx_inp, port->rx_outp, MNSC_BUFFER_SIZE);
+	count = tty_buffer_request_room(tty, count);
+	if (count == 0) {
+		if (!tty->low_latency)
+			tty_flip_buffer_push(tty);
+		return;
+	}
+
+try_again:
+	/* pull chars out of the hat */
+	ix = port->rx_outp;
+	if (ix == port->rx_inp) {
+		if (push && !tty->low_latency)
+			tty_flip_buffer_push(tty);
+		return;
+	}
+
+	ch = port->rx_buffer[ix++];
+	st = port->rx_buffer[ix++];
+	smp_rmb();
+	port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
+	port->uart.icount.rx++;
+
+	st &= SC01STR_FEF | SC01STR_PEF | SC01STR_OEF;
+	status = 0;
+	overrun = 0;
+
+	/* the UART doesn't detect BREAK, so we have to do that ourselves
+	 * - it starts as a framing error on a NUL character
+	 * - then we count another two NUL characters before issuing TTY_BREAK
+	 * - then we end on a normal char or one that has all the bottom bits
+	 *   zero and the top bits set
+	 */
+	switch (port->rx_brk) {
+	case 0:
+		/* not breaking at the moment */
+		break;
+
+	case 1:
+		if (st & SC01STR_FEF && ch == 0) {
+			port->rx_brk = 2;
+			goto try_again;
+		}
+		goto not_break;
+
+	case 2:
+		if (st & SC01STR_FEF && ch == 0) {
+			port->rx_brk = 3;
+			_proto("Rx Break Detected");
+			icount->brk++;
+			if (uart_handle_break(&port->uart))
+				goto ignore_char;
+			status |= 1 << TTY_BREAK;
+			goto insert;
+		}
+		goto not_break;
+
+	default:
+		if (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF))
+			goto try_again; /* still breaking */
+
+		port->rx_brk = 0; /* end of the break */
+
+		switch (ch) {
+		case 0xFF:
+		case 0xFE:
+		case 0xFC:
+		case 0xF8:
+		case 0xF0:
+		case 0xE0:
+		case 0xC0:
+		case 0x80:
+		case 0x00:
+			/* discard char at probable break end */
+			goto try_again;
+		}
+		break;
+	}
+
+process_errors:
+	/* handle framing error */
+	if (st & SC01STR_FEF) {
+		if (ch == 0) {
+			/* framing error with NUL char is probably a BREAK */
+			port->rx_brk = 1;
+			goto try_again;
+		}
+
+		_proto("Rx Framing Error");
+		icount->frame++;
+		status |= 1 << TTY_FRAME;
+	}
+
+	/* handle parity error */
+	if (st & SC01STR_PEF) {
+		_proto("Rx Parity Error");
+		icount->parity++;
+		status = TTY_PARITY;
+	}
+
+	/* handle normal char */
+	if (status == 0) {
+		if (uart_handle_sysrq_char(&port->uart, ch))
+			goto ignore_char;
+		status = (1 << TTY_NORMAL);
+	}
+
+	/* handle overrun error */
+	if (st & SC01STR_OEF) {
+		if (port->rx_brk)
+			goto try_again;
+
+		_proto("Rx Overrun Error");
+		icount->overrun++;
+		overrun = 1;
+	}
+
+insert:
+	status &= port->uart.read_status_mask;
+
+	if (!overrun && !(status & port->uart.ignore_status_mask)) {
+		int flag;
+
+		if (status & (1 << TTY_BREAK))
+			flag = TTY_BREAK;
+		else if (status & (1 << TTY_PARITY))
+			flag = TTY_PARITY;
+		else if (status & (1 << TTY_FRAME))
+			flag = TTY_FRAME;
+		else
+			flag = TTY_NORMAL;
+
+		tty_insert_flip_char(tty, ch, flag);
+	}
+
+	/* overrun is special, since it's reported immediately, and doesn't
+	 * affect the current character
+	 */
+	if (overrun)
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+
+	count--;
+	if (count <= 0) {
+		if (!tty->low_latency)
+			tty_flip_buffer_push(tty);
+		return;
+	}
+
+ignore_char:
+	push = 1;
+	goto try_again;
+
+not_break:
+	port->rx_brk = 0;
+	goto process_errors;
+}
+
+/*
+ * handle an interrupt from the serial transmission "virtual DMA" driver
+ * - note: the interrupt routine will disable its own interrupts when the Tx
+ *   buffer is empty
+ */
+static void mn10300_serial_transmit_interrupt(struct mn10300_serial_port *port)
+{
+	_enter("%s", port->name);
+
+	if (uart_tx_stopped(&port->uart) ||
+	    uart_circ_empty(&port->uart.info->xmit))
+		mn10300_serial_dis_tx_intr(port);
+
+	if (uart_circ_chars_pending(&port->uart.info->xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&port->uart);
+}
+
+/*
+ * deal with a change in the status of the CTS line
+ */
+static void mn10300_serial_cts_changed(struct mn10300_serial_port *port, u8 st)
+{
+	u16 ctr;
+
+	port->tx_cts = st;
+	port->uart.icount.cts++;
+
+	/* flip the CTS state selector flag to interrupt when it changes
+	 * back */
+	ctr = *port->_control;
+	ctr ^= SC2CTR_TWS;
+	*port->_control = ctr;
+
+	uart_handle_cts_change(&port->uart, st & SC2STR_CTS);
+	wake_up_interruptible(&port->uart.info->delta_msr_wait);
+}
+
+/*
+ * handle a virtual interrupt generated by the lower level "virtual DMA"
+ * routines (irq is the baud timer interrupt)
+ */
+static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id)
+{
+	struct mn10300_serial_port *port = dev_id;
+	u8 st;
+
+	spin_lock(&port->uart.lock);
+
+	if (port->intr_flags) {
+		_debug("INT %s: %x", port->name, port->intr_flags);
+
+		if (mask_test_and_clear(&port->intr_flags, MNSCx_RX_AVAIL))
+			mn10300_serial_receive_interrupt(port);
+
+		if (mask_test_and_clear(&port->intr_flags,
+					MNSCx_TX_SPACE | MNSCx_TX_EMPTY))
+			mn10300_serial_transmit_interrupt(port);
+	}
+
+	/* the only modem control line amongst the whole lot is CTS on
+	 * serial port 2 */
+	if (port->type == PORT_MN10300_CTS) {
+		st = *port->_status;
+		if ((port->tx_cts ^ st) & SC2STR_CTS)
+			mn10300_serial_cts_changed(port, st);
+	}
+
+	spin_unlock(&port->uart.lock);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * return indication of whether the hardware transmit buffer is empty
+ */
+static unsigned int mn10300_serial_tx_empty(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	return (*port->_status & (SC01STR_TXF | SC01STR_TBF)) ?
+		0 : TIOCSER_TEMT;
+}
+
+/*
+ * set the modem control lines (we don't have any)
+ */
+static void mn10300_serial_set_mctrl(struct uart_port *_port,
+				     unsigned int mctrl)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s,%x", port->name, mctrl);
+}
+
+/*
+ * get the modem control line statuses
+ */
+static unsigned int mn10300_serial_get_mctrl(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	if (port->type == PORT_MN10300_CTS && !(*port->_status & SC2STR_CTS))
+		return TIOCM_CAR | TIOCM_DSR;
+
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
+}
+
+/*
+ * stop transmitting characters
+ */
+static void mn10300_serial_stop_tx(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	/* disable the virtual DMA */
+	mn10300_serial_dis_tx_intr(port);
+}
+
+/*
+ * start transmitting characters
+ * - jump-start transmission if it has stalled
+ *   - enable the serial Tx interrupt (used by the virtual DMA controller)
+ *   - force an interrupt to happen if necessary
+ */
+static void mn10300_serial_start_tx(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	u16 x;
+
+	_enter("%s{%lu}",
+	       port->name,
+	       CIRC_CNT(&port->uart.info->xmit.head,
+			&port->uart.info->xmit.tail,
+			UART_XMIT_SIZE));
+
+	/* kick the virtual DMA controller */
+	x = *port->tx_icr;
+	x |= GxICR_ENABLE;
+
+	if (*port->_status & SC01STR_TBF)
+		x &= ~(GxICR_REQUEST | GxICR_DETECT);
+	else
+		x |= GxICR_REQUEST | GxICR_DETECT;
+
+	_debug("CTR=%04hx ICR=%02hx STR=%04x TMD=%02hx TBR=%04hx ICR=%04hx",
+	       *port->_control, *port->_intr, *port->_status,
+	       *port->_tmxmd, *port->_tmxbr, *port->tx_icr);
+
+	*port->tx_icr = x;
+	x = *port->tx_icr;
+}
+
+/*
+ * transmit a high-priority XON/XOFF character
+ */
+static void mn10300_serial_send_xchar(struct uart_port *_port, char ch)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s,%02x", port->name, ch);
+
+	if (likely(port->gdbstub)) {
+		port->tx_xchar = ch;
+		if (ch)
+			mn10300_serial_en_tx_intr(port);
+	}
+}
+
+/*
+ * stop receiving characters
+ * - called whilst the port is being closed
+ */
+static void mn10300_serial_stop_rx(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	u16 ctr;
+
+	_enter("%s", port->name);
+
+	ctr = *port->_control;
+	ctr &= ~SC01CTR_RXE;
+	*port->_control = ctr;
+
+	mn10300_serial_dis_rx_intr(port);
+}
+
+/*
+ * enable modem status interrupts
+ */
+static void mn10300_serial_enable_ms(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	u16 ctr, cts;
+
+	_enter("%s", port->name);
+
+	if (port->type == PORT_MN10300_CTS) {
+		/* want to interrupt when CTS goes low if CTS is now high and
+		 * vice versa
+		 */
+		port->tx_cts = *port->_status;
+
+		cts = (port->tx_cts & SC2STR_CTS) ?
+			SC2CTR_TWE : SC2CTR_TWE | SC2CTR_TWS;
+
+		ctr = *port->_control;
+		ctr &= ~SC2CTR_TWS;
+		ctr |= cts;
+		*port->_control = ctr;
+
+		mn10300_serial_en_tx_intr(port);
+	}
+}
+
+/*
+ * transmit or cease transmitting a break signal
+ */
+static void mn10300_serial_break_ctl(struct uart_port *_port, int ctl)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s,%d", port->name, ctl);
+
+	if (ctl) {
+		/* tell the virtual DMA handler to assert BREAK */
+		port->tx_break = 1;
+		mn10300_serial_en_tx_intr(port);
+	} else {
+		port->tx_break = 0;
+		*port->_control &= ~SC01CTR_BKE;
+		mn10300_serial_en_tx_intr(port);
+	}
+}
+
+/*
+ * grab the interrupts and enable the port for reception
+ */
+static int mn10300_serial_startup(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+	struct mn10300_serial_int *pint;
+
+	_enter("%s{%d}", port->name, port->gdbstub);
+
+	if (unlikely(port->gdbstub))
+		return -EBUSY;
+
+	/* allocate an Rx buffer for the virtual DMA handler */
+	port->rx_buffer = kmalloc(MNSC_BUFFER_SIZE, GFP_KERNEL);
+	if (!port->rx_buffer)
+		return -ENOMEM;
+
+	port->rx_inp = port->rx_outp = 0;
+
+	/* finally, enable the device */
+	*port->_intr = SC01ICR_TI;
+	*port->_control |= SC01CTR_TXE | SC01CTR_RXE;
+
+	pint = &mn10300_serial_int_tbl[port->rx_irq];
+	pint->port = port;
+	pint->vdma = mn10300_serial_vdma_rx_handler;
+	pint = &mn10300_serial_int_tbl[port->tx_irq];
+	pint->port = port;
+	pint->vdma = mn10300_serial_vdma_tx_handler;
+
+	set_intr_level(port->rx_irq, GxICR_LEVEL_1);
+	set_intr_level(port->tx_irq, GxICR_LEVEL_1);
+	set_irq_chip(port->tm_irq, &mn10300_serial_pic);
+
+	if (request_irq(port->rx_irq, mn10300_serial_interrupt,
+			IRQF_DISABLED, port->rx_name, port) < 0)
+		goto error;
+
+	if (request_irq(port->tx_irq, mn10300_serial_interrupt,
+			IRQF_DISABLED, port->tx_name, port) < 0)
+		goto error2;
+
+	if (request_irq(port->tm_irq, mn10300_serial_interrupt,
+			IRQF_DISABLED, port->tm_name, port) < 0)
+		goto error3;
+	mn10300_serial_mask_ack(port->tm_irq);
+
+	return 0;
+
+error3:
+	free_irq(port->tx_irq, port);
+error2:
+	free_irq(port->rx_irq, port);
+error:
+	kfree(port->rx_buffer);
+	port->rx_buffer = NULL;
+	return -EBUSY;
+}
+
+/*
+ * shutdown the port and release interrupts
+ */
+static void mn10300_serial_shutdown(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	/* disable the serial port and its baud rate timer */
+	port->tx_break = 0;
+	*port->_control &= ~(SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
+	*port->_tmxmd = 0;
+
+	if (port->rx_buffer) {
+		void *buf = port->rx_buffer;
+		port->rx_buffer = NULL;
+		kfree(buf);
+	}
+
+	/* disable all intrs */
+	free_irq(port->tm_irq, port);
+	free_irq(port->rx_irq, port);
+	free_irq(port->tx_irq, port);
+
+	*port->rx_icr = GxICR_LEVEL_1;
+	*port->tx_icr = GxICR_LEVEL_1;
+}
+
+/*
+ * this routine is called to set the UART divisor registers to match the
+ * specified baud rate for a serial port.
+ */
+static void mn10300_serial_change_speed(struct mn10300_serial_port *port,
+					  struct ktermios *new,
+					  struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned long ioclk = port->ioclk;
+	unsigned cflag;
+	int baud, bits, xdiv, tmp;
+	u16 tmxbr, scxctr;
+	u8 tmxmd, battempt;
+	u8 div_timer = port->div_timer;
+
+	_enter("%s{%lu}", port->name, ioclk);
+
+	/* byte size and parity */
+	cflag = new->c_cflag;
+	switch (cflag & CSIZE) {
+	case CS7: scxctr = SC01CTR_CLN_7BIT; bits = 9;  break;
+	case CS8: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
+	default:  scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
+	}
+
+	if (cflag & CSTOPB) {
+		scxctr |= SC01CTR_STB_2BIT;
+		bits++;
+	}
+
+	if (cflag & PARENB) {
+		bits++;
+		if (cflag & PARODD)
+			scxctr |= SC01CTR_PB_ODD;
+#ifdef CMSPAR
+		else if (cflag & CMSPAR)
+			scxctr |= SC01CTR_PB_FIXED0;
+#endif
+		else
+			scxctr |= SC01CTR_PB_EVEN;
+	}
+
+	/* Determine divisor based on baud rate */
+	battempt = 0;
+
+	if (div_timer == MNSCx_DIV_TIMER_16BIT)
+		scxctr |= SC0CTR_CK_TM8UFLOW_8; /* ( == SC1CTR_CK_TM9UFLOW_8
+						 *   == SC2CTR_CK_TM10UFLOW) */
+	else if (div_timer == MNSCx_DIV_TIMER_8BIT)
+		scxctr |= SC0CTR_CK_TM2UFLOW_8;
+
+try_alternative:
+	baud = uart_get_baud_rate(&port->uart, new, old, 0,
+				  port->ioclk / 8);
+
+	_debug("ALT %d [baud %d]", battempt, baud);
+
+	if (!baud)
+		baud = 9600;	/* B0 transition handled in rs_set_termios */
+	xdiv = 1;
+	if (baud == 134) {
+		baud = 269;	/* 134 is really 134.5 */
+		xdiv = 2;
+	}
+
+	if (baud == 38400 &&
+	    (port->uart.flags & UPF_SPD_MASK) == UPF_SPD_CUST
+	    ) {
+		_debug("CUSTOM %u", port->uart.custom_divisor);
+
+		if (div_timer == MNSCx_DIV_TIMER_16BIT) {
+			if (port->uart.custom_divisor <= 65535) {
+				tmxmd = TM8MD_SRC_IOCLK;
+				tmxbr = port->uart.custom_divisor;
+				port->uart.uartclk = ioclk;
+				goto timer_okay;
+			}
+			if (port->uart.custom_divisor / 8 <= 65535) {
+				tmxmd = TM8MD_SRC_IOCLK_8;
+				tmxbr = port->uart.custom_divisor / 8;
+				port->uart.custom_divisor = tmxbr * 8;
+				port->uart.uartclk = ioclk / 8;
+				goto timer_okay;
+			}
+			if (port->uart.custom_divisor / 32 <= 65535) {
+				tmxmd = TM8MD_SRC_IOCLK_32;
+				tmxbr = port->uart.custom_divisor / 32;
+				port->uart.custom_divisor = tmxbr * 32;
+				port->uart.uartclk = ioclk / 32;
+				goto timer_okay;
+			}
+
+		} else if (div_timer == MNSCx_DIV_TIMER_8BIT) {
+			if (port->uart.custom_divisor <= 255) {
+				tmxmd = TM2MD_SRC_IOCLK;
+				tmxbr = port->uart.custom_divisor;
+				port->uart.uartclk = ioclk;
+				goto timer_okay;
+			}
+			if (port->uart.custom_divisor / 8 <= 255) {
+				tmxmd = TM2MD_SRC_IOCLK_8;
+				tmxbr = port->uart.custom_divisor / 8;
+				port->uart.custom_divisor = tmxbr * 8;
+				port->uart.uartclk = ioclk / 8;
+				goto timer_okay;
+			}
+			if (port->uart.custom_divisor / 32 <= 255) {
+				tmxmd = TM2MD_SRC_IOCLK_32;
+				tmxbr = port->uart.custom_divisor / 32;
+				port->uart.custom_divisor = tmxbr * 32;
+				port->uart.uartclk = ioclk / 32;
+				goto timer_okay;
+			}
+		}
+	}
+
+	switch (div_timer) {
+	case MNSCx_DIV_TIMER_16BIT:
+		port->uart.uartclk = ioclk;
+		tmxmd = TM8MD_SRC_IOCLK;
+		tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 65535)
+			goto timer_okay;
+
+		port->uart.uartclk = ioclk / 8;
+		tmxmd = TM8MD_SRC_IOCLK_8;
+		tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 65535)
+			goto timer_okay;
+
+		port->uart.uartclk = ioclk / 32;
+		tmxmd = TM8MD_SRC_IOCLK_32;
+		tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 65535)
+			goto timer_okay;
+		break;
+
+	case MNSCx_DIV_TIMER_8BIT:
+		port->uart.uartclk = ioclk;
+		tmxmd = TM2MD_SRC_IOCLK;
+		tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 255)
+			goto timer_okay;
+
+		port->uart.uartclk = ioclk / 8;
+		tmxmd = TM2MD_SRC_IOCLK_8;
+		tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 255)
+			goto timer_okay;
+
+		port->uart.uartclk = ioclk / 32;
+		tmxmd = TM2MD_SRC_IOCLK_32;
+		tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
+		if (tmp > 0 && tmp <= 255)
+			goto timer_okay;
+		break;
+
+	default:
+		BUG();
+		return;
+	}
+
+	/* refuse to change to a baud rate we can't support */
+	_debug("CAN'T SUPPORT");
+
+	switch (battempt) {
+	case 0:
+		if (old) {
+			new->c_cflag &= ~CBAUD;
+			new->c_cflag |= (old->c_cflag & CBAUD);
+			battempt = 1;
+			goto try_alternative;
+		}
+
+	case 1:
+		/* as a last resort, if the quotient is zero, default to 9600
+		 * bps */
+		new->c_cflag &= ~CBAUD;
+		new->c_cflag |= B9600;
+		battempt = 2;
+		goto try_alternative;
+
+	default:
+		/* hmmm... can't seem to support 9600 either
+		 * - we could try iterating through the speeds we know about to
+		 *   find the lowest
+		 */
+		new->c_cflag &= ~CBAUD;
+		new->c_cflag |= B0;
+
+		if (div_timer == MNSCx_DIV_TIMER_16BIT)
+			tmxmd = TM8MD_SRC_IOCLK_32;
+		else if (div_timer == MNSCx_DIV_TIMER_8BIT)
+			tmxmd = TM2MD_SRC_IOCLK_32;
+		tmxbr = 1;
+
+		port->uart.uartclk = ioclk / 32;
+		break;
+	}
+timer_okay:
+
+	_debug("UARTCLK: %u / %hu", port->uart.uartclk, tmxbr);
+
+	/* make the changes */
+	spin_lock_irqsave(&port->uart.lock, flags);
+
+	uart_update_timeout(&port->uart, new->c_cflag, baud);
+
+	/* set the timer to produce the required baud rate */
+	switch (div_timer) {
+	case MNSCx_DIV_TIMER_16BIT:
+		*port->_tmxmd = 0;
+		*port->_tmxbr = tmxbr;
+		*port->_tmxmd = TM8MD_INIT_COUNTER;
+		*port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
+		break;
+
+	case MNSCx_DIV_TIMER_8BIT:
+		*port->_tmxmd = 0;
+		*(volatile u8 *) port->_tmxbr = (u8) tmxbr;
+		*port->_tmxmd = TM2MD_INIT_COUNTER;
+		*port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
+		break;
+	}
+
+	/* CTS flow control flag and modem status interrupts */
+	scxctr &= ~(SC2CTR_TWE | SC2CTR_TWS);
+
+	if (port->type == PORT_MN10300_CTS && cflag & CRTSCTS) {
+		/* want to interrupt when CTS goes low if CTS is now
+		 * high and vice versa
+		 */
+		port->tx_cts = *port->_status;
+
+		if (port->tx_cts & SC2STR_CTS)
+			scxctr |= SC2CTR_TWE;
+		else
+			scxctr |= SC2CTR_TWE | SC2CTR_TWS;
+	}
+
+	/* set up parity check flag */
+	port->uart.read_status_mask = (1 << TTY_NORMAL) | (1 << TTY_OVERRUN);
+	if (new->c_iflag & INPCK)
+		port->uart.read_status_mask |=
+			(1 << TTY_PARITY) | (1 << TTY_FRAME);
+	if (new->c_iflag & (BRKINT | PARMRK))
+		port->uart.read_status_mask |= (1 << TTY_BREAK);
+
+	/* characters to ignore */
+	port->uart.ignore_status_mask = 0;
+	if (new->c_iflag & IGNPAR)
+		port->uart.ignore_status_mask |=
+			(1 << TTY_PARITY) | (1 << TTY_FRAME);
+	if (new->c_iflag & IGNBRK) {
+		port->uart.ignore_status_mask |= (1 << TTY_BREAK);
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns to (for real raw support).
+		 */
+		if (new->c_iflag & IGNPAR)
+			port->uart.ignore_status_mask |= (1 << TTY_OVERRUN);
+	}
+
+	/* Ignore all characters if CREAD is not set */
+	if ((new->c_cflag & CREAD) == 0)
+		port->uart.ignore_status_mask |= (1 << TTY_NORMAL);
+
+	scxctr |= *port->_control & (SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
+	*port->_control = scxctr;
+
+	spin_unlock_irqrestore(&port->uart.lock, flags);
+}
+
+/*
+ * set the terminal I/O parameters
+ */
+static void mn10300_serial_set_termios(struct uart_port *_port,
+					 struct ktermios *new,
+					 struct ktermios *old)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s,%p,%p", port->name, new, old);
+
+	mn10300_serial_change_speed(port, new, old);
+
+	/* handle turning off CRTSCTS */
+	if (!(new->c_cflag & CRTSCTS)) {
+		u16 ctr = *port->_control;
+		ctr &= ~SC2CTR_TWE;
+		*port->_control = ctr;
+	}
+}
+
+/*
+ * return description of port type
+ */
+static const char *mn10300_serial_type(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	if (port->uart.type == PORT_MN10300_CTS)
+		return "MN10300 SIF_CTS";
+
+	return "MN10300 SIF";
+}
+
+/*
+ * release I/O and memory regions in use by port
+ */
+static void mn10300_serial_release_port(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	release_mem_region((unsigned long) port->_iobase, 16);
+}
+
+/*
+ * request I/O and memory regions for port
+ */
+static int mn10300_serial_request_port(struct uart_port *_port)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	request_mem_region((unsigned long) port->_iobase, 16, port->name);
+	return 0;
+}
+
+/*
+ * configure the type and reserve the ports
+ */
+static void mn10300_serial_config_port(struct uart_port *_port, int type)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+
+	_enter("%s", port->name);
+
+	port->uart.type = PORT_MN10300;
+
+	if (port->options & MNSCx_OPT_CTS)
+		port->uart.type = PORT_MN10300_CTS;
+
+	mn10300_serial_request_port(_port);
+}
+
+/*
+ * verify serial parameters are suitable for this port type
+ */
+static int mn10300_serial_verify_port(struct uart_port *_port,
+					struct serial_struct *ss)
+{
+	struct mn10300_serial_port *port =
+		container_of(_port, struct mn10300_serial_port, uart);
+	void *mapbase = (void *) (unsigned long) port->uart.mapbase;
+
+	_enter("%s", port->name);
+
+	/* these things may not be changed */
+	if (ss->irq		!= port->uart.irq	||
+	    ss->port		!= port->uart.iobase	||
+	    ss->io_type		!= port->uart.iotype	||
+	    ss->iomem_base	!= mapbase ||
+	    ss->iomem_reg_shift	!= port->uart.regshift	||
+	    ss->hub6		!= port->uart.hub6	||
+	    ss->xmit_fifo_size	!= port->uart.fifosize)
+		return -EINVAL;
+
+	/* type may be changed on a port that supports CTS */
+	if (ss->type != port->uart.type) {
+		if (!(port->options & MNSCx_OPT_CTS))
+			return -EINVAL;
+
+		if (ss->type != PORT_MN10300 &&
+		    ss->type != PORT_MN10300_CTS)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * initialise the MN10300 on-chip UARTs
+ */
+static int __init mn10300_serial_init(void)
+{
+	struct mn10300_serial_port *port;
+	int ret, i;
+
+	printk(KERN_INFO "%s version %s (%s)\n",
+	       serial_name, serial_version, serial_revdate);
+
+#ifdef CONFIG_MN10300_TTYSM2
+	SC2TIM = 8; /* make the baud base of timer 2 IOCLK/8 */
+#endif
+
+	set_intr_stub(EXCEP_IRQ_LEVEL1, mn10300_serial_vdma_interrupt);
+
+	ret = uart_register_driver(&mn10300_serial_driver);
+	if (!ret) {
+		for (i = 0 ; i < NR_PORTS ; i++) {
+			port = mn10300_serial_ports[i];
+			if (!port || port->gdbstub)
+				continue;
+
+			switch (port->clock_src) {
+			case MNSCx_CLOCK_SRC_IOCLK:
+				port->ioclk = MN10300_IOCLK;
+				break;
+
+#ifdef MN10300_IOBCLK
+			case MNSCx_CLOCK_SRC_IOBCLK:
+				port->ioclk = MN10300_IOBCLK;
+				break;
+#endif
+			default:
+				BUG();
+			}
+
+			ret = uart_add_one_port(&mn10300_serial_driver,
+						&port->uart);
+
+			if (ret < 0) {
+				_debug("ERROR %d", -ret);
+				break;
+			}
+		}
+
+		if (ret)
+			uart_unregister_driver(&mn10300_serial_driver);
+	}
+
+	return ret;
+}
+
+__initcall(mn10300_serial_init);
+
+
+#ifdef CONFIG_MN10300_TTYSM_CONSOLE
+
+/*
+ * print a string to the serial port without disturbing the real user of the
+ * port too much
+ * - the console must be locked by the caller
+ */
+static void mn10300_serial_console_write(struct console *co,
+					   const char *s, unsigned count)
+{
+	struct mn10300_serial_port *port;
+	unsigned i;
+	u16 scxctr, txicr, tmp;
+	u8 tmxmd;
+
+	port = mn10300_serial_ports[co->index];
+
+	/* firstly hijack the serial port from the "virtual DMA" controller */
+	txicr = *port->tx_icr;
+	*port->tx_icr = GxICR_LEVEL_1;
+	tmp = *port->tx_icr;
+
+	/* the transmitter may be disabled */
+	scxctr = *port->_control;
+	if (!(scxctr & SC01CTR_TXE)) {
+		/* restart the UART clock */
+		tmxmd = *port->_tmxmd;
+
+		switch (port->div_timer) {
+		case MNSCx_DIV_TIMER_16BIT:
+			*port->_tmxmd = 0;
+			*port->_tmxmd = TM8MD_INIT_COUNTER;
+			*port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
+			break;
+
+		case MNSCx_DIV_TIMER_8BIT:
+			*port->_tmxmd = 0;
+			*port->_tmxmd = TM2MD_INIT_COUNTER;
+			*port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
+			break;
+		}
+
+		/* enable the transmitter */
+		*port->_control = (scxctr & ~SC01CTR_BKE) | SC01CTR_TXE;
+
+	} else if (scxctr & SC01CTR_BKE) {
+		/* stop transmitting BREAK */
+		*port->_control = (scxctr & ~SC01CTR_BKE);
+	}
+
+	/* send the chars into the serial port (with LF -> LFCR conversion) */
+	for (i = 0; i < count; i++) {
+		char ch = *s++;
+
+		while (*port->_status & SC01STR_TBF)
+			continue;
+		*(u8 *) port->_txb = ch;
+
+		if (ch == 0x0a) {
+			while (*port->_status & SC01STR_TBF)
+				continue;
+			*(u8 *) port->_txb = 0xd;
+		}
+	}
+
+	/* can't let the transmitter be turned off if it's actually
+	 * transmitting */
+	while (*port->_status & (SC01STR_TXF | SC01STR_TBF))
+		continue;
+
+	/* disable the transmitter if we re-enabled it */
+	if (!(scxctr & SC01CTR_TXE))
+		*port->_control = scxctr;
+
+	*port->tx_icr = txicr;
+	tmp = *port->tx_icr;
+}
+
+/*
+ * set up a serial port as a console
+ * - construct a cflag setting for the first rs_open()
+ * - initialize the serial port
+ * - return non-zero if we didn't find a serial port.
+ */
+static int __init mn10300_serial_console_setup(struct console *co,
+						 char *options)
+{
+	struct mn10300_serial_port *port;
+	int i, parity = 'n', baud = 9600, bits = 8, flow = 0;
+
+	for (i = 0 ; i < NR_PORTS ; i++) {
+		port = mn10300_serial_ports[i];
+		if (port && !port->gdbstub && port->uart.line == co->index)
+			goto found_device;
+	}
+
+	return -ENODEV;
+
+found_device:
+	switch (port->clock_src) {
+	case MNSCx_CLOCK_SRC_IOCLK:
+		port->ioclk = MN10300_IOCLK;
+		break;
+
+#ifdef MN10300_IOBCLK
+	case MNSCx_CLOCK_SRC_IOBCLK:
+		port->ioclk = MN10300_IOBCLK;
+		break;
+#endif
+	default:
+		BUG();
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&port->uart, co, baud, parity, bits, flow);
+}
+
+/*
+ * register console
+ */
+static int __init mn10300_serial_console_init(void)
+{
+	register_console(&mn10300_serial_console);
+	return 0;
+}
+
+console_initcall(mn10300_serial_console_init);
+#endif