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 unsigned int (*get_mctrl)(struct uart_port *); 127 void (*set_mctrl)(struct uart_port *, unsigned int); 128 int (*startup)(struct uart_port *port); 129 void (*shutdown)(struct uart_port *port); 130 void (*throttle)(struct uart_port *port); 131 void (*unthrottle)(struct uart_port *port); 132 int (*handle_irq)(struct uart_port *); 133 void (*pm)(struct uart_port *, unsigned int state, 134 unsigned int old); 135 void (*handle_break)(struct uart_port *); 136 int (*rs485_config)(struct uart_port *, 137 struct serial_rs485 *rs485); 138 unsigned int irq; /* irq number */ 139 unsigned long irqflags; /* irq flags */ 140 unsigned int uartclk; /* base uart clock */ 141 unsigned int fifosize; /* tx fifo size */ 142 unsigned char x_char; /* xon/xoff char */ 143 unsigned char regshift; /* reg offset shift */ 144 unsigned char iotype; /* io access style */ 145 unsigned char unused1; 146 147 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 148 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 149 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 150 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 151 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 152 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 153 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 154 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 155 156 unsigned int read_status_mask; /* driver specific */ 157 unsigned int ignore_status_mask; /* driver specific */ 158 struct uart_state *state; /* pointer to parent state */ 159 struct uart_icount icount; /* statistics */ 160 161 struct console *cons; /* struct console, if any */ 162 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ) 163 unsigned long sysrq; /* sysrq timeout */ 164 #endif 165 166 /* flags must be updated while holding port mutex */ 167 upf_t flags; 168 169 /* 170 * These flags must be equivalent to the flags defined in 171 * include/uapi/linux/tty_flags.h which are the userspace definitions 172 * assigned from the serial_struct flags in uart_set_info() 173 * [for bit definitions in the UPF_CHANGE_MASK] 174 * 175 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable 176 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off. 177 * The remaining bits are serial-core specific and not modifiable by 178 * userspace. 179 */ 180 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 181 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 182 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 183 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 184 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 185 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 186 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 187 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 188 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 189 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 190 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 191 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 192 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 193 #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15)) 194 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 195 196 /* Port has hardware-assisted h/w flow control */ 197 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20)) 198 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21)) 199 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 200 /* Port has hardware-assisted s/w flow control */ 201 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) 202 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) 203 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) 204 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25)) 205 #define UPF_BUG_THRE ((__force upf_t) (1 << 26)) 206 /* The exact UART type is known and should not be probed. */ 207 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27)) 208 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28)) 209 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29)) 210 #define UPF_DEAD ((__force upf_t) (1 << 30)) 211 #define UPF_IOREMAP ((__force upf_t) (1 << 31)) 212 213 #define __UPF_CHANGE_MASK 0x17fff 214 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 215 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 216 217 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 218 #error Change mask not equivalent to userspace-visible bit defines 219 #endif 220 221 /* 222 * Must hold termios_rwsem, port mutex and port lock to change; 223 * can hold any one lock to read. 224 */ 225 upstat_t status; 226 227 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 228 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 229 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 230 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 231 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 232 233 int hw_stopped; /* sw-assisted CTS flow state */ 234 unsigned int mctrl; /* current modem ctrl settings */ 235 unsigned int timeout; /* character-based timeout */ 236 unsigned int type; /* port type */ 237 const struct uart_ops *ops; 238 unsigned int custom_divisor; 239 unsigned int line; /* port index */ 240 unsigned int minor; 241 resource_size_t mapbase; /* for ioremap */ 242 resource_size_t mapsize; 243 struct device *dev; /* parent device */ 244 unsigned char hub6; /* this should be in the 8250 driver */ 245 unsigned char suspended; 246 unsigned char irq_wake; 247 unsigned char unused[2]; 248 struct attribute_group *attr_group; /* port specific attributes */ 249 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 250 struct serial_rs485 rs485; 251 void *private_data; /* generic platform data pointer */ 252 }; 253 254 static inline int serial_port_in(struct uart_port *up, int offset) 255 { 256 return up->serial_in(up, offset); 257 } 258 259 static inline void serial_port_out(struct uart_port *up, int offset, int value) 260 { 261 up->serial_out(up, offset, value); 262 } 263 264 /** 265 * enum uart_pm_state - power states for UARTs 266 * @UART_PM_STATE_ON: UART is powered, up and operational 267 * @UART_PM_STATE_OFF: UART is powered off 268 * @UART_PM_STATE_UNDEFINED: sentinel 269 */ 270 enum uart_pm_state { 271 UART_PM_STATE_ON = 0, 272 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 273 UART_PM_STATE_UNDEFINED, 274 }; 275 276 /* 277 * This is the state information which is persistent across opens. 278 */ 279 struct uart_state { 280 struct tty_port port; 281 282 enum uart_pm_state pm_state; 283 struct circ_buf xmit; 284 285 atomic_t refcount; 286 wait_queue_head_t remove_wait; 287 struct uart_port *uart_port; 288 }; 289 290 #define UART_XMIT_SIZE PAGE_SIZE 291 292 293 /* number of characters left in xmit buffer before we ask for more */ 294 #define WAKEUP_CHARS 256 295 296 struct module; 297 struct tty_driver; 298 299 struct uart_driver { 300 struct module *owner; 301 const char *driver_name; 302 const char *dev_name; 303 int major; 304 int minor; 305 int nr; 306 struct console *cons; 307 308 /* 309 * these are private; the low level driver should not 310 * touch these; they should be initialised to NULL 311 */ 312 struct uart_state *state; 313 struct tty_driver *tty_driver; 314 }; 315 316 void uart_write_wakeup(struct uart_port *port); 317 318 /* 319 * Baud rate helpers. 320 */ 321 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 322 unsigned int baud); 323 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 324 struct ktermios *old, unsigned int min, 325 unsigned int max); 326 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 327 328 /* Base timer interval for polling */ 329 static inline int uart_poll_timeout(struct uart_port *port) 330 { 331 int timeout = port->timeout; 332 333 return timeout > 6 ? (timeout / 2 - 2) : 1; 334 } 335 336 /* 337 * Console helpers. 338 */ 339 struct earlycon_device { 340 struct console *con; 341 struct uart_port port; 342 char options[16]; /* e.g., 115200n8 */ 343 unsigned int baud; 344 }; 345 346 struct earlycon_id { 347 char name[16]; 348 char compatible[128]; 349 int (*setup)(struct earlycon_device *, const char *options); 350 } __aligned(32); 351 352 extern const struct earlycon_id __earlycon_table[]; 353 extern const struct earlycon_id __earlycon_table_end[]; 354 355 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 356 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 357 __used __section(__earlycon_table) \ 358 = { .name = __stringify(_name), \ 359 .compatible = compat, \ 360 .setup = fn } 361 362 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 363 364 extern int setup_earlycon(char *buf); 365 extern int of_setup_earlycon(const struct earlycon_id *match, 366 unsigned long node, 367 const char *options); 368 369 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 370 struct console *c); 371 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr, 372 char **options); 373 void uart_parse_options(char *options, int *baud, int *parity, int *bits, 374 int *flow); 375 int uart_set_options(struct uart_port *port, struct console *co, int baud, 376 int parity, int bits, int flow); 377 struct tty_driver *uart_console_device(struct console *co, int *index); 378 void uart_console_write(struct uart_port *port, const char *s, 379 unsigned int count, 380 void (*putchar)(struct uart_port *, int)); 381 382 /* 383 * Port/driver registration/removal 384 */ 385 int uart_register_driver(struct uart_driver *uart); 386 void uart_unregister_driver(struct uart_driver *uart); 387 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 388 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 389 int uart_match_port(struct uart_port *port1, struct uart_port *port2); 390 391 /* 392 * Power Management 393 */ 394 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 395 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 396 397 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 398 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 399 400 #define uart_circ_chars_pending(circ) \ 401 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 402 403 #define uart_circ_chars_free(circ) \ 404 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 405 406 static inline int uart_tx_stopped(struct uart_port *port) 407 { 408 struct tty_struct *tty = port->state->port.tty; 409 if (tty->stopped || port->hw_stopped) 410 return 1; 411 return 0; 412 } 413 414 static inline bool uart_cts_enabled(struct uart_port *uport) 415 { 416 return !!(uport->status & UPSTAT_CTS_ENABLE); 417 } 418 419 static inline bool uart_softcts_mode(struct uart_port *uport) 420 { 421 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 422 423 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 424 } 425 426 /* 427 * The following are helper functions for the low level drivers. 428 */ 429 430 extern void uart_handle_dcd_change(struct uart_port *uport, 431 unsigned int status); 432 extern void uart_handle_cts_change(struct uart_port *uport, 433 unsigned int status); 434 435 extern void uart_insert_char(struct uart_port *port, unsigned int status, 436 unsigned int overrun, unsigned int ch, unsigned int flag); 437 438 #ifdef SUPPORT_SYSRQ 439 static inline int 440 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 441 { 442 if (port->sysrq) { 443 if (ch && time_before(jiffies, port->sysrq)) { 444 handle_sysrq(ch); 445 port->sysrq = 0; 446 return 1; 447 } 448 port->sysrq = 0; 449 } 450 return 0; 451 } 452 #else 453 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; }) 454 #endif 455 456 /* 457 * We do the SysRQ and SAK checking like this... 458 */ 459 static inline int uart_handle_break(struct uart_port *port) 460 { 461 struct uart_state *state = port->state; 462 463 if (port->handle_break) 464 port->handle_break(port); 465 466 #ifdef SUPPORT_SYSRQ 467 if (port->cons && port->cons->index == port->line) { 468 if (!port->sysrq) { 469 port->sysrq = jiffies + HZ*5; 470 return 1; 471 } 472 port->sysrq = 0; 473 } 474 #endif 475 if (port->flags & UPF_SAK) 476 do_SAK(state->port.tty); 477 return 0; 478 } 479 480 /* 481 * UART_ENABLE_MS - determine if port should enable modem status irqs 482 */ 483 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 484 (cflag) & CRTSCTS || \ 485 !((cflag) & CLOCAL)) 486 487 #endif /* LINUX_SERIAL_CORE_H */ 488