1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * linux/drivers/char/serial_core.h 4 * 5 * Copyright (C) 2000 Deep Blue Solutions Ltd. 6 */ 7 #ifndef LINUX_SERIAL_CORE_H 8 #define LINUX_SERIAL_CORE_H 9 10 #include <linux/bitops.h> 11 #include <linux/compiler.h> 12 #include <linux/console.h> 13 #include <linux/interrupt.h> 14 #include <linux/circ_buf.h> 15 #include <linux/spinlock.h> 16 #include <linux/sched.h> 17 #include <linux/tty.h> 18 #include <linux/mutex.h> 19 #include <linux/sysrq.h> 20 #include <uapi/linux/serial_core.h> 21 22 #ifdef CONFIG_SERIAL_CORE_CONSOLE 23 #define uart_console(port) \ 24 ((port)->cons && (port)->cons->index == (port)->line) 25 #else 26 #define uart_console(port) ({ (void)port; 0; }) 27 #endif 28 29 struct uart_port; 30 struct serial_struct; 31 struct device; 32 33 /* 34 * This structure describes all the operations that can be done on the 35 * physical hardware. See Documentation/driver-api/serial/driver.rst for details. 36 */ 37 struct uart_ops { 38 unsigned int (*tx_empty)(struct uart_port *); 39 void (*set_mctrl)(struct uart_port *, unsigned int mctrl); 40 unsigned int (*get_mctrl)(struct uart_port *); 41 void (*stop_tx)(struct uart_port *); 42 void (*start_tx)(struct uart_port *); 43 void (*throttle)(struct uart_port *); 44 void (*unthrottle)(struct uart_port *); 45 void (*send_xchar)(struct uart_port *, char ch); 46 void (*stop_rx)(struct uart_port *); 47 void (*enable_ms)(struct uart_port *); 48 void (*break_ctl)(struct uart_port *, int ctl); 49 int (*startup)(struct uart_port *); 50 void (*shutdown)(struct uart_port *); 51 void (*flush_buffer)(struct uart_port *); 52 void (*set_termios)(struct uart_port *, struct ktermios *new, 53 struct ktermios *old); 54 void (*set_ldisc)(struct uart_port *, struct ktermios *); 55 void (*pm)(struct uart_port *, unsigned int state, 56 unsigned int oldstate); 57 58 /* 59 * Return a string describing the type of the port 60 */ 61 const char *(*type)(struct uart_port *); 62 63 /* 64 * Release IO and memory resources used by the port. 65 * This includes iounmap if necessary. 66 */ 67 void (*release_port)(struct uart_port *); 68 69 /* 70 * Request IO and memory resources used by the port. 71 * This includes iomapping the port if necessary. 72 */ 73 int (*request_port)(struct uart_port *); 74 void (*config_port)(struct uart_port *, int); 75 int (*verify_port)(struct uart_port *, struct serial_struct *); 76 int (*ioctl)(struct uart_port *, unsigned int, unsigned long); 77 #ifdef CONFIG_CONSOLE_POLL 78 int (*poll_init)(struct uart_port *); 79 void (*poll_put_char)(struct uart_port *, unsigned char); 80 int (*poll_get_char)(struct uart_port *); 81 #endif 82 }; 83 84 #define NO_POLL_CHAR 0x00ff0000 85 #define UART_CONFIG_TYPE (1 << 0) 86 #define UART_CONFIG_IRQ (1 << 1) 87 88 struct uart_icount { 89 __u32 cts; 90 __u32 dsr; 91 __u32 rng; 92 __u32 dcd; 93 __u32 rx; 94 __u32 tx; 95 __u32 frame; 96 __u32 overrun; 97 __u32 parity; 98 __u32 brk; 99 __u32 buf_overrun; 100 }; 101 102 typedef unsigned int __bitwise upf_t; 103 typedef unsigned int __bitwise upstat_t; 104 105 struct uart_port { 106 spinlock_t lock; /* port lock */ 107 unsigned long iobase; /* in/out[bwl] */ 108 unsigned char __iomem *membase; /* read/write[bwl] */ 109 unsigned int (*serial_in)(struct uart_port *, int); 110 void (*serial_out)(struct uart_port *, int, int); 111 void (*set_termios)(struct uart_port *, 112 struct ktermios *new, 113 struct ktermios *old); 114 void (*set_ldisc)(struct uart_port *, 115 struct ktermios *); 116 unsigned int (*get_mctrl)(struct uart_port *); 117 void (*set_mctrl)(struct uart_port *, unsigned int); 118 unsigned int (*get_divisor)(struct uart_port *, 119 unsigned int baud, 120 unsigned int *frac); 121 void (*set_divisor)(struct uart_port *, 122 unsigned int baud, 123 unsigned int quot, 124 unsigned int quot_frac); 125 int (*startup)(struct uart_port *port); 126 void (*shutdown)(struct uart_port *port); 127 void (*throttle)(struct uart_port *port); 128 void (*unthrottle)(struct uart_port *port); 129 int (*handle_irq)(struct uart_port *); 130 void (*pm)(struct uart_port *, unsigned int state, 131 unsigned int old); 132 void (*handle_break)(struct uart_port *); 133 int (*rs485_config)(struct uart_port *, 134 struct serial_rs485 *rs485); 135 int (*iso7816_config)(struct uart_port *, 136 struct serial_iso7816 *iso7816); 137 unsigned int irq; /* irq number */ 138 unsigned long irqflags; /* irq flags */ 139 unsigned int uartclk; /* base uart clock */ 140 unsigned int fifosize; /* tx fifo size */ 141 unsigned char x_char; /* xon/xoff char */ 142 unsigned char regshift; /* reg offset shift */ 143 unsigned char iotype; /* io access style */ 144 unsigned char quirks; /* internal quirks */ 145 146 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 147 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 148 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 149 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 150 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 151 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 152 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 153 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 154 155 /* quirks must be updated while holding port mutex */ 156 #define UPQ_NO_TXEN_TEST BIT(0) 157 158 unsigned int read_status_mask; /* driver specific */ 159 unsigned int ignore_status_mask; /* driver specific */ 160 struct uart_state *state; /* pointer to parent state */ 161 struct uart_icount icount; /* statistics */ 162 163 struct console *cons; /* struct console, if any */ 164 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ) 165 unsigned long sysrq; /* sysrq timeout */ 166 unsigned int sysrq_ch; /* char for sysrq */ 167 #endif 168 169 /* flags must be updated while holding port mutex */ 170 upf_t flags; 171 172 /* 173 * These flags must be equivalent to the flags defined in 174 * include/uapi/linux/tty_flags.h which are the userspace definitions 175 * assigned from the serial_struct flags in uart_set_info() 176 * [for bit definitions in the UPF_CHANGE_MASK] 177 * 178 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable 179 * The remaining bits are serial-core specific and not modifiable by 180 * userspace. 181 */ 182 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 183 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 184 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 185 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 186 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 187 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 188 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 189 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 190 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 191 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 192 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 193 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 194 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 195 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 196 197 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19)) 198 /* Port has hardware-assisted h/w flow control */ 199 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20)) 200 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21)) 201 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 202 /* Port has hardware-assisted s/w flow control */ 203 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) 204 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) 205 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) 206 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25)) 207 #define UPF_BUG_THRE ((__force upf_t) (1 << 26)) 208 /* The exact UART type is known and should not be probed. */ 209 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27)) 210 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28)) 211 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29)) 212 #define UPF_DEAD ((__force upf_t) (1 << 30)) 213 #define UPF_IOREMAP ((__force upf_t) (1 << 31)) 214 215 #define __UPF_CHANGE_MASK 0x17fff 216 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 217 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 218 219 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 220 #error Change mask not equivalent to userspace-visible bit defines 221 #endif 222 223 /* 224 * Must hold termios_rwsem, port mutex and port lock to change; 225 * can hold any one lock to read. 226 */ 227 upstat_t status; 228 229 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 230 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 231 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 232 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 233 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 234 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 235 236 int hw_stopped; /* sw-assisted CTS flow state */ 237 unsigned int mctrl; /* current modem ctrl settings */ 238 unsigned int timeout; /* character-based timeout */ 239 unsigned int type; /* port type */ 240 const struct uart_ops *ops; 241 unsigned int custom_divisor; 242 unsigned int line; /* port index */ 243 unsigned int minor; 244 resource_size_t mapbase; /* for ioremap */ 245 resource_size_t mapsize; 246 struct device *dev; /* parent device */ 247 unsigned char hub6; /* this should be in the 8250 driver */ 248 unsigned char suspended; 249 unsigned char unused[2]; 250 const char *name; /* port name */ 251 struct attribute_group *attr_group; /* port specific attributes */ 252 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 253 struct serial_rs485 rs485; 254 struct serial_iso7816 iso7816; 255 void *private_data; /* generic platform data pointer */ 256 }; 257 serial_port_in(struct uart_port * up,int offset)258 static inline int serial_port_in(struct uart_port *up, int offset) 259 { 260 return up->serial_in(up, offset); 261 } 262 serial_port_out(struct uart_port * up,int offset,int value)263 static inline void serial_port_out(struct uart_port *up, int offset, int value) 264 { 265 up->serial_out(up, offset, value); 266 } 267 268 /** 269 * enum uart_pm_state - power states for UARTs 270 * @UART_PM_STATE_ON: UART is powered, up and operational 271 * @UART_PM_STATE_OFF: UART is powered off 272 * @UART_PM_STATE_UNDEFINED: sentinel 273 */ 274 enum uart_pm_state { 275 UART_PM_STATE_ON = 0, 276 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 277 UART_PM_STATE_UNDEFINED, 278 }; 279 280 /* 281 * This is the state information which is persistent across opens. 282 */ 283 struct uart_state { 284 struct tty_port port; 285 286 enum uart_pm_state pm_state; 287 struct circ_buf xmit; 288 289 atomic_t refcount; 290 wait_queue_head_t remove_wait; 291 struct uart_port *uart_port; 292 }; 293 294 #define UART_XMIT_SIZE PAGE_SIZE 295 296 297 /* number of characters left in xmit buffer before we ask for more */ 298 #define WAKEUP_CHARS 256 299 300 struct module; 301 struct tty_driver; 302 303 struct uart_driver { 304 struct module *owner; 305 const char *driver_name; 306 const char *dev_name; 307 int major; 308 int minor; 309 int nr; 310 struct console *cons; 311 312 /* 313 * these are private; the low level driver should not 314 * touch these; they should be initialised to NULL 315 */ 316 struct uart_state *state; 317 struct tty_driver *tty_driver; 318 }; 319 320 void uart_write_wakeup(struct uart_port *port); 321 322 /* 323 * Baud rate helpers. 324 */ 325 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 326 unsigned int baud); 327 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 328 struct ktermios *old, unsigned int min, 329 unsigned int max); 330 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 331 332 /* Base timer interval for polling */ uart_poll_timeout(struct uart_port * port)333 static inline int uart_poll_timeout(struct uart_port *port) 334 { 335 int timeout = port->timeout; 336 337 return timeout > 6 ? (timeout / 2 - 2) : 1; 338 } 339 340 /* 341 * Console helpers. 342 */ 343 struct earlycon_device { 344 struct console *con; 345 struct uart_port port; 346 char options[16]; /* e.g., 115200n8 */ 347 unsigned int baud; 348 }; 349 350 struct earlycon_id { 351 char name[15]; 352 char name_term; /* In case compiler didn't '\0' term name */ 353 char compatible[128]; 354 int (*setup)(struct earlycon_device *, const char *options); 355 }; 356 357 extern const struct earlycon_id *__earlycon_table[]; 358 extern const struct earlycon_id *__earlycon_table_end[]; 359 360 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 361 #define EARLYCON_USED_OR_UNUSED __used 362 #else 363 #define EARLYCON_USED_OR_UNUSED __maybe_unused 364 #endif 365 366 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \ 367 static const struct earlycon_id unique_id \ 368 EARLYCON_USED_OR_UNUSED __initconst \ 369 = { .name = __stringify(_name), \ 370 .compatible = compat, \ 371 .setup = fn }; \ 372 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \ 373 __section(__earlycon_table) \ 374 * const __PASTE(__p, unique_id) = &unique_id 375 376 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 377 _OF_EARLYCON_DECLARE(_name, compat, fn, \ 378 __UNIQUE_ID(__earlycon_##_name)) 379 380 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 381 382 extern int of_setup_earlycon(const struct earlycon_id *match, 383 unsigned long node, 384 const char *options); 385 386 #ifdef CONFIG_SERIAL_EARLYCON 387 extern bool earlycon_acpi_spcr_enable __initdata; 388 int setup_earlycon(char *buf); 389 #else 390 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; setup_earlycon(char * buf)391 static inline int setup_earlycon(char *buf) { return 0; } 392 #endif 393 394 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 395 struct console *c); 396 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 397 char **options); 398 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 399 int *flow); 400 int uart_set_options(struct uart_port *port, struct console *co, int baud, 401 int parity, int bits, int flow); 402 struct tty_driver *uart_console_device(struct console *co, int *index); 403 void uart_console_write(struct uart_port *port, const char *s, 404 unsigned int count, 405 void (*putchar)(struct uart_port *, int)); 406 407 /* 408 * Port/driver registration/removal 409 */ 410 int uart_register_driver(struct uart_driver *uart); 411 void uart_unregister_driver(struct uart_driver *uart); 412 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 413 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 414 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 415 416 /* 417 * Power Management 418 */ 419 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 420 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 421 422 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 423 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 424 425 #define uart_circ_chars_pending(circ) \ 426 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 427 428 #define uart_circ_chars_free(circ) \ 429 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 430 uart_tx_stopped(struct uart_port * port)431 static inline int uart_tx_stopped(struct uart_port *port) 432 { 433 struct tty_struct *tty = port->state->port.tty; 434 if ((tty && tty->stopped) || port->hw_stopped) 435 return 1; 436 return 0; 437 } 438 uart_cts_enabled(struct uart_port * uport)439 static inline bool uart_cts_enabled(struct uart_port *uport) 440 { 441 return !!(uport->status & UPSTAT_CTS_ENABLE); 442 } 443 uart_softcts_mode(struct uart_port * uport)444 static inline bool uart_softcts_mode(struct uart_port *uport) 445 { 446 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 447 448 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 449 } 450 451 /* 452 * The following are helper functions for the low level drivers. 453 */ 454 455 extern void uart_handle_dcd_change(struct uart_port *uport, 456 unsigned int status); 457 extern void uart_handle_cts_change(struct uart_port *uport, 458 unsigned int status); 459 460 extern void uart_insert_char(struct uart_port *port, unsigned int status, 461 unsigned int overrun, unsigned int ch, unsigned int flag); 462 463 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL) 464 static inline int uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)465 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 466 { 467 if (port->sysrq) { 468 if (ch && time_before(jiffies, port->sysrq)) { 469 handle_sysrq(ch); 470 port->sysrq = 0; 471 return 1; 472 } 473 port->sysrq = 0; 474 } 475 return 0; 476 } 477 static inline int uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)478 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) 479 { 480 if (port->sysrq) { 481 if (ch && time_before(jiffies, port->sysrq)) { 482 port->sysrq_ch = ch; 483 port->sysrq = 0; 484 return 1; 485 } 486 port->sysrq = 0; 487 } 488 return 0; 489 } 490 static inline void uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)491 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 492 { 493 int sysrq_ch; 494 495 sysrq_ch = port->sysrq_ch; 496 port->sysrq_ch = 0; 497 498 spin_unlock_irqrestore(&port->lock, irqflags); 499 500 if (sysrq_ch) 501 handle_sysrq(sysrq_ch); 502 } 503 #else 504 static inline int uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)505 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 506 static inline int uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)507 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; } 508 static inline void uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)509 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) 510 { 511 spin_unlock_irqrestore(&port->lock, irqflags); 512 } 513 #endif 514 515 /* 516 * We do the SysRQ and SAK checking like this... 517 */ uart_handle_break(struct uart_port * port)518 static inline int uart_handle_break(struct uart_port *port) 519 { 520 struct uart_state *state = port->state; 521 522 if (port->handle_break) 523 port->handle_break(port); 524 525 #ifdef SUPPORT_SYSRQ 526 if (port->cons && port->cons->index == port->line) { 527 if (!port->sysrq) { 528 port->sysrq = jiffies + HZ*5; 529 return 1; 530 } 531 port->sysrq = 0; 532 } 533 #endif 534 if (port->flags & UPF_SAK) 535 do_SAK(state->port.tty); 536 return 0; 537 } 538 539 /* 540 * UART_ENABLE_MS - determine if port should enable modem status irqs 541 */ 542 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 543 (cflag) & CRTSCTS || \ 544 !((cflag) & CLOCAL)) 545 546 void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf); 547 #endif /* LINUX_SERIAL_CORE_H */ 548
