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