zs: move to the serial subsystem

This is a reimplementation of the zs driver for the serial subsystem.  Any
resemblance to the old driver is purely coincidential.  ;-) I do hope I got
the handling of modem lines right -- better do not tackle me about the
issue unless you feel too good...

Any users of the old driver: please note the numbers of the serial lines
have now been swapped, i.e.  ttyS0 <-> ttyS1 and ttyS2 <-> ttyS3.  It has
to do with the modem lines mentioned above; basically the port A in a given
chip has to be initialised before the port B if you want to use the latter
as the serial console (which is usually the case), as operations on modem
lines of the serial line associated with the port B access both ports (see
the comment at the top of the driver for the details of wiring used).
Please update your scripts.

This is also the reason each SCC now requests an IRQ once only (as seen in
"/proc/interrupts") -- the handler takes care of both ports at once as the
line associated with the port B has to take status update interrupts from
both ports (and yet the line of the port A takes its own for itself too).
The old driver never got it right...

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 2203 deletions

diff --git a/drivers/tc/zs.c b/drivers/tc/zs.c
deleted file mode 100644
index ed979f13908..00000000000
--- a/drivers/tc/zs.c
+++ /dev/null
@@ -1,2203 +0,0 @@
-/*
- * decserial.c: Serial port driver for IOASIC DECstations.
- *
- * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
- * Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
- *
- * DECstation changes
- * Copyright (C) 1998-2000 Harald Koerfgen
- * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005  Maciej W. Rozycki
- *
- * For the rest of the code the original Copyright applies:
- * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
- * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
- *
- *
- * Note: for IOASIC systems the wiring is as follows:
- *
- * mouse/keyboard:
- * DIN-7 MJ-4  signal        SCC
- * 2     1     TxD       <-  A.TxD
- * 3     4     RxD       ->  A.RxD
- *
- * EIA-232/EIA-423:
- * DB-25 MMJ-6 signal        SCC
- * 2     2     TxD       <-  B.TxD
- * 3     5     RxD       ->  B.RxD
- * 4           RTS       <- ~A.RTS
- * 5           CTS       -> ~B.CTS
- * 6     6     DSR       -> ~A.SYNC
- * 8           CD        -> ~B.DCD
- * 12          DSRS(DCE) -> ~A.CTS  (*)
- * 15          TxC       ->  B.TxC
- * 17          RxC       ->  B.RxC
- * 20    1     DTR       <- ~A.DTR
- * 22          RI        -> ~A.DCD
- * 23          DSRS(DTE) <- ~B.RTS
- *
- * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
- *     is shared with DSRS(DTE) at pin 23.
- */
-
-#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/fcntl.h>
-#include <linux/mm.h>
-#include <linux/kernel.h>
-#include <linux/delay.h>
-#include <linux/init.h>
-#include <linux/ioport.h>
-#include <linux/spinlock.h>
-#ifdef CONFIG_SERIAL_DEC_CONSOLE
-#include <linux/console.h>
-#endif
-
-#include <asm/io.h>
-#include <asm/pgtable.h>
-#include <asm/irq.h>
-#include <asm/system.h>
-#include <asm/bootinfo.h>
-
-#include <asm/dec/interrupts.h>
-#include <asm/dec/ioasic_addrs.h>
-#include <asm/dec/machtype.h>
-#include <asm/dec/serial.h>
-#include <asm/dec/system.h>
-
-#ifdef CONFIG_KGDB
-#include <asm/kgdb.h>
-#endif
-#ifdef CONFIG_MAGIC_SYSRQ
-#include <linux/sysrq.h>
-#endif
-
-#include "zs.h"
-
-/*
- * It would be nice to dynamically allocate everything that
- * depends on NUM_SERIAL, so we could support any number of
- * Z8530s, but for now...
- */
-#define NUM_SERIAL	2		/* Max number of ZS chips supported */
-#define NUM_CHANNELS	(NUM_SERIAL * 2)	/* 2 channels per chip */
-#define CHANNEL_A_NR  (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
-                                        /* Number of channel A in the chip */
-#define ZS_CHAN_IO_SIZE 8
-#define ZS_CLOCK        7372800 	/* Z8530 RTxC input clock rate */
-
-#define RECOVERY_DELAY  udelay(2)
-
-struct zs_parms {
-	unsigned long scc0;
-	unsigned long scc1;
-	int channel_a_offset;
-	int channel_b_offset;
-	int irq0;
-	int irq1;
-	int clock;
-};
-
-static struct zs_parms *zs_parms;
-
-#ifdef CONFIG_MACH_DECSTATION
-static struct zs_parms ds_parms = {
-	scc0 : IOASIC_SCC0,
-	scc1 : IOASIC_SCC1,
-	channel_a_offset : 1,
-	channel_b_offset : 9,
-	irq0 : -1,
-	irq1 : -1,
-	clock : ZS_CLOCK
-};
-#endif
-
-#ifdef CONFIG_MACH_DECSTATION
-#define DS_BUS_PRESENT (IOASIC)
-#else
-#define DS_BUS_PRESENT 0
-#endif
-
-#define BUS_PRESENT (DS_BUS_PRESENT)
-
-DEFINE_SPINLOCK(zs_lock);
-
-struct dec_zschannel zs_channels[NUM_CHANNELS];
-struct dec_serial zs_soft[NUM_CHANNELS];
-int zs_channels_found;
-struct dec_serial *zs_chain;	/* list of all channels */
-
-struct tty_struct zs_ttys[NUM_CHANNELS];
-
-#ifdef CONFIG_SERIAL_DEC_CONSOLE
-static struct console zs_console;
-#endif
-#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
-   !defined(MODULE)
-static unsigned long break_pressed; /* break, really ... */
-#endif
-
-static unsigned char zs_init_regs[16] __initdata = {
-	0,				/* write 0 */
-	0,				/* write 1 */
-	0,				/* write 2 */
-	0,				/* write 3 */
-	(X16CLK),			/* write 4 */
-	0,				/* write 5 */
-	0, 0, 0,			/* write 6, 7, 8 */
-	(MIE | DLC | NV),		/* write 9 */
-	(NRZ),				/* write 10 */
-	(TCBR | RCBR),			/* write 11 */
-	0, 0,				/* BRG time constant, write 12 + 13 */
-	(BRSRC | BRENABL),		/* write 14 */
-	0				/* write 15 */
-};
-
-static struct tty_driver *serial_driver;
-
-/* serial subtype definitions */
-#define SERIAL_TYPE_NORMAL	1
-
-/* number of characters left in xmit buffer before we ask for more */
-#define WAKEUP_CHARS 256
-
-/*
- * Debugging.
- */
-#undef SERIAL_DEBUG_OPEN
-#undef SERIAL_DEBUG_FLOW
-#undef SERIAL_DEBUG_THROTTLE
-#undef SERIAL_PARANOIA_CHECK
-
-#undef ZS_DEBUG_REGS
-
-#ifdef SERIAL_DEBUG_THROTTLE
-#define _tty_name(tty,buf) tty_name(tty,buf)
-#endif
-
-#define RS_STROBE_TIME 10
-#define RS_ISR_PASS_LIMIT 256
-
-static void probe_sccs(void);
-static void change_speed(struct dec_serial *info);
-static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
-
-static inline int serial_paranoia_check(struct dec_serial *info,
-					char *name, const char *routine)
-{
-#ifdef SERIAL_PARANOIA_CHECK
-	static const char *badmagic =
-		"Warning: bad magic number for serial struct %s in %s\n";
-	static const char *badinfo =
-		"Warning: null mac_serial for %s in %s\n";
-
-	if (!info) {
-		printk(badinfo, name, routine);
-		return 1;
-	}
-	if (info->magic != SERIAL_MAGIC) {
-		printk(badmagic, name, routine);
-		return 1;
-	}
-#endif
-	return 0;
-}
-
-/*
- * This is used to figure out the divisor speeds and the timeouts
- */
-static int baud_table[] = {
-	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
-	9600, 19200, 38400, 57600, 115200, 0 };
-
-/*
- * Reading and writing Z8530 registers.
- */
-static inline unsigned char read_zsreg(struct dec_zschannel *channel,
-				       unsigned char reg)
-{
-	unsigned char retval;
-
-	if (reg != 0) {
-		*channel->control = reg & 0xf;
-		fast_iob(); RECOVERY_DELAY;
-	}
-	retval = *channel->control;
-	RECOVERY_DELAY;
-	return retval;
-}
-
-static inline void write_zsreg(struct dec_zschannel *channel,
-			       unsigned char reg, unsigned char value)
-{
-	if (reg != 0) {
-		*channel->control = reg & 0xf;
-		fast_iob(); RECOVERY_DELAY;
-	}
-	*channel->control = value;
-	fast_iob(); RECOVERY_DELAY;
-	return;
-}
-
-static inline unsigned char read_zsdata(struct dec_zschannel *channel)
-{
-	unsigned char retval;
-
-	retval = *channel->data;
-	RECOVERY_DELAY;
-	return retval;
-}
-
-static inline void write_zsdata(struct dec_zschannel *channel,
-				unsigned char value)
-{
-	*channel->data = value;
-	fast_iob(); RECOVERY_DELAY;
-	return;
-}
-
-static inline void load_zsregs(struct dec_zschannel *channel,
-			       unsigned char *regs)
-{
-/*	ZS_CLEARERR(channel);
-	ZS_CLEARFIFO(channel); */
-	/* Load 'em up */
-	write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
-	write_zsreg(channel, R5, regs[R5] & ~TxENAB);
-	write_zsreg(channel, R4, regs[R4]);
-	write_zsreg(channel, R9, regs[R9]);
-	write_zsreg(channel, R1, regs[R1]);
-	write_zsreg(channel, R2, regs[R2]);
-	write_zsreg(channel, R10, regs[R10]);
-	write_zsreg(channel, R11, regs[R11]);
-	write_zsreg(channel, R12, regs[R12]);
-	write_zsreg(channel, R13, regs[R13]);
-	write_zsreg(channel, R14, regs[R14]);
-	write_zsreg(channel, R15, regs[R15]);
-	write_zsreg(channel, R3, regs[R3]);
-	write_zsreg(channel, R5, regs[R5]);
-	return;
-}
-
-/* Sets or clears DTR/RTS on the requested line */
-static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
-{
-        unsigned long flags;
-
-	spin_lock_irqsave(&zs_lock, flags);
-	if (info->zs_channel != info->zs_chan_a) {
-		if (set) {
-			info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
-		} else {
-			info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
-		}
-		write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
-	}
-	spin_unlock_irqrestore(&zs_lock, flags);
-}
-
-/* Utility routines for the Zilog */
-static inline int get_zsbaud(struct dec_serial *ss)
-{
-	struct dec_zschannel *channel = ss->zs_channel;
-	int brg;
-
-	/* The baud rate is split up between two 8-bit registers in
-	 * what is termed 'BRG time constant' format in my docs for
-	 * the chip, it is a function of the clk rate the chip is
-	 * receiving which happens to be constant.
-	 */
-	brg = (read_zsreg(channel, 13) << 8);
-	brg |= read_zsreg(channel, 12);
-	return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
-}
-
-/* On receive, this clears errors and the receiver interrupts */
-static inline void rs_recv_clear(struct dec_zschannel *zsc)
-{
-	write_zsreg(zsc, 0, ERR_RES);
-	write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
-}
-
-/*
- * ----------------------------------------------------------------------
- *
- * Here starts the interrupt handling routines.  All of the following
- * subroutines are declared as inline and are folded into
- * rs_interrupt().  They were separated out for readability's sake.
- *
- * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
- * -----------------------------------------------------------------------
- */
-
-/*
- * This routine is used by the interrupt handler to schedule
- * processing in the software interrupt portion of the driver.
- */
-static void rs_sched_event(struct dec_serial *info, int event)
-{
-	info->event |= 1 << event;
-	tasklet_schedule(&info->tlet);
-}
-
-static void receive_chars(struct dec_serial *info)
-{
-	struct tty_struct *tty = info->tty;
-	unsigned char ch, stat, flag;
-
-	while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
-
-		stat = read_zsreg(info->zs_channel, R1);
-		ch = read_zsdata(info->zs_channel);
-
-		if (!tty && (!info->hook || !info->hook->rx_char))
-			continue;
-
-		flag = TTY_NORMAL;
-		if (info->tty_break) {
-			info->tty_break = 0;
-			flag = TTY_BREAK;
-			if (info->flags & ZILOG_SAK)
-				do_SAK(tty);
-			/* Ignore the null char got when BREAK is removed.  */
-			if (ch == 0)
-				continue;
-		} else {
-			if (stat & Rx_OVR) {
-				flag = TTY_OVERRUN;
-			} else if (stat & FRM_ERR) {
-				flag = TTY_FRAME;
-			} else if (stat & PAR_ERR) {
-				flag = TTY_PARITY;
-			}
-			if (flag != TTY_NORMAL)
-				/* reset the error indication */
-				write_zsreg(info->zs_channel, R0, ERR_RES);
-		}
-
-#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
-   !defined(MODULE)
-		if (break_pressed && info->line == zs_console.index) {
-			/* Ignore the null char got when BREAK is removed.  */
-			if (ch == 0)
-				continue;
-			if (time_before(jiffies, break_pressed + HZ * 5)) {
-				handle_sysrq(ch, NULL);
-				break_pressed = 0;
-				continue;
-			}
-			break_pressed = 0;
-		}
-#endif
-
-		if (info->hook && info->hook->rx_char) {
-			(*info->hook->rx_char)(ch, flag);
-			return;
-  		}
-
-		tty_insert_flip_char(tty, ch, flag);
-	}
-	if (tty)
-		tty_flip_buffer_push(tty);
-}
-
-static void transmit_chars(struct dec_serial *info)
-{
-	if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
-		return;
-	info->tx_active = 0;
-
-	if (info->x_char) {
-		/* Send next char */
-		write_zsdata(info->zs_channel, info->x_char);
-		info->x_char = 0;
-		info->tx_active = 1;
-		return;
-	}
-
-	if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
-	    || info->tx_stopped) {
-		write_zsreg(info->zs_channel, R0, RES_Tx_P);
-		return;
-	}
-	/* Send char */
-	write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
-	info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
-	info->xmit_cnt--;
-	info->tx_active = 1;
-
-	if (info->xmit_cnt < WAKEUP_CHARS)
-		rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
-}
-
-static void status_handle(struct dec_serial *info)
-{
-	unsigned char stat;
-
-	/* Get status from Read Register 0 */
-	stat = read_zsreg(info->zs_channel, R0);
-
-	if ((stat & BRK_ABRT) && !(info->read_reg_zero & BRK_ABRT)) {
-#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
-   !defined(MODULE)
-		if (info->line == zs_console.index) {
-			if (!break_pressed)
-				break_pressed = jiffies;
-		} else
-#endif
-			info->tty_break = 1;
-	}
-
-	if (info->zs_channel != info->zs_chan_a) {
-
-		/* Check for DCD transitions */
-		if (info->tty && !C_CLOCAL(info->tty) &&
-		    ((stat ^ info->read_reg_zero) & DCD) != 0 ) {
-			if (stat & DCD) {
-				wake_up_interruptible(&info->open_wait);
-			} else {
-				tty_hangup(info->tty);
-			}
-		}
-
-		/* Check for CTS transitions */
-		if (info->tty && C_CRTSCTS(info->tty)) {
-			if ((stat & CTS) != 0) {
-				if (info->tx_stopped) {
-					info->tx_stopped = 0;
-					if (!info->tx_active)
-						transmit_chars(info);
-				}
-			} else {
-				info->tx_stopped = 1;
-			}
-		}
-
-	}
-
-	/* Clear status condition... */
-	write_zsreg(info->zs_channel, R0, RES_EXT_INT);
-	info->read_reg_zero = stat;
-}
-
-/*
- * This is the serial driver's generic interrupt routine
- */
-static irqreturn_t rs_interrupt(int irq, void *dev_id)
-{
-	struct dec_serial *info = (struct dec_serial *) dev_id;
-	irqreturn_t status = IRQ_NONE;
-	unsigned char zs_intreg;
-	int shift;
-
-	/* NOTE: The read register 3, which holds the irq status,
-	 *       does so for both channels on each chip.  Although
-	 *       the status value itself must be read from the A
-	 *       channel and is only valid when read from channel A.
-	 *       Yes... broken hardware...
-	 */
-#define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
-
-	if (info->zs_chan_a == info->zs_channel)
-		shift = 3;	/* Channel A */
-	else
-		shift = 0;	/* Channel B */
-
-	for (;;) {
-		zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
-		if ((zs_intreg & CHAN_IRQMASK) == 0)
-			break;
-
-		status = IRQ_HANDLED;
-
-		if (zs_intreg & CHBRxIP) {
-			receive_chars(info);
-		}
-		if (zs_intreg & CHBTxIP) {
-			transmit_chars(info);
-		}
-		if (zs_intreg & CHBEXT) {
-			status_handle(info);
-		}
-	}
-
-	/* Why do we need this ? */
-	write_zsreg(info->zs_channel, 0, RES_H_IUS);
-
-	return status;
-}
-
-#ifdef ZS_DEBUG_REGS
-void zs_dump (void) {
-	int i, j;
-	for (i = 0; i < zs_channels_found; i++) {
-		struct dec_zschannel *ch = &zs_channels[i];
-		if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
-			for (j = 0; j < 15; j++) {
-				printk("W%d = 0x%x\t",
-				       j, (int)ch->curregs[j]);
-			}
-			for (j = 0; j < 15; j++) {
-				printk("R%d = 0x%x\t",
-				       j, (int)read_zsreg(ch,j));
-			}
-			printk("\n\n");
-		}
-	}
-}
-#endif
-
-/*
- * -------------------------------------------------------------------
- * Here ends the serial interrupt routines.
- * -------------------------------------------------------------------
- */
-
-/*
- * ------------------------------------------------------------
- * rs_stop() and rs_start()
- *
- * This routines are called before setting or resetting tty->stopped.
- * ------------------------------------------------------------
- */
-static void rs_stop(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-	if (serial_paranoia_check(info, tty->name, "rs_stop"))
-		return;
-
-#if 1
-	spin_lock_irqsave(&zs_lock, flags);
-	if (info->zs_channel->curregs[5] & TxENAB) {
-		info->zs_channel->curregs[5] &= ~TxENAB;
-		write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
-	}
-	spin_unlock_irqrestore(&zs_lock, flags);
-#endif
-}
-
-static void rs_start(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-	if (serial_paranoia_check(info, tty->name, "rs_start"))
-		return;
-
-	spin_lock_irqsave(&zs_lock, flags);
-#if 1
-	if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
-		info->zs_channel->curregs[5] |= TxENAB;
-		write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
-	}
-#else
-	if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
-		transmit_chars(info);
-	}
-#endif
-	spin_unlock_irqrestore(&zs_lock, flags);
-}
-
-/*
- * This routine is used to handle the "bottom half" processing for the
- * serial driver, known also the "software interrupt" processing.
- * This processing is done at the kernel interrupt level, after the
- * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
- * is where time-consuming activities which can not be done in the
- * interrupt driver proper are done; the interrupt driver schedules
- * them using rs_sched_event(), and they get done here.
- */
-
-static void do_softint(unsigned long private_)
-{
-	struct dec_serial	*info = (struct dec_serial *) private_;
-	struct tty_struct	*tty;
-
-	tty = info->tty;
-	if (!tty)
-		return;
-
-	if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
-		tty_wakeup(tty);
-}
-
-static int zs_startup(struct dec_serial * info)
-{
-	unsigned long flags;
-
-	if (info->flags & ZILOG_INITIALIZED)
-		return 0;
-
-	if (!info->xmit_buf) {
-		info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
-		if (!info->xmit_buf)
-			return -ENOMEM;
-	}
-
-	spin_lock_irqsave(&zs_lock, flags);
-
-#ifdef SERIAL_DEBUG_OPEN
-	printk("starting up ttyS%d (irq %d)...", info->line, info->irq);
-#endif
-
-	/*
-	 * Clear the receive FIFO.
-	 */
-	ZS_CLEARFIFO(info->zs_channel);
-	info->xmit_fifo_size = 1;
-
-	/*
-	 * Clear the interrupt registers.
-	 */
-	write_zsreg(info->zs_channel, R0, ERR_RES);
-	write_zsreg(info->zs_channel, R0, RES_H_IUS);
-
-	/*
-	 * Set the speed of the serial port
-	 */
-	change_speed(info);
-
-	/*
-	 * Turn on RTS and DTR.
-	 */
-	zs_rtsdtr(info, RTS | DTR, 1);
-
-	/*
-	 * Finally, enable sequencing and interrupts
-	 */
-	info->zs_channel->curregs[R1] &= ~RxINT_MASK;
-	info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
-					  EXT_INT_ENAB);
-	info->zs_channel->curregs[R3] |= RxENABLE;
-	info->zs_channel->curregs[R5] |= TxENAB;
-	info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
-	write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
-	write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
-	write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
-	write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
-
-	/*
-	 * And clear the interrupt registers again for luck.
-	 */
-	write_zsreg(info->zs_channel, R0, ERR_RES);
-	write_zsreg(info->zs_channel, R0, RES_H_IUS);
-
-	/* Save the current value of RR0 */
-	info->read_reg_zero = read_zsreg(info->zs_channel, R0);
-
-	if (info->tty)
-		clear_bit(TTY_IO_ERROR, &info->tty->flags);
-	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
-
-	info->flags |= ZILOG_INITIALIZED;
-	spin_unlock_irqrestore(&zs_lock, flags);
-	return 0;
-}
-
-/*
- * This routine will shutdown a serial port; interrupts are disabled, and
- * DTR is dropped if the hangup on close termio flag is on.
- */
-static void shutdown(struct dec_serial * info)
-{
-	unsigned long	flags;
-
-	if (!(info->flags & ZILOG_INITIALIZED))
-		return;
-
-#ifdef SERIAL_DEBUG_OPEN
-	printk("Shutting down serial port %d (irq %d)....", info->line,
-	       info->irq);
-#endif
-
-	spin_lock_irqsave(&zs_lock, flags);
-
-	if (info->xmit_buf) {
-		free_page((unsigned long) info->xmit_buf);
-		info->xmit_buf = 0;
-	}
-
-	info->zs_channel->curregs[1] = 0;
-	write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);	/* no interrupts */
-
-	info->zs_channel->curregs[3] &= ~RxENABLE;
-	write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
-
-	info->zs_channel->curregs[5] &= ~TxENAB;
-	write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
-	if (!info->tty || C_HUPCL(info->tty)) {
-		zs_rtsdtr(info, RTS | DTR, 0);
-	}
-
-	if (info->tty)
-		set_bit(TTY_IO_ERROR, &info->tty->flags);
-
-	info->flags &= ~ZILOG_INITIALIZED;
-	spin_unlock_irqrestore(&zs_lock, flags);
-}
-
-/*
- * This routine is called to set the UART divisor registers to match
- * the specified baud rate for a serial port.
- */
-static void change_speed(struct dec_serial *info)
-{
-	unsigned cflag;
-	int	i;
-	int	brg, bits;
-	unsigned long flags;
-
-	if (!info->hook) {
-		if (!info->tty || !info->tty->termios)
-			return;
-		cflag = info->tty->termios->c_cflag;
-		if (!info->port)
-			return;
-	} else {
-		cflag = info->hook->cflags;
-	}
-
-	i = cflag & CBAUD;
-	if (i & CBAUDEX) {
-		i &= ~CBAUDEX;
-		if (i < 1 || i > 2) {
-			if (!info->hook)
-				info->tty->termios->c_cflag &= ~CBAUDEX;
-			else
-				info->hook->cflags &= ~CBAUDEX;
-		} else
-			i += 15;
-	}
-
-	spin_lock_irqsave(&zs_lock, flags);
-	info->zs_baud = baud_table[i];
-	if (info->zs_baud) {
-		brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
-		info->zs_channel->curregs[12] = (brg & 255);
-		info->zs_channel->curregs[13] = ((brg >> 8) & 255);
-		zs_rtsdtr(info, DTR, 1);
-	} else {
-		zs_rtsdtr(info, RTS | DTR, 0);
-		return;
-	}
-
-	/* byte size and parity */
-	info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
-	info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
-	switch (cflag & CSIZE) {
-	case CS5:
-		bits = 7;
-		info->zs_channel->curregs[3] |= Rx5;
-		info->zs_channel->curregs[5] |= Tx5;
-		break;
-	case CS6:
-		bits = 8;
-		info->zs_channel->curregs[3] |= Rx6;
-		info->zs_channel->curregs[5] |= Tx6;
-		break;
-	case CS7:
-		bits = 9;
-		info->zs_channel->curregs[3] |= Rx7;
-		info->zs_channel->curregs[5] |= Tx7;
-		break;
-	case CS8:
-	default: /* defaults to 8 bits */
-		bits = 10;
-		info->zs_channel->curregs[3] |= Rx8;
-		info->zs_channel->curregs[5] |= Tx8;
-		break;
-	}
-
-	info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
-        info->timeout += HZ/50;         /* Add .02 seconds of slop */
-
-	info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
-	if (cflag & CSTOPB) {
-		info->zs_channel->curregs[4] |= SB2;
-	} else {
-		info->zs_channel->curregs[4] |= SB1;
-	}
-	if (cflag & PARENB) {
-		info->zs_channel->curregs[4] |= PAR_ENA;
-	}
-	if (!(cflag & PARODD)) {
-		info->zs_channel->curregs[4] |= PAR_EVEN;
-	}
-
-	if (!(cflag & CLOCAL)) {
-		if (!(info->zs_channel->curregs[15] & DCDIE))
-			info->read_reg_zero = read_zsreg(info->zs_channel, 0);
-		info->zs_channel->curregs[15] |= DCDIE;
-	} else
-		info->zs_channel->curregs[15] &= ~DCDIE;
-	if (cflag & CRTSCTS) {
-		info->zs_channel->curregs[15] |= CTSIE;
-		if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
-			info->tx_stopped = 1;
-	} else {
-		info->zs_channel->curregs[15] &= ~CTSIE;
-		info->tx_stopped = 0;
-	}
-
-	/* Load up the new values */
-	load_zsregs(info->zs_channel, info->zs_channel->curregs);
-
-	spin_unlock_irqrestore(&zs_lock, flags);
-}
-
-static void rs_flush_chars(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
-		return;
-
-	if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
-	    !info->xmit_buf)
-		return;
-
-	/* Enable transmitter */
-	spin_lock_irqsave(&zs_lock, flags);
-	transmit_chars(info);
-	spin_unlock_irqrestore(&zs_lock, flags);
-}
-
-static int rs_write(struct tty_struct * tty,
-		    const unsigned char *buf, int count)
-{
-	int	c, total = 0;
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-	if (serial_paranoia_check(info, tty->name, "rs_write"))
-		return 0;
-
-	if (!tty || !info->xmit_buf)
-		return 0;
-
-	while (1) {
-		spin_lock_irqsave(&zs_lock, flags);
-		c = min(count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
-				   SERIAL_XMIT_SIZE - info->xmit_head));
-		if (c <= 0)
-			break;
-
-		memcpy(info->xmit_buf + info->xmit_head, buf, c);
-		info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
-		info->xmit_cnt += c;
-		spin_unlock_irqrestore(&zs_lock, flags);
-		buf += c;
-		count -= c;
-		total += c;
-	}
-
-	if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
-	    && !info->tx_active)
-		transmit_chars(info);
-	spin_unlock_irqrestore(&zs_lock, flags);
-	return total;
-}
-
-static int rs_write_room(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	int	ret;
-
-	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
-		return 0;
-	ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
-	if (ret < 0)
-		ret = 0;
-	return ret;
-}
-
-static int rs_chars_in_buffer(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-
-	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
-		return 0;
-	return info->xmit_cnt;
-}
-
-static void rs_flush_buffer(struct tty_struct *tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-
-	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
-		return;
-	spin_lock_irq(&zs_lock);
-	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
-	spin_unlock_irq(&zs_lock);
-	tty_wakeup(tty);
-}
-
-/*
- * ------------------------------------------------------------
- * rs_throttle()
- *
- * This routine is called by the upper-layer tty layer to signal that
- * incoming characters should be throttled.
- * ------------------------------------------------------------
- */
-static void rs_throttle(struct tty_struct * tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-#ifdef SERIAL_DEBUG_THROTTLE
-	char	buf[64];
-
-	printk("throttle %s: %d....\n", _tty_name(tty, buf),
-	       tty->ldisc.chars_in_buffer(tty));
-#endif
-
-	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
-		return;
-
-	if (I_IXOFF(tty)) {
-		spin_lock_irqsave(&zs_lock, flags);
-		info->x_char = STOP_CHAR(tty);
-		if (!info->tx_active)
-			transmit_chars(info);
-		spin_unlock_irqrestore(&zs_lock, flags);
-	}
-
-	if (C_CRTSCTS(tty)) {
-		zs_rtsdtr(info, RTS, 0);
-	}
-}
-
-static void rs_unthrottle(struct tty_struct * tty)
-{
-	struct dec_serial *info = (struct dec_serial *)tty->driver_data;
-	unsigned long flags;
-
-#ifdef SERIAL_DEBUG_THROTTLE
-	char	buf[64];
-
-	printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
-	       tty->ldisc.chars_in_buffer(tty));
-#endif
-
-	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
-		return;
-
-	if (I_IXOFF(tty)) {
-		spin_lock_irqsave(&zs_lock, flags);
-		if (info->x_char)
-			info->x_char = 0;
-		else {
-			info->x_char = START_CHAR(tty);
-			if (!info->tx_active)
-				transmit_chars(info);
-		}
-		spin_unlock_irqrestore(&zs_lock, flags);
-	}
-
-	if (C_CRTSCTS(tty)) {
-		zs_rtsdtr(info, RTS, 1);
-	}
-}
-
-/*
- * ------------------------------------------------------------
- * rs_ioctl() and friends
- * ------------------------------------------------------------
- */
-
-static int get_serial_info(struct dec_serial * info,
-			   struct serial_struct * retinfo)
-{
-	struct serial_struct tmp;
-
-	if (!retinfo)
-		return -EFAULT;
-	memset(&tmp, 0, sizeof(tmp));
-	tmp.type = info->type;
-	tmp.line = info->line;
-	tmp.port = info->port;
-	tmp.irq = info->irq;
-	tmp.flags = info->flags;
-	tmp.baud_base = info->baud_base;
-	tmp.close_delay = info->close_delay;
-	tmp.closing_wait = info->closing_wait;
-	tmp.custom_divisor = info->custom_divisor;
-	return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
-}
-
-static int set_serial_info(struct dec_serial * info,
-			   struct serial_struct * new_info)
-{
-	struct serial_struct new_serial;
-	struct dec_serial old_info;
-	int 			retval = 0;
-
-	if (!new_info)
-		return -EFAULT;
-	copy_from_user(&new_serial,new_info,sizeof(new_serial));
-	old_info = *info;
-
-	if (!capable(CAP_SYS_ADMIN)) {
-		if ((new_serial.baud_base != info->baud_base) ||
-		    (new_serial.type != info->type) ||
-		    (new_serial.close_delay != info->close_delay) ||
-		    ((new_serial.flags & ~ZILOG_USR_MASK) !=
-		     (info->flags & ~ZILOG_USR_MASK)))
-			return -EPERM;
-		info->flags = ((info->flags & ~ZILOG_USR_MASK) |
-			       (new_serial.flags & ZILOG_USR_MASK));
-		info->custom_divisor = new_serial.custom_divisor;
-		goto check_and_exit;
-	}
-
-	if (info->count > 1)
-		return -EBUSY;
-
-	/*
-	 * OK, past this point, all the error checking has been done.
-	 * At this point, we start making changes.....
-	 */
-
-	info->baud_base = new_serial.baud_base;
-	info->flags = ((info->flags & ~ZILOG_FLAGS) |
-			(new_serial.flags & ZILOG_FLAGS));
-	info->type = new_serial.type;
-	info->close_delay = new_serial.close_delay;
-	info->closing_wait = new_serial.closing_wait;
-
-check_and_exit:
-	retval = zs_startup(info);
-	return retval;
-}
-
-/*
- * get_lsr_info - get line status register info
- *
- * Purpose: Let user call ioctl() to get info when the UART physically
- * 	    is emptied.  On bus types like RS485, the transmitter must
- * 	    release the bus after transmitting. This must be done when
- * 	    the transmit shift register is empty, not be done when the
- * 	    transmit holding register is empty.  This functionality
- * 	    allows an RS485 driver to be written in user space.
- */
-static int get_lsr_info(struct dec_serial * info, unsigned int *value)
-{
-	unsigned char status;
-
-	spin_lock(&zs_lock);
-	status = read_zsreg(info->zs_channel, 0);
-	spin_unlock_irq(&zs_lock);
-	put_user(status,value);
-	return 0;
-}
-
-static int rs_tiocmget(struct tty_struct *tty, struct file *file)
-{
-	struct dec_serial * info = (struct dec_serial *)tty->driver_data;
-	unsigned char control, status_a, status_b;
-	unsigned int result;
-
-	if (info->hook)
-		return -ENODEV;
-
-	if (serial_paranoia_check(info, tty->name, __FUNCTION__))
-		return -ENODEV;
-
-	if (tty->flags & (1 << TTY_IO_ERROR))
-		return -EIO;
-
-	if (info->zs_channel == info->zs_chan_a)
-		result = 0;
-	else {
-		spin_lock(&zs_lock);
-		control = info->zs_chan_a->curregs[5];
-		status_a = read_zsreg(info->zs_chan_a, 0);
-		status_b = read_zsreg(info->zs_channel, 0);
-		spin_unlock_irq(&zs_lock);
-		result =  ((control  & RTS) ? TIOCM_RTS: 0)
-			| ((control  & DTR) ? TIOCM_DTR: 0)
-			| ((status_b & DCD) ? TIOCM_CAR: 0)
-			| ((status_a & DCD) ? TIOCM_RNG: 0)
-			| ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
-			| ((status_b & CTS) ? TIOCM_CTS: 0);
-	}
-	return result;
-}
-
-static int rs_tiocmset(struct tty_struct *tty, struct file *file,
-                       unsigned int set, unsigned int clear)
-{
-	struct dec_serial * info = (struct dec_serial *)tty->driver_data;
-
-	if (info->hook)
-		return -ENODEV;
-
-	if (serial_paranoia_check(info, tty->name, __FUN