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