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 <uapi/linux/serial_core.h>
  33
  34struct uart_port;
  35struct serial_struct;
  36struct device;
  37
  38/*
  39 * This structure describes all the operations that can be done on the
  40 * physical hardware.  See Documentation/serial/driver for details.
  41 */
  42struct uart_ops {
  43        unsigned int    (*tx_empty)(struct uart_port *);
  44        void            (*set_mctrl)(struct uart_port *, unsigned int mctrl);
  45        unsigned int    (*get_mctrl)(struct uart_port *);
  46        void            (*stop_tx)(struct uart_port *);
  47        void            (*start_tx)(struct uart_port *);
  48        void            (*throttle)(struct uart_port *);
  49        void            (*unthrottle)(struct uart_port *);
  50        void            (*send_xchar)(struct uart_port *, char ch);
  51        void            (*stop_rx)(struct uart_port *);
  52        void            (*enable_ms)(struct uart_port *);
  53        void            (*break_ctl)(struct uart_port *, int ctl);
  54        int             (*startup)(struct uart_port *);
  55        void            (*shutdown)(struct uart_port *);
  56        void            (*flush_buffer)(struct uart_port *);
  57        void            (*set_termios)(struct uart_port *, struct ktermios *new,
  58                                       struct ktermios *old);
  59        void            (*set_ldisc)(struct uart_port *, int new);
  60        void            (*pm)(struct uart_port *, unsigned int state,
  61                              unsigned int oldstate);
  62        int             (*set_wake)(struct uart_port *, unsigned int state);
  63
  64        /*
  65         * Return a string describing the type of the port
  66         */
  67        const char      *(*type)(struct uart_port *);
  68
  69        /*
  70         * Release IO and memory resources used by the port.
  71         * This includes iounmap if necessary.
  72         */
  73        void            (*release_port)(struct uart_port *);
  74
  75        /*
  76         * Request IO and memory resources used by the port.
  77         * This includes iomapping the port if necessary.
  78         */
  79        int             (*request_port)(struct uart_port *);
  80        void            (*config_port)(struct uart_port *, int);
  81        int             (*verify_port)(struct uart_port *, struct serial_struct *);
  82        int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  83#ifdef CONFIG_CONSOLE_POLL
  84        int             (*poll_init)(struct uart_port *);
  85        void            (*poll_put_char)(struct uart_port *, unsigned char);
  86        int             (*poll_get_char)(struct uart_port *);
  87#endif
  88};
  89
  90#define NO_POLL_CHAR            0x00ff0000
  91#define UART_CONFIG_TYPE        (1 << 0)
  92#define UART_CONFIG_IRQ         (1 << 1)
  93
  94struct uart_icount {
  95        __u32   cts;
  96        __u32   dsr;
  97        __u32   rng;
  98        __u32   dcd;
  99        __u32   rx;
 100        __u32   tx;
 101        __u32   frame;
 102        __u32   overrun;
 103        __u32   parity;
 104        __u32   brk;
 105        __u32   buf_overrun;
 106};
 107
 108typedef unsigned int __bitwise__ upf_t;
 109
 110struct uart_port {
 111        spinlock_t              lock;                   /* port lock */
 112        unsigned long           iobase;                 /* in/out[bwl] */
 113        unsigned char __iomem   *membase;               /* read/write[bwl] */
 114        unsigned int            (*serial_in)(struct uart_port *, int);
 115        void                    (*serial_out)(struct uart_port *, int, int);
 116        void                    (*set_termios)(struct uart_port *,
 117                                               struct ktermios *new,
 118                                               struct ktermios *old);
 119        int                     (*handle_irq)(struct uart_port *);
 120        void                    (*pm)(struct uart_port *, unsigned int state,
 121                                      unsigned int old);
 122        void                    (*handle_break)(struct uart_port *);
 123        unsigned int            irq;                    /* irq number */
 124        unsigned long           irqflags;               /* irq flags  */
 125        unsigned int            uartclk;                /* base uart clock */
 126        unsigned int            fifosize;               /* tx fifo size */
 127        unsigned char           x_char;                 /* xon/xoff char */
 128        unsigned char           regshift;               /* reg offset shift */
 129        unsigned char           iotype;                 /* io access style */
 130        unsigned char           unused1;
 131
 132#define UPIO_PORT               (0)
 133#define UPIO_HUB6               (1)
 134#define UPIO_MEM                (2)
 135#define UPIO_MEM32              (3)
 136#define UPIO_AU                 (4)                     /* Au1x00 and RT288x type IO */
 137#define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 138
 139        unsigned int            read_status_mask;       /* driver specific */
 140        unsigned int            ignore_status_mask;     /* driver specific */
 141        struct uart_state       *state;                 /* pointer to parent state */
 142        struct uart_icount      icount;                 /* statistics */
 143
 144        struct console          *cons;                  /* struct console, if any */
 145#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 146        unsigned long           sysrq;                  /* sysrq timeout */
 147#endif
 148
 149        upf_t                   flags;
 150
 151#define UPF_FOURPORT            ((__force upf_t) (1 << 1))
 152#define UPF_SAK                 ((__force upf_t) (1 << 2))
 153#define UPF_SPD_MASK            ((__force upf_t) (0x1030))
 154#define UPF_SPD_HI              ((__force upf_t) (0x0010))
 155#define UPF_SPD_VHI             ((__force upf_t) (0x0020))
 156#define UPF_SPD_CUST            ((__force upf_t) (0x0030))
 157#define UPF_SPD_SHI             ((__force upf_t) (0x1000))
 158#define UPF_SPD_WARP            ((__force upf_t) (0x1010))
 159#define UPF_SKIP_TEST           ((__force upf_t) (1 << 6))
 160#define UPF_AUTO_IRQ            ((__force upf_t) (1 << 7))
 161#define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 162#define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 163#define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 164#define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 165#define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 166/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 167#define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 168/* Port has hardware-assisted s/w flow control */
 169#define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 170#define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 171#define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 172#define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 173#define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 174/* The exact UART type is known and should not be probed.  */
 175#define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 176#define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 177#define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 178#define UPF_DEAD                ((__force upf_t) (1 << 30))
 179#define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 180
 181#define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 182#define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 183
 184        unsigned int            mctrl;                  /* current modem ctrl settings */
 185        unsigned int            timeout;                /* character-based timeout */
 186        unsigned int            type;                   /* port type */
 187        const struct uart_ops   *ops;
 188        unsigned int            custom_divisor;
 189        unsigned int            line;                   /* port index */
 190        resource_size_t         mapbase;                /* for ioremap */
 191        struct device           *dev;                   /* parent device */
 192        unsigned char           hub6;                   /* this should be in the 8250 driver */
 193        unsigned char           suspended;
 194        unsigned char           irq_wake;
 195        unsigned char           unused[2];
 196        void                    *private_data;          /* generic platform data pointer */
 197};
 198
 199static inline int serial_port_in(struct uart_port *up, int offset)
 200{
 201        return up->serial_in(up, offset);
 202}
 203
 204static inline void serial_port_out(struct uart_port *up, int offset, int value)
 205{
 206        up->serial_out(up, offset, value);
 207}
 208
 209/**
 210 * enum uart_pm_state - power states for UARTs
 211 * @UART_PM_STATE_ON: UART is powered, up and operational
 212 * @UART_PM_STATE_OFF: UART is powered off
 213 * @UART_PM_STATE_UNDEFINED: sentinel
 214 */
 215enum uart_pm_state {
 216        UART_PM_STATE_ON = 0,
 217        UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 218        UART_PM_STATE_UNDEFINED,
 219};
 220
 221/*
 222 * This is the state information which is persistent across opens.
 223 */
 224struct uart_state {
 225        struct tty_port         port;
 226
 227        enum uart_pm_state      pm_state;
 228        struct circ_buf         xmit;
 229
 230        struct uart_port        *uart_port;
 231};
 232
 233#define UART_XMIT_SIZE  PAGE_SIZE
 234
 235
 236/* number of characters left in xmit buffer before we ask for more */
 237#define WAKEUP_CHARS            256
 238
 239struct module;
 240struct tty_driver;
 241
 242struct uart_driver {
 243        struct module           *owner;
 244        const char              *driver_name;
 245        const char              *dev_name;
 246        int                      major;
 247        int                      minor;
 248        int                      nr;
 249        struct console          *cons;
 250
 251        /*
 252         * these are private; the low level driver should not
 253         * touch these; they should be initialised to NULL
 254         */
 255        struct uart_state       *state;
 256        struct tty_driver       *tty_driver;
 257};
 258
 259void uart_write_wakeup(struct uart_port *port);
 260
 261/*
 262 * Baud rate helpers.
 263 */
 264void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 265                         unsigned int baud);
 266unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 267                                struct ktermios *old, unsigned int min,
 268                                unsigned int max);
 269unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 270
 271/* Base timer interval for polling */
 272static inline int uart_poll_timeout(struct uart_port *port)
 273{
 274        int timeout = port->timeout;
 275
 276        return timeout > 6 ? (timeout / 2 - 2) : 1;
 277}
 278
 279/*
 280 * Console helpers.
 281 */
 282struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 283                                   struct console *c);
 284void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 285                        int *flow);
 286int uart_set_options(struct uart_port *port, struct console *co, int baud,
 287                     int parity, int bits, int flow);
 288struct tty_driver *uart_console_device(struct console *co, int *index);
 289void uart_console_write(struct uart_port *port, const char *s,
 290                        unsigned int count,
 291                        void (*putchar)(struct uart_port *, int));
 292
 293/*
 294 * Port/driver registration/removal
 295 */
 296int uart_register_driver(struct uart_driver *uart);
 297void uart_unregister_driver(struct uart_driver *uart);
 298int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 299int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 300int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 301
 302/*
 303 * Power Management
 304 */
 305int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 306int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 307
 308#define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 309#define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 310
 311#define uart_circ_chars_pending(circ)   \
 312        (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 313
 314#define uart_circ_chars_free(circ)      \
 315        (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 316
 317static inline int uart_tx_stopped(struct uart_port *port)
 318{
 319        struct tty_struct *tty = port->state->port.tty;
 320        if(tty->stopped || tty->hw_stopped)
 321                return 1;
 322        return 0;
 323}
 324
 325/*
 326 * The following are helper functions for the low level drivers.
 327 */
 328
 329extern void uart_handle_dcd_change(struct uart_port *uport,
 330                unsigned int status);
 331extern void uart_handle_cts_change(struct uart_port *uport,
 332                unsigned int status);
 333
 334extern void uart_insert_char(struct uart_port *port, unsigned int status,
 335                 unsigned int overrun, unsigned int ch, unsigned int flag);
 336
 337#ifdef SUPPORT_SYSRQ
 338static inline int
 339uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 340{
 341        if (port->sysrq) {
 342                if (ch && time_before(jiffies, port->sysrq)) {
 343                        handle_sysrq(ch);
 344                        port->sysrq = 0;
 345                        return 1;
 346                }
 347                port->sysrq = 0;
 348        }
 349        return 0;
 350}
 351#else
 352#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 353#endif
 354
 355/*
 356 * We do the SysRQ and SAK checking like this...
 357 */
 358static inline int uart_handle_break(struct uart_port *port)
 359{
 360        struct uart_state *state = port->state;
 361
 362        if (port->handle_break)
 363                port->handle_break(port);
 364
 365#ifdef SUPPORT_SYSRQ
 366        if (port->cons && port->cons->index == port->line) {
 367                if (!port->sysrq) {
 368                        port->sysrq = jiffies + HZ*5;
 369                        return 1;
 370                }
 371                port->sysrq = 0;
 372        }
 373#endif
 374        if (port->flags & UPF_SAK)
 375                do_SAK(state->port.tty);
 376        return 0;
 377}
 378
 379/*
 380 *      UART_ENABLE_MS - determine if port should enable modem status irqs
 381 */
 382#define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 383                                         (cflag) & CRTSCTS || \
 384                                         !((cflag) & CLOCAL))
 385
 386#endif /* LINUX_SERIAL_CORE_H */
 387
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