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 struct attribute_group *attr_group; /* port specific attributes */ 251 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 252 struct serial_rs485 rs485; 253 void *private_data; /* generic platform data pointer */ 254 }; 255 256 static inline int serial_port_in(struct uart_port *up, int offset) 257 { 258 return up->serial_in(up, offset); 259 } 260 261 static inline void serial_port_out(struct uart_port *up, int offset, int value) 262 { 263 up->serial_out(up, offset, value); 264 } 265 266 /** 267 * enum uart_pm_state - power states for UARTs 268 * @UART_PM_STATE_ON: UART is powered, up and operational 269 * @UART_PM_STATE_OFF: UART is powered off 270 * @UART_PM_STATE_UNDEFINED: sentinel 271 */ 272 enum uart_pm_state { 273 UART_PM_STATE_ON = 0, 274 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 275 UART_PM_STATE_UNDEFINED, 276 }; 277 278 /* 279 * This is the state information which is persistent across opens. 280 */ 281 struct uart_state { 282 struct tty_port port; 283 284 enum uart_pm_state pm_state; 285 struct circ_buf xmit; 286 287 atomic_t refcount; 288 wait_queue_head_t remove_wait; 289 struct uart_port *uart_port; 290 }; 291 292 #define UART_XMIT_SIZE PAGE_SIZE 293 294 295 /* number of characters left in xmit buffer before we ask for more */ 296 #define WAKEUP_CHARS 256 297 298 struct module; 299 struct tty_driver; 300 301 struct uart_driver { 302 struct module *owner; 303 const char *driver_name; 304 const char *dev_name; 305 int major; 306 int minor; 307 int nr; 308 struct console *cons; 309 310 /* 311 * these are private; the low level driver should not 312 * touch these; they should be initialised to NULL 313 */ 314 struct uart_state *state; 315 struct tty_driver *tty_driver; 316 }; 317 318 void uart_write_wakeup(struct uart_port *port); 319 320 /* 321 * Baud rate helpers. 322 */ 323 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 324 unsigned int baud); 325 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 326 struct ktermios *old, unsigned int min, 327 unsigned int max); 328 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 329 330 /* Base timer interval for polling */ 331 static inline int uart_poll_timeout(struct uart_port *port) 332 { 333 int timeout = port->timeout; 334 335 return timeout > 6 ? (timeout / 2 - 2) : 1; 336 } 337 338 /* 339 * Console helpers. 340 */ 341 struct earlycon_device { 342 struct console *con; 343 struct uart_port port; 344 char options[16]; /* e.g., 115200n8 */ 345 unsigned int baud; 346 }; 347 348 struct earlycon_id { 349 char name[16]; 350 char compatible[128]; 351 int (*setup)(struct earlycon_device *, const char *options); 352 } __aligned(32); 353 354 extern const struct earlycon_id __earlycon_table[]; 355 extern const struct earlycon_id __earlycon_table_end[]; 356 357 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 358 #define EARLYCON_USED_OR_UNUSED __used 359 #else 360 #define EARLYCON_USED_OR_UNUSED __maybe_unused 361 #endif 362 363 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 364 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 365 EARLYCON_USED_OR_UNUSED __section(__earlycon_table) \ 366 = { .name = __stringify(_name), \ 367 .compatible = compat, \ 368 .setup = fn } 369 370 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 371 372 extern int of_setup_earlycon(const struct earlycon_id *match, 373 unsigned long node, 374 const char *options); 375 376 #ifdef CONFIG_SERIAL_EARLYCON 377 extern bool earlycon_init_is_deferred __initdata; 378 int setup_earlycon(char *buf); 379 #else 380 static const bool earlycon_init_is_deferred; 381 static inline int setup_earlycon(char *buf) { return 0; } 382 #endif 383 384 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 385 struct console *c); 386 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 387 char **options); 388 void uart_parse_options(char *options, int *baud, int *parity, int *bits, 389 int *flow); 390 int uart_set_options(struct uart_port *port, struct console *co, int baud, 391 int parity, int bits, int flow); 392 struct tty_driver *uart_console_device(struct console *co, int *index); 393 void uart_console_write(struct uart_port *port, const char *s, 394 unsigned int count, 395 void (*putchar)(struct uart_port *, int)); 396 397 /* 398 * Port/driver registration/removal 399 */ 400 int uart_register_driver(struct uart_driver *uart); 401 void uart_unregister_driver(struct uart_driver *uart); 402 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 403 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 404 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 405 406 /* 407 * Power Management 408 */ 409 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 410 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 411 412 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 413 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 414 415 #define uart_circ_chars_pending(circ) \ 416 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 417 418 #define uart_circ_chars_free(circ) \ 419 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 420 421 static inline int uart_tx_stopped(struct uart_port *port) 422 { 423 struct tty_struct *tty = port->state->port.tty; 424 if ((tty && tty->stopped) || port->hw_stopped) 425 return 1; 426 return 0; 427 } 428 429 static inline bool uart_cts_enabled(struct uart_port *uport) 430 { 431 return !!(uport->status & UPSTAT_CTS_ENABLE); 432 } 433 434 static inline bool uart_softcts_mode(struct uart_port *uport) 435 { 436 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 437 438 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 439 } 440 441 /* 442 * The following are helper functions for the low level drivers. 443 */ 444 445 extern void uart_handle_dcd_change(struct uart_port *uport, 446 unsigned int status); 447 extern void uart_handle_cts_change(struct uart_port *uport, 448 unsigned int status); 449 450 extern void uart_insert_char(struct uart_port *port, unsigned int status, 451 unsigned int overrun, unsigned int ch, unsigned int flag); 452 453 #ifdef SUPPORT_SYSRQ 454 static inline int 455 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 456 { 457 if (port->sysrq) { 458 if (ch && time_before(jiffies, port->sysrq)) { 459 handle_sysrq(ch); 460 port->sysrq = 0; 461 return 1; 462 } 463 port->sysrq = 0; 464 } 465 return 0; 466 } 467 #else 468 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; }) 469 #endif 470 471 /* 472 * We do the SysRQ and SAK checking like this... 473 */ 474 static inline int uart_handle_break(struct uart_port *port) 475 { 476 struct uart_state *state = port->state; 477 478 if (port->handle_break) 479 port->handle_break(port); 480 481 #ifdef SUPPORT_SYSRQ 482 if (port->cons && port->cons->index == port->line) { 483 if (!port->sysrq) { 484 port->sysrq = jiffies + HZ*5; 485 return 1; 486 } 487 port->sysrq = 0; 488 } 489 #endif 490 if (port->flags & UPF_SAK) 491 do_SAK(state->port.tty); 492 return 0; 493 } 494 495 /* 496 * UART_ENABLE_MS - determine if port should enable modem status irqs 497 */ 498 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 499 (cflag) & CRTSCTS || \ 500 !((cflag) & CLOCAL)) 501 502 #endif /* LINUX_SERIAL_CORE_H */ 503