tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2027 insertions, 0 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
new file mode 100644
index 000000000000..c291b3add1d2
--- /dev/null
+++ b/drivers/tty/serial/sh-sci.c
@@ -0,0 +1,2027 @@
+/*
+ * drivers/serial/sh-sci.c
+ *
+ * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
+ *
+ *  Copyright (C) 2002 - 2008  Paul Mundt
+ *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
+ *
+ * based off of the old drivers/char/sh-sci.c by:
+ *
+ *   Copyright (C) 1999, 2000  Niibe Yutaka
+ *   Copyright (C) 2000  Sugioka Toshinobu
+ *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
+ *   Modified to support SecureEdge. David McCullough (2002)
+ *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
+ *   Removed SH7300 support (Jul 2007).
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#undef DEBUG
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/sysrq.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/console.h>
+#include <linux/platform_device.h>
+#include <linux/serial_sci.h>
+#include <linux/notifier.h>
+#include <linux/cpufreq.h>
+#include <linux/clk.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/dmaengine.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_SUPERH
+#include <asm/sh_bios.h>
+#endif
+
+#ifdef CONFIG_H8300
+#include <asm/gpio.h>
+#endif
+
+#include "sh-sci.h"
+
+struct sci_port {
+	struct uart_port	port;
+
+	/* Port type */
+	unsigned int		type;
+
+	/* Port IRQs: ERI, RXI, TXI, BRI (optional) */
+	unsigned int		irqs[SCIx_NR_IRQS];
+
+	/* Port enable callback */
+	void			(*enable)(struct uart_port *port);
+
+	/* Port disable callback */
+	void			(*disable)(struct uart_port *port);
+
+	/* Break timer */
+	struct timer_list	break_timer;
+	int			break_flag;
+
+	/* Interface clock */
+	struct clk		*iclk;
+	/* Function clock */
+	struct clk		*fclk;
+
+	struct list_head	node;
+	struct dma_chan			*chan_tx;
+	struct dma_chan			*chan_rx;
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	struct device			*dma_dev;
+	unsigned int			slave_tx;
+	unsigned int			slave_rx;
+	struct dma_async_tx_descriptor	*desc_tx;
+	struct dma_async_tx_descriptor	*desc_rx[2];
+	dma_cookie_t			cookie_tx;
+	dma_cookie_t			cookie_rx[2];
+	dma_cookie_t			active_rx;
+	struct scatterlist		sg_tx;
+	unsigned int			sg_len_tx;
+	struct scatterlist		sg_rx[2];
+	size_t				buf_len_rx;
+	struct sh_dmae_slave		param_tx;
+	struct sh_dmae_slave		param_rx;
+	struct work_struct		work_tx;
+	struct work_struct		work_rx;
+	struct timer_list		rx_timer;
+	unsigned int			rx_timeout;
+#endif
+};
+
+struct sh_sci_priv {
+	spinlock_t lock;
+	struct list_head ports;
+	struct notifier_block clk_nb;
+};
+
+/* Function prototypes */
+static void sci_stop_tx(struct uart_port *port);
+
+#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
+
+static struct sci_port sci_ports[SCI_NPORTS];
+static struct uart_driver sci_uart_driver;
+
+static inline struct sci_port *
+to_sci_port(struct uart_port *uart)
+{
+	return container_of(uart, struct sci_port, port);
+}
+
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
+
+#ifdef CONFIG_CONSOLE_POLL
+static inline void handle_error(struct uart_port *port)
+{
+	/* Clear error flags */
+	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
+}
+
+static int sci_poll_get_char(struct uart_port *port)
+{
+	unsigned short status;
+	int c;
+
+	do {
+		status = sci_in(port, SCxSR);
+		if (status & SCxSR_ERRORS(port)) {
+			handle_error(port);
+			continue;
+		}
+		break;
+	} while (1);
+
+	if (!(status & SCxSR_RDxF(port)))
+		return NO_POLL_CHAR;
+
+	c = sci_in(port, SCxRDR);
+
+	/* Dummy read */
+	sci_in(port, SCxSR);
+	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+
+	return c;
+}
+#endif
+
+static void sci_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned short status;
+
+	do {
+		status = sci_in(port, SCxSR);
+	} while (!(status & SCxSR_TDxE(port)));
+
+	sci_out(port, SCxTDR, c);
+	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
+}
+#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
+
+#if defined(__H8300H__) || defined(__H8300S__)
+static void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	int ch = (port->mapbase - SMR0) >> 3;
+
+	/* set DDR regs */
+	H8300_GPIO_DDR(h8300_sci_pins[ch].port,
+		       h8300_sci_pins[ch].rx,
+		       H8300_GPIO_INPUT);
+	H8300_GPIO_DDR(h8300_sci_pins[ch].port,
+		       h8300_sci_pins[ch].tx,
+		       H8300_GPIO_OUTPUT);
+
+	/* tx mark output*/
+	H8300_SCI_DR(ch) |= h8300_sci_pins[ch].tx;
+}
+#elif defined(CONFIG_CPU_SUBTYPE_SH7710) || defined(CONFIG_CPU_SUBTYPE_SH7712)
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	if (port->mapbase == 0xA4400000) {
+		__raw_writew(__raw_readw(PACR) & 0xffc0, PACR);
+		__raw_writew(__raw_readw(PBCR) & 0x0fff, PBCR);
+	} else if (port->mapbase == 0xA4410000)
+		__raw_writew(__raw_readw(PBCR) & 0xf003, PBCR);
+}
+#elif defined(CONFIG_CPU_SUBTYPE_SH7720) || defined(CONFIG_CPU_SUBTYPE_SH7721)
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	unsigned short data;
+
+	if (cflag & CRTSCTS) {
+		/* enable RTS/CTS */
+		if (port->mapbase == 0xa4430000) { /* SCIF0 */
+			/* Clear PTCR bit 9-2; enable all scif pins but sck */
+			data = __raw_readw(PORT_PTCR);
+			__raw_writew((data & 0xfc03), PORT_PTCR);
+		} else if (port->mapbase == 0xa4438000) { /* SCIF1 */
+			/* Clear PVCR bit 9-2 */
+			data = __raw_readw(PORT_PVCR);
+			__raw_writew((data & 0xfc03), PORT_PVCR);
+		}
+	} else {
+		if (port->mapbase == 0xa4430000) { /* SCIF0 */
+			/* Clear PTCR bit 5-2; enable only tx and rx  */
+			data = __raw_readw(PORT_PTCR);
+			__raw_writew((data & 0xffc3), PORT_PTCR);
+		} else if (port->mapbase == 0xa4438000) { /* SCIF1 */
+			/* Clear PVCR bit 5-2 */
+			data = __raw_readw(PORT_PVCR);
+			__raw_writew((data & 0xffc3), PORT_PVCR);
+		}
+	}
+}
+#elif defined(CONFIG_CPU_SH3)
+/* For SH7705, SH7706, SH7707, SH7709, SH7709A, SH7729 */
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	unsigned short data;
+
+	/* We need to set SCPCR to enable RTS/CTS */
+	data = __raw_readw(SCPCR);
+	/* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/
+	__raw_writew(data & 0x0fcf, SCPCR);
+
+	if (!(cflag & CRTSCTS)) {
+		/* We need to set SCPCR to enable RTS/CTS */
+		data = __raw_readw(SCPCR);
+		/* Clear out SCP7MD1,0, SCP4MD1,0,
+		   Set SCP6MD1,0 = {01} (output)  */
+		__raw_writew((data & 0x0fcf) | 0x1000, SCPCR);
+
+		data = __raw_readb(SCPDR);
+		/* Set /RTS2 (bit6) = 0 */
+		__raw_writeb(data & 0xbf, SCPDR);
+	}
+}
+#elif defined(CONFIG_CPU_SUBTYPE_SH7722)
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	unsigned short data;
+
+	if (port->mapbase == 0xffe00000) {
+		data = __raw_readw(PSCR);
+		data &= ~0x03cf;
+		if (!(cflag & CRTSCTS))
+			data |= 0x0340;
+
+		__raw_writew(data, PSCR);
+	}
+}
+#elif defined(CONFIG_CPU_SUBTYPE_SH7757) || \
+      defined(CONFIG_CPU_SUBTYPE_SH7763) || \
+      defined(CONFIG_CPU_SUBTYPE_SH7780) || \
+      defined(CONFIG_CPU_SUBTYPE_SH7785) || \
+      defined(CONFIG_CPU_SUBTYPE_SH7786) || \
+      defined(CONFIG_CPU_SUBTYPE_SHX3)
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	if (!(cflag & CRTSCTS))
+		__raw_writew(0x0080, SCSPTR0); /* Set RTS = 1 */
+}
+#elif defined(CONFIG_CPU_SH4) && !defined(CONFIG_CPU_SH4A)
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	if (!(cflag & CRTSCTS))
+		__raw_writew(0x0080, SCSPTR2); /* Set RTS = 1 */
+}
+#else
+static inline void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	/* Nothing to do */
+}
+#endif
+
+#if defined(CONFIG_CPU_SUBTYPE_SH7760) || \
+    defined(CONFIG_CPU_SUBTYPE_SH7780) || \
+    defined(CONFIG_CPU_SUBTYPE_SH7785) || \
+    defined(CONFIG_CPU_SUBTYPE_SH7786)
+static int scif_txfill(struct uart_port *port)
+{
+	return sci_in(port, SCTFDR) & 0xff;
+}
+
+static int scif_txroom(struct uart_port *port)
+{
+	return SCIF_TXROOM_MAX - scif_txfill(port);
+}
+
+static int scif_rxfill(struct uart_port *port)
+{
+	return sci_in(port, SCRFDR) & 0xff;
+}
+#elif defined(CONFIG_CPU_SUBTYPE_SH7763)
+static int scif_txfill(struct uart_port *port)
+{
+	if (port->mapbase == 0xffe00000 ||
+	    port->mapbase == 0xffe08000)
+		/* SCIF0/1*/
+		return sci_in(port, SCTFDR) & 0xff;
+	else
+		/* SCIF2 */
+		return sci_in(port, SCFDR) >> 8;
+}
+
+static int scif_txroom(struct uart_port *port)
+{
+	if (port->mapbase == 0xffe00000 ||
+	    port->mapbase == 0xffe08000)
+		/* SCIF0/1*/
+		return SCIF_TXROOM_MAX - scif_txfill(port);
+	else
+		/* SCIF2 */
+		return SCIF2_TXROOM_MAX - scif_txfill(port);
+}
+
+static int scif_rxfill(struct uart_port *port)
+{
+	if ((port->mapbase == 0xffe00000) ||
+	    (port->mapbase == 0xffe08000)) {
+		/* SCIF0/1*/
+		return sci_in(port, SCRFDR) & 0xff;
+	} else {
+		/* SCIF2 */
+		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
+	}
+}
+#elif defined(CONFIG_ARCH_SH7372)
+static int scif_txfill(struct uart_port *port)
+{
+	if (port->type == PORT_SCIFA)
+		return sci_in(port, SCFDR) >> 8;
+	else
+		return sci_in(port, SCTFDR);
+}
+
+static int scif_txroom(struct uart_port *port)
+{
+	return port->fifosize - scif_txfill(port);
+}
+
+static int scif_rxfill(struct uart_port *port)
+{
+	if (port->type == PORT_SCIFA)
+		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
+	else
+		return sci_in(port, SCRFDR);
+}
+#else
+static int scif_txfill(struct uart_port *port)
+{
+	return sci_in(port, SCFDR) >> 8;
+}
+
+static int scif_txroom(struct uart_port *port)
+{
+	return SCIF_TXROOM_MAX - scif_txfill(port);
+}
+
+static int scif_rxfill(struct uart_port *port)
+{
+	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
+}
+#endif
+
+static int sci_txfill(struct uart_port *port)
+{
+	return !(sci_in(port, SCxSR) & SCI_TDRE);
+}
+
+static int sci_txroom(struct uart_port *port)
+{
+	return !sci_txfill(port);
+}
+
+static int sci_rxfill(struct uart_port *port)
+{
+	return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
+}
+
+/* ********************************************************************** *
+ *                   the interrupt related routines                       *
+ * ********************************************************************** */
+
+static void sci_transmit_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int stopped = uart_tx_stopped(port);
+	unsigned short status;
+	unsigned short ctrl;
+	int count;
+
+	status = sci_in(port, SCxSR);
+	if (!(status & SCxSR_TDxE(port))) {
+		ctrl = sci_in(port, SCSCR);
+		if (uart_circ_empty(xmit))
+			ctrl &= ~SCI_CTRL_FLAGS_TIE;
+		else
+			ctrl |= SCI_CTRL_FLAGS_TIE;
+		sci_out(port, SCSCR, ctrl);
+		return;
+	}
+
+	if (port->type == PORT_SCI)
+		count = sci_txroom(port);
+	else
+		count = scif_txroom(port);
+
+	do {
+		unsigned char c;
+
+		if (port->x_char) {
+			c = port->x_char;
+			port->x_char = 0;
+		} else if (!uart_circ_empty(xmit) && !stopped) {
+			c = xmit->buf[xmit->tail];
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		} else {
+			break;
+		}
+
+		sci_out(port, SCxTDR, c);
+
+		port->icount.tx++;
+	} while (--count > 0);
+
+	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+	if (uart_circ_empty(xmit)) {
+		sci_stop_tx(port);
+	} else {
+		ctrl = sci_in(port, SCSCR);
+
+		if (port->type != PORT_SCI) {
+			sci_in(port, SCxSR); /* Dummy read */
+			sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
+		}
+
+		ctrl |= SCI_CTRL_FLAGS_TIE;
+		sci_out(port, SCSCR, ctrl);
+	}
+}
+
+/* On SH3, SCIF may read end-of-break as a space->mark char */
+#define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
+
+static inline void sci_receive_chars(struct uart_port *port)
+{
+	struct sci_port *sci_port = to_sci_port(port);
+	struct tty_struct *tty = port->state->port.tty;
+	int i, count, copied = 0;
+	unsigned short status;
+	unsigned char flag;
+
+	status = sci_in(port, SCxSR);
+	if (!(status & SCxSR_RDxF(port)))
+		return;
+
+	while (1) {
+		if (port->type == PORT_SCI)
+			count = sci_rxfill(port);
+		else
+			count = scif_rxfill(port);
+
+		/* Don't copy more bytes than there is room for in the buffer */
+		count = tty_buffer_request_room(tty, count);
+
+		/* If for any reason we can't copy more data, we're done! */
+		if (count == 0)
+			break;
+
+		if (port->type == PORT_SCI) {
+			char c = sci_in(port, SCxRDR);
+			if (uart_handle_sysrq_char(port, c) ||
+			    sci_port->break_flag)
+				count = 0;
+			else
+				tty_insert_flip_char(tty, c, TTY_NORMAL);
+		} else {
+			for (i = 0; i < count; i++) {
+				char c = sci_in(port, SCxRDR);
+				status = sci_in(port, SCxSR);
+#if defined(CONFIG_CPU_SH3)
+				/* Skip "chars" during break */
+				if (sci_port->break_flag) {
+					if ((c == 0) &&
+					    (status & SCxSR_FER(port))) {
+						count--; i--;
+						continue;
+					}
+
+					/* Nonzero => end-of-break */
+					dev_dbg(port->dev, "debounce<%02x>\n", c);
+					sci_port->break_flag = 0;
+
+					if (STEPFN(c)) {
+						count--; i--;
+						continue;
+					}
+				}
+#endif /* CONFIG_CPU_SH3 */
+				if (uart_handle_sysrq_char(port, c)) {
+					count--; i--;
+					continue;
+				}
+
+				/* Store data and status */
+				if (status & SCxSR_FER(port)) {
+					flag = TTY_FRAME;
+					dev_notice(port->dev, "frame error\n");
+				} else if (status & SCxSR_PER(port)) {
+					flag = TTY_PARITY;
+					dev_notice(port->dev, "parity error\n");
+				} else
+					flag = TTY_NORMAL;
+
+				tty_insert_flip_char(tty, c, flag);
+			}
+		}
+
+		sci_in(port, SCxSR); /* dummy read */
+		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+
+		copied += count;
+		port->icount.rx += count;
+	}
+
+	if (copied) {
+		/* Tell the rest of the system the news. New characters! */
+		tty_flip_buffer_push(tty);
+	} else {
+		sci_in(port, SCxSR); /* dummy read */
+		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+	}
+}
+
+#define SCI_BREAK_JIFFIES (HZ/20)
+/* The sci generates interrupts during the break,
+ * 1 per millisecond or so during the break period, for 9600 baud.
+ * So dont bother disabling interrupts.
+ * But dont want more than 1 break event.
+ * Use a kernel timer to periodically poll the rx line until
+ * the break is finished.
+ */
+static void sci_schedule_break_timer(struct sci_port *port)
+{
+	port->break_timer.expires = jiffies + SCI_BREAK_JIFFIES;
+	add_timer(&port->break_timer);
+}
+/* Ensure that two consecutive samples find the break over. */
+static void sci_break_timer(unsigned long data)
+{
+	struct sci_port *port = (struct sci_port *)data;
+
+	if (sci_rxd_in(&port->port) == 0) {
+		port->break_flag = 1;
+		sci_schedule_break_timer(port);
+	} else if (port->break_flag == 1) {
+		/* break is over. */
+		port->break_flag = 2;
+		sci_schedule_break_timer(port);
+	} else
+		port->break_flag = 0;
+}
+
+static inline int sci_handle_errors(struct uart_port *port)
+{
+	int copied = 0;
+	unsigned short status = sci_in(port, SCxSR);
+	struct tty_struct *tty = port->state->port.tty;
+
+	if (status & SCxSR_ORER(port)) {
+		/* overrun error */
+		if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
+			copied++;
+
+		dev_notice(port->dev, "overrun error");
+	}
+
+	if (status & SCxSR_FER(port)) {
+		if (sci_rxd_in(port) == 0) {
+			/* Notify of BREAK */
+			struct sci_port *sci_port = to_sci_port(port);
+
+			if (!sci_port->break_flag) {
+				sci_port->break_flag = 1;
+				sci_schedule_break_timer(sci_port);
+
+				/* Do sysrq handling. */
+				if (uart_handle_break(port))
+					return 0;
+
+				dev_dbg(port->dev, "BREAK detected\n");
+
+				if (tty_insert_flip_char(tty, 0, TTY_BREAK))
+					copied++;
+			}
+
+		} else {
+			/* frame error */
+			if (tty_insert_flip_char(tty, 0, TTY_FRAME))
+				copied++;
+
+			dev_notice(port->dev, "frame error\n");
+		}
+	}
+
+	if (status & SCxSR_PER(port)) {
+		/* parity error */
+		if (tty_insert_flip_char(tty, 0, TTY_PARITY))
+			copied++;
+
+		dev_notice(port->dev, "parity error");
+	}
+
+	if (copied)
+		tty_flip_buffer_push(tty);
+
+	return copied;
+}
+
+static inline int sci_handle_fifo_overrun(struct uart_port *port)
+{
+	struct tty_struct *tty = port->state->port.tty;
+	int copied = 0;
+
+	if (port->type != PORT_SCIF)
+		return 0;
+
+	if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) {
+		sci_out(port, SCLSR, 0);
+
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		tty_flip_buffer_push(tty);
+
+		dev_notice(port->dev, "overrun error\n");
+		copied++;
+	}
+
+	return copied;
+}
+
+static inline int sci_handle_breaks(struct uart_port *port)
+{
+	int copied = 0;
+	unsigned short status = sci_in(port, SCxSR);
+	struct tty_struct *tty = port->state->port.tty;
+	struct sci_port *s = to_sci_port(port);
+
+	if (uart_handle_break(port))
+		return 0;
+
+	if (!s->break_flag && status & SCxSR_BRK(port)) {
+#if defined(CONFIG_CPU_SH3)
+		/* Debounce break */
+		s->break_flag = 1;
+#endif
+		/* Notify of BREAK */
+		if (tty_insert_flip_char(tty, 0, TTY_BREAK))
+			copied++;
+
+		dev_dbg(port->dev, "BREAK detected\n");
+	}
+
+	if (copied)
+		tty_flip_buffer_push(tty);
+
+	copied += sci_handle_fifo_overrun(port);
+
+	return copied;
+}
+
+static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
+{
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	struct uart_port *port = ptr;
+	struct sci_port *s = to_sci_port(port);
+
+	if (s->chan_rx) {
+		u16 scr = sci_in(port, SCSCR);
+		u16 ssr = sci_in(port, SCxSR);
+
+		/* Disable future Rx interrupts */
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+			disable_irq_nosync(irq);
+			scr |= 0x4000;
+		} else {
+			scr &= ~SCI_CTRL_FLAGS_RIE;
+		}
+		sci_out(port, SCSCR, scr);
+		/* Clear current interrupt */
+		sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
+		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
+			jiffies, s->rx_timeout);
+		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
+
+		return IRQ_HANDLED;
+	}
+#endif
+
+	/* I think sci_receive_chars has to be called irrespective
+	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
+	 * to be disabled?
+	 */
+	sci_receive_chars(ptr);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	sci_transmit_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_er_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+
+	/* Handle errors */
+	if (port->type == PORT_SCI) {
+		if (sci_handle_errors(port)) {
+			/* discard character in rx buffer */
+			sci_in(port, SCxSR);
+			sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+		}
+	} else {
+		sci_handle_fifo_overrun(port);
+		sci_rx_interrupt(irq, ptr);
+	}
+
+	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
+
+	/* Kick the transmission */
+	sci_tx_interrupt(irq, ptr);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_br_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+
+	/* Handle BREAKs */
+	sci_handle_breaks(port);
+	sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
+{
+	unsigned short ssr_status, scr_status, err_enabled;
+	struct uart_port *port = ptr;
+	struct sci_port *s = to_sci_port(port);
+	irqreturn_t ret = IRQ_NONE;
+
+	ssr_status = sci_in(port, SCxSR);
+	scr_status = sci_in(port, SCSCR);
+	err_enabled = scr_status & (SCI_CTRL_FLAGS_REIE | SCI_CTRL_FLAGS_RIE);
+
+	/* Tx Interrupt */
+	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCI_CTRL_FLAGS_TIE) &&
+	    !s->chan_tx)
+		ret = sci_tx_interrupt(irq, ptr);
+	/*
+	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
+	 * DR flags
+	 */
+	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
+	    (scr_status & SCI_CTRL_FLAGS_RIE))
+		ret = sci_rx_interrupt(irq, ptr);
+	/* Error Interrupt */
+	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
+		ret = sci_er_interrupt(irq, ptr);
+	/* Break Interrupt */
+	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
+		ret = sci_br_interrupt(irq, ptr);
+
+	return ret;
+}
+
+/*
+ * Here we define a transistion notifier so that we can update all of our
+ * ports' baud rate when the peripheral clock changes.
+ */
+static int sci_notifier(struct notifier_block *self,
+			unsigned long phase, void *p)
+{
+	struct sh_sci_priv *priv = container_of(self,
+						struct sh_sci_priv, clk_nb);
+	struct sci_port *sci_port;
+	unsigned long flags;
+
+	if ((phase == CPUFREQ_POSTCHANGE) ||
+	    (phase == CPUFREQ_RESUMECHANGE)) {
+		spin_lock_irqsave(&priv->lock, flags);
+		list_for_each_entry(sci_port, &priv->ports, node)
+			sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	return NOTIFY_OK;
+}
+
+static void sci_clk_enable(struct uart_port *port)
+{
+	struct sci_port *sci_port = to_sci_port(port);
+
+	clk_enable(sci_port->iclk);
+	sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
+	clk_enable(sci_port->fclk);
+}
+
+static void sci_clk_disable(struct uart_port *port)
+{
+	struct sci_port *sci_port = to_sci_port(port);
+
+	clk_disable(sci_port->fclk);
+	clk_disable(sci_port->iclk);
+}
+
+static int sci_request_irq(struct sci_port *port)
+{
+	int i;
+	irqreturn_t (*handlers[4])(int irq, void *ptr) = {
+		sci_er_interrupt, sci_rx_interrupt, sci_tx_interrupt,
+		sci_br_interrupt,
+	};
+	const char *desc[] = { "SCI Receive Error", "SCI Receive Data Full",
+			       "SCI Transmit Data Empty", "SCI Break" };
+
+	if (port->irqs[0] == port->irqs[1]) {
+		if (unlikely(!port->irqs[0]))
+			return -ENODEV;
+
+		if (request_irq(port->irqs[0], sci_mpxed_interrupt,
+				IRQF_DISABLED, "sci", port)) {
+			dev_err(port->port.dev, "Can't allocate IRQ\n");
+			return -ENODEV;
+		}
+	} else {
+		for (i = 0; i < ARRAY_SIZE(handlers); i++) {
+			if (unlikely(!port->irqs[i]))
+				continue;
+
+			if (request_irq(port->irqs[i], handlers[i],
+					IRQF_DISABLED, desc[i], port)) {
+				dev_err(port->port.dev, "Can't allocate IRQ\n");
+				return -ENODEV;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static void sci_free_irq(struct sci_port *port)
+{
+	int i;
+
+	if (port->irqs[0] == port->irqs[1])
+		free_irq(port->irqs[0], port);
+	else {
+		for (i = 0; i < ARRAY_SIZE(port->irqs); i++) {
+			if (!port->irqs[i])
+				continue;
+
+			free_irq(port->irqs[i], port);
+		}
+	}
+}
+
+static unsigned int sci_tx_empty(struct uart_port *port)
+{
+	unsigned short status = sci_in(port, SCxSR);
+	unsigned short in_tx_fifo = scif_txfill(port);
+
+	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
+}
+
+static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
+	/* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
+	/* If you have signals for DTR and DCD, please implement here. */
+}
+
+static unsigned int sci_get_mctrl(struct uart_port *port)
+{
+	/* This routine is used for getting signals of: DTR, DCD, DSR, RI,
+	   and CTS/RTS */
+
+	return TIOCM_DTR | TIOCM_RTS | TIOCM_DSR;
+}
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+static void sci_dma_tx_complete(void *arg)
+{
+	struct sci_port *s = arg;
+	struct uart_port *port = &s->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	xmit->tail += sg_dma_len(&s->sg_tx);
+	xmit->tail &= UART_XMIT_SIZE - 1;
+
+	port->icount.tx += sg_dma_len(&s->sg_tx);
+
+	async_tx_ack(s->desc_tx);
+	s->cookie_tx = -EINVAL;
+	s->desc_tx = NULL;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (!uart_circ_empty(xmit)) {
+		schedule_work(&s->work_tx);
+	} else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		u16 ctrl = sci_in(port, SCSCR);
+		sci_out(port, SCSCR, ctrl & ~SCI_CTRL_FLAGS_TIE);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Locking: called with port lock held */
+static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
+			   size_t count)
+{
+	struct uart_port *port = &s->port;
+	int i, active, room;
+
+	room = tty_buffer_request_room(tty, count);
+
+	if (s->active_rx == s->cookie_rx[0]) {
+		active = 0;
+	} else if (s->active_rx == s->cookie_rx[1]) {
+		active = 1;
+	} else {
+		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
+		return 0;
+	}
+
+	if (room < count)
+		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
+			 count - room);
+	if (!room)
+		return room;
+
+	for (i = 0; i < room; i++)
+		tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
+				     TTY_NORMAL);
+
+	port->icount.rx += room;
+
+	return room;
+}
+
+static void sci_dma_rx_complete(void *arg)
+{
+	struct sci_port *s = arg;
+	struct uart_port *port = &s->port;
+	struct tty_struct *tty = port->state->port.tty;
+	unsigned long flags;
+	int count;
+
+	dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	count = sci_dma_rx_push(s, tty, s->buf_len_rx);
+
+	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (count)
+		tty_flip_buffer_push(tty);
+
+	schedule_work(&s->work_rx);
+}
+
+static void sci_start_rx(struct uart_port *port);
+static void sci_start_tx(struct uart_port *port);
+
+static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
+{
+	struct dma_chan *chan = s->chan_rx;
+	struct uart_port *port = &s->port;
+
+	s->chan_rx = NULL;
+	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
+	dma_release_channel(chan);
+	if (sg_dma_address(&s->sg_rx[0]))
+		dma_free_coherent(port->dev, s->buf_len_rx * 2,
+				  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
+	if (enable_pio)
+		sci_start_rx(port);
+}
+
+static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
+{
+	struct dma_chan *chan = s->chan_tx;
+	struct uart_port *port = &s->port;
+
+	s->chan_tx = NULL;
+	s->cookie_tx = -EINVAL;
+	dma_release_channel(chan);
+	if (enable_pio)
+		sci_start_tx(port);
+}
+
+static void sci_submit_rx(struct sci_port *s)
+{
+	struct dma_chan *chan = s->chan_rx;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct scatterlist *sg = &s->sg_rx[i];
+		struct dma_async_tx_descriptor *desc;
+
+		desc = chan->device->device_prep_slave_sg(chan,
+			sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
+
+		if (desc) {
+			s->desc_rx[i] = desc;
+			desc->callback = sci_dma_rx_complete;
+			desc->callback_param = s;
+			s->cookie_rx[i] = desc->tx_submit(desc);
+		}
+
+		if (!desc || s->cookie_rx[i] < 0) {
+			if (i) {
+				async_tx_ack(s->desc_rx[0]);
+				s->cookie_rx[0] = -EINVAL;
+			}
+			if (desc) {
+				async_tx_ack(desc);
+				s->cookie_rx[i] = -EINVAL;
+			}
+			dev_warn(s->port.dev,
+				 "failed to re-start DMA, using PIO\n");
+			sci_rx_dma_release(s, true);
+			return;
+		}
+		dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
+			s->cookie_rx[i], i);
+	}
+
+	s->active_rx = s->cookie_rx[0];
+
+	dma_async_issue_pending(chan);
+}
+
+static void work_fn_rx(struct work_struct *work)
+{
+	struct sci_port *s = container_of(work, struct sci_port, work_rx);
+	struct uart_port *port = &s->port;
+	struct dma_async_tx_descriptor *desc;
+	int new;
+
+	if (s->active_rx == s->cookie_rx[0]) {
+		new = 0;
+	} else if (s->active_rx == s->cookie_rx[1]) {
+		new = 1;
+	} else {
+		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
+		return;
+	}
+	desc = s->desc_rx[new];
+
+	if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
+	    DMA_SUCCESS) {
+		/* Handle incomplete DMA receive */
+		struct tty_struct *tty = port->state->port.tty;
+		struct dma_chan *chan = s->chan_rx;
+		struct sh_desc *sh_desc = container_of(desc, struct sh_desc,
+						       async_tx);
+		unsigned long flags;
+		int count;
+
+		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
+		dev_dbg(port->dev, "Read %u bytes with cookie %d\n",
+			sh_desc->partial, sh_desc->cookie);
+
+		spin_lock_irqsave(&port->lock, flags);
+		count = sci_dma_rx_push(s, tty, sh_desc->partial);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		if (count)
+			tty_flip_buffer_push(tty);
+
+		sci_submit_rx(s);
+
+		return;
+	}
+
+	s->cookie_rx[new] = desc->tx_submit(desc);
+	if (s->cookie_rx[new] < 0) {
+		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
+		sci_rx_dma_release(s, true);
+		return;
+	}
+
+	s->active_rx = s->cookie_rx[!new];
+
+	dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
+		s->cookie_rx[new], new, s->active_rx);
+}
+
+static void work_fn_tx(struct work_struct *work)
+{
+	struct sci_port *s = container_of(work, struct sci_port, work_tx);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *chan = s->chan_tx;
+	struct uart_port *port = &s->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct scatterlist *sg = &s->sg_tx;
+
+	/*
+	 * DMA is idle now.
+	 * Port xmit buffer is already mapped, and it is one page... Just adjust
+	 * offsets and lengths. Since it is a circular buffer, we have to
+	 * transmit till the end, and then the rest. Take the port lock to get a
+	 * consistent xmit buffer state.
+	 */
+	spin_lock_irq(&port->lock);
+	sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
+	sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
+		sg->offset;
+	sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
+		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
+	spin_unlock_irq(&port->lock);
+
+	BUG_ON(!sg_dma_len(sg));
+
+	desc = chan->device->device_prep_slave_sg(chan,
+			sg, s->sg_len_tx, DMA_TO_DEVICE,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		/* switch to PIO */
+		sci_tx_dma_release(s, true);
+		return;
+	}
+
+	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
+
+	spin_lock_irq(&port->lock);
+	s->desc_tx = desc;
+	desc->callback = sci_dma_tx_complete;
+	desc->callback_param = s;
+	spin_unlock_irq(&port->lock);
+	s->cookie_tx = desc->tx_submit(desc);
+	if (s->cookie_tx < 0) {
+		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
+		/* switch to PIO */
+		sci_tx_dma_release(s, true);
+		return;
+	}
+
+	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
+		xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
+
+	dma_async_issue_pending(chan);
+}
+#endif
+
+static void sci_start_tx(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	unsigned short ctrl;
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		u16 new, scr = sci_in(port, SCSCR);
+		if (s->chan_tx)
+			new = scr | 0x8000;
+		else
+			new = scr & ~0x8000;
+		if (new != scr)
+			sci_out(port, SCSCR, new);
+	}
+	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
+	    s->cookie_tx < 0)
+		schedule_work(&s->work_tx);
+#endif
+	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
+		ctrl = sci_in(port, SCSCR);
+		sci_out(port, SCSCR, ctrl | SCI_CTRL_FLAGS_TIE);
+	}
+}
+
+static void sci_stop_tx(struct uart_port *port)
+{
+	unsigned short ctrl;
+
+	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
+	ctrl = sci_in(port, SCSCR);
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~0x8000;
+	ctrl &= ~SCI_CTRL_FLAGS_TIE;
+	sci_out(port, SCSCR, ctrl);
+}
+
+static void sci_start_rx(struct uart_port *port)
+{
+	unsigned short ctrl = SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE;
+
+	/* Set RIE (Receive Interrupt Enable) bit in SCSCR */
+	ctrl |= sci_in(port, SCSCR);
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~0x4000;
+	sci_out(port, SCSCR, ctrl);
+}
+
+static void sci_stop_rx(struct uart_port *port)
+{
+	unsigned short ctrl;
+
+	/* Clear RIE (Receive Interrupt Enable) bit in SCSCR */
+	ctrl = sci_in(port, SCSCR);
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~0x4000;
+	ctrl &= ~(SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE);
+	sci_out(port, SCSCR, ctrl);
+}
+
+static void sci_enable_ms(struct uart_port *port)
+{
+	/* Nothing here yet .. */
+}
+
+static void sci_break_ctl(struct uart_port *port, int break_state)
+{
+	/* Nothing here yet .. */
+}
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+static bool filter(struct dma_chan *chan, void *slave)
+{
+	struct sh_dmae_slave *param = slave;
+
+	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
+		param->slave_id);
+
+	if (param->dma_dev == chan->device->dev) {
+		chan->private = param;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static void rx_timer_fn(unsigned long arg)
+{
+	struct sci_port *s = (struct sci_port *)arg;
+	struct uart_port *port = &s->port;
+	u16 scr = sci_in(port, SCSCR);
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		scr &= ~0x4000;
+		enable_irq(s->irqs[1]);
+	}
+	sci_out(port, SCSCR, scr | SCI_CTRL_FLAGS_RIE);
+	dev_dbg(port->dev, "DMA Rx timed out\n");
+	schedule_work(&s->work_rx);
+}
+
+static void sci_request_dma(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	struct sh_dmae_slave *param;
+	struct dma_chan *chan;
+	dma_cap_mask_t mask;
+	int nent;
+
+	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
+		port->line, s->dma_dev);
+
+	if (!s->dma_dev)
+		return;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	param = &s->param_tx;
+
+	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
+	param->slave_id = s->slave_tx;
+	param->dma_dev = s->dma_dev;
+
+	s->cookie_tx = -EINVAL;
+	chan = dma_request_channel(mask, filter, param);
+	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
+	if (chan) {
+		s->chan_tx = chan;
+		sg_init_table(&s->sg_tx, 1);
+		/* UART circular tx buffer is an aligned page. */
+		BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
+		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
+			    UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);
+		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
+		if (!nent)
+			sci_tx_dma_release(s, false);
+		else
+			dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
+				sg_dma_len(&s->sg_tx),
+				port->state->xmit.buf, sg_dma_address(&s->sg_tx));
+
+		s->sg_len_tx = nent;
+
+		INIT_WORK(&s->work_tx, work_fn_tx);
+	}
+
+	param = &s->param_rx;
+
+	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
+	param->slave_id = s->slave_rx;
+	param->dma_dev = s->dma_dev;
+
+	chan = dma_request_channel(mask, filter, param);
+	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
+	if (chan) {
+		dma_addr_t dma[2];
+		void *buf[2];
+		int i;
+
+		s->chan_rx = chan;
+
+		s->buf_len_rx = 2 * max(16, (int)port->fifosize);
+		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
+					    &dma[0], GFP_KERNEL);
+
+		if (!buf[0]) {
+			dev_warn(port->dev,
+				 "failed to allocate dma buffer, using PIO\n");
+			sci_rx_dma_release(s, true);
+			return;
+		}
+
+		buf[1] = buf[0] + s->buf_len_rx;
+		dma[1] = dma[0] + s->buf_len_rx;
+
+		for (i = 0; i < 2; i++) {
+			struct scatterlist *sg = &s->sg_rx[i];
+
+			sg_init_table(sg, 1);
+			sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
+				    (int)buf[i] & ~PAGE_MASK);
+			sg_dma_address(sg) = dma[i];
+		}
+
+		INIT_WORK(&s->work_rx, work_fn_rx);
+		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
+
+		sci_submit_rx(s);
+	}
+}
+
+static void sci_free_dma(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	if (!s->dma_dev)
+		return;
+
+	if (s->chan_tx)
+		sci_tx_dma_release(s, false);
+	if (s->chan_rx)
+		sci_rx_dma_release(s, false);
+}
+#endif
+
+static int sci_startup(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	if (s->enable)
+		s->enable(port);
+
+	sci_request_irq(s);
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	sci_request_dma(port);
+#endif
+	sci_start_tx(port);
+	sci_start_rx(port);
+
+	return 0;
+}
+
+static void sci_shutdown(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	sci_stop_rx(port);
+	sci_stop_tx(port);
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	sci_free_dma(port);
+#endif
+	sci_free_irq(s);
+
+	if (s->disable)
+		s->disable(port);
+}
+
+static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
+			    struct ktermios *old)
+{
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	struct sci_port *s = to_sci_port(port);
+#endif
+	unsigned int status, baud, smr_val, max_baud;
+	int t = -1;
+	u16 scfcr = 0;
+
+	/*
+	 * earlyprintk comes here early on with port->uartclk set to zero.
+	 * the clock framework is not up and running at this point so here
+	 * we assume that 115200 is the maximum baud rate. please note that
+	 * the baud rate is not programmed during earlyprintk - it is assumed
+	 * that the previous boot loader has enabled required clocks and
+	 * setup the baud rate generator hardware for us already.
+	 */
+	max_baud = port->uartclk ? port->uartclk / 16 : 115200;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
+	if (likely(baud && port->uartclk))
+		t = SCBRR_VALUE(baud, port->uartclk);
+
+	do {
+		status = sci_in(port, SCxSR);
+	} while (!(status & SCxSR_TEND(port)));
+
+	sci_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */
+
+	if (port->type != PORT_SCI)
+		sci_out(port, SCFCR, scfcr | SCFCR_RFRST | SCFCR_TFRST);
+
+	smr_val = sci_in(port, SCSMR) & 3;
+	if ((termios->c_cflag & CSIZE) == CS7)
+		smr_val |= 0x40;
+	if (termios->c_cflag & PARENB)
+		smr_val |= 0x20;
+	if (termios->c_cflag & PARODD)
+		smr_val |= 0x30;
+	if (termios->c_cflag & CSTOPB)
+		smr_val |= 0x08;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	sci_out(port, SCSMR, smr_val);
+
+	dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
+		SCSCR_INIT(port));
+
+	if (t > 0) {
+		if (t >= 256) {
+			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
+			t >>= 2;
+		} else
+			sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
+
+		sci_out(port, SCBRR, t);
+		udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
+	}
+
+	sci_init_pins(port, termios->c_cflag);
+	sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
+
+	sci_out(port, SCSCR, SCSCR_INIT(port));
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	/*
+	 * Calculate delay for 1.5 DMA buffers: see
+	 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
+	 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
+	 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
+	 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
+	 * sizes), but it has been found out experimentally, that this is not
+	 * enough: the driver too often needlessly runs on a DMA timeout. 20ms
+	 * as a minimum seem to work perfectly.
+	 */
+	if (s->chan_rx) {
+		s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
+			port->fifosize / 2;
+		dev_dbg(port->dev,
+			"DMA Rx t-out %ums, tty t-out %u jiffies\n",
+			s->rx_timeout * 1000 / HZ, port->timeout);
+		if (s->rx_timeout < msecs_to_jiffies(20))
+			s->rx_timeout = msecs_to_jiffies(20);
+	}
+#endif
+
+	if ((termios->c_cflag & CREAD) != 0)
+		sci_start_rx(port);
+}
+
+static const char *sci_type(struct uart_port *port)
+{
+	switch (port->type) {
+	case PORT_IRDA:
+		return "irda";
+	case PORT_SCI:
+		return "sci";
+	case PORT_SCIF:
+		return "scif";
+	case PORT_SCIFA:
+		return "scifa";
+	case PORT_SCIFB:
+		return "scifb";
+	}
+
+	return NULL;
+}
+
+static void sci_release_port(struct uart_port *port)
+{
+	/* Nothing here yet .. */
+}
+
+static int sci_request_port(struct uart_port *port)
+{
+	/* Nothing here yet .. */
+	return 0;
+}
+
+static void sci_config_port(struct uart_port *port, int flags)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	port->type = s->type;
+
+	if (port->membase)
+		return;
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = ioremap_nocache(port->mapbase, 0x40);
+
+		if (IS_ERR(port->membase))
+			dev_err(port->dev, "can't remap port#%d\n", port->line);
+	} else {
+		/*
+		 * For the simple (and majority of) cases where we don't
+		 * need to do any remapping, just cast the cookie
+		 * directly.
+		 */
+		port->membase = (void __iomem *)port->mapbase;
+	}
+}
+
+static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	if (ser->irq != s->irqs[SCIx_TXI_IRQ] || ser->irq > nr_irqs)
+		return -EINVAL;
+	if (ser->baud_base < 2400)
+		/* No paper tape reader for Mitch.. */
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct uart_ops sci_uart_ops = {
+	.tx_empty	= sci_tx_empty,
+	.set_mctrl	= sci_set_mctrl,
+	.get_mctrl	= sci_get_mctrl,
+	.start_tx	= sci_start_tx,
+	.stop_tx	= sci_stop_tx,
+	.stop_rx	= sci_stop_rx,
+	.enable_ms	= sci_enable_ms,
+	.break_ctl	= sci_break_ctl,
+	.startup	= sci_startup,
+	.shutdown	= sci_shutdown,
+	.set_termios	= sci_set_termios,
+	.type		= sci_type,
+	.release_port	= sci_release_port,
+	.request_port	= sci_request_port,
+	.config_port	= sci_config_port,
+	.verify_port	= sci_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= sci_poll_get_char,
+	.poll_put_char	= sci_poll_put_char,
+#endif
+};
+
+static int __devinit sci_init_single(struct platform_device *dev,
+				     struct sci_port *sci_port,
+				     unsigned int index,
+				     struct plat_sci_port *p)
+{
+	struct uart_port *port = &sci_port->port;
+
+	port->ops	= &sci_uart_ops;
+	port->iotype	= UPIO_MEM;
+	port->line	= index;
+
+	switch (p->type) {
+	case PORT_SCIFB:
+		port->fifosize = 256;
+		break;
+	case PORT_SCIFA:
+		port->fifosize = 64;
+		break;
+	case PORT_SCIF:
+		port->fifosize = 16;
+		break;
+	default:
+		port->fifosize = 1;
+		break;
+	}
+
+	if (dev) {
+		sci_port->iclk = clk_get(&dev->dev, "sci_ick");
+		if (IS_ERR(sci_port->iclk)) {
+			sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
+			if (IS_ERR(sci_port->iclk)) {
+				dev_err(&dev->dev, "can't get iclk\n");
+				return PTR_ERR(sci_port->iclk);
+			}
+		}
+
+		/*
+		 * The function clock is optional, ignore it if we can't
+		 * find it.
+		 */
+		sci_port->fclk = clk_get(&dev->dev, "sci_fck");
+		if (IS_ERR(sci_port->fclk))
+			sci_port->fclk = NULL;
+
+		sci_port->enable = sci_clk_enable;
+		sci_port->disable = sci_clk_disable;
+		port->dev = &dev->dev;
+	}
+
+	sci_port->break_timer.data = (unsigned long)sci_port;
+	sci_port->break_timer.function = sci_break_timer;
+	init_timer(&sci_port->break_timer);
+
+	port->mapbase	= p->mapbase;
+	port->membase	= p->membase;
+
+	port->irq	= p->irqs[SCIx_TXI_IRQ];
+	port->flags	= p->flags;
+	sci_port->type	= port->type = p->type;
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	sci_port->dma_dev	= p->dma_dev;
+	sci_port->slave_tx	= p->dma_slave_tx;
+	sci_port->slave_rx	= p->dma_slave_rx;
+
+	dev_dbg(port->dev, "%s: DMA device %p, tx %d, rx %d\n", __func__,
+		p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
+#endif
+
+	memcpy(&sci_port->irqs, &p->irqs, sizeof(p->irqs));
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
+static struct tty_driver *serial_console_device(struct console *co, int *index)
+{
+	struct uart_driver *p = &sci_uart_driver;
+	*index = co->index;
+	return p->tty_driver;
+}
+
+static void serial_console_putchar(struct uart_port *port, int ch)
+{
+	sci_poll_put_char(port, ch);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ */
+static void serial_console_write(struct console *co, const char *s,
+				 unsigned count)
+{
+	struct uart_port *port = co->data;
+	struct sci_port *sci_port = to_sci_port(port);
+	unsigned short bits;
+
+	if (sci_port->enable)
+		sci_port->enable(port);
+
+	uart_console_write(port, s, count, serial_console_putchar);
+
+	/* wait until fifo is empty and last bit has been transmitted */
+	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
+	while ((sci_in(port, SCxSR) & bits) != bits)
+		cpu_relax();
+
+	if (sci_port->disable)
+		sci_port->disable(port);
+}
+
+static int __devinit serial_console_setup(struct console *co, char *options)
+{
+	struct sci_port *sci_port;
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= SCI_NPORTS)
+		co->index = 0;
+
+	if (co->data) {
+		port = co->data;
+		sci_port = to_sci_port(port);
+	} else {
+		sci_port = &sci_ports[co->index];
+		port = &sci_port->port;
+		co->data = port;
+	}
+
+	/*
+	 * Also need to check port->type, we don't actually have any
+	 * UPIO_PORT ports, but uart_report_port() handily misreports
+	 * it anyways if we don't have a port available by the time this is
+	 * called.
+	 */
+	if (!port->type)
+		return -ENODEV;
+
+	sci_config_port(port, 0);
+
+	if (sci_port->enable)
+		sci_port->enable(port);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	ret = uart_set_options(port, co, baud, parity, bits, flow);
+#if defined(__H8300H__) || defined(__H8300S__)
+	/* disable rx interrupt */
+	if (ret == 0)
+		sci_stop_rx(port);
+#endif
+	/* TODO: disable clock */
+	return ret;
+}
+
+static struct console serial_console = {
+	.name		= "ttySC",
+	.device		= serial_console_device,
+	.write		= serial_console_write,
+	.setup		= serial_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+static int __init sci_console_init(void)
+{
+	register_console(&serial_console);
+	return 0;
+}
+console_initcall(sci_console_init);
+
+static struct sci_port early_serial_port;
+static struct console early_serial_console = {
+	.name           = "early_ttySC",
+	.write          = serial_console_write,
+	.flags          = CON_PRINTBUFFER,
+};
+static char early_serial_buf[32];
+
+#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
+
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
+#define SCI_CONSOLE	(&serial_console)
+#else
+#define SCI_CONSOLE	0
+#endif
+
+static char banner[] __initdata =
+	KERN_INFO "SuperH SCI(F) driver initialized\n";
+
+static struct uart_driver sci_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "sci",
+	.dev_name	= "ttySC",
+	.major		= SCI_MAJOR,
+	.minor		= SCI_MINOR_START,
+	.nr		= SCI_NPORTS,
+	.cons		= SCI_CONSOLE,
+};
+
+
+static int sci_remove(struct platform_device *dev)
+{
+	struct sh_sci_priv *priv = platform_get_drvdata(dev);
+	struct sci_port *p;
+	unsigned long flags;
+
+	cpufreq_unregister_notifier(&priv->clk_nb, CPUFREQ_TRANSITION_NOTIFIER);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_for_each_entry(p, &priv->ports, node) {
+		uart_remove_one_port(&sci_uart_driver, &p->port);
+		clk_put(p->iclk);
+		clk_put(p->fclk);
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	kfree(priv);
+	return 0;
+}
+
+static int __devinit sci_probe_single(struct platform_device *dev,
+				      unsigned int index,
+				      struct plat_sci_port *p,
+				      struct sci_port *sciport)
+{
+	struct sh_sci_priv *priv = platform_get_drvdata(dev);
+	unsigned long flags;
+	int ret;
+
+	/* Sanity check */
+	if (unlikely(index >= SCI_NPORTS)) {
+		dev_notice(&dev->dev, "Attempting to register port "
+			   "%d when only %d are available.\n",
+			   index+1, SCI_NPORTS);
+		dev_notice(&dev->dev, "Consider bumping "
+			   "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
+		return 0;
+	}
+
+	ret = sci_init_single(dev, sciport, index, p);
+	if (ret)
+		return ret;
+
+	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
+	if (ret)
+		return ret;
+
+	INIT_LIST_HEAD(&sciport->node);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_add(&sciport->node, &priv->ports);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+/*
+ * Register a set of serial devices attached to a platform device.  The
+ * list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set. Platforms that need
+ * remapping (such as sh64) should also set UPF_IOREMAP.
+ */
+static int __devinit sci_probe(struct platform_device *dev)
+{
+	struct plat_sci_port *p = dev->dev.platform_data;
+	struct sh_sci_priv *priv;
+	int i, ret = -EINVAL;
+
+#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
+	if (is_early_platform_device(dev)) {
+		if (dev->id == -1)
+			return -ENOTSUPP;
+		early_serial_console.index = dev->id;
+		early_serial_console.data = &early_serial_port.port;
+		sci_init_single(NULL, &early_serial_port, dev->id, p);
+		serial_console_setup(&early_serial_console, early_serial_buf);
+		if (!strstr(early_serial_buf, "keep"))
+			early_serial_console.flags |= CON_BOOT;
+		register_console(&early_serial_console);
+		return 0;
+	}
+#endif
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&priv->ports);
+	spin_lock_init(&priv->lock);
+	platform_set_drvdata(dev, priv);
+
+	priv->clk_nb.notifier_call = sci_notifier;
+	cpufreq_register_notifier(&priv->clk_nb, CPUFREQ_TRANSITION_NOTIFIER);
+
+	if (dev->id != -1) {
+		ret = sci_probe_single(dev, dev->id, p, &sci_ports[dev->id]);
+		if (ret)
+			goto err_unreg;
+	} else {
+		for (i = 0; p && p->flags != 0; p++, i++) {
+			ret = sci_probe_single(dev, i, p, &sci_ports[i]);
+			if (ret)
+				goto err_unreg;
+		}
+	}
+
+#ifdef CONFIG_SH_STANDARD_BIOS
+	sh_bios_gdb_detach();
+#endif
+
+	return 0;
+
+err_unreg:
+	sci_remove(dev);
+	return ret;
+}
+
+static int sci_suspend(struct device *dev)
+{
+	struct sh_sci_priv *priv = dev_get_drvdata(dev);
+	struct sci_port *p;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_for_each_entry(p, &priv->ports, node)
+		uart_suspend_port(&sci_uart_driver, &p->port);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static int sci_resume(struct device *dev)
+{
+	struct sh_sci_priv *priv = dev_get_drvdata(dev);
+	struct sci_port *p;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_for_each_entry(p, &priv->ports, node)
+		uart_resume_port(&sci_uart_driver, &p->port);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sci_dev_pm_ops = {
+	.suspend	= sci_suspend,
+	.resume		= sci_resume,
+};
+
+static struct platform_driver sci_driver = {
+	.probe		= sci_probe,
+	.remove		= sci_remove,
+	.driver		= {
+		.name	= "sh-sci",
+		.owner	= THIS_MODULE,
+		.pm	= &sci_dev_pm_ops,
+	},
+};
+
+static int __init sci_init(void)
+{
+	int ret;
+
+	printk(banner);
+
+	ret = uart_register_driver(&sci_uart_driver);
+	if (likely(ret == 0)) {
+		ret = platform_driver_register(&sci_driver);
+		if (unlikely(ret))
+			uart_unregister_driver(&sci_uart_driver);
+	}
+
+	return ret;
+}
+
+static void __exit sci_exit(void)
+{
+	platform_driver_unregister(&sci_driver);
+	uart_unregister_driver(&sci_uart_driver);
+}
+
+#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
+early_platform_init_buffer("earlyprintk", &sci_driver,
+			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
+#endif
+module_init(sci_init);
+module_exit(sci_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sh-sci");