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
  64         /*
  65          * Return a string describing the type of the port
  66          */
  67         const char      *(*type)(struct uart_port *);
  68
  69         /*
  70          * Release IO and memory resources used by the port.
  71          * This includes iounmap if necessary.
  72          */
  73         void            (*release_port)(struct uart_port *);
  74
  75         /*
  76          * Request IO and memory resources used by the port.
  77          * This includes iomapping the port if necessary.
  78          */
  79         int             (*request_port)(struct uart_port *);
  80         void            (*config_port)(struct uart_port *, int);
  81         int             (*verify_port)(struct uart_port *, struct serial_struct *);
  82         int             (*ioctl)(struct uart_port *, unsigned int, unsigned long);
  83 #ifdef CONFIG_CONSOLE_POLL
  84         int             (*poll_init)(struct uart_port *);
  85         void            (*poll_put_char)(struct uart_port *, unsigned char);
  86         int             (*poll_get_char)(struct uart_port *);
  87 #endif
  88 };
  89
  90 #define NO_POLL_CHAR            0x00ff0000
  91 #define UART_CONFIG_TYPE        (1 << 0)
  92 #define UART_CONFIG_IRQ         (1 << 1)
  93
  94 struct uart_icount {
  95         __u32   cts;
  96         __u32   dsr;
  97         __u32   rng;
  98         __u32   dcd;
  99         __u32   rx;
 100         __u32   tx;
 101         __u32   frame;
 102         __u32   overrun;
 103         __u32   parity;
 104         __u32   brk;
 105         __u32   buf_overrun;
 106 };
 107
 108 typedef unsigned int __bitwise__ upf_t;
 109
 110 struct uart_port {
 111         spinlock_t              lock;                   /* port lock */
 112         unsigned long           iobase;                 /* in/out[bwl] */
 113         unsigned char __iomem   *membase;               /* read/write[bwl] */
 114         unsigned int            (*serial_in)(struct uart_port *, int);
 115         void                    (*serial_out)(struct uart_port *, int, int);
 116         void                    (*set_termios)(struct uart_port *,
 117                                                struct ktermios *new,
 118                                                struct ktermios *old);
 119         int                     (*handle_irq)(struct uart_port *);
 120         void                    (*pm)(struct uart_port *, unsigned int state,
 121                                       unsigned int old);
 122         void                    (*handle_break)(struct uart_port *);
 123         unsigned int            irq;                    /* irq number */
 124         unsigned long           irqflags;               /* irq flags  */
 125         unsigned int            uartclk;                /* base uart clock */
 126         unsigned int            fifosize;               /* tx fifo size */
 127         unsigned char           x_char;                 /* xon/xoff char */
 128         unsigned char           regshift;               /* reg offset shift */
 129         unsigned char           iotype;                 /* io access style */
 130         unsigned char           unused1;
 131
 132 #define UPIO_PORT               (0)
 133 #define UPIO_HUB6               (1)
 134 #define UPIO_MEM                (2)
 135 #define UPIO_MEM32              (3)
 136 #define UPIO_AU                 (4)                     /* Au1x00 and RT288x type IO */
 137 #define UPIO_TSI                (5)                     /* Tsi108/109 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 /* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
 167 #define UPF_HARD_FLOW           ((__force upf_t) (1 << 21))
 168 /* Port has hardware-assisted s/w flow control */
 169 #define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 170 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 171 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 172 #define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))
 173 #define UPF_BUG_THRE            ((__force upf_t) (1 << 26))
 174 /* The exact UART type is known and should not be probed.  */
 175 #define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 176 #define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 177 #define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 178 #define UPF_DEAD                ((__force upf_t) (1 << 30))
 179 #define UPF_IOREMAP             ((__force upf_t) (1 << 31))
 180
 181 #define UPF_CHANGE_MASK         ((__force upf_t) (0x17fff))
 182 #define UPF_USR_MASK            ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 183
 184         unsigned int            mctrl;                  /* current modem ctrl settings */
 185         unsigned int            timeout;                /* character-based timeout */
 186         unsigned int            type;                   /* port type */
 187         const struct uart_ops   *ops;
 188         unsigned int            custom_divisor;
 189         unsigned int            line;                   /* port index */
 190         resource_size_t         mapbase;                /* for ioremap */
 191         struct device           *dev;                   /* parent device */
 192         unsigned char           hub6;                   /* this should be in the 8250 driver */
 193         unsigned char           suspended;
 194         unsigned char           irq_wake;
 195         unsigned char           unused[2];
 196         void                    *private_data;          /* generic platform data pointer */
 197 };
 198
 199 static inline int serial_port_in(struct uart_port *up, int offset)
 200 {
 201         return up->serial_in(up, offset);
 202 }
 203
 204 static inline void serial_port_out(struct uart_port *up, int offset, int value)
 205 {
 206         up->serial_out(up, offset, value);
 207 }
 208
 209 /**
 210  * enum uart_pm_state - power states for UARTs
 211  * @UART_PM_STATE_ON: UART is powered, up and operational
 212  * @UART_PM_STATE_OFF: UART is powered off
 213  * @UART_PM_STATE_UNDEFINED: sentinel
 214  */
 215 enum uart_pm_state {
 216         UART_PM_STATE_ON = 0,
 217         UART_PM_STATE_OFF = 3, /* number taken from ACPI */
 218         UART_PM_STATE_UNDEFINED,
 219 };
 220
 221 /*
 222  * This is the state information which is persistent across opens.
 223  */
 224 struct uart_state {
 225         struct tty_port         port;
 226
 227         enum uart_pm_state      pm_state;
 228         struct circ_buf         xmit;
 229
 230         struct uart_port        *uart_port;
 231 };
 232
 233 #define UART_XMIT_SIZE  PAGE_SIZE
 234
 235
 236 /* number of characters left in xmit buffer before we ask for more */
 237 #define WAKEUP_CHARS            256
 238
 239 struct module;
 240 struct tty_driver;
 241
 242 struct uart_driver {
 243         struct module           *owner;
 244         const char              *driver_name;
 245         const char              *dev_name;
 246         int                      major;
 247         int                      minor;
 248         int                      nr;
 249         struct console          *cons;
 250
 251         /*
 252          * these are private; the low level driver should not
 253          * touch these; they should be initialised to NULL
 254          */
 255         struct uart_state       *state;
 256         struct tty_driver       *tty_driver;
 257 };
 258
 259 void uart_write_wakeup(struct uart_port *port);
 260
 261 /*
 262  * Baud rate helpers.
 263  */
 264 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
 265                          unsigned int baud);
 266 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 267                                 struct ktermios *old, unsigned int min,
 268                                 unsigned int max);
 269 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 270
 271 /* Base timer interval for polling */
 272 static inline int uart_poll_timeout(struct uart_port *port)
 273 {
 274         int timeout = port->timeout;
 275
 276         return timeout > 6 ? (timeout / 2 - 2) : 1;
 277 }
 278
 279 /*
 280  * Console helpers.
 281  */
 282 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 283                                    struct console *c);
 284 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
 285                         int *flow);
 286 int uart_set_options(struct uart_port *port, struct console *co, int baud,
 287                      int parity, int bits, int flow);
 288 struct tty_driver *uart_console_device(struct console *co, int *index);
 289 void uart_console_write(struct uart_port *port, const char *s,
 290                         unsigned int count,
 291                         void (*putchar)(struct uart_port *, int));
 292
 293 /*
 294  * Port/driver registration/removal
 295  */
 296 int uart_register_driver(struct uart_driver *uart);
 297 void uart_unregister_driver(struct uart_driver *uart);
 298 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 299 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 300 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
 301
 302 /*
 303  * Power Management
 304  */
 305 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
 306 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 307
 308 #define uart_circ_empty(circ)           ((circ)->head == (circ)->tail)
 309 #define uart_circ_clear(circ)           ((circ)->head = (circ)->tail = 0)
 310
 311 #define uart_circ_chars_pending(circ)   \
 312         (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 313
 314 #define uart_circ_chars_free(circ)      \
 315         (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
 316
 317 static inline int uart_tx_stopped(struct uart_port *port)
 318 {
 319         struct tty_struct *tty = port->state->port.tty;
 320         if(tty->stopped || tty->hw_stopped)
 321                 return 1;
 322         return 0;
 323 }
 324
 325 /*
 326  * The following are helper functions for the low level drivers.
 327  */
 328
 329 extern void uart_handle_dcd_change(struct uart_port *uport,
 330                 unsigned int status);
 331 extern void uart_handle_cts_change(struct uart_port *uport,
 332                 unsigned int status);
 333
 334 extern void uart_insert_char(struct uart_port *port, unsigned int status,
 335                  unsigned int overrun, unsigned int ch, unsigned int flag);
 336
 337 #ifdef SUPPORT_SYSRQ
 338 static inline int
 339 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 340 {
 341         if (port->sysrq) {
 342                 if (ch && time_before(jiffies, port->sysrq)) {
 343                         handle_sysrq(ch);
 344                         port->sysrq = 0;
 345                         return 1;
 346                 }
 347                 port->sysrq = 0;
 348         }
 349         return 0;
 350 }
 351 #else
 352 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
 353 #endif
 354
 355 /*
 356  * We do the SysRQ and SAK checking like this...
 357  */
 358 static inline int uart_handle_break(struct uart_port *port)
 359 {
 360         struct uart_state *state = port->state;
 361
 362         if (port->handle_break)
 363                 port->handle_break(port);
 364
 365 #ifdef SUPPORT_SYSRQ
 366         if (port->cons && port->cons->index == port->line) {
 367                 if (!port->sysrq) {
 368                         port->sysrq = jiffies + HZ*5;
 369                         return 1;
 370                 }
 371                 port->sysrq = 0;
 372         }
 373 #endif
 374         if (port->flags & UPF_SAK)
 375                 do_SAK(state->port.tty);
 376         return 0;
 377 }
 378
 379 /*
 380  *      UART_ENABLE_MS - determine if port should enable modem status irqs
 381  */
 382 #define UART_ENABLE_MS(port,cflag)      ((port)->flags & UPF_HARDPPS_CD || \
 383                                          (cflag) & CRTSCTS || \
 384                                          !((cflag) & CLOCAL))
 385
 386 #endif /* LINUX_SERIAL_CORE_H */