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)      ({ (void)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_ldisc)(struct uart_port *,
 127                                             struct ktermios *);
 128        unsigned int            (*get_mctrl)(struct uart_port *);
 129        void                    (*set_mctrl)(struct uart_port *, unsigned int);
 130        int                     (*startup)(struct uart_port *port);
 131        void                    (*shutdown)(struct uart_port *port);
 132        void                    (*throttle)(struct uart_port *port);
 133        void                    (*unthrottle)(struct uart_port *port);
 134        int                     (*handle_irq)(struct uart_port *);
 135        void                    (*pm)(struct uart_port *, unsigned int state,
 136                                      unsigned int old);
 137        void                    (*handle_break)(struct uart_port *);
 138        int                     (*rs485_config)(struct uart_port *,
 139                                                struct serial_rs485 *rs485);
 140        unsigned int            irq;                    /* irq number */
 141        unsigned long           irqflags;               /* irq flags  */
 142        unsigned int            uartclk;                /* base uart clock */
 143        unsigned int            fifosize;               /* tx fifo size */
 144        unsigned char           x_char;                 /* xon/xoff char */
 145        unsigned char           regshift;               /* reg offset shift */
 146        unsigned char           iotype;                 /* io access style */
 147        unsigned char           unused1;
 148
 149#define UPIO_PORT               (SERIAL_IO_PORT)        /* 8b I/O port access */
 150#define UPIO_HUB6               (SERIAL_IO_HUB6)        /* Hub6 ISA card */
 151#define UPIO_MEM                (SERIAL_IO_MEM)         /* driver-specific */
 152#define UPIO_MEM32              (SERIAL_IO_MEM32)       /* 32b little endian */
 153#define UPIO_AU                 (SERIAL_IO_AU)          /* Au1x00 and RT288x type IO */
 154#define UPIO_TSI                (SERIAL_IO_TSI)         /* Tsi108/109 type IO */
 155#define UPIO_MEM32BE            (SERIAL_IO_MEM32BE)     /* 32b big endian */
 156#define UPIO_MEM16              (SERIAL_IO_MEM16)       /* 16b little endian */
 157
 158        unsigned int            read_status_mask;       /* driver specific */
 159        unsigned int            ignore_status_mask;     /* driver specific */
 160        struct uart_state       *state;                 /* pointer to parent state */
 161        struct uart_icount      icount;                 /* statistics */
 162
 163        struct console          *cons;                  /* struct console, if any */
 164#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 165        unsigned long           sysrq;                  /* sysrq timeout */
 166#endif
 167
 168        /* flags must be updated while holding port mutex */
 169        upf_t                   flags;
 170
 171        /*
 172         * These flags must be equivalent to the flags defined in
 173         * include/uapi/linux/tty_flags.h which are the userspace definitions
 174         * assigned from the serial_struct flags in uart_set_info()
 175         * [for bit definitions in the UPF_CHANGE_MASK]
 176         *
 177         * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
 178         * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
 179         * The remaining bits are serial-core specific and not modifiable by
 180         * userspace.
 181         */
 182#define UPF_FOURPORT            ((__force upf_t) ASYNC_FOURPORT       /* 1  */ )
 183#define UPF_SAK                 ((__force upf_t) ASYNC_SAK            /* 2  */ )
 184#define UPF_SPD_HI              ((__force upf_t) ASYNC_SPD_HI         /* 4  */ )
 185#define UPF_SPD_VHI             ((__force upf_t) ASYNC_SPD_VHI        /* 5  */ )
 186#define UPF_SPD_CUST            ((__force upf_t) ASYNC_SPD_CUST   /* 0x0030 */ )
 187#define UPF_SPD_WARP            ((__force upf_t) ASYNC_SPD_WARP   /* 0x1010 */ )
 188#define UPF_SPD_MASK            ((__force upf_t) ASYNC_SPD_MASK   /* 0x1030 */ )
 189#define UPF_SKIP_TEST           ((__force upf_t) ASYNC_SKIP_TEST      /* 6  */ )
 190#define UPF_AUTO_IRQ            ((__force upf_t) ASYNC_AUTO_IRQ       /* 7  */ )
 191#define UPF_HARDPPS_CD          ((__force upf_t) ASYNC_HARDPPS_CD     /* 11 */ )
 192#define UPF_SPD_SHI             ((__force upf_t) ASYNC_SPD_SHI        /* 12 */ )
 193#define UPF_LOW_LATENCY         ((__force upf_t) ASYNC_LOW_LATENCY    /* 13 */ )
 194#define UPF_BUGGY_UART          ((__force upf_t) ASYNC_BUGGY_UART     /* 14 */ )
 195#define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 196#define UPF_MAGIC_MULTIPLIER    ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
 197
 198/* Port has hardware-assisted h/w flow control */
 199#define UPF_AUTO_CTS            ((__force upf_t) (1 << 20))
 200#define UPF_AUTO_RTS            ((__force upf_t) (1 << 21))
 201#define UPF_HARD_FLOW           ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
 202/* Port has hardware-assisted s/w flow control */
 203#define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 204#define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 205#define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 206#define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 207#define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 208/* The exact UART type is known and should not be probed.  */
 209#define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 210#define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 211#define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 212#define UPF_DEAD                ((__force upf_t) (1 << 30))
 213#define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 214
 215#define __UPF_CHANGE_MASK       0x17fff
 216#define UPF_CHANGE_MASK         ((__force upf_t) __UPF_CHANGE_MASK)
 217#define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 218
 219#if __UPF_CHANGE_MASK > ASYNC_FLAGS
 220#error Change mask not equivalent to userspace-visible bit defines
 221#endif
 222
 223        /*
 224         * Must hold termios_rwsem, port mutex and port lock to change;
 225         * can hold any one lock to read.
 226         */
 227        upstat_t                status;
 228
 229#define UPSTAT_CTS_ENABLE       ((__force upstat_t) (1 << 0))
 230#define UPSTAT_DCD_ENABLE       ((__force upstat_t) (1 << 1))
 231#define UPSTAT_AUTORTS          ((__force upstat_t) (1 << 2))
 232#define UPSTAT_AUTOCTS          ((__force upstat_t) (1 << 3))
 233#define UPSTAT_AUTOXOFF         ((__force upstat_t) (1 << 4))
 234
 235        int                     hw_stopped;             /* sw-assisted CTS flow state */
 236        unsigned int            mctrl;                  /* current modem ctrl settings */
 237        unsigned int            timeout;                /* character-based timeout */
 238        unsigned int            type;                   /* port type */
 239        const struct uart_ops   *ops;
 240        unsigned int            custom_divisor;
 241        unsigned int            line;                   /* port index */
 242        unsigned int            minor;
 243        resource_size_t         mapbase;                /* for ioremap */
 244        resource_size_t         mapsize;
 245        struct device           *dev;                   /* parent device */
 246        unsigned char           hub6;                   /* this should be in the 8250 driver */
 247        unsigned char           suspended;
 248        unsigned char           irq_wake;
 249        unsigned char           unused[2];
 250        struct attribute_group  *attr_group;            /* port specific attributes */
 251        const struct attribute_group **tty_groups;      /* all attributes (serial core use only) */
 252        struct serial_rs485     rs485;
 253        void                    *private_data;          /* generic platform data pointer */
 254};
 255
 256static inline int serial_port_in(struct uart_port *up, int offset)
 257{
 258        return up->serial_in(up, offset);
 259}
 260
 261static inline void serial_port_out(struct uart_port *up, int offset, int value)
 262{
 263        up->serial_out(up, offset, value);
 264}
 265
 266/**
 267 * enum uart_pm_state - power states for UARTs
 268 * @UART_PM_STATE_ON: UART is powered, up and operational
 269 * @UART_PM_STATE_OFF: UART is powered off
 270 * @UART_PM_STATE_UNDEFINED: sentinel
 271 */
 272enum uart_pm_state {
 273        UART_PM_STATE_ON = 0,
 274        UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 275        UART_PM_STATE_UNDEFINED,
 276};
 277
 278/*
 279 * This is the state information which is persistent across opens.
 280 */
 281struct uart_state {
 282        struct tty_port         port;
 283
 284        enum uart_pm_state      pm_state;
 285        struct circ_buf         xmit;
 286
 287        atomic_t                refcount;
 288        wait_queue_head_t       remove_wait;
 289        struct uart_port        *uart_port;
 290};
 291
 292#define UART_XMIT_SIZE  PAGE_SIZE
 293
 294
 295/* number of characters left in xmit buffer before we ask for more */
 296#define WAKEUP_CHARS            256
 297
 298struct module;
 299struct tty_driver;
 300
 301struct uart_driver {
 302        struct module           *owner;
 303        const char              *driver_name;
 304        const char              *dev_name;
 305        int                      major;
 306        int                      minor;
 307        int                      nr;
 308        struct console          *cons;
 309
 310        /*
 311         * these are private; the low level driver should not
 312         * touch these; they should be initialised to NULL
 313         */
 314        struct uart_state       *state;
 315        struct tty_driver       *tty_driver;
 316};
 317
 318void uart_write_wakeup(struct uart_port *port);
 319
 320/*
 321 * Baud rate helpers.
 322 */
 323void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 324                         unsigned int baud);
 325unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 326                                struct ktermios *old, unsigned int min,
 327                                unsigned int max);
 328unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 329
 330/* Base timer interval for polling */
 331static inline int uart_poll_timeout(struct uart_port *port)
 332{
 333        int timeout = port->timeout;
 334
 335        return timeout > 6 ? (timeout / 2 - 2) : 1;
 336}
 337
 338/*
 339 * Console helpers.
 340 */
 341struct earlycon_device {
 342        struct console *con;
 343        struct uart_port port;
 344        char options[16];               /* e.g., 115200n8 */
 345        unsigned int baud;
 346};
 347
 348struct earlycon_id {
 349        char    name[16];
 350        char    compatible[128];
 351        int     (*setup)(struct earlycon_device *, const char *options);
 352} __aligned(32);
 353
 354extern const struct earlycon_id __earlycon_table[];
 355extern const struct earlycon_id __earlycon_table_end[];
 356
 357#if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
 358#define EARLYCON_USED_OR_UNUSED __used
 359#else
 360#define EARLYCON_USED_OR_UNUSED __maybe_unused
 361#endif
 362
 363#define OF_EARLYCON_DECLARE(_name, compat, fn)                          \
 364        static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \
 365             EARLYCON_USED_OR_UNUSED __section(__earlycon_table)        \
 366                = { .name = __stringify(_name),                         \
 367                    .compatible = compat,                               \
 368                    .setup = fn  }
 369
 370#define EARLYCON_DECLARE(_name, fn)     OF_EARLYCON_DECLARE(_name, "", fn)
 371
 372extern int of_setup_earlycon(const struct earlycon_id *match,
 373                             unsigned long node,
 374                             const char *options);
 375
 376#ifdef CONFIG_SERIAL_EARLYCON
 377extern bool earlycon_init_is_deferred __initdata;
 378int setup_earlycon(char *buf);
 379#else
 380static const bool earlycon_init_is_deferred;
 381static inline int setup_earlycon(char *buf) { return 0; }
 382#endif
 383
 384struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 385                                   struct console *c);
 386int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
 387                        char **options);
 388void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 389                        int *flow);
 390int uart_set_options(struct uart_port *port, struct console *co, int baud,
 391                     int parity, int bits, int flow);
 392struct tty_driver *uart_console_device(struct console *co, int *index);
 393void uart_console_write(struct uart_port *port, const char *s,
 394                        unsigned int count,
 395                        void (*putchar)(struct uart_port *, int));
 396
 397/*
 398 * Port/driver registration/removal
 399 */
 400int uart_register_driver(struct uart_driver *uart);
 401void uart_unregister_driver(struct uart_driver *uart);
 402int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 403int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 404int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 405
 406/*
 407 * Power Management
 408 */
 409int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 410int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 411
 412#define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 413#define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 414
 415#define uart_circ_chars_pending(circ)   \
 416        (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 417
 418#define uart_circ_chars_free(circ)      \
 419        (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 420
 421static inline int uart_tx_stopped(struct uart_port *port)
 422{
 423        struct tty_struct *tty = port->state->port.tty;
 424        if ((tty && tty->stopped) || port->hw_stopped)
 425                return 1;
 426        return 0;
 427}
 428
 429static inline bool uart_cts_enabled(struct uart_port *uport)
 430{
 431        return !!(uport->status & UPSTAT_CTS_ENABLE);
 432}
 433
 434static inline bool uart_softcts_mode(struct uart_port *uport)
 435{
 436        upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
 437
 438        return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
 439}
 440
 441/*
 442 * The following are helper functions for the low level drivers.
 443 */
 444
 445extern void uart_handle_dcd_change(struct uart_port *uport,
 446                unsigned int status);
 447extern void uart_handle_cts_change(struct uart_port *uport,
 448                unsigned int status);
 449
 450extern void uart_insert_char(struct uart_port *port, unsigned int status,
 451                 unsigned int overrun, unsigned int ch, unsigned int flag);
 452
 453#ifdef SUPPORT_SYSRQ
 454static inline int
 455uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 456{
 457        if (port->sysrq) {
 458                if (ch && time_before(jiffies, port->sysrq)) {
 459                        handle_sysrq(ch);
 460                        port->sysrq = 0;
 461                        return 1;
 462                }
 463                port->sysrq = 0;
 464        }
 465        return 0;
 466}
 467#else
 468#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 469#endif
 470
 471/*
 472 * We do the SysRQ and SAK checking like this...
 473 */
 474static inline int uart_handle_break(struct uart_port *port)
 475{
 476        struct uart_state *state = port->state;
 477
 478        if (port->handle_break)
 479                port->handle_break(port);
 480
 481#ifdef SUPPORT_SYSRQ
 482        if (port->cons && port->cons->index == port->line) {
 483                if (!port->sysrq) {
 484                        port->sysrq = jiffies + HZ*5;
 485                        return 1;
 486                }
 487                port->sysrq = 0;
 488        }
 489#endif
 490        if (port->flags & UPF_SAK)
 491                do_SAK(state->port.tty);
 492        return 0;
 493}
 494
 495/*
 496 *      UART_ENABLE_MS - determine if port should enable modem status irqs
 497 */
 498#define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 499                                         (cflag) & CRTSCTS || \
 500                                         !((cflag) & CLOCAL))
 501
 502#endif /* LINUX_SERIAL_CORE_H */
 503