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         int             (*set_wake)(struct uart_port *, unsigned int state);
  70
  71         /*
  72          * Return a string describing the type of the port
  73          */
  74         const char      *(*type)(struct uart_port *);
  75
  76         /*
  77          * Release IO and memory resources used by the port.
  78          * This includes iounmap if necessary.
  79          */
  80         void            (*release_port)(struct uart_port *);
  81
  82         /*
  83          * Request IO and memory resources used by the port.
  84          * This includes iomapping the port if necessary.
  85          */
  86         int             (*request_port)(struct uart_port *);
  87         void            (*config_port)(struct uart_port *, int);
  88         int             (*verify_port)(struct uart_port *, struct serial_struct *);
  89         int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  90 #ifdef CONFIG_CONSOLE_POLL
  91         int             (*poll_init)(struct uart_port *);
  92         void            (*poll_put_char)(struct uart_port *, unsigned char);
  93         int             (*poll_get_char)(struct uart_port *);
  94 #endif
  95 };
  96
  97 #define NO_POLL_CHAR            0x00ff0000
  98 #define UART_CONFIG_TYPE        (1 << 0)
  99 #define UART_CONFIG_IRQ         (1 << 1)
 100
 101 struct uart_icount {
 102         __u32   cts;
 103         __u32   dsr;
 104         __u32   rng;
 105         __u32   dcd;
 106         __u32   rx;
 107         __u32   tx;
 108         __u32   frame;
 109         __u32   overrun;
 110         __u32   parity;
 111         __u32   brk;
 112         __u32   buf_overrun;
 113 };
 114
 115 typedef unsigned int __bitwise__ upf_t;
 116
 117 struct 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         int                     (*handle_irq)(struct uart_port *);
 127         void                    (*pm)(struct uart_port *, unsigned int state,
 128                                       unsigned int old);
 129         void                    (*handle_break)(struct uart_port *);
 130         unsigned int            irq;                    /* irq number */
 131         unsigned long           irqflags;               /* irq flags  */
 132         unsigned int            uartclk;                /* base uart clock */
 133         unsigned int            fifosize;               /* tx fifo size */
 134         unsigned char           x_char;                 /* xon/xoff char */
 135         unsigned char           regshift;               /* reg offset shift */
 136         unsigned char           iotype;                 /* io access style */
 137         unsigned char           unused1;
 138
 139 #define UPIO_PORT               (0)
 140 #define UPIO_HUB6               (1)
 141 #define UPIO_MEM                (2)
 142 #define UPIO_MEM32              (3)
 143 #define UPIO_AU                 (4)                     /* Au1x00 and RT288x type IO */
 144 #define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 145
 146         unsigned int            read_status_mask;       /* driver specific */
 147         unsigned int            ignore_status_mask;     /* driver specific */
 148         struct uart_state       *state;                 /* pointer to parent state */
 149         struct uart_icount      icount;                 /* statistics */
 150
 151         struct console          *cons;                  /* struct console, if any */
 152 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
 153         unsigned long           sysrq;                  /* sysrq timeout */
 154 #endif
 155
 156         upf_t                   flags;
 157
 158 #define UPF_FOURPORT            ((__force upf_t) (1 << 1))
 159 #define UPF_SAK                 ((__force upf_t) (1 << 2))
 160 #define UPF_SPD_MASK            ((__force upf_t) (0x1030))
 161 #define UPF_SPD_HI              ((__force upf_t) (0x0010))
 162 #define UPF_SPD_VHI             ((__force upf_t) (0x0020))
 163 #define UPF_SPD_CUST            ((__force upf_t) (0x0030))
 164 #define UPF_SPD_SHI             ((__force upf_t) (0x1000))
 165 #define UPF_SPD_WARP            ((__force upf_t) (0x1010))
 166 #define UPF_SKIP_TEST           ((__force upf_t) (1 << 6))
 167 #define UPF_AUTO_IRQ            ((__force upf_t) (1 << 7))
 168 #define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 169 #define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 170 #define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 171 #define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 172 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 173 /* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 174 #define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 175 /* Port has hardware-assisted s/w flow control */
 176 #define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 177 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 178 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 179 #define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 180 #define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 181 /* The exact UART type is known and should not be probed.  */
 182 #define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 183 #define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 184 #define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 185 #define UPF_DEAD                ((__force upf_t) (1 << 30))
 186 #define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 187
 188 #define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 189 #define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 190
 191         unsigned int            mctrl;                  /* current modem ctrl settings */
 192         unsigned int            timeout;                /* character-based timeout */
 193         unsigned int            type;                   /* port type */
 194         const struct uart_ops   *ops;
 195         unsigned int            custom_divisor;
 196         unsigned int            line;                   /* port index */
 197         resource_size_t         mapbase;                /* for ioremap */
 198         struct device           *dev;                   /* parent device */
 199         unsigned char           hub6;                   /* this should be in the 8250 driver */
 200         unsigned char           suspended;
 201         unsigned char           irq_wake;
 202         unsigned char           unused[2];
 203         void                    *private_data;          /* generic platform data pointer */
 204 };
 205
 206 static inline int serial_port_in(struct uart_port *up, int offset)
 207 {
 208         return up->serial_in(up, offset);
 209 }
 210
 211 static inline void serial_port_out(struct uart_port *up, int offset, int value)
 212 {
 213         up->serial_out(up, offset, value);
 214 }
 215
 216 /**
 217  * enum uart_pm_state - power states for UARTs
 218  * @UART_PM_STATE_ON: UART is powered, up and operational
 219  * @UART_PM_STATE_OFF: UART is powered off
 220  * @UART_PM_STATE_UNDEFINED: sentinel
 221  */
 222 enum uart_pm_state {
 223         UART_PM_STATE_ON = 0,
 224         UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 225         UART_PM_STATE_UNDEFINED,
 226 };
 227
 228 /*
 229  * This is the state information which is persistent across opens.
 230  */
 231 struct uart_state {
 232         struct tty_port         port;
 233
 234         enum uart_pm_state      pm_state;
 235         struct circ_buf         xmit;
 236
 237         struct uart_port        *uart_port;
 238 };
 239
 240 #define UART_XMIT_SIZE  PAGE_SIZE
 241
 242
 243 /* number of characters left in xmit buffer before we ask for more */
 244 #define WAKEUP_CHARS            256
 245
 246 struct module;
 247 struct tty_driver;
 248
 249 struct uart_driver {
 250         struct module           *owner;
 251         const char              *driver_name;
 252         const char              *dev_name;
 253         int                      major;
 254         int                      minor;
 255         int                      nr;
 256         struct console          *cons;
 257
 258         /*
 259          * these are private; the low level driver should not
 260          * touch these; they should be initialised to NULL
 261          */
 262         struct uart_state       *state;
 263         struct tty_driver       *tty_driver;
 264 };
 265
 266 void uart_write_wakeup(struct uart_port *port);
 267
 268 /*
 269  * Baud rate helpers.
 270  */
 271 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 272                          unsigned int baud);
 273 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 274                                 struct ktermios *old, unsigned int min,
 275                                 unsigned int max);
 276 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 277
 278 /* Base timer interval for polling */
 279 static inline int uart_poll_timeout(struct uart_port *port)
 280 {
 281         int timeout = port->timeout;
 282
 283         return timeout > 6 ? (timeout / 2 - 2) : 1;
 284 }
 285
 286 /*
 287  * Console helpers.
 288  */
 289 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 290                                    struct console *c);
 291 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 292                         int *flow);
 293 int uart_set_options(struct uart_port *port, struct console *co, int baud,
 294                      int parity, int bits, int flow);
 295 struct tty_driver *uart_console_device(struct console *co, int *index);
 296 void uart_console_write(struct uart_port *port, const char *s,
 297                         unsigned int count,
 298                         void (*putchar)(struct uart_port *, int));
 299
 300 /*
 301  * Port/driver registration/removal
 302  */
 303 int uart_register_driver(struct uart_driver *uart);
 304 void uart_unregister_driver(struct uart_driver *uart);
 305 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 306 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 307 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 308
 309 /*
 310  * Power Management
 311  */
 312 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 313 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 314
 315 #define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 316 #define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 317
 318 #define uart_circ_chars_pending(circ)   \
 319         (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 320
 321 #define uart_circ_chars_free(circ)      \
 322         (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 323
 324 static inline int uart_tx_stopped(struct uart_port *port)
 325 {
 326         struct tty_struct *tty = port->state->port.tty;
 327         if(tty->stopped || tty->hw_stopped)
 328                 return 1;
 329         return 0;
 330 }
 331
 332 /*
 333  * The following are helper functions for the low level drivers.
 334  */
 335
 336 extern void uart_handle_dcd_change(struct uart_port *uport,
 337                 unsigned int status);
 338 extern void uart_handle_cts_change(struct uart_port *uport,
 339                 unsigned int status);
 340
 341 extern void uart_insert_char(struct uart_port *port, unsigned int status,
 342                  unsigned int overrun, unsigned int ch, unsigned int flag);
 343
 344 #ifdef SUPPORT_SYSRQ
 345 static inline int
 346 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 347 {
 348         if (port->sysrq) {
 349                 if (ch && time_before(jiffies, port->sysrq)) {
 350                         handle_sysrq(ch);
 351                         port->sysrq = 0;
 352                         return 1;
 353                 }
 354                 port->sysrq = 0;
 355         }
 356         return 0;
 357 }
 358 #else
 359 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 360 #endif
 361
 362 /*
 363  * We do the SysRQ and SAK checking like this...
 364  */
 365 static inline int uart_handle_break(struct uart_port *port)
 366 {
 367         struct uart_state *state = port->state;
 368
 369         if (port->handle_break)
 370                 port->handle_break(port);
 371
 372 #ifdef SUPPORT_SYSRQ
 373         if (port->cons && port->cons->index == port->line) {
 374                 if (!port->sysrq) {
 375                         port->sysrq = jiffies + HZ*5;
 376                         return 1;
 377                 }
 378                 port->sysrq = 0;
 379         }
 380 #endif
 381         if (port->flags & UPF_SAK)
 382                 do_SAK(state->port.tty);
 383         return 0;
 384 }
 385
 386 /*
 387  *      UART_ENABLE_MS - determine if port should enable modem status irqs
 388  */
 389 #define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 390                                          (cflag) & CRTSCTS || \
 391                                          !((cflag) & CLOCAL))
 392
 393 #endif /* LINUX_SERIAL_CORE_H */