include/linux/serial_core.h

   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
  41 struct uart_port;
  42 struct serial_struct;
  43 struct 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  */
  49 struct 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 *, int new);
  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
 100 struct 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
 114 typedef unsigned int __bitwise__ upf_t;
 115
 116 struct uart_port {
 117         spinlock_t              lock;                   /* port lock */
 118         unsigned long           iobase;                 /* in/out[bwl] */
 119         unsigned char __iomem   *membase;               /* read/write[bwl] */
 120         unsigned int            (*serial_in)(struct uart_port *, int);
 121         void                    (*serial_out)(struct uart_port *, int, int);
 122         void                    (*set_termios)(struct uart_port *,
 123                                                struct ktermios *new,
 124                                                struct ktermios *old);
 125         int                     (*startup)(struct uart_port *port);
 126         void                    (*shutdown)(struct uart_port *port);
 127         int                     (*handle_irq)(struct uart_port *);
 128         void                    (*pm)(struct uart_port *, unsigned int state,
 129                                       unsigned int old);
 130         void                    (*handle_break)(struct uart_port *);
 131         unsigned int            irq;                    /* irq number */
 132         unsigned long           irqflags;               /* irq flags  */
 133         unsigned int            uartclk;                /* base uart clock */
 134         unsigned int            fifosize;               /* tx fifo size */
 135         unsigned char           x_char;                 /* xon/xoff char */
 136         unsigned char           regshift;               /* reg offset shift */
 137         unsigned char           iotype;                 /* io access style */
 138         unsigned char           unused1;
 139
 140 #define UPIO_PORT               (0)
 141 #define UPIO_HUB6               (1)
 142 #define UPIO_MEM                (2)
 143 #define UPIO_MEM32              (3)
 144 #define UPIO_AU                 (4)                     /* Au1x00 and RT288x type IO */
 145 #define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 146
 147         unsigned int            read_status_mask;       /* driver specific */
 148         unsigned int            ignore_status_mask;     /* driver specific */
 149         struct uart_state       *state;                 /* pointer to parent state */
 150         struct uart_icount      icount;                 /* statistics */
 151
 152         struct console          *cons;                  /* struct console, if any */
 153 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 154         unsigned long           sysrq;                  /* sysrq timeout */
 155 #endif
 156
 157         /* flags must be updated while holding port mutex */
 158         upf_t                   flags;
 159
 160 #define UPF_FOURPORT            ((__force upf_t) (1 << 1))
 161 #define UPF_SAK                 ((__force upf_t) (1 << 2))
 162 #define UPF_SPD_MASK            ((__force upf_t) (0x1030))
 163 #define UPF_SPD_HI              ((__force upf_t) (0x0010))
 164 #define UPF_SPD_VHI             ((__force upf_t) (0x0020))
 165 #define UPF_SPD_CUST            ((__force upf_t) (0x0030))
 166 #define UPF_SPD_SHI             ((__force upf_t) (0x1000))
 167 #define UPF_SPD_WARP            ((__force upf_t) (0x1010))
 168 #define UPF_SKIP_TEST           ((__force upf_t) (1 << 6))
 169 #define UPF_AUTO_IRQ            ((__force upf_t) (1 << 7))
 170 #define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 171 #define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 172 #define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 173 #define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 174 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 175 /* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 176 #define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 177 /* Port has hardware-assisted s/w flow control */
 178 #define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 179 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 180 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 181 #define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 182 #define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 183 /* The exact UART type is known and should not be probed.  */
 184 #define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 185 #define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 186 #define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 187 #define UPF_DEAD                ((__force upf_t) (1 << 30))
 188 #define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 189
 190 #define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 191 #define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 192
 193         unsigned int            mctrl;                  /* current modem ctrl settings */
 194         unsigned int            timeout;                /* character-based timeout */
 195         unsigned int            type;                   /* port type */
 196         const struct uart_ops   *ops;
 197         unsigned int            custom_divisor;
 198         unsigned int            line;                   /* port index */
 199         resource_size_t         mapbase;                /* for ioremap */
 200         struct device           *dev;                   /* parent device */
 201         unsigned char           hub6;                   /* this should be in the 8250 driver */
 202         unsigned char           suspended;
 203         unsigned char           irq_wake;
 204         unsigned char           unused[2];
 205         struct attribute_group  *attr_group;            /* port specific attributes */
 206         const struct attribute_group **tty_groups;      /* all attributes (serial core use only) */
 207         void                    *private_data;          /* generic platform data pointer */
 208 };
 209
 210 static inline int serial_port_in(struct uart_port *up, int offset)
 211 {
 212         return up->serial_in(up, offset);
 213 }
 214
 215 static inline void serial_port_out(struct uart_port *up, int offset, int value)
 216 {
 217         up->serial_out(up, offset, value);
 218 }
 219
 220 /**
 221  * enum uart_pm_state - power states for UARTs
 222  * @UART_PM_STATE_ON: UART is powered, up and operational
 223  * @UART_PM_STATE_OFF: UART is powered off
 224  * @UART_PM_STATE_UNDEFINED: sentinel
 225  */
 226 enum uart_pm_state {
 227         UART_PM_STATE_ON = 0,
 228         UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 229         UART_PM_STATE_UNDEFINED,
 230 };
 231
 232 /*
 233  * This is the state information which is persistent across opens.
 234  */
 235 struct uart_state {
 236         struct tty_port         port;
 237
 238         enum uart_pm_state      pm_state;
 239         struct circ_buf         xmit;
 240
 241         struct uart_port        *uart_port;
 242 };
 243
 244 #define UART_XMIT_SIZE  PAGE_SIZE
 245
 246
 247 /* number of characters left in xmit buffer before we ask for more */
 248 #define WAKEUP_CHARS            256
 249
 250 struct module;
 251 struct tty_driver;
 252
 253 struct uart_driver {
 254         struct module           *owner;
 255         const char              *driver_name;
 256         const char              *dev_name;
 257         int                      major;
 258         int                      minor;
 259         int                      nr;
 260         struct console          *cons;
 261
 262         /*
 263          * these are private; the low level driver should not
 264          * touch these; they should be initialised to NULL
 265          */
 266         struct uart_state       *state;
 267         struct tty_driver       *tty_driver;
 268 };
 269
 270 void uart_write_wakeup(struct uart_port *port);
 271
 272 /*
 273  * Baud rate helpers.
 274  */
 275 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 276                          unsigned int baud);
 277 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 278                                 struct ktermios *old, unsigned int min,
 279                                 unsigned int max);
 280 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 281
 282 /* Base timer interval for polling */
 283 static inline int uart_poll_timeout(struct uart_port *port)
 284 {
 285         int timeout = port->timeout;
 286
 287         return timeout > 6 ? (timeout / 2 - 2) : 1;
 288 }
 289
 290 /*
 291  * Console helpers.
 292  */
 293 struct earlycon_device {
 294         struct console *con;
 295         struct uart_port port;
 296         char options[16];               /* e.g., 115200n8 */
 297         unsigned int baud;
 298 };
 299 int setup_earlycon(char *buf, const char *match,
 300                    int (*setup)(struct earlycon_device *, const char *));
 301
 302 extern int of_setup_earlycon(unsigned long addr,
 303                              int (*setup)(struct earlycon_device *, const char *));
 304
 305 #define EARLYCON_DECLARE(name, func) \
 306 static int __init name ## _setup_earlycon(char *buf) \
 307 { \
 308         return setup_earlycon(buf, __stringify(name), func); \
 309 } \
 310 early_param("earlycon", name ## _setup_earlycon);
 311
 312 #define OF_EARLYCON_DECLARE(name, compat, fn)                           \
 313         _OF_DECLARE(earlycon, name, compat, fn, void *)
 314
 315 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 316                                    struct console *c);
 317 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 318                         int *flow);
 319 int uart_set_options(struct uart_port *port, struct console *co, int baud,
 320                      int parity, int bits, int flow);
 321 struct tty_driver *uart_console_device(struct console *co, int *index);
 322 void uart_console_write(struct uart_port *port, const char *s,
 323                         unsigned int count,
 324                         void (*putchar)(struct uart_port *, int));
 325
 326 /*
 327  * Port/driver registration/removal
 328  */
 329 int uart_register_driver(struct uart_driver *uart);
 330 void uart_unregister_driver(struct uart_driver *uart);
 331 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 332 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 333 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 334
 335 /*
 336  * Power Management
 337  */
 338 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 339 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 340
 341 #define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 342 #define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 343
 344 #define uart_circ_chars_pending(circ)   \
 345         (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 346
 347 #define uart_circ_chars_free(circ)      \
 348         (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 349
 350 static inline int uart_tx_stopped(struct uart_port *port)
 351 {
 352         struct tty_struct *tty = port->state->port.tty;
 353         if(tty->stopped || tty->hw_stopped)
 354                 return 1;
 355         return 0;
 356 }
 357
 358 /*
 359  * The following are helper functions for the low level drivers.
 360  */
 361
 362 extern void uart_handle_dcd_change(struct uart_port *uport,
 363                 unsigned int status);
 364 extern void uart_handle_cts_change(struct uart_port *uport,
 365                 unsigned int status);
 366
 367 extern void uart_insert_char(struct uart_port *port, unsigned int status,
 368                  unsigned int overrun, unsigned int ch, unsigned int flag);
 369
 370 #ifdef SUPPORT_SYSRQ
 371 static inline int
 372 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 373 {
 374         if (port->sysrq) {
 375                 if (ch && time_before(jiffies, port->sysrq)) {
 376                         handle_sysrq(ch);
 377                         port->sysrq = 0;
 378                         return 1;
 379                 }
 380                 port->sysrq = 0;
 381         }
 382         return 0;
 383 }
 384 #else
 385 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 386 #endif
 387
 388 /*
 389  * We do the SysRQ and SAK checking like this...
 390  */
 391 static inline int uart_handle_break(struct uart_port *port)
 392 {
 393         struct uart_state *state = port->state;
 394
 395         if (port->handle_break)
 396                 port->handle_break(port);
 397
 398 #ifdef SUPPORT_SYSRQ
 399         if (port->cons && port->cons->index == port->line) {
 400                 if (!port->sysrq) {
 401                         port->sysrq = jiffies + HZ*5;
 402                         return 1;
 403                 }
 404                 port->sysrq = 0;
 405         }
 406 #endif
 407         if (port->flags & UPF_SAK)
 408                 do_SAK(state->port.tty);
 409         return 0;
 410 }
 411
 412 /*
 413  *      UART_ENABLE_MS - determine if port should enable modem status irqs
 414  */
 415 #define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 416                                          (cflag) & CRTSCTS || \
 417                                          !((cflag) & CLOCAL))
 418
 419 #endif /* LINUX_SERIAL_CORE_H */