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/console.h> 26 #include <linux/interrupt.h> 27 #include <linux/circ_buf.h> 28 #include <linux/spinlock.h> 29 #include <linux/sched.h> 30 #include <linux/tty.h> 31 #include <linux/mutex.h> 32 #include <linux/sysrq.h> 33 #include <uapi/linux/serial_core.h> 34 35 #ifdef CONFIG_SERIAL_CORE_CONSOLE 36 #define uart_console(port) \ 37 ((port)->cons && (port)->cons->index == (port)->line) 38 #else 39 #define uart_console(port) ({ (void)port; 0; }) 40 #endif 41 42 struct uart_port; 43 struct serial_struct; 44 struct device; 45 46 /* 47 * This structure describes all the operations that can be done on the 48 * physical hardware. See Documentation/serial/driver.rst for details. 49 */ 50 struct uart_ops { 51 unsigned int (*tx_empty)(struct uart_port *); 52 void (*set_mctrl)(struct uart_port *, unsigned int mctrl); 53 unsigned int (*get_mctrl)(struct uart_port *); 54 void (*stop_tx)(struct uart_port *); 55 void (*start_tx)(struct uart_port *); 56 void (*throttle)(struct uart_port *); 57 void (*unthrottle)(struct uart_port *); 58 void (*send_xchar)(struct uart_port *, char ch); 59 void (*stop_rx)(struct uart_port *); 60 void (*enable_ms)(struct uart_port *); 61 void (*break_ctl)(struct uart_port *, int ctl); 62 int (*startup)(struct uart_port *); 63 void (*shutdown)(struct uart_port *); 64 void (*flush_buffer)(struct uart_port *); 65 void (*set_termios)(struct uart_port *, struct ktermios *new, 66 struct ktermios *old); 67 void (*set_ldisc)(struct uart_port *, struct ktermios *); 68 void (*pm)(struct uart_port *, unsigned int state, 69 unsigned int oldstate); 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 typedef unsigned int __bitwise upstat_t; 117 118 struct uart_port { 119 spinlock_t lock; /* port lock */ 120 unsigned long iobase; /* in/out[bwl] */ 121 unsigned char __iomem *membase; /* read/write[bwl] */ 122 unsigned int (*serial_in)(struct uart_port *, int); 123 void (*serial_out)(struct uart_port *, int, int); 124 void (*set_termios)(struct uart_port *, 125 struct ktermios *new, 126 struct ktermios *old); 127 void (*set_ldisc)(struct uart_port *, 128 struct ktermios *); 129 unsigned int (*get_mctrl)(struct uart_port *); 130 void (*set_mctrl)(struct uart_port *, unsigned int); 131 unsigned int (*get_divisor)(struct uart_port *, 132 unsigned int baud, 133 unsigned int *frac); 134 void (*set_divisor)(struct uart_port *, 135 unsigned int baud, 136 unsigned int quot, 137 unsigned int quot_frac); 138 int (*startup)(struct uart_port *port); 139 void (*shutdown)(struct uart_port *port); 140 void (*throttle)(struct uart_port *port); 141 void (*unthrottle)(struct uart_port *port); 142 int (*handle_irq)(struct uart_port *); 143 void (*pm)(struct uart_port *, unsigned int state, 144 unsigned int old); 145 void (*handle_break)(struct uart_port *); 146 int (*rs485_config)(struct uart_port *, 147 struct serial_rs485 *rs485); 148 int (*iso7816_config)(struct uart_port *, 149 struct serial_iso7816 *iso7816); 150 unsigned int irq; /* irq number */ 151 unsigned long irqflags; /* irq flags */ 152 unsigned int uartclk; /* base uart clock */ 153 unsigned int fifosize; /* tx fifo size */ 154 unsigned char x_char; /* xon/xoff char */ 155 unsigned char regshift; /* reg offset shift */ 156 unsigned char iotype; /* io access style */ 157 unsigned char quirks; /* internal quirks */ 158 159 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 160 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 161 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 162 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 163 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 164 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 165 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 166 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 167 168 /* quirks must be updated while holding port mutex */ 169 #define UPQ_NO_TXEN_TEST BIT(0) 170 171 unsigned int read_status_mask; /* driver specific */ 172 unsigned int ignore_status_mask; /* driver specific */ 173 struct uart_state *state; /* pointer to parent state */ 174 struct uart_icount icount; /* statistics */ 175 176 struct console *cons; /* struct console, if any */ 177 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ) 178 unsigned long sysrq; /* sysrq timeout */ 179 unsigned int sysrq_ch; /* char for sysrq */ 180 #endif 181 182 /* flags must be updated while holding port mutex */ 183 upf_t flags; 184 185 /* 186 * These flags must be equivalent to the flags defined in 187 * include/uapi/linux/tty_flags.h which are the userspace definitions 188 * assigned from the serial_struct flags in uart_set_info() 189 * [for bit definitions in the UPF_CHANGE_MASK] 190 * 191 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable 192 * The remaining bits are serial-core specific and not modifiable by 193 * userspace. 194 */ 195 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 196 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 197 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 198 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 199 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 200 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 201 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 202 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 203 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 204 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 205 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 206 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 207 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 208 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 209 210 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19)) 211 /* Port has hardware-assisted h/w flow control */ 212 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20)) 213 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21)) 214 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 215 /* Port has hardware-assisted s/w flow control */ 216 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) 217 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) 218 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) 219 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25)) 220 #define UPF_BUG_THRE ((__force upf_t) (1 << 26)) 221 /* The exact UART type is known and should not be probed. */ 222 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27)) 223 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28)) 224 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29)) 225 #define UPF_DEAD ((__force upf_t) (1 << 30)) 226 #define UPF_IOREMAP ((__force upf_t) (1 << 31)) 227 228 #define __UPF_CHANGE_MASK 0x17fff 229 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 230 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 231 232 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 233 #error Change mask not equivalent to userspace-visible bit defines 234 #endif 235 236 /* 237 * Must hold termios_rwsem, port mutex and port lock to change; 238 * can hold any one lock to read. 239 */ 240 upstat_t status; 241 242 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 243 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 244 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 245 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 246 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 247 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 248 249 int hw_stopped; /* sw-assisted CTS flow state */ 250 unsigned int mctrl; /* current modem ctrl settings */ 251 unsigned int timeout; /* character-based timeout */ 252 unsigned int type; /* port type */ 253 const struct uart_ops *ops; 254 unsigned int custom_divisor; 255 unsigned int line; /* port index */ 256 unsigned int minor; 257 resource_size_t mapbase; /* for ioremap */ 258 resource_size_t mapsize; 259 struct device *dev; /* parent device */ 260 unsigned char hub6; /* this should be in the 8250 driver */ 261 unsigned char suspended; 262 unsigned char unused[2]; 263 const char *name; /* port name */ 264 struct attribute_group *attr_group; /* port specific attributes */ 265 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 266 struct serial_rs485 rs485; 267 struct serial_iso7816 iso7816; 268 void *private_data; /* generic platform data pointer */ 269 }; 270 271 static inline int serial_port_in(struct uart_port *up, int offset) 272 { 273 return up->serial_in(up, offset); 274 } 275 276 static inline void serial_port_out(struct uart_port *up, int offset, int value) 277 { 278 up->serial_out(up, offset, value); 279 } 280 281 /** 282 * enum uart_pm_state - power states for UARTs 283 * @UART_PM_STATE_ON: UART is powered, up and operational 284 * @UART_PM_STATE_OFF: UART is powered off 285 * @UART_PM_STATE_UNDEFINED: sentinel 286 */ 287 enum uart_pm_state { 288 UART_PM_STATE_ON = 0, 289 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 290 UART_PM_STATE_UNDEFINED, 291 }; 292 293 /* 294 * This is the state information which is persistent across opens. 295 */ 296 struct uart_state { 297 struct tty_port port; 298 299 enum uart_pm_state pm_state; 300 struct circ_buf xmit; 301 302 atomic_t refcount; 303 wait_queue_head_t remove_wait; 304 struct uart_port *uart_port; 305 }; 306 307 #define UART_XMIT_SIZE PAGE_SIZE 308 309 310 /* number of characters left in xmit buffer before we ask for more */ 311 #define WAKEUP_CHARS 256 312 313 struct module; 314 struct tty_driver; 315 316 struct uart_driver { 317 struct module *owner; 318 const char *driver_name; 319 const char *dev_name; 320 int major; 321 int minor; 322 int nr; 323 struct console *cons; 324 325 /* 326 * these are private; the low level driver should not 327 * touch these; they should be initialised to NULL 328 */ 329 struct uart_state *state; 330 struct tty_driver *tty_driver; 331 }; 332 333 void uart_write_wakeup(struct uart_port *port); 334 335 /* 336 * Baud rate helpers. 337 */ 338 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 339 unsigned int baud); 340 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 341 struct ktermios *old, unsigned int min, 342 unsigned int max); 343 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 344 345 /* Base timer interval for polling */ 346 static inline int uart_poll_timeout(struct uart_port *port) 347 { 348 int timeout = port->timeout; 349 350 return timeout > 6 ? (timeout / 2 - 2) : 1; 351 } 352 353 /* 354 * Console helpers. 355 */ 356 struct earlycon_device { 357 struct console *con; 358 struct uart_port port; 359 char options[16]; /* e.g., 115200n8 */ 360 unsigned int baud; 361 }; 362 363 struct earlycon_id { 364 char name[15]; 365 char name_term; /* In case compiler didn't '\0' term name */ 366 char compatible[128]; 367 int (*setup)(struct earlycon_device *, const char *options); 368 }; 369 370 extern const struct earlycon_id *__earlycon_table[]; 371 extern const struct earlycon_id *__earlycon_table_end[]; 372 373 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 374 #define EARLYCON_USED_OR_UNUSED __used 375 #else 376 #define EARLYCON_USED_OR_UNUSED __maybe_unused 377 #endif 378 379 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \ 380 static const struct earlycon_id unique_id \ 381 EARLYCON_USED_OR_UNUSED __initconst \ 382 = { .name = __stringify(_name), \ 383 .compatible = compat, \ 384 .setup = fn }; \ 385 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \ 386 __section(__earlycon_table) \ 387 * const __PASTE(__p, unique_id) = &unique_id 388 389 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 390 _OF_EARLYCON_DECLARE(_name, compat, fn, \ 391 __UNIQUE_ID(__earlycon_##_name)) 392 393 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 394 395 extern int of_setup_earlycon(const struct earlycon_id *match, 396 unsigned long node, 397 const char *options); 398 399 #ifdef CONFIG_SERIAL_EARLYCON 400 extern bool earlycon_acpi_spcr_enable __initdata; 401 int setup_earlycon(char *buf); 402 #else 403 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; 404 static inline int setup_earlycon(char *buf) { return 0; } 405 #endif 406 407 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 408 struct console *c); 409 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 410 char **options); 411 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 412 int *flow); 413 int uart_set_options(struct uart_port *port, struct console *co, int baud, 414 int parity, int bits, int flow); 415 struct tty_driver *uart_console_device(struct console *co, int *index); 416 void uart_console_write(struct uart_port *port, const char *s, 417 unsigned int count, 418 void (*putchar)(struct uart_port *, int)); 419 420 /* 421 * Port/driver registration/removal 422 */ 423 int uart_register_driver(struct uart_driver *uart); 424 void uart_unregister_driver(struct uart_driver *uart); 425 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 426 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 427 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 428 429 /* 430 * Power Management 431 */ 432 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 433 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 434 435 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 436 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 437 438 #define uart_circ_chars_pending(circ) \ 439 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 440 441 #define uart_circ_chars_free(circ) \ 442 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 443 444 static inline int uart_tx_stopped(struct uart_port *port) 445 { 446 struct tty_struct *tty = port->state->port.tty; 447 if ((tty && tty->stopped) || port->hw_stopped) 448 return 1; 449 return 0; 450 } 451 452 static inline bool uart_cts_enabled(struct uart_port *uport) 453 { 454 return !!(uport->status & UPSTAT_CTS_ENABLE); 455 } 456 457 static inline bool uart_softcts_mode(struct uart_port *uport) 458 { 459 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 460 461 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 462 } 463 464 /* 465 * The following are helper functions for the low level drivers. 466 */ 467 468 extern void uart_handle_dcd_change(struct uart_port *uport, 469 unsigned int status); 470 extern void uart_handle_cts_change(struct uart_port *uport, 471 unsigned int status); 472 473 extern void uart_insert_char(struct uart_port *port, unsigned int status, 474 unsigned int overrun, unsigned int ch, unsigned int flag); 475 476 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL) 477 static inline int 478 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 479 { 480 if (port->sysrq) { 481 if (ch && time_before(jiffies, port->sysrq)) { 482 handle_sysrq(ch); 483 port->sysrq = 0; 484 return 1; 485 } 486 port->sysrq = 0; 487 } 488 return 0; 489 } 490 static inline int 491 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) 492 { 493 if (port->sysrq) { 494 if (ch && time_before(jiffies, port->sysrq)) { 495 port->sysrq_ch = ch; 496 port->sysrq = 0; 497 return 1; 498 } 499 port->sysrq = 0; 500 } 501 return 0; 502 } 503 static inline void 504 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 505 { 506 int sysrq_ch; 507 508 sysrq_ch = port->sysrq_ch; 509 port->sysrq_ch = 0; 510 511 spin_unlock_irqrestore(&port->lock, irqflags); 512 513 if (sysrq_ch) 514 handle_sysrq(sysrq_ch); 515 } 516 #else 517 static inline int 518 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 519 static inline int 520 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 521 static inline void 522 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 523 { 524 spin_unlock_irqrestore(&port->lock, irqflags); 525 } 526 #endif 527 528 /* 529 * We do the SysRQ and SAK checking like this... 530 */ 531 static inline int uart_handle_break(struct uart_port *port) 532 { 533 struct uart_state *state = port->state; 534 535 if (port->handle_break) 536 port->handle_break(port); 537 538 #ifdef SUPPORT_SYSRQ 539 if (port->cons && port->cons->index == port->line) { 540 if (!port->sysrq) { 541 port->sysrq = jiffies + HZ*5; 542 return 1; 543 } 544 port->sysrq = 0; 545 } 546 #endif 547 if (port->flags & UPF_SAK) 548 do_SAK(state->port.tty); 549 return 0; 550 } 551 552 /* 553 * UART_ENABLE_MS - determine if port should enable modem status irqs 554 */ 555 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 556 (cflag) & CRTSCTS || \ 557 !((cflag) & CLOCAL)) 558 559 void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf); 560 #endif /* LINUX_SERIAL_CORE_H */ 561