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 <linux/pps_kernel.h>
  33 #include <uapi/linux/serial_core.h>
  34
  35 struct uart_port;
  36 struct serial_struct;
  37 struct device;
  38
  39 /*
  40  * This structure describes all the operations that can be
  41  * done on the physical hardware.
  42  */
  43 struct uart_ops {
  44         unsigned int    (*tx_empty)(struct uart_port *);
  45         void            (*set_mctrl)(struct uart_port *, unsigned int mctrl);
  46         unsigned int    (*get_mctrl)(struct uart_port *);
  47         void            (*stop_tx)(struct uart_port *);
  48         void            (*start_tx)(struct uart_port *);
  49         void            (*throttle)(struct uart_port *);
  50         void            (*unthrottle)(struct uart_port *);
  51         void            (*send_xchar)(struct uart_port *, char ch);
  52         void            (*stop_rx)(struct uart_port *);
  53         void            (*enable_ms)(struct uart_port *);
  54         void            (*break_ctl)(struct uart_port *, int ctl);
  55         int             (*startup)(struct uart_port *);
  56         void            (*shutdown)(struct uart_port *);
  57         void            (*flush_buffer)(struct uart_port *);
  58         void            (*set_termios)(struct uart_port *, struct ktermios *new,
  59                                        struct ktermios *old);
  60         void            (*set_ldisc)(struct uart_port *, int new);
  61         void            (*pm)(struct uart_port *, unsigned int state,
  62                               unsigned int oldstate);
  63         int             (*set_wake)(struct uart_port *, unsigned int state);
  64
  65         /*
  66          * Return a string describing the type of the port
  67          */
  68         const char *(*type)(struct uart_port *);
  69
  70         /*
  71          * Release IO and memory resources used by the port.
  72          * This includes iounmap if necessary.
  73          */
  74         void            (*release_port)(struct uart_port *);
  75
  76         /*
  77          * Request IO and memory resources used by the port.
  78          * This includes iomapping the port if necessary.
  79          */
  80         int             (*request_port)(struct uart_port *);
  81         void            (*config_port)(struct uart_port *, int);
  82         int             (*verify_port)(struct uart_port *, struct serial_struct *);
  83         int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  84 #ifdef CONFIG_CONSOLE_POLL
  85         int             (*poll_init)(struct uart_port *);
  86         void    (*poll_put_char)(struct uart_port *, unsigned char);
  87         int             (*poll_get_char)(struct uart_port *);
  88 #endif
  89 };
  90
  91 #define NO_POLL_CHAR            0x00ff0000
  92 #define UART_CONFIG_TYPE        (1 << 0)
  93 #define UART_CONFIG_IRQ         (1 << 1)
  94
  95 struct uart_icount {
  96         __u32   cts;
  97         __u32   dsr;
  98         __u32   rng;
  99         __u32   dcd;
 100         __u32   rx;
 101         __u32   tx;
 102         __u32   frame;
 103         __u32   overrun;
 104         __u32   parity;
 105         __u32   brk;
 106         __u32   buf_overrun;
 107 };
 108
 109 typedef unsigned int __bitwise__ upf_t;
 110
 111 struct uart_port {
 112         spinlock_t              lock;                   /* port lock */
 113         unsigned long           iobase;                 /* in/out[bwl] */
 114         unsigned char __iomem   *membase;               /* read/write[bwl] */
 115         unsigned int            (*serial_in)(struct uart_port *, int);
 116         void                    (*serial_out)(struct uart_port *, int, int);
 117         void                    (*set_termios)(struct uart_port *,
 118                                                struct ktermios *new,
 119                                                struct ktermios *old);
 120         int                     (*handle_irq)(struct uart_port *);
 121         void                    (*pm)(struct uart_port *, unsigned int state,
 122                                       unsigned int old);
 123         void                    (*handle_break)(struct uart_port *);
 124         unsigned int            irq;                    /* irq number */
 125         unsigned long           irqflags;               /* irq flags  */
 126         unsigned int            uartclk;                /* base uart clock */
 127         unsigned int            fifosize;               /* tx fifo size */
 128         unsigned char           x_char;                 /* xon/xoff char */
 129         unsigned char           regshift;               /* reg offset shift */
 130         unsigned char           iotype;                 /* io access style */
 131         unsigned char           unused1;
 132
 133 #define UPIO_PORT               (0)
 134 #define UPIO_HUB6               (1)
 135 #define UPIO_MEM                (2)
 136 #define UPIO_MEM32              (3)
 137 #define UPIO_AU                 (4)                     /* Au1x00 type IO */
 138 #define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 139 #define UPIO_RM9000             (6)                     /* RM9000 type IO */
 140
 141         unsigned int            read_status_mask;       /* driver specific */
 142         unsigned int            ignore_status_mask;     /* driver specific */
 143         struct uart_state       *state;                 /* pointer to parent state */
 144         struct uart_icount      icount;                 /* statistics */
 145
 146         struct console          *cons;                  /* struct console, if any */
 147 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 148         unsigned long           sysrq;                  /* sysrq timeout */
 149 #endif
 150
 151         upf_t                   flags;
 152
 153 #define UPF_FOURPORT            ((__force upf_t) (1 << 1))
 154 #define UPF_SAK                 ((__force upf_t) (1 << 2))
 155 #define UPF_SPD_MASK            ((__force upf_t) (0x1030))
 156 #define UPF_SPD_HI              ((__force upf_t) (0x0010))
 157 #define UPF_SPD_VHI             ((__force upf_t) (0x0020))
 158 #define UPF_SPD_CUST            ((__force upf_t) (0x0030))
 159 #define UPF_SPD_SHI             ((__force upf_t) (0x1000))
 160 #define UPF_SPD_WARP            ((__force upf_t) (0x1010))
 161 #define UPF_SKIP_TEST           ((__force upf_t) (1 << 6))
 162 #define UPF_AUTO_IRQ            ((__force upf_t) (1 << 7))
 163 #define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 164 #define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 165 #define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 166 #define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 167 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 168 /* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 169 #define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 170 /* Port has hardware-assisted s/w flow control */
 171 #define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 172 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 173 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 174 #define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 175 #define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 176 /* The exact UART type is known and should not be probed.  */
 177 #define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 178 #define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 179 #define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 180 #define UPF_DEAD                ((__force upf_t) (1 << 30))
 181 #define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 182
 183 #define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 184 #define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 185
 186         unsigned int            mctrl;                  /* current modem ctrl settings */
 187         unsigned int            timeout;                /* character-based timeout */
 188         unsigned int            type;                   /* port type */
 189         const struct uart_ops   *ops;
 190         unsigned int            custom_divisor;
 191         unsigned int            line;                   /* port index */
 192         resource_size_t         mapbase;                /* for ioremap */
 193         struct device           *dev;                   /* parent device */
 194         unsigned char           hub6;                   /* this should be in the 8250 driver */
 195         unsigned char           suspended;
 196         unsigned char           irq_wake;
 197         unsigned char           unused[2];
 198         void                    *private_data;          /* generic platform data pointer */
 199 };
 200
 201 static inline int serial_port_in(struct uart_port *up, int offset)
 202 {
 203         return up->serial_in(up, offset);
 204 }
 205
 206 static inline void serial_port_out(struct uart_port *up, int offset, int value)
 207 {
 208         up->serial_out(up, offset, value);
 209 }
 210
 211 /*
 212  * This is the state information which is persistent across opens.
 213  */
 214 struct uart_state {
 215         struct tty_port         port;
 216
 217         int                     pm_state;
 218         struct circ_buf         xmit;
 219
 220         struct uart_port        *uart_port;
 221 };
 222
 223 #define UART_XMIT_SIZE  PAGE_SIZE
 224
 225
 226 /* number of characters left in xmit buffer before we ask for more */
 227 #define WAKEUP_CHARS            256
 228
 229 struct module;
 230 struct tty_driver;
 231
 232 struct uart_driver {
 233         struct module           *owner;
 234         const char              *driver_name;
 235         const char              *dev_name;
 236         int                      major;
 237         int                      minor;
 238         int                      nr;
 239         struct console          *cons;
 240
 241         /*
 242          * these are private; the low level driver should not
 243          * touch these; they should be initialised to NULL
 244          */
 245         struct uart_state       *state;
 246         struct tty_driver       *tty_driver;
 247 };
 248
 249 void uart_write_wakeup(struct uart_port *port);
 250
 251 /*
 252  * Baud rate helpers.
 253  */
 254 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 255                          unsigned int baud);
 256 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 257                                 struct ktermios *old, unsigned int min,
 258                                 unsigned int max);
 259 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 260
 261 /* Base timer interval for polling */
 262 static inline int uart_poll_timeout(struct uart_port *port)
 263 {
 264         int timeout = port->timeout;
 265
 266         return timeout > 6 ? (timeout / 2 - 2) : 1;
 267 }
 268
 269 /*
 270  * Console helpers.
 271  */
 272 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 273                                    struct console *c);
 274 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 275                         int *flow);
 276 int uart_set_options(struct uart_port *port, struct console *co, int baud,
 277                      int parity, int bits, int flow);
 278 struct tty_driver *uart_console_device(struct console *co, int *index);
 279 void uart_console_write(struct uart_port *port, const char *s,
 280                         unsigned int count,
 281                         void (*putchar)(struct uart_port *, int));
 282
 283 /*
 284  * Port/driver registration/removal
 285  */
 286 int uart_register_driver(struct uart_driver *uart);
 287 void uart_unregister_driver(struct uart_driver *uart);
 288 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 289 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 290 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 291
 292 /*
 293  * Power Management
 294  */
 295 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 296 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 297
 298 #define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 299 #define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 300
 301 #define uart_circ_chars_pending(circ)   \
 302         (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 303
 304 #define uart_circ_chars_free(circ)      \
 305         (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 306
 307 static inline int uart_tx_stopped(struct uart_port *port)
 308 {
 309         struct tty_struct *tty = port->state->port.tty;
 310         if(tty->stopped || tty->hw_stopped)
 311                 return 1;
 312         return 0;
 313 }
 314
 315 /*
 316  * The following are helper functions for the low level drivers.
 317  */
 318
 319 extern void uart_handle_dcd_change(struct uart_port *uport,
 320                 unsigned int status);
 321 extern void uart_handle_cts_change(struct uart_port *uport,
 322                 unsigned int status);
 323
 324 extern void uart_insert_char(struct uart_port *port, unsigned int status,
 325                  unsigned int overrun, unsigned int ch, unsigned int flag);
 326
 327 #ifdef SUPPORT_SYSRQ
 328 static inline int
 329 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 330 {
 331         if (port->sysrq) {
 332                 if (ch && time_before(jiffies, port->sysrq)) {
 333                         handle_sysrq(ch);
 334                         port->sysrq = 0;
 335                         return 1;
 336                 }
 337                 port->sysrq = 0;
 338         }
 339         return 0;
 340 }
 341 #else
 342 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 343 #endif
 344
 345 /*
 346  * We do the SysRQ and SAK checking like this...
 347  */
 348 static inline int uart_handle_break(struct uart_port *port)
 349 {
 350         struct uart_state *state = port->state;
 351
 352         if (port->handle_break)
 353                 port->handle_break(port);
 354
 355 #ifdef SUPPORT_SYSRQ
 356         if (port->cons && port->cons->index == port->line) {
 357                 if (!port->sysrq) {
 358                         port->sysrq = jiffies + HZ*5;
 359                         return 1;
 360                 }
 361                 port->sysrq = 0;
 362         }
 363 #endif
 364         if (port->flags & UPF_SAK)
 365                 do_SAK(state->port.tty);
 366         return 0;
 367 }
 368
 369 /*
 370  *      UART_ENABLE_MS - determine if port should enable modem status irqs
 371  */
 372 #define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 373                                          (cflag) & CRTSCTS || \
 374                                          !((cflag) & CLOCAL))
 375
 376 #endif /* LINUX_SERIAL_CORE_H */