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 #include <linux/bitops.h> 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) ({ (void)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 *, struct ktermios *); 67 void (*pm)(struct uart_port *, unsigned int state, 68 unsigned int oldstate); 69 70 /* 71 * Return a string describing the type of the port 72 */ 73 const char *(*type)(struct uart_port *); 74 75 /* 76 * Release IO and memory resources used by the port. 77 * This includes iounmap if necessary. 78 */ 79 void (*release_port)(struct uart_port *); 80 81 /* 82 * Request IO and memory resources used by the port. 83 * This includes iomapping the port if necessary. 84 */ 85 int (*request_port)(struct uart_port *); 86 void (*config_port)(struct uart_port *, int); 87 int (*verify_port)(struct uart_port *, struct serial_struct *); 88 int (*ioctl)(struct uart_port *, unsigned int, unsigned long); 89 #ifdef CONFIG_CONSOLE_POLL 90 int (*poll_init)(struct uart_port *); 91 void (*poll_put_char)(struct uart_port *, unsigned char); 92 int (*poll_get_char)(struct uart_port *); 93 #endif 94 }; 95 96 #define NO_POLL_CHAR 0x00ff0000 97 #define UART_CONFIG_TYPE (1 << 0) 98 #define UART_CONFIG_IRQ (1 << 1) 99 100 struct uart_icount { 101 __u32 cts; 102 __u32 dsr; 103 __u32 rng; 104 __u32 dcd; 105 __u32 rx; 106 __u32 tx; 107 __u32 frame; 108 __u32 overrun; 109 __u32 parity; 110 __u32 brk; 111 __u32 buf_overrun; 112 }; 113 114 typedef unsigned int __bitwise upf_t; 115 typedef unsigned int __bitwise upstat_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 void (*set_ldisc)(struct uart_port *, 127 struct ktermios *); 128 unsigned int (*get_mctrl)(struct uart_port *); 129 void (*set_mctrl)(struct uart_port *, unsigned int); 130 int (*startup)(struct uart_port *port); 131 void (*shutdown)(struct uart_port *port); 132 void (*throttle)(struct uart_port *port); 133 void (*unthrottle)(struct uart_port *port); 134 int (*handle_irq)(struct uart_port *); 135 void (*pm)(struct uart_port *, unsigned int state, 136 unsigned int old); 137 void (*handle_break)(struct uart_port *); 138 int (*rs485_config)(struct uart_port *, 139 struct serial_rs485 *rs485); 140 unsigned int irq; /* irq number */ 141 unsigned long irqflags; /* irq flags */ 142 unsigned int uartclk; /* base uart clock */ 143 unsigned int fifosize; /* tx fifo size */ 144 unsigned char x_char; /* xon/xoff char */ 145 unsigned char regshift; /* reg offset shift */ 146 unsigned char iotype; /* io access style */ 147 unsigned char quirks; /* internal quirks */ 148 149 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 150 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 151 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 152 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 153 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 154 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 155 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 156 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 157 158 /* quirks must be updated while holding port mutex */ 159 #define UPQ_NO_TXEN_TEST BIT(0) 160 161 unsigned int read_status_mask; /* driver specific */ 162 unsigned int ignore_status_mask; /* driver specific */ 163 struct uart_state *state; /* pointer to parent state */ 164 struct uart_icount icount; /* statistics */ 165 166 struct console *cons; /* struct console, if any */ 167 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ) 168 unsigned long sysrq; /* sysrq timeout */ 169 unsigned int sysrq_ch; /* char for sysrq */ 170 #endif 171 172 /* flags must be updated while holding port mutex */ 173 upf_t flags; 174 175 /* 176 * These flags must be equivalent to the flags defined in 177 * include/uapi/linux/tty_flags.h which are the userspace definitions 178 * assigned from the serial_struct flags in uart_set_info() 179 * [for bit definitions in the UPF_CHANGE_MASK] 180 * 181 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable 182 * The remaining bits are serial-core specific and not modifiable by 183 * userspace. 184 */ 185 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 186 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 187 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 188 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 189 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 190 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 191 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 192 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 193 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 194 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 195 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 196 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 197 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 198 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 199 200 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19)) 201 /* Port has hardware-assisted h/w flow control */ 202 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20)) 203 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21)) 204 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 205 /* Port has hardware-assisted s/w flow control */ 206 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) 207 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) 208 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) 209 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25)) 210 #define UPF_BUG_THRE ((__force upf_t) (1 << 26)) 211 /* The exact UART type is known and should not be probed. */ 212 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27)) 213 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28)) 214 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29)) 215 #define UPF_DEAD ((__force upf_t) (1 << 30)) 216 #define UPF_IOREMAP ((__force upf_t) (1 << 31)) 217 218 #define __UPF_CHANGE_MASK 0x17fff 219 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 220 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 221 222 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 223 #error Change mask not equivalent to userspace-visible bit defines 224 #endif 225 226 /* 227 * Must hold termios_rwsem, port mutex and port lock to change; 228 * can hold any one lock to read. 229 */ 230 upstat_t status; 231 232 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 233 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 234 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 235 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 236 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 237 238 int hw_stopped; /* sw-assisted CTS flow state */ 239 unsigned int mctrl; /* current modem ctrl settings */ 240 unsigned int timeout; /* character-based timeout */ 241 unsigned int type; /* port type */ 242 const struct uart_ops *ops; 243 unsigned int custom_divisor; 244 unsigned int line; /* port index */ 245 unsigned int minor; 246 resource_size_t mapbase; /* for ioremap */ 247 resource_size_t mapsize; 248 struct device *dev; /* parent device */ 249 unsigned char hub6; /* this should be in the 8250 driver */ 250 unsigned char suspended; 251 unsigned char unused[2]; 252 const char *name; /* port name */ 253 struct attribute_group *attr_group; /* port specific attributes */ 254 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 255 struct serial_rs485 rs485; 256 void *private_data; /* generic platform data pointer */ 257 }; 258 serial_port_in(struct uart_port * up,int offset)259 static inline int serial_port_in(struct uart_port *up, int offset) 260 { 261 return up->serial_in(up, offset); 262 } 263 serial_port_out(struct uart_port * up,int offset,int value)264 static inline void serial_port_out(struct uart_port *up, int offset, int value) 265 { 266 up->serial_out(up, offset, value); 267 } 268 269 /** 270 * enum uart_pm_state - power states for UARTs 271 * @UART_PM_STATE_ON: UART is powered, up and operational 272 * @UART_PM_STATE_OFF: UART is powered off 273 * @UART_PM_STATE_UNDEFINED: sentinel 274 */ 275 enum uart_pm_state { 276 UART_PM_STATE_ON = 0, 277 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 278 UART_PM_STATE_UNDEFINED, 279 }; 280 281 /* 282 * This is the state information which is persistent across opens. 283 */ 284 struct uart_state { 285 struct tty_port port; 286 287 enum uart_pm_state pm_state; 288 struct circ_buf xmit; 289 290 atomic_t refcount; 291 wait_queue_head_t remove_wait; 292 struct uart_port *uart_port; 293 }; 294 295 #define UART_XMIT_SIZE PAGE_SIZE 296 297 298 /* number of characters left in xmit buffer before we ask for more */ 299 #define WAKEUP_CHARS 256 300 301 struct module; 302 struct tty_driver; 303 304 struct uart_driver { 305 struct module *owner; 306 const char *driver_name; 307 const char *dev_name; 308 int major; 309 int minor; 310 int nr; 311 struct console *cons; 312 313 /* 314 * these are private; the low level driver should not 315 * touch these; they should be initialised to NULL 316 */ 317 struct uart_state *state; 318 struct tty_driver *tty_driver; 319 }; 320 321 void uart_write_wakeup(struct uart_port *port); 322 323 /* 324 * Baud rate helpers. 325 */ 326 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 327 unsigned int baud); 328 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 329 struct ktermios *old, unsigned int min, 330 unsigned int max); 331 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 332 333 /* Base timer interval for polling */ uart_poll_timeout(struct uart_port * port)334 static inline int uart_poll_timeout(struct uart_port *port) 335 { 336 int timeout = port->timeout; 337 338 return timeout > 6 ? (timeout / 2 - 2) : 1; 339 } 340 341 /* 342 * Console helpers. 343 */ 344 struct earlycon_device { 345 struct console *con; 346 struct uart_port port; 347 char options[16]; /* e.g., 115200n8 */ 348 unsigned int baud; 349 }; 350 351 struct earlycon_id { 352 char name[15]; 353 char name_term; /* In case compiler didn't '\0' term name */ 354 char compatible[128]; 355 int (*setup)(struct earlycon_device *, const char *options); 356 }; 357 358 extern const struct earlycon_id *__earlycon_table[]; 359 extern const struct earlycon_id *__earlycon_table_end[]; 360 361 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 362 #define EARLYCON_USED_OR_UNUSED __used 363 #else 364 #define EARLYCON_USED_OR_UNUSED __maybe_unused 365 #endif 366 367 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \ 368 static const struct earlycon_id unique_id \ 369 EARLYCON_USED_OR_UNUSED __initconst \ 370 = { .name = __stringify(_name), \ 371 .compatible = compat, \ 372 .setup = fn }; \ 373 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \ 374 __section(__earlycon_table) \ 375 * const __PASTE(__p, unique_id) = &unique_id 376 377 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 378 _OF_EARLYCON_DECLARE(_name, compat, fn, \ 379 __UNIQUE_ID(__earlycon_##_name)) 380 381 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 382 383 extern int of_setup_earlycon(const struct earlycon_id *match, 384 unsigned long node, 385 const char *options); 386 387 #ifdef CONFIG_SERIAL_EARLYCON 388 extern bool earlycon_init_is_deferred __initdata; 389 int setup_earlycon(char *buf); 390 #else 391 static const bool earlycon_init_is_deferred; setup_earlycon(char * buf)392 static inline int setup_earlycon(char *buf) { return 0; } 393 #endif 394 395 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 396 struct console *c); 397 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 398 char **options); 399 void uart_parse_options(char *options, int *baud, int *parity, int *bits, 400 int *flow); 401 int uart_set_options(struct uart_port *port, struct console *co, int baud, 402 int parity, int bits, int flow); 403 struct tty_driver *uart_console_device(struct console *co, int *index); 404 void uart_console_write(struct uart_port *port, const char *s, 405 unsigned int count, 406 void (*putchar)(struct uart_port *, int)); 407 408 /* 409 * Port/driver registration/removal 410 */ 411 int uart_register_driver(struct uart_driver *uart); 412 void uart_unregister_driver(struct uart_driver *uart); 413 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 414 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 415 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 416 417 /* 418 * Power Management 419 */ 420 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 421 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 422 423 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 424 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 425 426 #define uart_circ_chars_pending(circ) \ 427 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 428 429 #define uart_circ_chars_free(circ) \ 430 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 431 uart_tx_stopped(struct uart_port * port)432 static inline int uart_tx_stopped(struct uart_port *port) 433 { 434 struct tty_struct *tty = port->state->port.tty; 435 if ((tty && tty->stopped) || port->hw_stopped) 436 return 1; 437 return 0; 438 } 439 uart_cts_enabled(struct uart_port * uport)440 static inline bool uart_cts_enabled(struct uart_port *uport) 441 { 442 return !!(uport->status & UPSTAT_CTS_ENABLE); 443 } 444 uart_softcts_mode(struct uart_port * uport)445 static inline bool uart_softcts_mode(struct uart_port *uport) 446 { 447 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 448 449 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 450 } 451 452 /* 453 * The following are helper functions for the low level drivers. 454 */ 455 456 extern void uart_handle_dcd_change(struct uart_port *uport, 457 unsigned int status); 458 extern void uart_handle_cts_change(struct uart_port *uport, 459 unsigned int status); 460 461 extern void uart_insert_char(struct uart_port *port, unsigned int status, 462 unsigned int overrun, unsigned int ch, unsigned int flag); 463 464 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL) 465 static inline int uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)466 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 467 { 468 if (port->sysrq) { 469 if (ch && time_before(jiffies, port->sysrq)) { 470 handle_sysrq(ch); 471 port->sysrq = 0; 472 return 1; 473 } 474 port->sysrq = 0; 475 } 476 return 0; 477 } 478 static inline int uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)479 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) 480 { 481 if (port->sysrq) { 482 if (ch && time_before(jiffies, port->sysrq)) { 483 port->sysrq_ch = ch; 484 port->sysrq = 0; 485 return 1; 486 } 487 port->sysrq = 0; 488 } 489 return 0; 490 } 491 static inline void uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)492 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 493 { 494 int sysrq_ch; 495 496 sysrq_ch = port->sysrq_ch; 497 port->sysrq_ch = 0; 498 499 spin_unlock_irqrestore(&port->lock, irqflags); 500 501 if (sysrq_ch) 502 handle_sysrq(sysrq_ch); 503 } 504 #else 505 static inline int uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)506 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 507 static inline int uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)508 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 509 static inline void uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)510 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 511 { 512 spin_unlock_irqrestore(&port->lock, irqflags); 513 } 514 #endif 515 516 /* 517 * We do the SysRQ and SAK checking like this... 518 */ uart_handle_break(struct uart_port * port)519 static inline int uart_handle_break(struct uart_port *port) 520 { 521 struct uart_state *state = port->state; 522 523 if (port->handle_break) 524 port->handle_break(port); 525 526 #ifdef SUPPORT_SYSRQ 527 if (port->cons && port->cons->index == port->line) { 528 if (!port->sysrq) { 529 port->sysrq = jiffies + HZ*5; 530 return 1; 531 } 532 port->sysrq = 0; 533 } 534 #endif 535 if (port->flags & UPF_SAK) 536 do_SAK(state->port.tty); 537 return 0; 538 } 539 540 /* 541 * UART_ENABLE_MS - determine if port should enable modem status irqs 542 */ 543 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 544 (cflag) & CRTSCTS || \ 545 !((cflag) & CLOCAL)) 546 547 #endif /* LINUX_SERIAL_CORE_H */ 548