linux/include/linux/serial_core.h
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   1/*
   2 *  linux/drivers/char/serial_core.h
   3 *
   4 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20#ifndef LINUX_SERIAL_CORE_H
  21#define LINUX_SERIAL_CORE_H
  22
  23
  24#include <linux/compiler.h>
  25#include <linux/interrupt.h>
  26#include <linux/circ_buf.h>
  27#include <linux/spinlock.h>
  28#include <linux/sched.h>
  29#include <linux/tty.h>
  30#include <linux/mutex.h>
  31#include <linux/sysrq.h>
  32#include <linux/pps_kernel.h>
  33#include <uapi/linux/serial_core.h>
  34
  35struct uart_port;
  36struct serial_struct;
  37struct device;
  38
  39/*
  40 * This structure describes all the operations that can be
  41 * done on the physical hardware.
  42 */
  43struct uart_ops {
  44        unsigned int    (*tx_empty)(struct uart_port *);
  45        void            (*set_mctrl)(struct uart_port *, unsigned int mctrl);
  46        unsigned int    (*get_mctrl)(struct uart_port *);
  47        void            (*stop_tx)(struct uart_port *);
  48        void            (*start_tx)(struct uart_port *);
  49        void            (*throttle)(struct uart_port *);
  50        void            (*unthrottle)(struct uart_port *);
  51        void            (*send_xchar)(struct uart_port *, char ch);
  52        void            (*stop_rx)(struct uart_port *);
  53        void            (*enable_ms)(struct uart_port *);
  54        void            (*break_ctl)(struct uart_port *, int ctl);
  55        int             (*startup)(struct uart_port *);
  56        void            (*shutdown)(struct uart_port *);
  57        void            (*flush_buffer)(struct uart_port *);
  58        void            (*set_termios)(struct uart_port *, struct ktermios *new,
  59                                       struct ktermios *old);
  60        void            (*set_ldisc)(struct uart_port *, int new);
  61        void            (*pm)(struct uart_port *, unsigned int state,
  62                              unsigned int oldstate);
  63        int             (*set_wake)(struct uart_port *, unsigned int state);
  64
  65        /*
  66         * Return a string describing the type of the port
  67         */
  68        const char *(*type)(struct uart_port *);
  69
  70        /*
  71         * Release IO and memory resources used by the port.
  72         * This includes iounmap if necessary.
  73         */
  74        void            (*release_port)(struct uart_port *);
  75
  76        /*
  77         * Request IO and memory resources used by the port.
  78         * This includes iomapping the port if necessary.
  79         */
  80        int             (*request_port)(struct uart_port *);
  81        void            (*config_port)(struct uart_port *, int);
  82        int             (*verify_port)(struct uart_port *, struct serial_struct *);
  83        int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  84#ifdef CONFIG_CONSOLE_POLL
  85        int             (*poll_init)(struct uart_port *);
  86        void    (*poll_put_char)(struct uart_port *, unsigned char);
  87        int             (*poll_get_char)(struct uart_port *);
  88#endif
  89};
  90
  91#define NO_POLL_CHAR            0x00ff0000
  92#define UART_CONFIG_TYPE        (1 << 0)
  93#define UART_CONFIG_IRQ         (1 << 1)
  94
  95struct uart_icount {
  96        __u32   cts;
  97        __u32   dsr;
  98        __u32   rng;
  99        __u32   dcd;
 100        __u32   rx;
 101        __u32   tx;
 102        __u32   frame;
 103        __u32   overrun;
 104        __u32   parity;
 105        __u32   brk;
 106        __u32   buf_overrun;
 107};
 108
 109typedef unsigned int __bitwise__ upf_t;
 110
 111struct uart_port {
 112        spinlock_t              lock;                   /* port lock */
 113        unsigned long           iobase;                 /* in/out[bwl] */
 114        unsigned char __iomem   *membase;               /* read/write[bwl] */
 115        unsigned int            (*serial_in)(struct uart_port *, int);
 116        void                    (*serial_out)(struct uart_port *, int, int);
 117        void                    (*set_termios)(struct uart_port *,
 118                                               struct ktermios *new,
 119                                               struct ktermios *old);
 120        int                     (*handle_irq)(struct uart_port *);
 121        void                    (*pm)(struct uart_port *, unsigned int state,
 122                                      unsigned int old);
 123        void                    (*handle_break)(struct uart_port *);
 124        unsigned int            irq;                    /* irq number */
 125        unsigned long           irqflags;               /* irq flags  */
 126        unsigned int            uartclk;                /* base uart clock */
 127        unsigned int            fifosize;               /* tx fifo size */
 128        unsigned char           x_char;                 /* xon/xoff char */
 129        unsigned char           regshift;               /* reg offset shift */
 130        unsigned char           iotype;                 /* io access style */
 131        unsigned char           unused1;
 132
 133#define UPIO_PORT               (0)
 134#define UPIO_HUB6               (1)
 135#define UPIO_MEM                (2)
 136#define UPIO_MEM32              (3)
 137#define UPIO_AU                 (4)                     /* Au1x00 type IO */
 138#define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 139#define UPIO_RM9000             (6)                     /* RM9000 type IO */
 140
 141        unsigned int            read_status_mask;       /* driver specific */
 142        unsigned int            ignore_status_mask;     /* driver specific */
 143        struct uart_state       *state;                 /* pointer to parent state */
 144        struct uart_icount      icount;                 /* statistics */
 145
 146        struct console          *cons;                  /* struct console, if any */
 147#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 148        unsigned long           sysrq;                  /* sysrq timeout */
 149#endif
 150
 151        upf_t                   flags;
 152
 153#define UPF_FOURPORT            ((__force upf_t) (1 << 1))
 154#define UPF_SAK                 ((__force upf_t) (1 << 2))
 155#define UPF_SPD_MASK            ((__force upf_t) (0x1030))
 156#define UPF_SPD_HI              ((__force upf_t) (0x0010))
 157#define UPF_SPD_VHI             ((__force upf_t) (0x0020))
 158#define UPF_SPD_CUST            ((__force upf_t) (0x0030))
 159#define UPF_SPD_SHI             ((__force upf_t) (0x1000))
 160#define UPF_SPD_WARP            ((__force upf_t) (0x1010))
 161#define UPF_SKIP_TEST           ((__force upf_t) (1 << 6))
 162#define UPF_AUTO_IRQ            ((__force upf_t) (1 << 7))
 163#define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 164#define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 165#define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 166#define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 167#define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 168/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 169#define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 170/* Port has hardware-assisted s/w flow control */
 171#define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 172#define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 173#define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 174#define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 175#define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 176/* The exact UART type is known and should not be probed.  */
 177#define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 178#define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 179#define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 180#define UPF_DEAD                ((__force upf_t) (1 << 30))
 181#define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 182
 183#define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 184#define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 185
 186        unsigned int            mctrl;                  /* current modem ctrl settings */
 187        unsigned int            timeout;                /* character-based timeout */
 188        unsigned int            type;                   /* port type */
 189        const struct uart_ops   *ops;
 190        unsigned int            custom_divisor;
 191        unsigned int            line;                   /* port index */
 192        resource_size_t         mapbase;                /* for ioremap */
 193        struct device           *dev;                   /* parent device */
 194        unsigned char           hub6;                   /* this should be in the 8250 driver */
 195        unsigned char           suspended;
 196        unsigned char           irq_wake;
 197        unsigned char           unused[2];
 198        void                    *private_data;          /* generic platform data pointer */
 199};
 200
 201static inline int serial_port_in(struct uart_port *up, int offset)
 202{
 203        return up->serial_in(up, offset);
 204}
 205
 206static inline void serial_port_out(struct uart_port *up, int offset, int value)
 207{
 208        up->serial_out(up, offset, value);
 209}
 210
 211/*
 212 * This is the state information which is persistent across opens.
 213 */
 214struct uart_state {
 215        struct tty_port         port;
 216
 217        int                     pm_state;
 218        struct circ_buf         xmit;
 219
 220        struct uart_port        *uart_port;
 221};
 222
 223#define UART_XMIT_SIZE  PAGE_SIZE
 224
 225
 226/* number of characters left in xmit buffer before we ask for more */
 227#define WAKEUP_CHARS            256
 228
 229struct module;
 230struct tty_driver;
 231
 232struct uart_driver {
 233        struct module           *owner;
 234        const char              *driver_name;
 235        const char              *dev_name;
 236        int                      major;
 237        int                      minor;
 238        int                      nr;
 239        struct console          *cons;
 240
 241        /*
 242         * these are private; the low level driver should not
 243         * touch these; they should be initialised to NULL
 244         */
 245        struct uart_state       *state;
 246        struct tty_driver       *tty_driver;
 247};
 248
 249void uart_write_wakeup(struct uart_port *port);
 250
 251/*
 252 * Baud rate helpers.
 253 */
 254void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 255                         unsigned int baud);
 256unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 257                                struct ktermios *old, unsigned int min,
 258                                unsigned int max);
 259unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 260
 261/* Base timer interval for polling */
 262static inline int uart_poll_timeout(struct uart_port *port)
 263{
 264        int timeout = port->timeout;
 265
 266        return timeout > 6 ? (timeout / 2 - 2) : 1;
 267}
 268
 269/*
 270 * Console helpers.
 271 */
 272struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 273                                   struct console *c);
 274void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 275                        int *flow);
 276int uart_set_options(struct uart_port *port, struct console *co, int baud,
 277                     int parity, int bits, int flow);
 278struct tty_driver *uart_console_device(struct console *co, int *index);
 279void uart_console_write(struct uart_port *port, const char *s,
 280                        unsigned int count,
 281                        void (*putchar)(struct uart_port *, int));
 282
 283/*
 284 * Port/driver registration/removal
 285 */
 286int uart_register_driver(struct uart_driver *uart);
 287void uart_unregister_driver(struct uart_driver *uart);
 288int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 289int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 290int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 291
 292/*
 293 * Power Management
 294 */
 295int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 296int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 297
 298#define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 299#define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 300
 301#define uart_circ_chars_pending(circ)   \
 302        (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 303
 304#define uart_circ_chars_free(circ)      \
 305        (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 306
 307static inline int uart_tx_stopped(struct uart_port *port)
 308{
 309        struct tty_struct *tty = port->state->port.tty;
 310        if(tty->stopped || tty->hw_stopped)
 311                return 1;
 312        return 0;
 313}
 314
 315/*
 316 * The following are helper functions for the low level drivers.
 317 */
 318
 319extern void uart_handle_dcd_change(struct uart_port *uport,
 320                unsigned int status);
 321extern void uart_handle_cts_change(struct uart_port *uport,
 322                unsigned int status);
 323
 324extern void uart_insert_char(struct uart_port *port, unsigned int status,
 325                 unsigned int overrun, unsigned int ch, unsigned int flag);
 326
 327#ifdef SUPPORT_SYSRQ
 328static inline int
 329uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 330{
 331        if (port->sysrq) {
 332                if (ch && time_before(jiffies, port->sysrq)) {
 333                        handle_sysrq(ch);
 334                        port->sysrq = 0;
 335                        return 1;
 336                }
 337                port->sysrq = 0;
 338        }
 339        return 0;
 340}
 341#else
 342#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 343#endif
 344
 345/*
 346 * We do the SysRQ and SAK checking like this...
 347 */
 348static inline int uart_handle_break(struct uart_port *port)
 349{
 350        struct uart_state *state = port->state;
 351
 352        if (port->handle_break)
 353                port->handle_break(port);
 354
 355#ifdef SUPPORT_SYSRQ
 356        if (port->cons && port->cons->index == port->line) {
 357                if (!port->sysrq) {
 358                        port->sysrq = jiffies + HZ*5;
 359                        return 1;
 360                }
 361                port->sysrq = 0;
 362        }
 363#endif
 364        if (port->flags & UPF_SAK)
 365                do_SAK(state->port.tty);
 366        return 0;
 367}
 368
 369/*
 370 *      UART_ENABLE_MS - determine if port should enable modem status irqs
 371 */
 372#define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 373                                         (cflag) & CRTSCTS || \
 374                                         !((cflag) & CLOCAL))
 375
 376#endif /* LINUX_SERIAL_CORE_H */
 377
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