/*****************************************************************************/

/*
 *	stallion.c  -- stallion multiport serial driver.
 *
 *	Copyright (C) 1996-1999  Stallion Technologies
 *	Copyright (C) 1994-1996  Greg Ungerer.
 *
 *	This code is loosely based on the Linux serial driver, written by
 *	Linus Torvalds, Theodore T'so and others.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*****************************************************************************/

#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/cd1400.h>
#include <linux/sc26198.h>
#include <linux/comstats.h>
#include <linux/stallion.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/device.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#ifdef CONFIG_PCI
#include <linux/pci.h>
#endif

/*****************************************************************************/

/*
 *	Define different board types. Use the standard Stallion "assigned"
 *	board numbers. Boards supported in this driver are abbreviated as
 *	EIO = EasyIO and ECH = EasyConnection 8/32.
 */
#define	BRD_EASYIO	20
#define	BRD_ECH		21
#define	BRD_ECHMC	22
#define	BRD_ECHPCI	26
#define	BRD_ECH64PCI	27
#define	BRD_EASYIOPCI	28

/*
 *	Define a configuration structure to hold the board configuration.
 *	Need to set this up in the code (for now) with the boards that are
 *	to be configured into the system. This is what needs to be modified
 *	when adding/removing/modifying boards. Each line entry in the
 *	stl_brdconf[] array is a board. Each line contains io/irq/memory
 *	ranges for that board (as well as what type of board it is).
 *	Some examples:
 *		{ BRD_EASYIO, 0x2a0, 0, 0, 10, 0 },
 *	This line would configure an EasyIO board (4 or 8, no difference),
 *	at io address 2a0 and irq 10.
 *	Another example:
 *		{ BRD_ECH, 0x2a8, 0x280, 0, 12, 0 },
 *	This line will configure an EasyConnection 8/32 board at primary io
 *	address 2a8, secondary io address 280 and irq 12.
 *	Enter as many lines into this array as you want (only the first 4
 *	will actually be used!). Any combination of EasyIO and EasyConnection
 *	boards can be specified. EasyConnection 8/32 boards can share their
 *	secondary io addresses between each other.
 *
 *	NOTE: there is no need to put any entries in this table for PCI
 *	boards. They will be found automatically by the driver - provided
 *	PCI BIOS32 support is compiled into the kernel.
 */

typedef struct {
	int		brdtype;
	int		ioaddr1;
	int		ioaddr2;
	unsigned long	memaddr;
	int		irq;
	int		irqtype;
} stlconf_t;

static stlconf_t	stl_brdconf[] = {
	/*{ BRD_EASYIO, 0x2a0, 0, 0, 10, 0 },*/
};

static int	stl_nrbrds = sizeof(stl_brdconf) / sizeof(stlconf_t);

/*****************************************************************************/

/*
 *	Define some important driver characteristics. Device major numbers
 *	allocated as per Linux Device Registry.
 */
#ifndef	STL_SIOMEMMAJOR
#define	STL_SIOMEMMAJOR		28
#endif
#ifndef	STL_SERIALMAJOR
#define	STL_SERIALMAJOR		24
#endif
#ifndef	STL_CALLOUTMAJOR
#define	STL_CALLOUTMAJOR	25
#endif

/*
 *	Set the TX buffer size. Bigger is better, but we don't want
 *	to chew too much memory with buffers!
 */
#define	STL_TXBUFLOW		512
#define	STL_TXBUFSIZE		4096

/*****************************************************************************/

/*
 *	Define our local driver identity first. Set up stuff to deal with
 *	all the local structures required by a serial tty driver.
 */
static char	*stl_drvtitle = "Stallion Multiport Serial Driver";
static char	*stl_drvname = "stallion";
static char	*stl_drvversion = "5.6.0";

static struct tty_driver	*stl_serial;

/*
 *	We will need to allocate a temporary write buffer for chars that
 *	come direct from user space. The problem is that a copy from user
 *	space might cause a page fault (typically on a system that is
 *	swapping!). All ports will share one buffer - since if the system
 *	is already swapping a shared buffer won't make things any worse.
 */
static char			*stl_tmpwritebuf;
static DECLARE_MUTEX(stl_tmpwritesem);

/*
 *	Define a local default termios struct. All ports will be created
 *	with this termios initially. Basically all it defines is a raw port
 *	at 9600, 8 data bits, 1 stop bit.
 */
static struct termios		stl_deftermios = {
	.c_cflag	= (B9600 | CS8 | CREAD | HUPCL | CLOCAL),
	.c_cc		= INIT_C_CC,
};

/*
 *	Define global stats structures. Not used often, and can be
 *	re-used for each stats call.
 */
static comstats_t	stl_comstats;
static combrd_t		stl_brdstats;
static stlbrd_t		stl_dummybrd;
static stlport_t	stl_dummyport;

/*
 *	Define global place to put buffer overflow characters.
 */
static char		stl_unwanted[SC26198_RXFIFOSIZE];

/*****************************************************************************/

static stlbrd_t		*stl_brds[STL_MAXBRDS];

/*
 *	Per board state flags. Used with the state field of the board struct.
 *	Not really much here!
 */
#define	BRD_FOUND	0x1

/*
 *	Define the port structure istate flags. These set of flags are
 *	modified at interrupt time - so setting and reseting them needs
 *	to be atomic. Use the bit clear/setting routines for this.
 */
#define	ASYI_TXBUSY	1
#define	ASYI_TXLOW	2
#define	ASYI_DCDCHANGE	3
#define	ASYI_TXFLOWED	4

/*
 *	Define an array of board names as printable strings. Handy for
 *	referencing boards when printing trace and stuff.
 */
static char	*stl_brdnames[] = {
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	"EasyIO",
	"EC8/32-AT",
	"EC8/32-MC",
	(char *) NULL,
	(char *) NULL,
	(char *) NULL,
	"EC8/32-PCI",
	"EC8/64-PCI",
	"EasyIO-PCI",
};

/*****************************************************************************/

/*
 *	Define some string labels for arguments passed from the module
 *	load line. These allow for easy board definitions, and easy
 *	modification of the io, memory and irq resoucres.
 */
static int	stl_nargs = 0;
static char	*board0[4];
static char	*board1[4];
static char	*board2[4];
static char	*board3[4];

static char	**stl_brdsp[] = {
	(char **) &board0,
	(char **) &board1,
	(char **) &board2,
	(char **) &board3
};

/*
 *	Define a set of common board names, and types. This is used to
 *	parse any module arguments.
 */

typedef struct stlbrdtype {
	char	*name;
	int	type;
} stlbrdtype_t;

static stlbrdtype_t	stl_brdstr[] = {
	{ "easyio", BRD_EASYIO },
	{ "eio", BRD_EASYIO },
	{ "20", BRD_EASYIO },
	{ "ec8/32", BRD_ECH },
	{ "ec8/32-at", BRD_ECH },
	{ "ec8/32-isa", BRD_ECH },
	{ "ech", BRD_ECH },
	{ "echat", BRD_ECH },
	{ "21", BRD_ECH },
	{ "ec8/32-mc", BRD_ECHMC },
	{ "ec8/32-mca", BRD_ECHMC },
	{ "echmc", BRD_ECHMC },
	{ "echmca", BRD_ECHMC },
	{ "22", BRD_ECHMC },
	{ "ec8/32-pc", BRD_ECHPCI },
	{ "ec8/32-pci", BRD_ECHPCI },
	{ "26", BRD_ECHPCI },
	{ "ec8/64-pc", BRD_ECH64PCI },
	{ "ec8/64-pci", BRD_ECH64PCI },
	{ "ech-pci", BRD_ECH64PCI },
	{ "echpci", BRD_ECH64PCI },
	{ "echpc", BRD_ECH64PCI },
	{ "27", BRD_ECH64PCI },
	{ "easyio-pc", BRD_EASYIOPCI },
	{ "easyio-pci", BRD_EASYIOPCI },
	{ "eio-pci", BRD_EASYIOPCI },
	{ "eiopci", BRD_EASYIOPCI },
	{ "28", BRD_EASYIOPCI },
};

/*
 *	Define the module agruments.
 */
MODULE_AUTHOR("Greg Ungerer");
MODULE_DESCRIPTION("Stallion Multiport Serial Driver");
MODULE_LICENSE("GPL");

module_param_array(board0, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board0, "Board 0 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board1, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board1, "Board 1 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board2, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board2, "Board 2 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board3, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board3, "Board 3 config -> name[,ioaddr[,ioaddr2][,irq]]");

/*****************************************************************************/

/*
 *	Hardware ID bits for the EasyIO and ECH boards. These defines apply
 *	to the directly accessible io ports of these boards (not the uarts -
 *	they are in cd1400.h and sc26198.h).
 */
#define	EIO_8PORTRS	0x04
#define	EIO_4PORTRS	0x05
#define	EIO_8PORTDI	0x00
#define	EIO_8PORTM	0x06
#define	EIO_MK3		0x03
#define	EIO_IDBITMASK	0x07

#define	EIO_BRDMASK	0xf0
#define	ID_BRD4		0x10
#define	ID_BRD8		0x20
#define	ID_BRD16	0x30

#define	EIO_INTRPEND	0x08
#define	EIO_INTEDGE	0x00
#define	EIO_INTLEVEL	0x08
#define	EIO_0WS		0x10

#define	ECH_ID		0xa0
#define	ECH_IDBITMASK	0xe0
#define	ECH_BRDENABLE	0x08
#define	ECH_BRDDISABLE	0x00
#define	ECH_INTENABLE	0x01
#define	ECH_INTDISABLE	0x00
#define	ECH_INTLEVEL	0x02
#define	ECH_INTEDGE	0x00
#define	ECH_INTRPEND	0x01
#define	ECH_BRDRESET	0x01

#define	ECHMC_INTENABLE	0x01
#define	ECHMC_BRDRESET	0x02

#define	ECH_PNLSTATUS	2
#define	ECH_PNL16PORT	0x20
#define	ECH_PNLIDMASK	0x07
#define	ECH_PNLXPID	0x40
#define	ECH_PNLINTRPEND	0x80

#define	ECH_ADDR2MASK	0x1e0

/*
 *	Define the vector mapping bits for the programmable interrupt board
 *	hardware. These bits encode the interrupt for the board to use - it
 *	is software selectable (except the EIO-8M).
 */
static unsigned char	stl_vecmap[] = {
	0xff, 0xff, 0xff, 0x04, 0x06, 0x05, 0xff, 0x07,
	0xff, 0xff, 0x00, 0x02, 0x01, 0xff, 0xff, 0x03
};

/*
 *	Set up enable and disable macros for the ECH boards. They require
 *	the secondary io address space to be activated and deactivated.
 *	This way all ECH boards can share their secondary io region.
 *	If this is an ECH-PCI board then also need to set the page pointer
 *	to point to the correct page.
 */
#define	BRDENABLE(brdnr,pagenr)						\
	if (stl_brds[(brdnr)]->brdtype == BRD_ECH)			\
		outb((stl_brds[(brdnr)]->ioctrlval | ECH_BRDENABLE),	\
			stl_brds[(brdnr)]->ioctrl);			\
	else if (stl_brds[(brdnr)]->brdtype == BRD_ECHPCI)		\
		outb((pagenr), stl_brds[(brdnr)]->ioctrl);

#define	BRDDISABLE(brdnr)						\
	if (stl_brds[(brdnr)]->brdtype == BRD_ECH)			\
		outb((stl_brds[(brdnr)]->ioctrlval | ECH_BRDDISABLE),	\
			stl_brds[(brdnr)]->ioctrl);

#define	STL_CD1400MAXBAUD	230400
#define	STL_SC26198MAXBAUD	460800

#define	STL_BAUDBASE		115200
#define	STL_CLOSEDELAY		(5 * HZ / 10)

/*****************************************************************************/

#ifdef CONFIG_PCI

/*
 *	Define the Stallion PCI vendor and device IDs.
 */
#ifndef	PCI_VENDOR_ID_STALLION
#define	PCI_VENDOR_ID_STALLION		0x124d
#endif
#ifndef PCI_DEVICE_ID_ECHPCI832
#define	PCI_DEVICE_ID_ECHPCI832		0x0000
#endif
#ifndef PCI_DEVICE_ID_ECHPCI864
#define	PCI_DEVICE_ID_ECHPCI864		0x0002
#endif
#ifndef PCI_DEVICE_ID_EIOPCI
#define	PCI_DEVICE_ID_EIOPCI		0x0003
#endif

/*
 *	Define structure to hold all Stallion PCI boards.
 */
typedef struct stlpcibrd {
	unsigned short		vendid;
	unsigned short		devid;
	int			brdtype;
} stlpcibrd_t;

static stlpcibrd_t	stl_pcibrds[] = {
	{ PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_ECHPCI864, BRD_ECH64PCI },
	{ PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_EIOPCI, BRD_EASYIOPCI },
	{ PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_ECHPCI832, BRD_ECHPCI },
	{ PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_87410, BRD_ECHPCI },
};

static int	stl_nrpcibrds = sizeof(stl_pcibrds) / sizeof(stlpcibrd_t);

#endif

/*****************************************************************************/

/*
 *	Define macros to extract a brd/port number from a minor number.
 */
#define	MINOR2BRD(min)		(((min) & 0xc0) >> 6)
#define	MINOR2PORT(min)		((min) & 0x3f)

/*
 *	Define a baud rate table that converts termios baud rate selector
 *	into the actual baud rate value. All baud rate calculations are
 *	based on the actual baud rate required.
 */
static unsigned int	stl_baudrates[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
	9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
};

/*
 *	Define some handy local macros...
 */
#undef	MIN
#define	MIN(a,b)	(((a) <= (b)) ? (a) : (b))

#undef	TOLOWER
#define	TOLOWER(x)	((((x) >= 'A') && ((x) <= 'Z')) ? ((x) + 0x20) : (x))

/*****************************************************************************/

/*
 *	Declare all those functions in this driver!
 */

static void	stl_argbrds(void);
static int	stl_parsebrd(stlconf_t *confp, char **argp);

static unsigned long stl_atol(char *str);

int		stl_init(void);
static int	stl_open(struct tty_struct *tty, struct file *filp);
static void	stl_close(struct tty_struct *tty, struct file *filp);
static int	stl_write(struct tty_struct *tty, const unsigned char *buf, int count);
static void	stl_putchar(struct tty_struct *tty, unsigned char ch);
static void	stl_flushchars(struct tty_struct *tty);
static int	stl_writeroom(struct tty_struct *tty);
static int	stl_charsinbuffer(struct tty_struct *tty);
static int	stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg);
static void	stl_settermios(struct tty_struct *tty, struct termios *old);
static void	stl_throttle(struct tty_struct *tty);
static void	stl_unthrottle(struct tty_struct *tty);
static void	stl_stop(struct tty_struct *tty);
static void	stl_start(struct tty_struct *tty);
static void	stl_flushbuffer(struct tty_struct *tty);
static void	stl_breakctl(struct tty_struct *tty, int state);
static void	stl_waituntilsent(struct tty_struct *tty, int timeout);
static void	stl_sendxchar(struct tty_struct *tty, char ch);
static void	stl_hangup(struct tty_struct *tty);
static int	stl_memioctl(struct inode *ip, struct file *fp, unsigned int cmd, unsigned long arg);
static int	stl_portinfo(stlport_t *portp, int portnr, char *pos);
static int	stl_readproc(char *page, char **start, off_t off, int count, int *eof, void *data);

static int	stl_brdinit(stlbrd_t *brdp);
static int	stl_initports(stlbrd_t *brdp, stlpanel_t *panelp);
static int	stl_getserial(stlport_t *portp, struct serial_struct __user *sp);
static int	stl_setserial(stlport_t *portp, struct serial_struct __user *sp);
static int	stl_getbrdstats(combrd_t __user *bp);
static int	stl_getportstats(stlport_t *portp, comstats_t __user *cp);
static int	stl_clrportstats(stlport_t *portp, comstats_t __user *cp);
static int	stl_getportstruct(stlport_t __user *arg);
static int	stl_getbrdstruct(stlbrd_t __user *arg);
static int	stl_waitcarrier(stlport_t *portp, struct file *filp);
static int	stl_eiointr(stlbrd_t *brdp);
static int	stl_echatintr(stlbrd_t *brdp);
static int	stl_echmcaintr(stlbrd_t *brdp);
static int	stl_echpciintr(stlbrd_t *brdp);
static int	stl_echpci64intr(stlbrd_t *brdp);
static void	stl_offintr(void *private);
static void	*stl_memalloc(int len);
static stlbrd_t *stl_allocbrd(void);
static stlport_t *stl_getport(int brdnr, int panelnr, int portnr);

static inline int	stl_initbrds(void);
static inline int	stl_initeio(stlbrd_t *brdp);
static inline int	stl_initech(stlbrd_t *brdp);
static inline int	stl_getbrdnr(void);

#ifdef	CONFIG_PCI
static inline int	stl_findpcibrds(void);
static inline int	stl_initpcibrd(int brdtype, struct pci_dev *devp);
#endif

/*
 *	CD1400 uart specific handling functions.
 */
static void	stl_cd1400setreg(stlport_t *portp, int regnr, int value);
static int	stl_cd1400getreg(stlport_t *portp, int regnr);
static int	stl_cd1400updatereg(stlport_t *portp, int regnr, int value);
static int	stl_cd1400panelinit(stlbrd_t *brdp, stlpanel_t *panelp);
static void	stl_cd1400portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
static void	stl_cd1400setport(stlport_t *portp, struct termios *tiosp);
static int	stl_cd1400getsignals(stlport_t *portp);
static void	stl_cd1400setsignals(stlport_t *portp, int dtr, int rts);
static void	stl_cd1400ccrwait(stlport_t *portp);
static void	stl_cd1400enablerxtx(stlport_t *portp, int rx, int tx);
static void	stl_cd1400startrxtx(stlport_t *portp, int rx, int tx);
static void	stl_cd1400disableintrs(stlport_t *portp);
static void	stl_cd1400sendbreak(stlport_t *portp, int len);
static void	stl_cd1400flowctrl(stlport_t *portp, int state);
static void	stl_cd1400sendflow(stlport_t *portp, int state);
static void	stl_cd1400flush(stlport_t *portp);
static int	stl_cd1400datastate(stlport_t *portp);
static void	stl_cd1400eiointr(stlpanel_t *panelp, unsigned int iobase);
static void	stl_cd1400echintr(stlpanel_t *panelp, unsigned int iobase);
static void	stl_cd1400txisr(stlpanel_t *panelp, int ioaddr);
static void	stl_cd1400rxisr(stlpanel_t *panelp, int ioaddr);
static void	stl_cd1400mdmisr(stlpanel_t *panelp, int ioaddr);

static inline int	stl_cd1400breakisr(stlport_t *portp, int ioaddr);

/*
 *	SC26198 uart specific handling functions.
 */
static void	stl_sc26198setreg(stlport_t *portp, int regnr, int value);
static int	stl_sc26198getreg(stlport_t *portp, int regnr);
static int	stl_sc26198updatereg(stlport_t *portp, int regnr, int value);
static int	stl_sc26198getglobreg(stlport_t *portp, int regnr);
static int	stl_sc26198panelinit(stlbrd_t *brdp, stlpanel_t *panelp);
static void	stl_sc26198portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
static void	stl_sc26198setport(stlport_t *portp, struct termios *tiosp);
static int	stl_sc26198getsignals(stlport_t *portp);
static void	stl_sc26198setsignals(stlport_t *portp, int dtr, int rts);
static void	stl_sc26198enablerxtx(stlport_t *portp, int rx, int tx);
static void	stl_sc26198startrxtx(stlport_t *portp, int rx, int tx);
static void	stl_sc26198disableintrs(stlport_t *portp);
static void	stl_sc26198sendbreak(stlport_t *portp, int len);
static void	stl_sc26198flowctrl(stlport_t *portp, int state);
static void	stl_sc26198sendflow(stlport_t *portp, int state);
static void	stl_sc26198flush(stlport_t *portp);
static int	stl_sc26198datastate(stlport_t *portp);
static void	stl_sc26198wait(stlport_t *portp);
static void	stl_sc26198txunflow(stlport_t *portp, struct tty_struct *tty);
static void	stl_sc26198intr(stlpanel_t *panelp, unsigned int iobase);
static void	stl_sc26198txisr(stlport_t *port);
static void	stl_sc26198rxisr(stlport_t *port, unsigned int iack);
static void	stl_sc26198rxbadch(stlport_t *portp, unsigned char status, char ch);
static void	stl_sc26198rxbadchars(stlport_t *portp);
static void	stl_sc26198otherisr(stlport_t *port, unsigned int iack);

/*****************************************************************************/

/*
 *	Generic UART support structure.
 */
typedef struct uart {
	int	(*panelinit)(stlbrd_t *brdp, stlpanel_t *panelp);
	void	(*portinit)(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
	void	(*setport)(stlport_t *portp, struct termios *tiosp);
	int	(*getsignals)(stlport_t *portp);
	void	(*setsignals)(stlport_t *portp, int dtr, int rts);
	void	(*enablerxtx)(stlport_t *portp, int rx, int tx);
	void	(*startrxtx)(stlport_t *portp, int rx, int tx);
	void	(*disableintrs)(stlport_t *portp);
	void	(*sendbreak)(stlport_t *portp, int len);
	void	(*flowctrl)(stlport_t *portp, int state);
	void	(*sendflow)(stlport_t *portp, int state);
	void	(*flush)(stlport_t *portp);
	int	(*datastate)(stlport_t *portp);
	void	(*intr)(stlpanel_t *panelp, unsigned int iobase);
} uart_t;

/*
 *	Define some macros to make calling these functions nice and clean.
 */
#define	stl_panelinit		(* ((uart_t *) panelp->uartp)->panelinit)
#define	stl_portinit		(* ((uart_t *) portp->uartp)->portinit)
#define	stl_setport		(* ((uart_t *) portp->uartp)->setport)
#define	stl_getsignals		(* ((uart_t *) portp->uartp)->getsignals)
#define	stl_setsignals		(* ((uart_t *) portp->uartp)->setsignals)
#define	stl_enablerxtx		(* ((uart_t *) portp->uartp)->enablerxtx)
#define	stl_startrxtx		(* ((uart_t *) portp->uartp)->startrxtx)
#define	stl_disableintrs	(* ((uart_t *) portp->uartp)->disableintrs)
#define	stl_sendbreak		(* ((uart_t *) portp->uartp)->sendbreak)
#define	stl_flowctrl		(* ((uart_t *) portp->uartp)->flowctrl)
#define	stl_sendflow		(* ((uart_t *) portp->uartp)->sendflow)
#define	stl_flush		(* ((uart_t *) portp->uartp)->flush)
#define	stl_datastate		(* ((uart_t *) portp->uartp)->datastate)

/*****************************************************************************/

/*
 *	CD1400 UART specific data initialization.
 */
static uart_t stl_cd1400uart = {
	stl_cd1400panelinit,
	stl_cd1400portinit,
	stl_cd1400setport,
	stl_cd1400getsignals,
	stl_cd1400setsignals,
	stl_cd1400enablerxtx,
	stl_cd1400startrxtx,
	stl_cd1400disableintrs,
	stl_cd1400sendbreak,
	stl_cd1400flowctrl,
	stl_cd1400sendflow,
	stl_cd1400flush,
	stl_cd1400datastate,
	stl_cd1400eiointr
};

/*
 *	Define the offsets within the register bank of a cd1400 based panel.
 *	These io address offsets are common to the EasyIO board as well.
 */
#define	EREG_ADDR	0
#define	EREG_DATA	4
#define	EREG_RXACK	5
#define	EREG_TXACK	6
#define	EREG_MDACK	7

#define	EREG_BANKSIZE	8

#define	CD1400_CLK	25000000
#define	CD1400_CLK8M	20000000

/*
 *	Define the cd1400 baud rate clocks. These are used when calculating
 *	what clock and divisor to use for the required baud rate. Also
 *	define the maximum baud rate allowed, and the default base baud.
 */
static int	stl_cd1400clkdivs[] = {
	CD1400_CLK0, CD1400_CLK1, CD1400_CLK2, CD1400_CLK3, CD1400_CLK4
};

/*****************************************************************************/

/*
 *	SC26198 UART specific data initization.
 */
static uart_t stl_sc26198uart = {
	stl_sc26198panelinit,
	stl_sc26198portinit,
	stl_sc26198setport,
	stl_sc26198getsignals,
	stl_sc26198setsignals,
	stl_sc26198enablerxtx,
	stl_sc26198startrxtx,
	stl_sc26198disableintrs,
	stl_sc26198sendbreak,
	stl_sc26198flowctrl,
	stl_sc26198sendflow,
	stl_sc26198flush,
	stl_sc26198datastate,
	stl_sc26198intr
};

/*
 *	Define the offsets within the register bank of a sc26198 based panel.
 */
#define	XP_DATA		0
#define	XP_ADDR		1
#define	XP_MODID	2
#define	XP_STATUS	2
#define	XP_IACK		3

#define	XP_BANKSIZE	4

/*
 *	Define the sc26198 baud rate table. Offsets within the table
 *	represent the actual baud rate selector of sc26198 registers.
 */
static unsigned int	sc26198_baudtable[] = {
	50, 75, 150, 200, 300, 450, 600, 900, 1200, 1800, 2400, 3600,
	4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200,
	230400, 460800, 921600
};

#define	SC26198_NRBAUDS		(sizeof(sc26198_baudtable) / sizeof(unsigned int))

/*****************************************************************************/

/*
 *	Define the driver info for a user level control device. Used mainly
 *	to get at port stats - only not using the port device itself.
 */
static struct file_operations	stl_fsiomem = {
	.owner		= THIS_MODULE,
	.ioctl		= stl_memioctl,
};

/*****************************************************************************/

static struct class_simple *stallion_class;

/*
 *	Loadable module initialization stuff.
 */

static int __init stallion_module_init(void)
{
	unsigned long	flags;

#ifdef DEBUG
	printk("init_module()\n");
#endif

	save_flags(flags);
	cli();
	stl_init();
	restore_flags(flags);

	return(0);
}

/*****************************************************************************/

static void __exit stallion_module_exit(void)
{
	stlbrd_t	*brdp;
	stlpanel_t	*panelp;
	stlport_t	*portp;
	unsigned long	flags;
	int		i, j, k;

#ifdef DEBUG
	printk("cleanup_module()\n");
#endif

	printk(KERN_INFO "Unloading %s: version %s\n", stl_drvtitle,
		stl_drvversion);

	save_flags(flags);
	cli();

/*
 *	Free up all allocated resources used by the ports. This includes
 *	memory and interrupts. As part of this process we will also do
 *	a hangup on every open port - to try to flush out any processes
 *	hanging onto ports.
 */
	i = tty_unregister_driver(stl_serial);
	put_tty_driver(stl_serial);
	if (i) {
		printk("STALLION: failed to un-register tty driver, "
			"errno=%d\n", -i);
		restore_flags(flags);
		return;
	}
	for (i = 0; i < 4; i++) {
		devfs_remove("staliomem/%d", i);
		class_simple_device_remove(MKDEV(STL_SIOMEMMAJOR, i));
	}
	devfs_remove("staliomem");
	if ((i = unregister_chrdev(STL_SIOMEMMAJOR, "staliomem")))
		printk("STALLION: failed to un-register serial memory device, "
			"errno=%d\n", -i);
	class_simple_destroy(stallion_class);

	if (stl_tmpwritebuf != (char *) NULL)
		kfree(stl_tmpwritebuf);

	for (i = 0; (i < stl_nrbrds); i++) {
		if ((brdp = stl_brds[i]) == (stlbrd_t *) NULL)
			continue;

		free_irq(brdp->irq, brdp);

		for (j = 0; (j < STL_MAXPANELS); j++) {
			panelp = brdp->panels[j];
			if (panelp == (stlpanel_t *) NULL)
				continue;
			for (k = 0; (k < STL_PORTSPERPANEL); k++) {
				portp = panelp->ports[k];
				if (portp == (stlport_t *) NULL)
					continue;
				if (portp->tty != (struct tty_struct *) NULL)
					stl_hangup(portp->tty);
				if (portp->tx.buf != (char *) NULL)
					kfree(portp->tx.buf);
				kfree(portp);
			}
			kfree(panelp);
		}

		release_region(brdp->ioaddr1, brdp->iosize1);
		if (brdp->iosize2 > 0)
			release_region(brdp->ioaddr2, brdp->iosize2);

		kfree(brdp);
		stl_brds[i] = (stlbrd_t *) NULL;
	}

	restore_flags(flags);
}

module_init(stallion_module_init);
module_exit(stallion_module_exit);

/*****************************************************************************/

/*
 *	Check for any arguments passed in on the module load command line.
 */

static void stl_argbrds(void)
{
	stlconf_t	conf;
	stlbrd_t	*brdp;
	int		i;

#ifdef DEBUG
	printk("stl_argbrds()\n");
#endif

	for (i = stl_nrbrds; (i < stl_nargs); i++) {
		memset(&conf, 0, sizeof(conf));
		if (stl_parsebrd(&conf, stl_brdsp[i]) == 0)
			continue;
		if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
			continue;
		stl_nrbrds = i + 1;
		brdp->brdnr = i;
		brdp->brdtype = conf.brdtype;
		brdp->ioaddr1 = conf.ioaddr1;
		brdp->ioaddr2 = conf.ioaddr2;
		brdp->irq = conf.irq;
		brdp->irqtype = conf.irqtype;
		stl_brdinit(brdp);
	}
}

/*****************************************************************************/

/*
 *	Convert an ascii string number into an unsigned long.
 */

static unsigned long stl_atol(char *str)
{
	unsigned long	val;
	int		base, c;
	char		*sp;

	val = 0;
	sp = str;
	if ((*sp == '0') && (*(sp+1) == 'x')) {
		base = 16;
		sp += 2;
	} else if (*sp == '0') {
		base = 8;
		sp++;
	} else {
		base = 10;
	}

	for (; (*sp != 0); sp++) {
		c = (*sp > '9') ? (TOLOWER(*sp) - 'a' + 10) : (*sp - '0');
		if ((c < 0) || (c >= base)) {
			printk("STALLION: invalid argument %s\n", str);
			val = 0;
			break;
		}
		val = (val * base) + c;
	}
	return(val);
}

/*****************************************************************************/

/*
 *	Parse the supplied argument string, into the board conf struct.
 */

static int stl_parsebrd(stlconf_t *confp, char **argp)
{
	char	*sp;
	int	nrbrdnames, i;

#ifdef DEBUG
	printk("stl_parsebrd(confp=%x,argp=%x)\n", (int) confp, (int) argp);
#endif

	if ((argp[0] == (char *) NULL) || (*argp[0] == 0))
		return(0);

	for (sp = argp[0], i = 0; ((*sp != 0) && (i < 25)); sp++, i++)
		*sp = TOLOWER(*sp);

	nrbrdnames = sizeof(stl_brdstr) / sizeof(stlbrdtype_t);
	for (i = 0; (i < nrbrdnames); i++) {
		if (strcmp(stl_brdstr[i].name, argp[0]) == 0)
			break;
	}
	if (i >= nrbrdnames) {
		printk("STALLION: unknown board name, %s?\n", argp[0]);
		return(0);
	}

	confp->brdtype = stl_brdstr[i].type;

	i = 1;
	if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
		confp->ioaddr1 = stl_atol(argp[i]);
	i++;
	if (confp->brdtype == BRD_ECH) {
		if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
			confp->ioaddr2 = stl_atol(argp[i]);
		i++;
	}
	if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
		confp->irq = stl_atol(argp[i]);
	return(1);
}

/*****************************************************************************/

/*
 *	Local driver kernel memory allocation routine.
 */

static void *stl_memalloc(int len)
{
	return((void *) kmalloc(len, GFP_KERNEL));
}

/*****************************************************************************/

/*
 *	Allocate a new board structure. Fill out the basic info in it.
 */

static stlbrd_t *stl_allocbrd(void)
{
	stlbrd_t	*brdp;

	brdp = (stlbrd_t *) stl_memalloc(sizeof(stlbrd_t));
	if (brdp == (stlbrd_t *) NULL) {
		printk("STALLION: failed to allocate memory (size=%d)\n",
			sizeof(stlbrd_t));
		return((stlbrd_t *) NULL);
	}

	memset(brdp, 0, sizeof(stlbrd_t));
	brdp->magic = STL_BOARDMAGIC;
	return(brdp);
}

/*****************************************************************************/

static int stl_open(struct tty_struct *tty, struct file *filp)
{
	stlport_t	*portp;
	stlbrd_t	*brdp;
	unsigned int	minordev;
	int		brdnr, panelnr, portnr, rc;

#ifdef DEBUG
	printk("stl_open(tty=%x,filp=%x): device=%s\n", (int) tty,
		(int) filp, tty->name);
#endif

	minordev = tty->index;
	brdnr = MINOR2BRD(minordev);
	if (brdnr >= stl_nrbrds)
		return(-ENODEV);
	brdp = stl_brds[brdnr];
	if (brdp == (stlbrd_t *) NULL)
		return(-ENODEV);
	minordev = MINOR2PORT(minordev);
	for (portnr = -1, panelnr = 0; (panelnr < STL_MAXPANELS); panelnr++) {
		if (brdp->panels[panelnr] == (stlpanel_t *) NULL)
			break;
		if (minordev < brdp->panels[panelnr]->nrports) {
			portnr = minordev;
			break;
		}
		minordev -= brdp->panels[panelnr]->nrports;
	}
	if (portnr < 0)
		return(-ENODEV);

	portp = brdp->panels[panelnr]->ports[portnr];
	if (portp == (stlport_t *) NULL)
		return(-ENODEV);

/*
 *	On the first open of the device setup the port hardware, and
 *	initialize the per port data structure.
 */
	portp->tty = tty;
	tty->driver_data = portp;
	portp->refcount++;

	if ((portp->flags & ASYNC_INITIALIZED) == 0) {
		if (portp->tx.buf == (char *) NULL) {
			portp->tx.buf = (char *) stl_memalloc(STL_TXBUFSIZE);
			if (portp->tx.buf == (char *) NULL)
				return(-ENOMEM);
			portp->tx.head = portp->tx.buf;
			portp->tx.tail = portp->tx.buf;
		}
		stl_setport(portp, tty->termios);
		portp->sigs = stl_getsignals(portp);
		stl_setsignals(portp, 1, 1);
		stl_enablerxtx(portp, 1, 1);
		stl_startrxtx(portp, 1, 0);
		clear_bit(TTY_IO_ERROR, &tty->flags);
		portp->flags |= ASYNC_INITIALIZED;
	}

/*
 *	Check if this port is in the middle of closing. If so then wait
 *	until it is closed then return error status, based on flag settings.
 *	The sleep here does not need interrupt protection since the wakeup
 *	for it is done with the same context.
 */
	if (portp->flags & ASYNC_CLOSING) {
		interruptible_sleep_on(&portp->close_wait);
		if (portp->flags & ASYNC_HUP_NOTIFY)
			return(-EAGAIN);
		return(-ERESTARTSYS);
	}

/*
 *	Based on type of open being done check if it can overlap with any
 *	previous opens still in effect. If we are a normal serial device
 *	then also we might have to wait for carrier.
 */
	if (!(filp->f_flags & O_NONBLOCK)) {
		if ((rc = stl_waitcarrier(portp, filp)) != 0)
			return(rc);
	}
	portp->flags |= ASYNC_NORMAL_ACTIVE;

	return(0);
}

/*****************************************************************************/

/*
 *	Possibly need to wait for carrier (DCD signal) to come high. Say
 *	maybe because if we are clocal then we don't need to wait...
 */

static int stl_waitcarrier(stlport_t *portp, struct file *filp)
{
	unsigned long	flags;
	int		rc, doclocal;

#ifdef DEBUG
	printk("stl_waitcarrier(portp=%x,filp=%x)\n", (int) portp, (int) filp);
#endif

	rc = 0;
	doclocal = 0;

	if (portp->tty->termios->c_cflag & CLOCAL)
		doclocal++;

	save_flags(flags);
	cli();
	portp->openwaitcnt++;
	if (! tty_hung_up_p(filp))
		portp->refcount--;

	for (;;) {
		stl_setsignals(portp, 1, 1);
		if (tty_hung_up_p(filp) ||
		    ((portp->flags & ASYNC_INITIALIZED) == 0)) {
			if (portp->flags & ASYNC_HUP_NOTIFY)
				rc = -EBUSY;
			else
				rc = -ERESTARTSYS;
			break;
		}
		if (((portp->flags & ASYNC_CLOSING) == 0) &&
		    (doclocal || (portp->sigs & TIOCM_CD))) {
			break;
		}
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
		interruptible_sleep_on(&portp->open_wait);
	}

	if (! tty_hung_up_p(filp))
		portp->refcount++;
	portp->openwaitcnt--;
	restore_flags(flags);

	return(rc);
}

/*****************************************************************************/

static void stl_close(struct tty_struct *tty, struct file *filp)
{
	stlport_t	*portp;
	unsigned long	flags;

#ifdef DEBUG
	printk("stl_close(tty=%x,filp=%x)\n", (int) tty, (int) filp);
#endif

	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	save_flags(flags);
	cli();
	if (tty_hung_up_p(filp)) {
		restore_flags(flags);
		return;
	}
	if ((tty->count == 1) && (portp->refcount != 1))
		portp->refcount = 1;
	if (portp->refcount-- > 1) {
		restore_flags(flags);
		return;
	}

	portp->refcount = 0;
	portp->flags |= ASYNC_CLOSING;

/*
 *	May want to wait for any data to drain before closing. The BUSY
 *	flag keeps track of whether we are still sending or not - it is
 *	very accurate for the cd1400, not quite so for the sc26198.
 *	(The sc26198 has no "end-of-data" interrupt only empty FIFO)
 */
	tty->closing = 1;
	if (portp->closing_wait != ASYNC_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, portp->closing_wait);
	stl_waituntilsent(tty, (HZ / 2));

	portp->flags &= ~ASYNC_INITIALIZED;
	stl_disableintrs(portp);
	if (tty->termios->c_cflag & HUPCL)
		stl_setsignals(portp, 0, 0);
	stl_enablerxtx(portp, 0, 0);
	stl_flushbuffer(tty);
	portp->istate = 0;
	if (portp->tx.buf != (char *) NULL) {
		kfree(portp->tx.buf);
		portp->tx.buf = (char *) NULL;
		portp->tx.head = (char *) NULL;
		portp->tx.tail = (char *) NULL;
	}
	set_bit(TTY_IO_ERROR, &tty->flags);
	tty_ldisc_flush(tty);

	tty->closing = 0;
	portp->tty = (struct tty_struct *) NULL;

	if (portp->openwaitcnt) {
		if (portp->close_delay)
			msleep_interruptible(jiffies_to_msecs(portp->close_delay));
		wake_up_interruptible(&portp->open_wait);
	}

	portp->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
	wake_up_interruptible(&portp->close_wait);
	restore_flags(flags);
}

/*****************************************************************************/

/*
 *	Write routine. Take data and stuff it in to the TX ring queue.
 *	If transmit interrupts are not running then start them.
 */

static int stl_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
	stlport_t	*portp;
	unsigned int	len, stlen;
	unsigned char	*chbuf;
	char		*head, *tail;

#ifdef DEBUG
	printk("stl_write(tty=%x,buf=%x,count=%d)\n",
		(int) tty, (int) buf, count);
#endif

	if ((tty == (struct tty_struct *) NULL) ||
	    (stl_tmpwritebuf == (char *) NULL))
		return(0);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(0);
	if (portp->tx.buf == (char *) NULL)
		return(0);

/*
 *	If copying direct from user space we must cater for page faults,
 *	causing us to "sleep" here for a while. To handle this copy in all
 *	the data we need now, into a local buffer. Then when we got it all
 *	copy it into the TX buffer.
 */
	chbuf = (unsigned char *) buf;

	head = portp->tx.head;
	tail = portp->tx.tail;
	if (head >= tail) {
		len = STL_TXBUFSIZE - (head - tail) - 1;
		stlen = STL_TXBUFSIZE - (head - portp->tx.buf);
	} else {
		len = tail - head - 1;
		stlen = len;
	}

	len = MIN(len, count);
	count = 0;
	while (len > 0) {
		stlen = MIN(len, stlen);
		memcpy(head, chbuf, stlen);
		len -= stlen;
		chbuf += stlen;
		count += stlen;
		head += stlen;
		if (head >= (portp->tx.buf + STL_TXBUFSIZE)) {
			head = portp->tx.buf;
			stlen = tail - head;
		}
	}
	portp->tx.head = head;

	clear_bit(ASYI_TXLOW, &portp->istate);
	stl_startrxtx(portp, -1, 1);

	return(count);
}

/*****************************************************************************/

static void stl_putchar(struct tty_struct *tty, unsigned char ch)
{
	stlport_t	*portp;
	unsigned int	len;
	char		*head, *tail;

#ifdef DEBUG
	printk("stl_putchar(tty=%x,ch=%x)\n", (int) tty, (int) ch);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	if (portp->tx.buf == (char *) NULL)
		return;

	head = portp->tx.head;
	tail = portp->tx.tail;

	len = (head >= tail) ? (STL_TXBUFSIZE - (head - tail)) : (tail - head);
	len--;

	if (len > 0) {
		*head++ = ch;
		if (head >= (portp->tx.buf + STL_TXBUFSIZE))
			head = portp->tx.buf;
	}	
	portp->tx.head = head;
}

/*****************************************************************************/

/*
 *	If there are any characters in the buffer then make sure that TX
 *	interrupts are on and get'em out. Normally used after the putchar
 *	routine has been called.
 */

static void stl_flushchars(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_flushchars(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	if (portp->tx.buf == (char *) NULL)
		return;

#if 0
	if (tty->stopped || tty->hw_stopped ||
	    (portp->tx.head == portp->tx.tail))
		return;
#endif
	stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

static int stl_writeroom(struct tty_struct *tty)
{
	stlport_t	*portp;
	char		*head, *tail;

#ifdef DEBUG
	printk("stl_writeroom(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return(0);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(0);
	if (portp->tx.buf == (char *) NULL)
		return(0);

	head = portp->tx.head;
	tail = portp->tx.tail;
	return((head >= tail) ? (STL_TXBUFSIZE - (head - tail) - 1) : (tail - head - 1));
}

/*****************************************************************************/

/*
 *	Return number of chars in the TX buffer. Normally we would just
 *	calculate the number of chars in the buffer and return that, but if
 *	the buffer is empty and TX interrupts are still on then we return
 *	that the buffer still has 1 char in it. This way whoever called us
 *	will not think that ALL chars have drained - since the UART still
 *	must have some chars in it (we are busy after all).
 */

static int stl_charsinbuffer(struct tty_struct *tty)
{
	stlport_t	*portp;
	unsigned int	size;
	char		*head, *tail;

#ifdef DEBUG
	printk("stl_charsinbuffer(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return(0);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(0);
	if (portp->tx.buf == (char *) NULL)
		return(0);

	head = portp->tx.head;
	tail = portp->tx.tail;
	size = (head >= tail) ? (head - tail) : (STL_TXBUFSIZE - (tail - head));
	if ((size == 0) && test_bit(ASYI_TXBUSY, &portp->istate))
		size = 1;
	return(size);
}

/*****************************************************************************/

/*
 *	Generate the serial struct info.
 */

static int stl_getserial(stlport_t *portp, struct serial_struct __user *sp)
{
	struct serial_struct	sio;
	stlbrd_t		*brdp;

#ifdef DEBUG
	printk("stl_getserial(portp=%x,sp=%x)\n", (int) portp, (int) sp);
#endif

	memset(&sio, 0, sizeof(struct serial_struct));
	sio.line = portp->portnr;
	sio.port = portp->ioaddr;
	sio.flags = portp->flags;
	sio.baud_base = portp->baud_base;
	sio.close_delay = portp->close_delay;
	sio.closing_wait = portp->closing_wait;
	sio.custom_divisor = portp->custom_divisor;
	sio.hub6 = 0;
	if (portp->uartp == &stl_cd1400uart) {
		sio.type = PORT_CIRRUS;
		sio.xmit_fifo_size = CD1400_TXFIFOSIZE;
	} else {
		sio.type = PORT_UNKNOWN;
		sio.xmit_fifo_size = SC26198_TXFIFOSIZE;
	}

	brdp = stl_brds[portp->brdnr];
	if (brdp != (stlbrd_t *) NULL)
		sio.irq = brdp->irq;

	return copy_to_user(sp, &sio, sizeof(struct serial_struct)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *	Set port according to the serial struct info.
 *	At this point we do not do any auto-configure stuff, so we will
 *	just quietly ignore any requests to change irq, etc.
 */

static int stl_setserial(stlport_t *portp, struct serial_struct __user *sp)
{
	struct serial_struct	sio;

#ifdef DEBUG
	printk("stl_setserial(portp=%x,sp=%x)\n", (int) portp, (int) sp);
#endif

	if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
		return -EFAULT;
	if (!capable(CAP_SYS_ADMIN)) {
		if ((sio.baud_base != portp->baud_base) ||
		    (sio.close_delay != portp->close_delay) ||
		    ((sio.flags & ~ASYNC_USR_MASK) !=
		    (portp->flags & ~ASYNC_USR_MASK)))
			return(-EPERM);
	} 

	portp->flags = (portp->flags & ~ASYNC_USR_MASK) |
		(sio.flags & ASYNC_USR_MASK);
	portp->baud_base = sio.baud_base;
	portp->close_delay = sio.close_delay;
	portp->closing_wait = sio.closing_wait;
	portp->custom_divisor = sio.custom_divisor;
	stl_setport(portp, portp->tty->termios);
	return(0);
}

/*****************************************************************************/

static int stl_tiocmget(struct tty_struct *tty, struct file *file)
{
	stlport_t	*portp;

	if (tty == (struct tty_struct *) NULL)
		return(-ENODEV);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(-ENODEV);
	if (tty->flags & (1 << TTY_IO_ERROR))
		return(-EIO);

	return stl_getsignals(portp);
}

static int stl_tiocmset(struct tty_struct *tty, struct file *file,
			unsigned int set, unsigned int clear)
{
	stlport_t	*portp;
	int rts = -1, dtr = -1;

	if (tty == (struct tty_struct *) NULL)
		return(-ENODEV);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(-ENODEV);
	if (tty->flags & (1 << TTY_IO_ERROR))
		return(-EIO);

	if (set & TIOCM_RTS)
		rts = 1;
	if (set & TIOCM_DTR)
		dtr = 1;
	if (clear & TIOCM_RTS)
		rts = 0;
	if (clear & TIOCM_DTR)
		dtr = 0;

	stl_setsignals(portp, dtr, rts);
	return 0;
}

static int stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
	stlport_t	*portp;
	unsigned int	ival;
	int		rc;
	void __user *argp = (void __user *)arg;

#ifdef DEBUG
	printk("stl_ioctl(tty=%x,file=%x,cmd=%x,arg=%x)\n",
		(int) tty, (int) file, cmd, (int) arg);
#endif

	if (tty == (struct tty_struct *) NULL)
		return(-ENODEV);
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return(-ENODEV);

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 	    (cmd != COM_GETPORTSTATS) && (cmd != COM_CLRPORTSTATS)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
			return(-EIO);
	}

	rc = 0;

	switch (cmd) {
	case TIOCGSOFTCAR:
		rc = put_user(((tty->termios->c_cflag & CLOCAL) ? 1 : 0),
			(unsigned __user *) argp);
		break;
	case TIOCSSOFTCAR:
		if (get_user(ival, (unsigned int __user *) arg))
			return -EFAULT;
		tty->termios->c_cflag =
				(tty->termios->c_cflag & ~CLOCAL) |
				(ival ? CLOCAL : 0);
		break;
	case TIOCGSERIAL:
		rc = stl_getserial(portp, argp);
		break;
	case TIOCSSERIAL:
		rc = stl_setserial(portp, argp);
		break;
	case COM_GETPORTSTATS:
		rc = stl_getportstats(portp, argp);
		break;
	case COM_CLRPORTSTATS:
		rc = stl_clrportstats(portp, argp);
		break;
	case TIOCSERCONFIG:
	case TIOCSERGWILD:
	case TIOCSERSWILD:
	case TIOCSERGETLSR:
	case TIOCSERGSTRUCT:
	case TIOCSERGETMULTI:
	case TIOCSERSETMULTI:
	default:
		rc = -ENOIOCTLCMD;
		break;
	}

	return(rc);
}

/*****************************************************************************/

static void stl_settermios(struct tty_struct *tty, struct termios *old)
{
	stlport_t	*portp;
	struct termios	*tiosp;

#ifdef DEBUG
	printk("stl_settermios(tty=%x,old=%x)\n", (int) tty, (int) old);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	tiosp = tty->termios;
	if ((tiosp->c_cflag == old->c_cflag) &&
	    (tiosp->c_iflag == old->c_iflag))
		return;

	stl_setport(portp, tiosp);
	stl_setsignals(portp, ((tiosp->c_cflag & (CBAUD & ~CBAUDEX)) ? 1 : 0),
		-1);
	if ((old->c_cflag & CRTSCTS) && ((tiosp->c_cflag & CRTSCTS) == 0)) {
		tty->hw_stopped = 0;
		stl_start(tty);
	}
	if (((old->c_cflag & CLOCAL) == 0) && (tiosp->c_cflag & CLOCAL))
		wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

/*
 *	Attempt to flow control who ever is sending us data. Based on termios
 *	settings use software or/and hardware flow control.
 */

static void stl_throttle(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_throttle(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	stl_flowctrl(portp, 0);
}

/*****************************************************************************/

/*
 *	Unflow control the device sending us data...
 */

static void stl_unthrottle(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_unthrottle(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	stl_flowctrl(portp, 1);
}

/*****************************************************************************/

/*
 *	Stop the transmitter. Basically to do this we will just turn TX
 *	interrupts off.
 */

static void stl_stop(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_stop(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	stl_startrxtx(portp, -1, 0);
}

/*****************************************************************************/

/*
 *	Start the transmitter again. Just turn TX interrupts back on.
 */

static void stl_start(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_start(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;
	stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

/*
 *	Hangup this port. This is pretty much like closing the port, only
 *	a little more brutal. No waiting for data to drain. Shutdown the
 *	port and maybe drop signals.
 */

static void stl_hangup(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_hangup(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	portp->flags &= ~ASYNC_INITIALIZED;
	stl_disableintrs(portp);
	if (tty->termios->c_cflag & HUPCL)
		stl_setsignals(portp, 0, 0);
	stl_enablerxtx(portp, 0, 0);
	stl_flushbuffer(tty);
	portp->istate = 0;
	set_bit(TTY_IO_ERROR, &tty->flags);
	if (portp->tx.buf != (char *) NULL) {
		kfree(portp->tx.buf);
		portp->tx.buf = (char *) NULL;
		portp->tx.head = (char *) NULL;
		portp->tx.tail = (char *) NULL;
	}
	portp->tty = (struct tty_struct *) NULL;
	portp->flags &= ~ASYNC_NORMAL_ACTIVE;
	portp->refcount = 0;
	wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

static void stl_flushbuffer(struct tty_struct *tty)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_flushbuffer(tty=%x)\n", (int) tty);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	stl_flush(portp);
	tty_wakeup(tty);
}

/*****************************************************************************/

static void stl_breakctl(struct tty_struct *tty, int state)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_breakctl(tty=%x,state=%d)\n", (int) tty, state);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	stl_sendbreak(portp, ((state == -1) ? 1 : 2));
}

/*****************************************************************************/

static void stl_waituntilsent(struct tty_struct *tty, int timeout)
{
	stlport_t	*portp;
	unsigned long	tend;

#ifdef DEBUG
	printk("stl_waituntilsent(tty=%x,timeout=%d)\n", (int) tty, timeout);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	if (timeout == 0)
		timeout = HZ;
	tend = jiffies + timeout;

	while (stl_datastate(portp)) {
		if (signal_pending(current))
			break;
		msleep_interruptible(20);
		if (time_after_eq(jiffies, tend))
			break;
	}
}

/*****************************************************************************/

static void stl_sendxchar(struct tty_struct *tty, char ch)
{
	stlport_t	*portp;

#ifdef DEBUG
	printk("stl_sendxchar(tty=%x,ch=%x)\n", (int) tty, ch);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	portp = tty->driver_data;
	if (portp == (stlport_t *) NULL)
		return;

	if (ch == STOP_CHAR(tty))
		stl_sendflow(portp, 0);
	else if (ch == START_CHAR(tty))
		stl_sendflow(portp, 1);
	else
		stl_putchar(tty, ch);
}

/*****************************************************************************/

#define	MAXLINE		80

/*
 *	Format info for a specified port. The line is deliberately limited
 *	to 80 characters. (If it is too long it will be truncated, if too
 *	short then padded with spaces).
 */

static int stl_portinfo(stlport_t *portp, int portnr, char *pos)
{
	char	*sp;
	int	sigs, cnt;

	sp = pos;
	sp += sprintf(sp, "%d: uart:%s tx:%d rx:%d",
		portnr, (portp->hwid == 1) ? "SC26198" : "CD1400",
		(int) portp->stats.txtotal, (int) portp->stats.rxtotal);

	if (portp->stats.rxframing)
		sp += sprintf(sp, " fe:%d", (int) portp->stats.rxframing);
	if (portp->stats.rxparity)
		sp += spri…