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 00000000000..c291b3add1d
--- /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-