LXR linux/include/linux/serial

   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 <uapi/linux/serial_core.h>
  33
  34#ifdef CONFIG_SERIAL_CORE_CONSOLE
  35#define uart_console(port) \
  36        ((port)->cons && (port)->cons->index == (port)->line)
  37#else
  38#define uart_console(port)      (0)
  39#endif
  40
  41struct uart_port;
  42struct serial_struct;
  43struct device;
  44
  45/*
  46 * This structure describes all the operations that can be done on the
  47 * physical hardware.  See Documentation/serial/driver for details.
  48 */
  49struct uart_ops {
  50        unsigned int    (*tx_empty)(struct uart_port *);
  51        void            (*set_mctrl)(struct uart_port *, unsigned int mctrl);
  52        unsigned int    (*get_mctrl)(struct uart_port *);
  53        void            (*stop_tx)(struct uart_port *);
  54        void            (*start_tx)(struct uart_port *);
  55        void            (*throttle)(struct uart_port *);
  56        void            (*unthrottle)(struct uart_port *);
  57        void            (*send_xchar)(struct uart_port *, char ch);
  58        void            (*stop_rx)(struct uart_port *);
  59        void            (*enable_ms)(struct uart_port *);
  60        void            (*break_ctl)(struct uart_port *, int ctl);
  61        int             (*startup)(struct uart_port *);
  62        void            (*shutdown)(struct uart_port *);
  63        void            (*flush_buffer)(struct uart_port *);
  64        void            (*set_termios)(struct uart_port *, struct ktermios *new,
  65                                       struct ktermios *old);
  66        void            (*set_ldisc)(struct uart_port *, struct ktermios *);
  67        void            (*pm)(struct uart_port *, unsigned int state,
  68                              unsigned int oldstate);
  69
  70        /*
  71         * Return a string describing the type of the port
  72         */
  73        const char      *(*type)(struct uart_port *);
  74
  75        /*
  76         * Release IO and memory resources used by the port.
  77         * This includes iounmap if necessary.
  78         */
  79        void            (*release_port)(struct uart_port *);
  80
  81        /*
  82         * Request IO and memory resources used by the port.
  83         * This includes iomapping the port if necessary.
  84         */
  85        int             (*request_port)(struct uart_port *);
  86        void            (*config_port)(struct uart_port *, int);
  87        int             (*verify_port)(struct uart_port *, struct serial_struct *);
  88        int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  89#ifdef CONFIG_CONSOLE_POLL
  90        int             (*poll_init)(struct uart_port *);
  91        void            (*poll_put_char)(struct uart_port *, unsigned char);
  92        int             (*poll_get_char)(struct uart_port *);
  93#endif
  94};
  95
  96#define NO_POLL_CHAR            0x00ff0000
  97#define UART_CONFIG_TYPE        (1 << 0)
  98#define UART_CONFIG_IRQ         (1 << 1)
  99
 100struct uart_icount {
 101        __u32   cts;
 102        __u32   dsr;
 103        __u32   rng;
 104        __u32   dcd;
 105        __u32   rx;
 106        __u32   tx;
 107        __u32   frame;
 108        __u32   overrun;
 109        __u32   parity;
 110        __u32   brk;
 111        __u32   buf_overrun;
 112};
 113
 114typedef unsigned int __bitwise__ upf_t;
 115typedef unsigned int __bitwise__ upstat_t;
 116
 117struct uart_port {
 118        spinlock_t              lock;                   /* port lock */
 119        unsigned long           iobase;                 /* in/out[bwl] */
 120        unsigned char __iomem   *membase;               /* read/write[bwl] */
 121        unsigned int            (*serial_in)(struct uart_port *, int);
 122        void                    (*serial_out)(struct uart_port *, int, int);
 123        void                    (*set_termios)(struct uart_port *,
 124                                               struct ktermios *new,
 125                                               struct ktermios *old);
 126        void                    (*set_mctrl)(struct uart_port *, unsigned int);
 127        int                     (*startup)(struct uart_port *port);
 128        void                    (*shutdown)(struct uart_port *port);
 129        void                    (*throttle)(struct uart_port *port);
 130        void                    (*unthrottle)(struct uart_port *port);
 131        int                     (*handle_irq)(struct uart_port *);
 132        void                    (*pm)(struct uart_port *, unsigned int state,
 133                                      unsigned int old);
 134        void                    (*handle_break)(struct uart_port *);
 135        int                     (*rs485_config)(struct uart_port *,
 136                                                struct serial_rs485 *rs485);
 137        unsigned int            irq;                    /* irq number */
 138        unsigned long           irqflags;               /* irq flags  */
 139        unsigned int            uartclk;                /* base uart clock */
 140        unsigned int            fifosize;               /* tx fifo size */
 141        unsigned char           x_char;                 /* xon/xoff char */
 142        unsigned char           regshift;               /* reg offset shift */
 143        unsigned char           iotype;                 /* io access style */
 144        unsigned char           unused1;
 145
 146#define UPIO_PORT               (SERIAL_IO_PORT)        /* 8b I/O port access */
 147#define UPIO_HUB6               (SERIAL_IO_HUB6)        /* Hub6 ISA card */
 148#define UPIO_MEM                (SERIAL_IO_MEM)         /* 8b MMIO access */
 149#define UPIO_MEM32              (SERIAL_IO_MEM32)       /* 32b little endian */
 150#define UPIO_AU                 (SERIAL_IO_AU)          /* Au1x00 and RT288x type IO */
 151#define UPIO_TSI                (SERIAL_IO_TSI)         /* Tsi108/109 type IO */
 152#define UPIO_MEM32BE            (SERIAL_IO_MEM32BE)     /* 32b big endian */
 153
 154        unsigned int            read_status_mask;       /* driver specific */
 155        unsigned int            ignore_status_mask;     /* driver specific */
 156        struct uart_state       *state;                 /* pointer to parent state */
 157        struct uart_icount      icount;                 /* statistics */
 158
 159        struct console          *cons;                  /* struct console, if any */
 160#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 161        unsigned long           sysrq;                  /* sysrq timeout */
 162#endif
 163
 164        /* flags must be updated while holding port mutex */
 165        upf_t                   flags;
 166
 167        /*
 168         * These flags must be equivalent to the flags defined in
 169         * include/uapi/linux/tty_flags.h which are the userspace definitions
 170         * assigned from the serial_struct flags in uart_set_info()
 171         * [for bit definitions in the UPF_CHANGE_MASK]
 172         *
 173         * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
 174         * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
 175         * The remaining bits are serial-core specific and not modifiable by
 176         * userspace.
 177         */
 178#define UPF_FOURPORT            ((__force upf_t) ASYNC_FOURPORT       /* 1  */ )
 179#define UPF_SAK                 ((__force upf_t) ASYNC_SAK            /* 2  */ )
 180#define UPF_SPD_HI              ((__force upf_t) ASYNC_SPD_HI         /* 4  */ )
 181#define UPF_SPD_VHI             ((__force upf_t) ASYNC_SPD_VHI        /* 5  */ )
 182#define UPF_SPD_CUST            ((__force upf_t) ASYNC_SPD_CUST   /* 0x0030 */ )
 183#define UPF_SPD_WARP            ((__force upf_t) ASYNC_SPD_WARP   /* 0x1010 */ )
 184#define UPF_SPD_MASK            ((__force upf_t) ASYNC_SPD_MASK   /* 0x1030 */ )
 185#define UPF_SKIP_TEST           ((__force upf_t) ASYNC_SKIP_TEST      /* 6  */ )
 186#define UPF_AUTO_IRQ            ((__force upf_t) ASYNC_AUTO_IRQ       /* 7  */ )
 187#define UPF_HARDPPS_CD          ((__force upf_t) ASYNC_HARDPPS_CD     /* 11 */ )
 188#define UPF_SPD_SHI             ((__force upf_t) ASYNC_SPD_SHI        /* 12 */ )
 189#define UPF_LOW_LATENCY         ((__force upf_t) ASYNC_LOW_LATENCY    /* 13 */ )
 190#define UPF_BUGGY_UART          ((__force upf_t) ASYNC_BUGGY_UART     /* 14 */ )
 191#define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 192#define UPF_MAGIC_MULTIPLIER    ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
 193
 194/* Port has hardware-assisted h/w flow control */
 195#define UPF_AUTO_CTS            ((__force upf_t) (1 << 20))
 196#define UPF_AUTO_RTS            ((__force upf_t) (1 << 21))
 197#define UPF_HARD_FLOW           ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
 198/* Port has hardware-assisted s/w flow control */
 199#define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 200#define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 201#define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 202#define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 203#define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 204/* The exact UART type is known and should not be probed.  */
 205#define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 206#define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 207#define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 208#define UPF_DEAD                ((__force upf_t) (1 << 30))
 209#define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 210
 211#define __UPF_CHANGE_MASK       0x17fff
 212#define UPF_CHANGE_MASK         ((__force upf_t) __UPF_CHANGE_MASK)
 213#define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 214
 215#if __UPF_CHANGE_MASK > ASYNC_FLAGS
 216#error Change mask not equivalent to userspace-visible bit defines
 217#endif
 218
 219        /*
 220         * Must hold termios_rwsem, port mutex and port lock to change;
 221         * can hold any one lock to read.
 222         */
 223        upstat_t                status;
 224
 225#define UPSTAT_CTS_ENABLE       ((__force upstat_t) (1 << 0))
 226#define UPSTAT_DCD_ENABLE       ((__force upstat_t) (1 << 1))
 227#define UPSTAT_AUTORTS          ((__force upstat_t) (1 << 2))
 228#define UPSTAT_AUTOCTS          ((__force upstat_t) (1 << 3))
 229#define UPSTAT_AUTOXOFF         ((__force upstat_t) (1 << 4))
 230
 231        int                     hw_stopped;             /* sw-assisted CTS flow state */
 232        unsigned int            mctrl;                  /* current modem ctrl settings */
 233        unsigned int            timeout;                /* character-based timeout */
 234        unsigned int            type;                   /* port type */
 235        const struct uart_ops   *ops;
 236        unsigned int            custom_divisor;
 237        unsigned int            line;                   /* port index */
 238        unsigned int            minor;
 239        resource_size_t         mapbase;                /* for ioremap */
 240        resource_size_t         mapsize;
 241        struct device           *dev;                   /* parent device */
 242        unsigned char           hub6;                   /* this should be in the 8250 driver */
 243        unsigned char           suspended;
 244        unsigned char           irq_wake;
 245        unsigned char           unused[2];
 246        struct attribute_group  *attr_group;            /* port specific attributes */
 247        const struct attribute_group **tty_groups;      /* all attributes (serial core use only) */
 248        struct serial_rs485     rs485;
 249        void                    *private_data;          /* generic platform data pointer */
 250};
 251
 252static inline int serial_port_in(struct uart_port *up, int offset)
 253{
 254        return up->serial_in(up, offset);
 255}
 256
 257static inline void serial_port_out(struct uart_port *up, int offset, int value)
 258{
 259        up->serial_out(up, offset, value);
 260}
 261
 262/**
 263 * enum uart_pm_state - power states for UARTs
 264 * @UART_PM_STATE_ON: UART is powered, up and operational
 265 * @UART_PM_STATE_OFF: UART is powered off
 266 * @UART_PM_STATE_UNDEFINED: sentinel
 267 */
 268enum uart_pm_state {
 269        UART_PM_STATE_ON = 0,
 270        UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 271        UART_PM_STATE_UNDEFINED,
 272};
 273
 274/*
 275 * This is the state information which is persistent across opens.
 276 */
 277struct uart_state {
 278        struct tty_port         port;
 279
 280        enum uart_pm_state      pm_state;
 281        struct circ_buf         xmit;
 282
 283        struct uart_port        *uart_port;
 284};
 285
 286#define UART_XMIT_SIZE  PAGE_SIZE
 287
 288
 289/* number of characters left in xmit buffer before we ask for more */
 290#define WAKEUP_CHARS            256
 291
 292struct module;
 293struct tty_driver;
 294
 295struct uart_driver {
 296        struct module           *owner;
 297        const char              *driver_name;
 298        const char              *dev_name;
 299        int                      major;
 300        int                      minor;
 301        int                      nr;
 302        struct console          *cons;
 303
 304        /*
 305         * these are private; the low level driver should not
 306         * touch these; they should be initialised to NULL
 307         */
 308        struct uart_state       *state;
 309        struct tty_driver       *tty_driver;
 310};
 311
 312void uart_write_wakeup(struct uart_port *port);
 313
 314/*
 315 * Baud rate helpers.
 316 */
 317void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 318                         unsigned int baud);
 319unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 320                                struct ktermios *old, unsigned int min,
 321                                unsigned int max);
 322unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 323
 324/* Base timer interval for polling */
 325static inline int uart_poll_timeout(struct uart_port *port)
 326{
 327        int timeout = port->timeout;
 328
 329        return timeout > 6 ? (timeout / 2 - 2) : 1;
 330}
 331
 332/*
 333 * Console helpers.
 334 */
 335struct earlycon_device {
 336        struct console *con;
 337        struct uart_port port;
 338        char options[16];               /* e.g., 115200n8 */
 339        unsigned int baud;
 340};
 341
 342struct earlycon_id {
 343        char    name[16];
 344        int     (*setup)(struct earlycon_device *, const char *options);
 345} __aligned(32);
 346
 347extern int setup_earlycon(char *buf);
 348extern int of_setup_earlycon(unsigned long addr,
 349                             int (*setup)(struct earlycon_device *, const char *));
 350
 351#define EARLYCON_DECLARE(_name, func)                                   \
 352        static const struct earlycon_id __earlycon_##_name              \
 353                __used __section(__earlycon_table)                      \
 354                 = { .name  = __stringify(_name),                       \
 355                     .setup = func  }
 356
 357#define OF_EARLYCON_DECLARE(name, compat, fn)                           \
 358        _OF_DECLARE(earlycon, name, compat, fn, void *)
 359
 360struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 361                                   struct console *c);
 362int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
 363                        char **options);
 364void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 365                        int *flow);
 366int uart_set_options(struct uart_port *port, struct console *co, int baud,
 367                     int parity, int bits, int flow);
 368struct tty_driver *uart_console_device(struct console *co, int *index);
 369void uart_console_write(struct uart_port *port, const char *s,
 370                        unsigned int count,
 371                        void (*putchar)(struct uart_port *, int));
 372
 373/*
 374 * Port/driver registration/removal
 375 */
 376int uart_register_driver(struct uart_driver *uart);
 377void uart_unregister_driver(struct uart_driver *uart);
 378int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 379int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 380int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 381
 382/*
 383 * Power Management
 384 */
 385int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 386int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 387
 388#define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 389#define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 390
 391#define uart_circ_chars_pending(circ)   \
 392        (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 393
 394#define uart_circ_chars_free(circ)      \
 395        (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 396
 397static inline int uart_tx_stopped(struct uart_port *port)
 398{
 399        struct tty_struct *tty = port->state->port.tty;
 400        if (tty->stopped || port->hw_stopped)
 401                return 1;
 402        return 0;
 403}
 404
 405static inline bool uart_cts_enabled(struct uart_port *uport)
 406{
 407        return !!(uport->status & UPSTAT_CTS_ENABLE);
 408}
 409
 410static inline bool uart_softcts_mode(struct uart_port *uport)
 411{
 412        upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
 413
 414        return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
 415}
 416
 417/*
 418 * The following are helper functions for the low level drivers.
 419 */
 420
 421extern void uart_handle_dcd_change(struct uart_port *uport,
 422                unsigned int status);
 423extern void uart_handle_cts_change(struct uart_port *uport,
 424                unsigned int status);
 425
 426extern void uart_insert_char(struct uart_port *port, unsigned int status,
 427                 unsigned int overrun, unsigned int ch, unsigned int flag);
 428
 429#ifdef SUPPORT_SYSRQ
 430static inline int
 431uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 432{
 433        if (port->sysrq) {
 434                if (ch && time_before(jiffies, port->sysrq)) {
 435                        handle_sysrq(ch);
 436                        port->sysrq = 0;
 437                        return 1;
 438                }
 439                port->sysrq = 0;
 440        }
 441        return 0;
 442}
 443#else
 444#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 445#endif
 446
 447/*
 448 * We do the SysRQ and SAK checking like this...
 449 */
 450static inline int uart_handle_break(struct uart_port *port)
 451{
 452        struct uart_state *state = port->state;
 453
 454        if (port->handle_break)
 455                port->handle_break(port);
 456
 457#ifdef SUPPORT_SYSRQ
 458        if (port->cons && port->cons->index == port->line) {
 459                if (!port->sysrq) {
 460                        port->sysrq = jiffies + HZ*5;
 461                        return 1;
 462                }
 463                port->sysrq = 0;
 464        }
 465#endif
 466        if (port->flags & UPF_SAK)
 467                do_SAK(state->port.tty);
 468        return 0;
 469}
 470
 471/*
 472 *      UART_ENABLE_MS - determine if port should enable modem status irqs
 473 */
 474#define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 475                                         (cflag) & CRTSCTS || \
 476                                         !((cflag) & CLOCAL))
 477
 478#endif /* LINUX_SERIAL_CORE_H */
 479