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/*
 *  linux/drivers/char/serial_core.h
 *
 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  $Id: serial_core.h,v 1.1 2004-01-28 15:26:38 giacomo Exp $
 */


/*
 * The type definitions.  These are from Ted Ts'o's serial.h
 */

#define PORT_UNKNOWN    0
#define PORT_8250       1
#define PORT_16450      2
#define PORT_16550      3
#define PORT_16550A     4
#define PORT_CIRRUS     5
#define PORT_16650      6
#define PORT_16650V2    7
#define PORT_16750      8
#define PORT_STARTECH   9
#define PORT_16C950     10
#define PORT_16654      11
#define PORT_16850      12
#define PORT_RSA        13
#define PORT_NS16550A   14
#define PORT_MAX_8250   14      /* max port ID */

/*
 * ARM specific type numbers.  These are not currently guaranteed
 * to be implemented, and will change in the future.  These are
 * separate so any additions to the old serial.c that occur before
 * we are merged can be easily merged here.
 */

#define PORT_AMBA       32
#define PORT_CLPS711X   33
#define PORT_SA1100     34
#define PORT_UART00     35
#define PORT_21285      37

/* Sparc type numbers.  */
#define PORT_SUNZILOG   38
#define PORT_SUNSAB     39

/* NEC v850.  */
#define PORT_V850E_UART 40

/* NEC PC-9800 */
#define PORT_8251_PC98  41
#define PORT_19K_PC98   42
#define PORT_FIFO_PC98  43
#define PORT_VFAST_PC98 44
#define PORT_PC9861     45
#define PORT_PC9801_101 46

/* DZ */
#define PORT_DZ         47

/* Parisc type numbers. */
#define PORT_MUX        48

/* Macintosh Zilog type numbers */
#define PORT_MAC_ZILOG  50      /* m68k : not yet implemented */
#define PORT_PMAC_ZILOG 51

#ifdef __KERNEL__

#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/circ_buf.h>
#include <linux/spinlock.h>

struct uart_port;
struct uart_info;
struct serial_struct;

/*
 * This structure describes all the operations that can be
 * done on the physical hardware.
 */

struct uart_ops {
        unsigned int    (*tx_empty)(struct uart_port *);
        void            (*set_mctrl)(struct uart_port *, unsigned int mctrl);
        unsigned int    (*get_mctrl)(struct uart_port *);
        void            (*stop_tx)(struct uart_port *, unsigned int tty_stop);
        void            (*start_tx)(struct uart_port *, unsigned int tty_start);
        void            (*send_xchar)(struct uart_port *, char ch);
        void            (*stop_rx)(struct uart_port *);
        void            (*enable_ms)(struct uart_port *);
        void            (*break_ctl)(struct uart_port *, int ctl);
        int             (*startup)(struct uart_port *);
        void            (*shutdown)(struct uart_port *);
        void            (*set_termios)(struct uart_port *, struct termios *new,
                                       struct termios *old);
        void            (*pm)(struct uart_port *, unsigned int state,
                              unsigned int oldstate);
        int             (*set_wake)(struct uart_port *, unsigned int state);

        /*
         * Return a string describing the type of the port
         */

        const char *(*type)(struct uart_port *);

        /*
         * Release IO and memory resources used by the port.
         * This includes iounmap if necessary.
         */

        void            (*release_port)(struct uart_port *);

        /*
         * Request IO and memory resources used by the port.
         * This includes iomapping the port if necessary.
         */

        int             (*request_port)(struct uart_port *);
        void            (*config_port)(struct uart_port *, int);
        int             (*verify_port)(struct uart_port *, struct serial_struct *);
        int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
};

#define UART_CONFIG_TYPE        (1 << 0)
#define UART_CONFIG_IRQ         (1 << 1)

struct uart_icount {
        __u32   cts;
        __u32   dsr;
        __u32   rng;
        __u32   dcd;
        __u32   rx;
        __u32   tx;
        __u32   frame;
        __u32   overrun;
        __u32   parity;
        __u32   brk;
        __u32   buf_overrun;
};

struct uart_port {
        spinlock_t              lock;                   /* port lock */
        unsigned int            iobase;                 /* in/out[bwl] */
        char                    *membase;               /* read/write[bwl] */
        unsigned int            irq;                    /* irq number */
        unsigned int            uartclk;                /* base uart clock */
        unsigned char           fifosize;               /* tx fifo size */
        unsigned char           x_char;                 /* xon/xoff char */
        unsigned char           regshift;               /* reg offset shift */
        unsigned char           iotype;                 /* io access style */

#define UPIO_PORT               (0)
#define UPIO_HUB6               (1)
#define UPIO_MEM                (2)

        unsigned int            read_status_mask;       /* driver specific */
        unsigned int            ignore_status_mask;     /* driver specific */
        struct uart_info        *info;                  /* pointer to parent info */
        struct uart_icount      icount;                 /* statistics */

        struct console          *cons;                  /* struct console, if any */
#ifdef CONFIG_SERIAL_CORE_CONSOLE
        unsigned long           sysrq;                  /* sysrq timeout */
#endif

        unsigned int            flags;

#define UPF_HUP_NOTIFY          (1 << 0)
#define UPF_FOURPORT            (1 << 1)
#define UPF_SAK                 (1 << 2)
#define UPF_SPD_MASK            (0x1030)
#define UPF_SPD_HI              (0x0010)
#define UPF_SPD_VHI             (0x0020)
#define UPF_SPD_CUST            (0x0030)
#define UPF_SPD_SHI             (0x1000)
#define UPF_SPD_WARP            (0x1010)
#define UPF_SKIP_TEST           (1 << 6)
#define UPF_AUTO_IRQ            (1 << 7)
#define UPF_HARDPPS_CD          (1 << 11)
#define UPF_LOW_LATENCY         (1 << 13)
#define UPF_BUGGY_UART          (1 << 14)
#define UPF_AUTOPROBE           (1 << 15)
#define UPF_MAGIC_MULTIPLIER    (1 << 16)
#define UPF_BOOT_ONLYMCA        (1 << 22)
#define UPF_CONS_FLOW           (1 << 23)
#define UPF_SHARE_IRQ           (1 << 24)
#define UPF_BOOT_AUTOCONF       (1 << 28)
#define UPF_RESOURCES           (1 << 30)
#define UPF_IOREMAP             (1 << 31)

#define UPF_CHANGE_MASK         (0x17fff)
#define UPF_USR_MASK            (UPF_SPD_MASK|UPF_LOW_LATENCY)

        unsigned int            mctrl;                  /* current modem ctrl settings */
        unsigned int            timeout;                /* character-based timeout */
        unsigned int            type;                   /* port type */
        struct uart_ops         *ops;
        unsigned int            custom_divisor;
        unsigned int            line;                   /* port index */
        unsigned long           mapbase;                /* for ioremap */
        unsigned char           hub6;                   /* this should be in the 8250 driver */
        unsigned char           unused[3];
};

/*
 * This is the state information which is persistent across opens.
 * The low level driver must not to touch any elements contained
 * within.
 */

struct uart_state {
        unsigned int            close_delay;
        unsigned int            closing_wait;

#define USF_CLOSING_WAIT_INF    (0)
#define USF_CLOSING_WAIT_NONE   (65535)

        int                     count;
        int                     pm_state;
        struct uart_info        *info;
        struct uart_port        *port;

        struct semaphore        sem;
};

#define UART_XMIT_SIZE 1024
/*
 * This is the state information which is only valid when the port
 * is open; it may be freed by the core driver once the device has
 * been closed.  Either the low level driver or the core can modify
 * stuff here.
 */

struct uart_info {
        struct tty_struct       *tty;
        struct circ_buf         xmit;
        unsigned int            flags;

/*
 * These are the flags that specific to info->flags, and reflect our
 * internal state.  They can not be accessed via port->flags.  Low
 * level drivers must not change these, but may query them instead.
 */

#define UIF_CHECK_CD            (1 << 25)
#define UIF_CTS_FLOW            (1 << 26)
#define UIF_NORMAL_ACTIVE       (1 << 29)
#define UIF_INITIALIZED         (1 << 31)

        unsigned char           *tmpbuf;
        struct semaphore        tmpbuf_sem;

        int                     blocked_open;

        struct tasklet_struct   tlet;

        wait_queue_head_t       open_wait;
        wait_queue_head_t       delta_msr_wait;
};

/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS            256

struct module;
struct tty_driver;

struct uart_driver {
        struct module           *owner;
        const char              *driver_name;
        const char              *dev_name;
        const char              *devfs_name;
        int                      major;
        int                      minor;
        int                      nr;
        struct console          *cons;

        /*
         * these are private; the low level driver should not
         * touch these; they should be initialised to NULL
         */

        struct uart_state       *state;
        struct tty_driver       *tty_driver;
};

void uart_write_wakeup(struct uart_port *port);

/*
 * Baud rate helpers.
 */

void uart_update_timeout(struct uart_port *port, unsigned int cflag,
                         unsigned int baud);
unsigned int uart_get_baud_rate(struct uart_port *port, struct termios *termios,
                                struct termios *old, unsigned int min,
                                unsigned int max);
unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);

/*
 * Console helpers.
 */

struct uart_port *uart_get_console(struct uart_port *ports, int nr,
                                   struct console *c);
void uart_parse_options(char *options, int *baud, int *parity, int *bits,
                        int *flow);
int uart_set_options(struct uart_port *port, struct console *co, int baud,
                     int parity, int bits, int flow);
struct tty_driver *uart_console_device(struct console *co, int *index);

/*
 * Port/driver registration/removal
 */

int uart_register_driver(struct uart_driver *uart);
void uart_unregister_driver(struct uart_driver *uart);
void uart_unregister_port(struct uart_driver *reg, int line);
int uart_register_port(struct uart_driver *reg, struct uart_port *port);
int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);

/*
 * Power Management
 */

int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
int uart_resume_port(struct uart_driver *reg, struct uart_port *port);

#define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
#define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)

#define uart_circ_chars_pending(circ)   \
        (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))


#define uart_circ_chars_free(circ)      \
        (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))


#define uart_tx_stopped(port)           \
        ((port)->info->tty->stopped || (port)->info->tty->hw_stopped)


/*
 * The following are helper functions for the low level drivers.
 */

#ifdef SUPPORT_SYSRQ
static inline int
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch,
                       struct pt_regs *regs)
{
        if (port->sysrq) {
                if (ch && time_before(jiffies, port->sysrq)) {
                        handle_sysrq(ch, regs, NULL);
                        port->sysrq = 0;
                        return 1;
                }
                port->sysrq = 0;
        }
        return 0;
}
#else
#define uart_handle_sysrq_char(port,ch,regs)    (0)
#endif

/*
 * We do the SysRQ and SAK checking like this...
 */

static inline int uart_handle_break(struct uart_port *port)
{
        struct uart_info *info = port->info;
#ifdef SUPPORT_SYSRQ
        if (port->cons && port->cons->index == port->line) {
                if (!port->sysrq) {
                        port->sysrq = jiffies + HZ*5;
                        return 1;
                }
                port->sysrq = 0;
        }
#endif
        if (info->flags & UPF_SAK)
                do_SAK(info->tty);
        return 0;
}

/**
 *      uart_handle_dcd_change - handle a change of carrier detect state
 *      @port: uart_port structure for the open port
 *      @status: new carrier detect status, nonzero if active
 */

static inline void
uart_handle_dcd_change(struct uart_port *port, unsigned int status)
{
        struct uart_info *info = port->info;

        port->icount.dcd++;

#ifdef CONFIG_HARD_PPS
        if ((port->flags & UPF_HARDPPS_CD) && status)
                hardpps();
#endif

        if (info->flags & UIF_CHECK_CD) {
                if (status)
                        wake_up_interruptible(&info->open_wait);
                else if (info->tty)
                        tty_hangup(info->tty);
        }
}

/**
 *      uart_handle_cts_change - handle a change of clear-to-send state
 *      @port: uart_port structure for the open port
 *      @status: new clear to send status, nonzero if active
 */

static inline void
uart_handle_cts_change(struct uart_port *port, unsigned int status)
{
        struct uart_info *info = port->info;
        struct tty_struct *tty = info->tty;

        port->icount.cts++;

        if (info->flags & UIF_CTS_FLOW) {
                if (tty->hw_stopped) {
                        if (status) {
                                tty->hw_stopped = 0;
                                port->ops->start_tx(port, 0);
                                uart_write_wakeup(port);
                        }
                } else {
                        if (!status) {
                                tty->hw_stopped = 1;
                                port->ops->stop_tx(port, 0);
                        }
                }
        }
}

/*
 *      UART_ENABLE_MS - determine if port should enable modem status irqs
 */

#define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
                                         (cflag) & CRTSCTS || \
                                         !((cflag) & CLOCAL))


#endif