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 #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 unused1; 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 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 #endif 167 168 /* flags must be updated while holding port mutex */ 169 upf_t flags; 170 171 /* 172 * These flags must be equivalent to the flags defined in 173 * include/uapi/linux/tty_flags.h which are the userspace definitions 174 * assigned from the serial_struct flags in uart_set_info() 175 * [for bit definitions in the UPF_CHANGE_MASK] 176 * 177 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable 178 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off. 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_NO_TXEN_TEST ((__force upf_t) (1 << 15)) 196 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 197 198 /* 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)) 234 235 int hw_stopped; /* sw-assisted CTS flow state */ 236 unsigned int mctrl; /* current modem ctrl settings */ 237 unsigned int timeout; /* character-based timeout */ 238 unsigned int type; /* port type */ 239 const struct uart_ops *ops; 240 unsigned int custom_divisor; 241 unsigned int line; /* port index */ 242 unsigned int minor; 243 resource_size_t mapbase; /* for ioremap */ 244 resource_size_t mapsize; 245 struct device *dev; /* parent device */ 246 unsigned char hub6; /* this should be in the 8250 driver */ 247 unsigned char suspended; 248 unsigned char irq_wake; 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 void *private_data; /* generic platform data pointer */ 255 }; 256 257 static inline int serial_port_in(struct uart_port *up, int offset) 258 { 259 return up->serial_in(up, offset); 260 } 261 262 static inline void serial_port_out(struct uart_port *up, int offset, int value) 263 { 264 up->serial_out(up, offset, value); 265 } 266 267 /** 268 * enum uart_pm_state - power states for UARTs 269 * @UART_PM_STATE_ON: UART is powered, up and operational 270 * @UART_PM_STATE_OFF: UART is powered off 271 * @UART_PM_STATE_UNDEFINED: sentinel 272 */ 273 enum uart_pm_state { 274 UART_PM_STATE_ON = 0, 275 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 276 UART_PM_STATE_UNDEFINED, 277 }; 278 279 /* 280 * This is the state information which is persistent across opens. 281 */ 282 struct uart_state { 283 struct tty_port port; 284 285 enum uart_pm_state pm_state; 286 struct circ_buf xmit; 287 288 atomic_t refcount; 289 wait_queue_head_t remove_wait; 290 struct uart_port *uart_port; 291 }; 292 293 #define UART_XMIT_SIZE PAGE_SIZE 294 295 296 /* number of characters left in xmit buffer before we ask for more */ 297 #define WAKEUP_CHARS 256 298 299 struct module; 300 struct tty_driver; 301 302 struct uart_driver { 303 struct module *owner; 304 const char *driver_name; 305 const char *dev_name; 306 int major; 307 int minor; 308 int nr; 309 struct console *cons; 310 311 /* 312 * these are private; the low level driver should not 313 * touch these; they should be initialised to NULL 314 */ 315 struct uart_state *state; 316 struct tty_driver *tty_driver; 317 }; 318 319 void uart_write_wakeup(struct uart_port *port); 320 321 /* 322 * Baud rate helpers. 323 */ 324 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 325 unsigned int baud); 326 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 327 struct ktermios *old, unsigned int min, 328 unsigned int max); 329 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 330 331 /* Base timer interval for polling */ 332 static inline int uart_poll_timeout(struct uart_port *port) 333 { 334 int timeout = port->timeout; 335 336 return timeout > 6 ? (timeout / 2 - 2) : 1; 337 } 338 339 /* 340 * Console helpers. 341 */ 342 struct earlycon_device { 343 struct console *con; 344 struct uart_port port; 345 char options[16]; /* e.g., 115200n8 */ 346 unsigned int baud; 347 }; 348 349 struct earlycon_id { 350 char name[16]; 351 char compatible[128]; 352 int (*setup)(struct earlycon_device *, const char *options); 353 } __aligned(32); 354 355 extern const struct earlycon_id __earlycon_table[]; 356 extern const struct earlycon_id __earlycon_table_end[]; 357 358 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 359 #define EARLYCON_USED_OR_UNUSED __used 360 #else 361 #define EARLYCON_USED_OR_UNUSED __maybe_unused 362 #endif 363 364 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 365 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 366 EARLYCON_USED_OR_UNUSED __section(__earlycon_table) \ 367 = { .name = __stringify(_name), \ 368 .compatible = compat, \ 369 .setup = fn } 370 371 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 372 373 extern int of_setup_earlycon(const struct earlycon_id *match, 374 unsigned long node, 375 const char *options); 376 377 #ifdef CONFIG_SERIAL_EARLYCON 378 extern bool earlycon_init_is_deferred __initdata; 379 int setup_earlycon(char *buf); 380 #else 381 static const bool earlycon_init_is_deferred; 382 static inline int setup_earlycon(char *buf) { return 0; } 383 #endif 384 385 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 386 struct console *c); 387 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 388 char **options); 389 void uart_parse_options(char *options, int *baud, int *parity, int *bits, 390 int *flow); 391 int uart_set_options(struct uart_port *port, struct console *co, int baud, 392 int parity, int bits, int flow); 393 struct tty_driver *uart_console_device(struct console *co, int *index); 394 void uart_console_write(struct uart_port *port, const char *s, 395 unsigned int count, 396 void (*putchar)(struct uart_port *, int)); 397 398 /* 399 * Port/driver registration/removal 400 */ 401 int uart_register_driver(struct uart_driver *uart); 402 void uart_unregister_driver(struct uart_driver *uart); 403 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 404 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 405 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 406 407 /* 408 * Power Management 409 */ 410 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 411 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 412 413 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 414 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 415 416 #define uart_circ_chars_pending(circ) \ 417 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 418 419 #define uart_circ_chars_free(circ) \ 420 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 421 422 static inline int uart_tx_stopped(struct uart_port *port) 423 { 424 struct tty_struct *tty = port->state->port.tty; 425 if ((tty && tty->stopped) || port->hw_stopped) 426 return 1; 427 return 0; 428 } 429 430 static inline bool uart_cts_enabled(struct uart_port *uport) 431 { 432 return !!(uport->status & UPSTAT_CTS_ENABLE); 433 } 434 435 static inline bool uart_softcts_mode(struct uart_port *uport) 436 { 437 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 438 439 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 440 } 441 442 /* 443 * The following are helper functions for the low level drivers. 444 */ 445 446 extern void uart_handle_dcd_change(struct uart_port *uport, 447 unsigned int status); 448 extern void uart_handle_cts_change(struct uart_port *uport, 449 unsigned int status); 450 451 extern void uart_insert_char(struct uart_port *port, unsigned int status, 452 unsigned int overrun, unsigned int ch, unsigned int flag); 453 454 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL) 455 static inline int 456 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 457 { 458 if (port->sysrq) { 459 if (ch && time_before(jiffies, port->sysrq)) { 460 handle_sysrq(ch); 461 port->sysrq = 0; 462 return 1; 463 } 464 port->sysrq = 0; 465 } 466 return 0; 467 } 468 #else 469 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; }) 470 #endif 471 472 /* 473 * We do the SysRQ and SAK checking like this... 474 */ 475 static inline int uart_handle_break(struct uart_port *port) 476 { 477 struct uart_state *state = port->state; 478 479 if (port->handle_break) 480 port->handle_break(port); 481 482 #ifdef SUPPORT_SYSRQ 483 if (port->cons && port->cons->index == port->line) { 484 if (!port->sysrq) { 485 port->sysrq = jiffies + HZ*5; 486 return 1; 487 } 488 port->sysrq = 0; 489 } 490 #endif 491 if (port->flags & UPF_SAK) 492 do_SAK(state->port.tty); 493 return 0; 494 } 495 496 /* 497 * UART_ENABLE_MS - determine if port should enable modem status irqs 498 */ 499 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 500 (cflag) & CRTSCTS || \ 501 !((cflag) & CLOCAL)) 502 503 #endif /* LINUX_SERIAL_CORE_H */ 504