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