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/lockdep.h> 15 #include <linux/printk.h> 16 #include <linux/spinlock.h> 17 #include <linux/sched.h> 18 #include <linux/tty.h> 19 #include <linux/mutex.h> 20 #include <linux/sysrq.h> 21 #include <uapi/linux/serial_core.h> 22 23 #ifdef CONFIG_SERIAL_CORE_CONSOLE 24 #define uart_console(port) \ 25 ((port)->cons && (port)->cons->index == (port)->line) 26 #else 27 #define uart_console(port) ({ (void)port; 0; }) 28 #endif 29 30 struct uart_port; 31 struct serial_struct; 32 struct serial_port_device; 33 struct device; 34 struct gpio_desc; 35 36 /** 37 * struct uart_ops -- interface between serial_core and the driver 38 * 39 * This structure describes all the operations that can be done on the 40 * physical hardware. 41 * 42 * @tx_empty: ``unsigned int ()(struct uart_port *port)`` 43 * 44 * This function tests whether the transmitter fifo and shifter for the 45 * @port is empty. If it is empty, this function should return 46 * %TIOCSER_TEMT, otherwise return 0. If the port does not support this 47 * operation, then it should return %TIOCSER_TEMT. 48 * 49 * Locking: none. 50 * Interrupts: caller dependent. 51 * This call must not sleep 52 * 53 * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)`` 54 * 55 * This function sets the modem control lines for @port to the state 56 * described by @mctrl. The relevant bits of @mctrl are: 57 * 58 * - %TIOCM_RTS RTS signal. 59 * - %TIOCM_DTR DTR signal. 60 * - %TIOCM_OUT1 OUT1 signal. 61 * - %TIOCM_OUT2 OUT2 signal. 62 * - %TIOCM_LOOP Set the port into loopback mode. 63 * 64 * If the appropriate bit is set, the signal should be driven 65 * active. If the bit is clear, the signal should be driven 66 * inactive. 67 * 68 * Locking: @port->lock taken. 69 * Interrupts: locally disabled. 70 * This call must not sleep 71 * 72 * @get_mctrl: ``unsigned int ()(struct uart_port *port)`` 73 * 74 * Returns the current state of modem control inputs of @port. The state 75 * of the outputs should not be returned, since the core keeps track of 76 * their state. The state information should include: 77 * 78 * - %TIOCM_CAR state of DCD signal 79 * - %TIOCM_CTS state of CTS signal 80 * - %TIOCM_DSR state of DSR signal 81 * - %TIOCM_RI state of RI signal 82 * 83 * The bit is set if the signal is currently driven active. If 84 * the port does not support CTS, DCD or DSR, the driver should 85 * indicate that the signal is permanently active. If RI is 86 * not available, the signal should not be indicated as active. 87 * 88 * Locking: @port->lock taken. 89 * Interrupts: locally disabled. 90 * This call must not sleep 91 * 92 * @stop_tx: ``void ()(struct uart_port *port)`` 93 * 94 * Stop transmitting characters. This might be due to the CTS line 95 * becoming inactive or the tty layer indicating we want to stop 96 * transmission due to an %XOFF character. 97 * 98 * The driver should stop transmitting characters as soon as possible. 99 * 100 * Locking: @port->lock taken. 101 * Interrupts: locally disabled. 102 * This call must not sleep 103 * 104 * @start_tx: ``void ()(struct uart_port *port)`` 105 * 106 * Start transmitting characters. 107 * 108 * Locking: @port->lock taken. 109 * Interrupts: locally disabled. 110 * This call must not sleep 111 * 112 * @throttle: ``void ()(struct uart_port *port)`` 113 * 114 * Notify the serial driver that input buffers for the line discipline are 115 * close to full, and it should somehow signal that no more characters 116 * should be sent to the serial port. 117 * This will be called only if hardware assisted flow control is enabled. 118 * 119 * Locking: serialized with @unthrottle() and termios modification by the 120 * tty layer. 121 * 122 * @unthrottle: ``void ()(struct uart_port *port)`` 123 * 124 * Notify the serial driver that characters can now be sent to the serial 125 * port without fear of overrunning the input buffers of the line 126 * disciplines. 127 * 128 * This will be called only if hardware assisted flow control is enabled. 129 * 130 * Locking: serialized with @throttle() and termios modification by the 131 * tty layer. 132 * 133 * @send_xchar: ``void ()(struct uart_port *port, char ch)`` 134 * 135 * Transmit a high priority character, even if the port is stopped. This 136 * is used to implement XON/XOFF flow control and tcflow(). If the serial 137 * driver does not implement this function, the tty core will append the 138 * character to the circular buffer and then call start_tx() / stop_tx() 139 * to flush the data out. 140 * 141 * Do not transmit if @ch == '\0' (%__DISABLED_CHAR). 142 * 143 * Locking: none. 144 * Interrupts: caller dependent. 145 * 146 * @start_rx: ``void ()(struct uart_port *port)`` 147 * 148 * Start receiving characters. 149 * 150 * Locking: @port->lock taken. 151 * Interrupts: locally disabled. 152 * This call must not sleep 153 * 154 * @stop_rx: ``void ()(struct uart_port *port)`` 155 * 156 * Stop receiving characters; the @port is in the process of being closed. 157 * 158 * Locking: @port->lock taken. 159 * Interrupts: locally disabled. 160 * This call must not sleep 161 * 162 * @enable_ms: ``void ()(struct uart_port *port)`` 163 * 164 * Enable the modem status interrupts. 165 * 166 * This method may be called multiple times. Modem status interrupts 167 * should be disabled when the @shutdown() method is called. 168 * 169 * Locking: @port->lock taken. 170 * Interrupts: locally disabled. 171 * This call must not sleep 172 * 173 * @break_ctl: ``void ()(struct uart_port *port, int ctl)`` 174 * 175 * Control the transmission of a break signal. If @ctl is nonzero, the 176 * break signal should be transmitted. The signal should be terminated 177 * when another call is made with a zero @ctl. 178 * 179 * Locking: caller holds tty_port->mutex 180 * 181 * @startup: ``int ()(struct uart_port *port)`` 182 * 183 * Grab any interrupt resources and initialise any low level driver state. 184 * Enable the port for reception. It should not activate RTS nor DTR; 185 * this will be done via a separate call to @set_mctrl(). 186 * 187 * This method will only be called when the port is initially opened. 188 * 189 * Locking: port_sem taken. 190 * Interrupts: globally disabled. 191 * 192 * @shutdown: ``void ()(struct uart_port *port)`` 193 * 194 * Disable the @port, disable any break condition that may be in effect, 195 * and free any interrupt resources. It should not disable RTS nor DTR; 196 * this will have already been done via a separate call to @set_mctrl(). 197 * 198 * Drivers must not access @port->state once this call has completed. 199 * 200 * This method will only be called when there are no more users of this 201 * @port. 202 * 203 * Locking: port_sem taken. 204 * Interrupts: caller dependent. 205 * 206 * @flush_buffer: ``void ()(struct uart_port *port)`` 207 * 208 * Flush any write buffers, reset any DMA state and stop any ongoing DMA 209 * transfers. 210 * 211 * This will be called whenever the @port->state->xmit circular buffer is 212 * cleared. 213 * 214 * Locking: @port->lock taken. 215 * Interrupts: locally disabled. 216 * This call must not sleep 217 * 218 * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new, 219 * struct ktermios *old)`` 220 * 221 * Change the @port parameters, including word length, parity, stop bits. 222 * Update @port->read_status_mask and @port->ignore_status_mask to 223 * indicate the types of events we are interested in receiving. Relevant 224 * ktermios::c_cflag bits are: 225 * 226 * - %CSIZE - word size 227 * - %CSTOPB - 2 stop bits 228 * - %PARENB - parity enable 229 * - %PARODD - odd parity (when %PARENB is in force) 230 * - %ADDRB - address bit (changed through uart_port::rs485_config()). 231 * - %CREAD - enable reception of characters (if not set, still receive 232 * characters from the port, but throw them away). 233 * - %CRTSCTS - if set, enable CTS status change reporting. 234 * - %CLOCAL - if not set, enable modem status change reporting. 235 * 236 * Relevant ktermios::c_iflag bits are: 237 * 238 * - %INPCK - enable frame and parity error events to be passed to the TTY 239 * layer. 240 * - %BRKINT / %PARMRK - both of these enable break events to be passed to 241 * the TTY layer. 242 * - %IGNPAR - ignore parity and framing errors. 243 * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun 244 * errors as well. 245 * 246 * The interaction of the ktermios::c_iflag bits is as follows (parity 247 * error given as an example): 248 * 249 * ============ ======= ======= ========================================= 250 * Parity error INPCK IGNPAR 251 * ============ ======= ======= ========================================= 252 * n/a 0 n/a character received, marked as %TTY_NORMAL 253 * None 1 n/a character received, marked as %TTY_NORMAL 254 * Yes 1 0 character received, marked as %TTY_PARITY 255 * Yes 1 1 character discarded 256 * ============ ======= ======= ========================================= 257 * 258 * Other flags may be used (eg, xon/xoff characters) if your hardware 259 * supports hardware "soft" flow control. 260 * 261 * Locking: caller holds tty_port->mutex 262 * Interrupts: caller dependent. 263 * This call must not sleep 264 * 265 * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)`` 266 * 267 * Notifier for discipline change. See 268 * Documentation/driver-api/tty/tty_ldisc.rst. 269 * 270 * Locking: caller holds tty_port->mutex 271 * 272 * @pm: ``void ()(struct uart_port *port, unsigned int state, 273 * unsigned int oldstate)`` 274 * 275 * Perform any power management related activities on the specified @port. 276 * @state indicates the new state (defined by enum uart_pm_state), 277 * @oldstate indicates the previous state. 278 * 279 * This function should not be used to grab any resources. 280 * 281 * This will be called when the @port is initially opened and finally 282 * closed, except when the @port is also the system console. This will 283 * occur even if %CONFIG_PM is not set. 284 * 285 * Locking: none. 286 * Interrupts: caller dependent. 287 * 288 * @type: ``const char *()(struct uart_port *port)`` 289 * 290 * Return a pointer to a string constant describing the specified @port, 291 * or return %NULL, in which case the string 'unknown' is substituted. 292 * 293 * Locking: none. 294 * Interrupts: caller dependent. 295 * 296 * @release_port: ``void ()(struct uart_port *port)`` 297 * 298 * Release any memory and IO region resources currently in use by the 299 * @port. 300 * 301 * Locking: none. 302 * Interrupts: caller dependent. 303 * 304 * @request_port: ``int ()(struct uart_port *port)`` 305 * 306 * Request any memory and IO region resources required by the port. If any 307 * fail, no resources should be registered when this function returns, and 308 * it should return -%EBUSY on failure. 309 * 310 * Locking: none. 311 * Interrupts: caller dependent. 312 * 313 * @config_port: ``void ()(struct uart_port *port, int type)`` 314 * 315 * Perform any autoconfiguration steps required for the @port. @type 316 * contains a bit mask of the required configuration. %UART_CONFIG_TYPE 317 * indicates that the port requires detection and identification. 318 * @port->type should be set to the type found, or %PORT_UNKNOWN if no 319 * port was detected. 320 * 321 * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal, 322 * which should be probed using standard kernel autoprobing techniques. 323 * This is not necessary on platforms where ports have interrupts 324 * internally hard wired (eg, system on a chip implementations). 325 * 326 * Locking: none. 327 * Interrupts: caller dependent. 328 * 329 * @verify_port: ``int ()(struct uart_port *port, 330 * struct serial_struct *serinfo)`` 331 * 332 * Verify the new serial port information contained within @serinfo is 333 * suitable for this port type. 334 * 335 * Locking: none. 336 * Interrupts: caller dependent. 337 * 338 * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd, 339 * unsigned long arg)`` 340 * 341 * Perform any port specific IOCTLs. IOCTL commands must be defined using 342 * the standard numbering system found in <asm/ioctl.h>. 343 * 344 * Locking: none. 345 * Interrupts: caller dependent. 346 * 347 * @poll_init: ``int ()(struct uart_port *port)`` 348 * 349 * Called by kgdb to perform the minimal hardware initialization needed to 350 * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this 351 * should not request interrupts. 352 * 353 * Locking: %tty_mutex and tty_port->mutex taken. 354 * Interrupts: n/a. 355 * 356 * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)`` 357 * 358 * Called by kgdb to write a single character @ch directly to the serial 359 * @port. It can and should block until there is space in the TX FIFO. 360 * 361 * Locking: none. 362 * Interrupts: caller dependent. 363 * This call must not sleep 364 * 365 * @poll_get_char: ``int ()(struct uart_port *port)`` 366 * 367 * Called by kgdb to read a single character directly from the serial 368 * port. If data is available, it should be returned; otherwise the 369 * function should return %NO_POLL_CHAR immediately. 370 * 371 * Locking: none. 372 * Interrupts: caller dependent. 373 * This call must not sleep 374 */ 375 struct uart_ops { 376 unsigned int (*tx_empty)(struct uart_port *); 377 void (*set_mctrl)(struct uart_port *, unsigned int mctrl); 378 unsigned int (*get_mctrl)(struct uart_port *); 379 void (*stop_tx)(struct uart_port *); 380 void (*start_tx)(struct uart_port *); 381 void (*throttle)(struct uart_port *); 382 void (*unthrottle)(struct uart_port *); 383 void (*send_xchar)(struct uart_port *, char ch); 384 void (*stop_rx)(struct uart_port *); 385 void (*start_rx)(struct uart_port *); 386 void (*enable_ms)(struct uart_port *); 387 void (*break_ctl)(struct uart_port *, int ctl); 388 int (*startup)(struct uart_port *); 389 void (*shutdown)(struct uart_port *); 390 void (*flush_buffer)(struct uart_port *); 391 void (*set_termios)(struct uart_port *, struct ktermios *new, 392 const struct ktermios *old); 393 void (*set_ldisc)(struct uart_port *, struct ktermios *); 394 void (*pm)(struct uart_port *, unsigned int state, 395 unsigned int oldstate); 396 const char *(*type)(struct uart_port *); 397 void (*release_port)(struct uart_port *); 398 int (*request_port)(struct uart_port *); 399 void (*config_port)(struct uart_port *, int); 400 int (*verify_port)(struct uart_port *, struct serial_struct *); 401 int (*ioctl)(struct uart_port *, unsigned int, unsigned long); 402 #ifdef CONFIG_CONSOLE_POLL 403 int (*poll_init)(struct uart_port *); 404 void (*poll_put_char)(struct uart_port *, unsigned char); 405 int (*poll_get_char)(struct uart_port *); 406 #endif 407 }; 408 409 #define NO_POLL_CHAR 0x00ff0000 410 #define UART_CONFIG_TYPE (1 << 0) 411 #define UART_CONFIG_IRQ (1 << 1) 412 413 struct uart_icount { 414 __u32 cts; 415 __u32 dsr; 416 __u32 rng; 417 __u32 dcd; 418 __u32 rx; 419 __u32 tx; 420 __u32 frame; 421 __u32 overrun; 422 __u32 parity; 423 __u32 brk; 424 __u32 buf_overrun; 425 }; 426 427 typedef u64 __bitwise upf_t; 428 typedef unsigned int __bitwise upstat_t; 429 430 struct uart_port { 431 spinlock_t lock; /* port lock */ 432 unsigned long iobase; /* in/out[bwl] */ 433 unsigned char __iomem *membase; /* read/write[bwl] */ 434 unsigned int (*serial_in)(struct uart_port *, int); 435 void (*serial_out)(struct uart_port *, int, int); 436 void (*set_termios)(struct uart_port *, 437 struct ktermios *new, 438 const struct ktermios *old); 439 void (*set_ldisc)(struct uart_port *, 440 struct ktermios *); 441 unsigned int (*get_mctrl)(struct uart_port *); 442 void (*set_mctrl)(struct uart_port *, unsigned int); 443 unsigned int (*get_divisor)(struct uart_port *, 444 unsigned int baud, 445 unsigned int *frac); 446 void (*set_divisor)(struct uart_port *, 447 unsigned int baud, 448 unsigned int quot, 449 unsigned int quot_frac); 450 int (*startup)(struct uart_port *port); 451 void (*shutdown)(struct uart_port *port); 452 void (*throttle)(struct uart_port *port); 453 void (*unthrottle)(struct uart_port *port); 454 int (*handle_irq)(struct uart_port *); 455 void (*pm)(struct uart_port *, unsigned int state, 456 unsigned int old); 457 void (*handle_break)(struct uart_port *); 458 int (*rs485_config)(struct uart_port *, 459 struct ktermios *termios, 460 struct serial_rs485 *rs485); 461 int (*iso7816_config)(struct uart_port *, 462 struct serial_iso7816 *iso7816); 463 unsigned int ctrl_id; /* optional serial core controller id */ 464 unsigned int port_id; /* optional serial core port id */ 465 unsigned int irq; /* irq number */ 466 unsigned long irqflags; /* irq flags */ 467 unsigned int uartclk; /* base uart clock */ 468 unsigned int fifosize; /* tx fifo size */ 469 unsigned char x_char; /* xon/xoff char */ 470 unsigned char regshift; /* reg offset shift */ 471 472 unsigned char iotype; /* io access style */ 473 474 #define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */ 475 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 476 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 477 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 478 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 479 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 480 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 481 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 482 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 483 484 unsigned char quirks; /* internal quirks */ 485 486 /* internal quirks must be updated while holding port mutex */ 487 #define UPQ_NO_TXEN_TEST BIT(0) 488 489 unsigned int read_status_mask; /* driver specific */ 490 unsigned int ignore_status_mask; /* driver specific */ 491 struct uart_state *state; /* pointer to parent state */ 492 struct uart_icount icount; /* statistics */ 493 494 struct console *cons; /* struct console, if any */ 495 /* flags must be updated while holding port mutex */ 496 upf_t flags; 497 498 /* 499 * These flags must be equivalent to the flags defined in 500 * include/uapi/linux/tty_flags.h which are the userspace definitions 501 * assigned from the serial_struct flags in uart_set_info() 502 * [for bit definitions in the UPF_CHANGE_MASK] 503 * 504 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable 505 * The remaining bits are serial-core specific and not modifiable by 506 * userspace. 507 */ 508 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 509 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 510 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 511 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 512 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 513 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 514 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 515 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 516 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 517 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 518 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 519 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 520 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 521 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 522 523 #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19)) 524 /* Port has hardware-assisted h/w flow control */ 525 #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20)) 526 #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21)) 527 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 528 /* Port has hardware-assisted s/w flow control */ 529 #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) 530 #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) 531 #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) 532 #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) 533 #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26)) 534 /* The exact UART type is known and should not be probed. */ 535 #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) 536 #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) 537 #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) 538 #define UPF_DEAD ((__force upf_t) BIT_ULL(30)) 539 #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) 540 #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) 541 542 #define __UPF_CHANGE_MASK 0x17fff 543 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 544 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 545 546 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 547 #error Change mask not equivalent to userspace-visible bit defines 548 #endif 549 550 /* 551 * Must hold termios_rwsem, port mutex and port lock to change; 552 * can hold any one lock to read. 553 */ 554 upstat_t status; 555 556 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 557 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 558 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 559 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 560 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 561 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 562 563 bool hw_stopped; /* sw-assisted CTS flow state */ 564 unsigned int mctrl; /* current modem ctrl settings */ 565 unsigned int frame_time; /* frame timing in ns */ 566 unsigned int type; /* port type */ 567 const struct uart_ops *ops; 568 unsigned int custom_divisor; 569 unsigned int line; /* port index */ 570 unsigned int minor; 571 resource_size_t mapbase; /* for ioremap */ 572 resource_size_t mapsize; 573 struct device *dev; /* serial port physical parent device */ 574 struct serial_port_device *port_dev; /* serial core port device */ 575 576 unsigned long sysrq; /* sysrq timeout */ 577 u8 sysrq_ch; /* char for sysrq */ 578 unsigned char has_sysrq; 579 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ 580 581 unsigned char hub6; /* this should be in the 8250 driver */ 582 unsigned char suspended; 583 unsigned char console_reinit; 584 const char *name; /* port name */ 585 struct attribute_group *attr_group; /* port specific attributes */ 586 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 587 struct serial_rs485 rs485; 588 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ 589 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ 590 struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */ 591 struct serial_iso7816 iso7816; 592 void *private_data; /* generic platform data pointer */ 593 }; 594 595 /* 596 * Only for console->device_lock()/_unlock() callbacks and internal 597 * port lock wrapper synchronization. 598 */ __uart_port_lock_irqsave(struct uart_port * up,unsigned long * flags)599 static inline void __uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) 600 { 601 spin_lock_irqsave(&up->lock, *flags); 602 } 603 604 /* 605 * Only for console->device_lock()/_unlock() callbacks and internal 606 * port lock wrapper synchronization. 607 */ __uart_port_unlock_irqrestore(struct uart_port * up,unsigned long flags)608 static inline void __uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) 609 { 610 spin_unlock_irqrestore(&up->lock, flags); 611 } 612 613 /** 614 * uart_port_set_cons - Safely set the @cons field for a uart 615 * @up: The uart port to set 616 * @con: The new console to set to 617 * 618 * This function must be used to set @up->cons. It uses the port lock to 619 * synchronize with the port lock wrappers in order to ensure that the console 620 * cannot change or disappear while another context is holding the port lock. 621 */ uart_port_set_cons(struct uart_port * up,struct console * con)622 static inline void uart_port_set_cons(struct uart_port *up, struct console *con) 623 { 624 unsigned long flags; 625 626 __uart_port_lock_irqsave(up, &flags); 627 up->cons = con; 628 __uart_port_unlock_irqrestore(up, flags); 629 } 630 631 /* Only for internal port lock wrapper usage. */ __uart_port_using_nbcon(struct uart_port * up)632 static inline bool __uart_port_using_nbcon(struct uart_port *up) 633 { 634 lockdep_assert_held_once(&up->lock); 635 636 if (likely(!uart_console(up))) 637 return false; 638 639 /* 640 * @up->cons is only modified under the port lock. Therefore it is 641 * certain that it cannot disappear here. 642 * 643 * @up->cons->node is added/removed from the console list under the 644 * port lock. Therefore it is certain that the registration status 645 * cannot change here, thus @up->cons->flags can be read directly. 646 */ 647 if (hlist_unhashed_lockless(&up->cons->node) || 648 !(up->cons->flags & CON_NBCON) || 649 !up->cons->write_atomic) { 650 return false; 651 } 652 653 return true; 654 } 655 656 /* Only for internal port lock wrapper usage. */ __uart_port_nbcon_try_acquire(struct uart_port * up)657 static inline bool __uart_port_nbcon_try_acquire(struct uart_port *up) 658 { 659 if (!__uart_port_using_nbcon(up)) 660 return true; 661 662 return nbcon_device_try_acquire(up->cons); 663 } 664 665 /* Only for internal port lock wrapper usage. */ __uart_port_nbcon_acquire(struct uart_port * up)666 static inline void __uart_port_nbcon_acquire(struct uart_port *up) 667 { 668 if (!__uart_port_using_nbcon(up)) 669 return; 670 671 while (!nbcon_device_try_acquire(up->cons)) 672 cpu_relax(); 673 } 674 675 /* Only for internal port lock wrapper usage. */ __uart_port_nbcon_release(struct uart_port * up)676 static inline void __uart_port_nbcon_release(struct uart_port *up) 677 { 678 if (!__uart_port_using_nbcon(up)) 679 return; 680 681 nbcon_device_release(up->cons); 682 } 683 684 /** 685 * uart_port_lock - Lock the UART port 686 * @up: Pointer to UART port structure 687 */ uart_port_lock(struct uart_port * up)688 static inline void uart_port_lock(struct uart_port *up) 689 { 690 spin_lock(&up->lock); 691 __uart_port_nbcon_acquire(up); 692 } 693 694 /** 695 * uart_port_lock_irq - Lock the UART port and disable interrupts 696 * @up: Pointer to UART port structure 697 */ uart_port_lock_irq(struct uart_port * up)698 static inline void uart_port_lock_irq(struct uart_port *up) 699 { 700 spin_lock_irq(&up->lock); 701 __uart_port_nbcon_acquire(up); 702 } 703 704 /** 705 * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts 706 * @up: Pointer to UART port structure 707 * @flags: Pointer to interrupt flags storage 708 */ uart_port_lock_irqsave(struct uart_port * up,unsigned long * flags)709 static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) 710 { 711 spin_lock_irqsave(&up->lock, *flags); 712 __uart_port_nbcon_acquire(up); 713 } 714 715 /** 716 * uart_port_trylock - Try to lock the UART port 717 * @up: Pointer to UART port structure 718 * 719 * Returns: True if lock was acquired, false otherwise 720 */ uart_port_trylock(struct uart_port * up)721 static inline bool uart_port_trylock(struct uart_port *up) 722 { 723 if (!spin_trylock(&up->lock)) 724 return false; 725 726 if (!__uart_port_nbcon_try_acquire(up)) { 727 spin_unlock(&up->lock); 728 return false; 729 } 730 731 return true; 732 } 733 734 /** 735 * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts 736 * @up: Pointer to UART port structure 737 * @flags: Pointer to interrupt flags storage 738 * 739 * Returns: True if lock was acquired, false otherwise 740 */ uart_port_trylock_irqsave(struct uart_port * up,unsigned long * flags)741 static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags) 742 { 743 if (!spin_trylock_irqsave(&up->lock, *flags)) 744 return false; 745 746 if (!__uart_port_nbcon_try_acquire(up)) { 747 spin_unlock_irqrestore(&up->lock, *flags); 748 return false; 749 } 750 751 return true; 752 } 753 754 /** 755 * uart_port_unlock - Unlock the UART port 756 * @up: Pointer to UART port structure 757 */ uart_port_unlock(struct uart_port * up)758 static inline void uart_port_unlock(struct uart_port *up) 759 { 760 __uart_port_nbcon_release(up); 761 spin_unlock(&up->lock); 762 } 763 764 /** 765 * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts 766 * @up: Pointer to UART port structure 767 */ uart_port_unlock_irq(struct uart_port * up)768 static inline void uart_port_unlock_irq(struct uart_port *up) 769 { 770 __uart_port_nbcon_release(up); 771 spin_unlock_irq(&up->lock); 772 } 773 774 /** 775 * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts 776 * @up: Pointer to UART port structure 777 * @flags: The saved interrupt flags for restore 778 */ uart_port_unlock_irqrestore(struct uart_port * up,unsigned long flags)779 static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) 780 { 781 __uart_port_nbcon_release(up); 782 spin_unlock_irqrestore(&up->lock, flags); 783 } 784 serial_port_in(struct uart_port * up,int offset)785 static inline int serial_port_in(struct uart_port *up, int offset) 786 { 787 return up->serial_in(up, offset); 788 } 789 serial_port_out(struct uart_port * up,int offset,int value)790 static inline void serial_port_out(struct uart_port *up, int offset, int value) 791 { 792 up->serial_out(up, offset, value); 793 } 794 795 /** 796 * enum uart_pm_state - power states for UARTs 797 * @UART_PM_STATE_ON: UART is powered, up and operational 798 * @UART_PM_STATE_OFF: UART is powered off 799 * @UART_PM_STATE_UNDEFINED: sentinel 800 */ 801 enum uart_pm_state { 802 UART_PM_STATE_ON = 0, 803 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 804 UART_PM_STATE_UNDEFINED, 805 }; 806 807 /* 808 * This is the state information which is persistent across opens. 809 */ 810 struct uart_state { 811 struct tty_port port; 812 813 enum uart_pm_state pm_state; 814 815 atomic_t refcount; 816 wait_queue_head_t remove_wait; 817 struct uart_port *uart_port; 818 }; 819 820 #define UART_XMIT_SIZE PAGE_SIZE 821 822 823 /* number of characters left in xmit buffer before we ask for more */ 824 #define WAKEUP_CHARS 256 825 826 /** 827 * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars 828 * @up: uart_port structure describing the port 829 * @chars: number of characters sent 830 * 831 * This function advances the tail of circular xmit buffer by the number of 832 * @chars transmitted and handles accounting of transmitted bytes (into 833 * @up's icount.tx). 834 */ uart_xmit_advance(struct uart_port * up,unsigned int chars)835 static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) 836 { 837 struct tty_port *tport = &up->state->port; 838 839 kfifo_skip_count(&tport->xmit_fifo, chars); 840 up->icount.tx += chars; 841 } 842 uart_fifo_out(struct uart_port * up,unsigned char * buf,unsigned int chars)843 static inline unsigned int uart_fifo_out(struct uart_port *up, 844 unsigned char *buf, unsigned int chars) 845 { 846 struct tty_port *tport = &up->state->port; 847 848 chars = kfifo_out(&tport->xmit_fifo, buf, chars); 849 up->icount.tx += chars; 850 851 return chars; 852 } 853 uart_fifo_get(struct uart_port * up,unsigned char * ch)854 static inline unsigned int uart_fifo_get(struct uart_port *up, 855 unsigned char *ch) 856 { 857 struct tty_port *tport = &up->state->port; 858 unsigned int chars; 859 860 chars = kfifo_get(&tport->xmit_fifo, ch); 861 up->icount.tx += chars; 862 863 return chars; 864 } 865 866 struct module; 867 struct tty_driver; 868 869 struct uart_driver { 870 struct module *owner; 871 const char *driver_name; 872 const char *dev_name; 873 int major; 874 int minor; 875 int nr; 876 struct console *cons; 877 878 /* 879 * these are private; the low level driver should not 880 * touch these; they should be initialised to NULL 881 */ 882 struct uart_state *state; 883 struct tty_driver *tty_driver; 884 }; 885 886 void uart_write_wakeup(struct uart_port *port); 887 888 /** 889 * enum UART_TX_FLAGS -- flags for uart_port_tx_flags() 890 * 891 * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer 892 */ 893 enum UART_TX_FLAGS { 894 UART_TX_NOSTOP = BIT(0), 895 }; 896 897 #define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \ 898 for_test, for_post) \ 899 ({ \ 900 struct uart_port *__port = (uport); \ 901 struct tty_port *__tport = &__port->state->port; \ 902 unsigned int pending; \ 903 \ 904 for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ 905 if (__port->x_char) { \ 906 (ch) = __port->x_char; \ 907 (put_char); \ 908 __port->x_char = 0; \ 909 continue; \ 910 } \ 911 \ 912 if (uart_tx_stopped(__port)) \ 913 break; \ 914 \ 915 if (!kfifo_get(&__tport->xmit_fifo, &(ch))) \ 916 break; \ 917 \ 918 (put_char); \ 919 } \ 920 \ 921 (tx_done); \ 922 \ 923 pending = kfifo_len(&__tport->xmit_fifo); \ 924 if (pending < WAKEUP_CHARS) { \ 925 uart_write_wakeup(__port); \ 926 \ 927 if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ 928 __port->ops->stop_tx(__port); \ 929 } \ 930 \ 931 pending; \ 932 }) 933 934 /** 935 * uart_port_tx_limited -- transmit helper for uart_port with count limiting 936 * @port: uart port 937 * @ch: variable to store a character to be written to the HW 938 * @count: a limit of characters to send 939 * @tx_ready: can HW accept more data function 940 * @put_char: function to write a character 941 * @tx_done: function to call after the loop is done 942 * 943 * This helper transmits characters from the xmit buffer to the hardware using 944 * @put_char(). It does so until @count characters are sent and while @tx_ready 945 * evaluates to true. 946 * 947 * Returns: the number of characters in the xmit buffer when done. 948 * 949 * The expression in macro parameters shall be designed as follows: 950 * * **tx_ready:** should evaluate to true if the HW can accept more data to 951 * be sent. This parameter can be %true, which means the HW is always ready. 952 * * **put_char:** shall write @ch to the device of @port. 953 * * **tx_done:** when the write loop is done, this can perform arbitrary 954 * action before potential invocation of ops->stop_tx() happens. If the 955 * driver does not need to do anything, use e.g. ({}). 956 * 957 * For all of them, @port->lock is held, interrupts are locally disabled and 958 * the expressions must not sleep. 959 */ 960 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ 961 unsigned int __count = (count); \ 962 __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \ 963 __count--); \ 964 }) 965 966 /** 967 * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags 968 * @port: uart port 969 * @ch: variable to store a character to be written to the HW 970 * @flags: %UART_TX_NOSTOP or similar 971 * @count: a limit of characters to send 972 * @tx_ready: can HW accept more data function 973 * @put_char: function to write a character 974 * @tx_done: function to call after the loop is done 975 * 976 * See uart_port_tx_limited() for more details. 977 */ 978 #define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \ 979 unsigned int __count = (count); \ 980 __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \ 981 __count--); \ 982 }) 983 984 /** 985 * uart_port_tx -- transmit helper for uart_port 986 * @port: uart port 987 * @ch: variable to store a character to be written to the HW 988 * @tx_ready: can HW accept more data function 989 * @put_char: function to write a character 990 * 991 * See uart_port_tx_limited() for more details. 992 */ 993 #define uart_port_tx(port, ch, tx_ready, put_char) \ 994 __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({})) 995 996 997 /** 998 * uart_port_tx_flags -- transmit helper for uart_port with flags 999 * @port: uart port 1000 * @ch: variable to store a character to be written to the HW 1001 * @flags: %UART_TX_NOSTOP or similar 1002 * @tx_ready: can HW accept more data function 1003 * @put_char: function to write a character 1004 * 1005 * See uart_port_tx_limited() for more details. 1006 */ 1007 #define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \ 1008 __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({})) 1009 /* 1010 * Baud rate helpers. 1011 */ 1012 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 1013 unsigned int baud); 1014 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 1015 const struct ktermios *old, unsigned int min, 1016 unsigned int max); 1017 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 1018 1019 /* 1020 * Calculates FIFO drain time. 1021 */ uart_fifo_timeout(struct uart_port * port)1022 static inline unsigned long uart_fifo_timeout(struct uart_port *port) 1023 { 1024 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; 1025 1026 /* Add .02 seconds of slop */ 1027 fifo_timeout += 20 * NSEC_PER_MSEC; 1028 1029 return max(nsecs_to_jiffies(fifo_timeout), 1UL); 1030 } 1031 1032 /* Base timer interval for polling */ uart_poll_timeout(struct uart_port * port)1033 static inline unsigned long uart_poll_timeout(struct uart_port *port) 1034 { 1035 unsigned long timeout = uart_fifo_timeout(port); 1036 1037 return timeout > 6 ? (timeout / 2 - 2) : 1; 1038 } 1039 1040 /* 1041 * Console helpers. 1042 */ 1043 struct earlycon_device { 1044 struct console *con; 1045 struct uart_port port; 1046 char options[32]; /* e.g., 115200n8 */ 1047 unsigned int baud; 1048 }; 1049 1050 struct earlycon_id { 1051 char name[15]; 1052 char name_term; /* In case compiler didn't '\0' term name */ 1053 char compatible[128]; 1054 int (*setup)(struct earlycon_device *, const char *options); 1055 }; 1056 1057 extern const struct earlycon_id __earlycon_table[]; 1058 extern const struct earlycon_id __earlycon_table_end[]; 1059 1060 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 1061 #define EARLYCON_USED_OR_UNUSED __used 1062 #else 1063 #define EARLYCON_USED_OR_UNUSED __maybe_unused 1064 #endif 1065 1066 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 1067 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 1068 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \ 1069 __aligned(__alignof__(struct earlycon_id)) \ 1070 = { .name = __stringify(_name), \ 1071 .compatible = compat, \ 1072 .setup = fn } 1073 1074 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 1075 1076 int of_setup_earlycon(const struct earlycon_id *match, unsigned long node, 1077 const char *options); 1078 1079 #ifdef CONFIG_SERIAL_EARLYCON 1080 extern bool earlycon_acpi_spcr_enable __initdata; 1081 int setup_earlycon(char *buf); 1082 #else 1083 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; setup_earlycon(char * buf)1084 static inline int setup_earlycon(char *buf) { return 0; } 1085 #endif 1086 1087 /* Variant of uart_console_registered() when the console_list_lock is held. */ uart_console_registered_locked(struct uart_port * port)1088 static inline bool uart_console_registered_locked(struct uart_port *port) 1089 { 1090 return uart_console(port) && console_is_registered_locked(port->cons); 1091 } 1092 uart_console_registered(struct uart_port * port)1093 static inline bool uart_console_registered(struct uart_port *port) 1094 { 1095 return uart_console(port) && console_is_registered(port->cons); 1096 } 1097 1098 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 1099 struct console *c); 1100 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 1101 char **options); 1102 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 1103 int *flow); 1104 int uart_set_options(struct uart_port *port, struct console *co, int baud, 1105 int parity, int bits, int flow); 1106 struct tty_driver *uart_console_device(struct console *co, int *index); 1107 void uart_console_write(struct uart_port *port, const char *s, 1108 unsigned int count, 1109 void (*putchar)(struct uart_port *, unsigned char)); 1110 1111 /* 1112 * Port/driver registration/removal 1113 */ 1114 int uart_register_driver(struct uart_driver *uart); 1115 void uart_unregister_driver(struct uart_driver *uart); 1116 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 1117 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 1118 int uart_read_port_properties(struct uart_port *port); 1119 int uart_read_and_validate_port_properties(struct uart_port *port); 1120 bool uart_match_port(const struct uart_port *port1, 1121 const struct uart_port *port2); 1122 1123 /* 1124 * Power Management 1125 */ 1126 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 1127 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 1128 uart_tx_stopped(struct uart_port * port)1129 static inline int uart_tx_stopped(struct uart_port *port) 1130 { 1131 struct tty_struct *tty = port->state->port.tty; 1132 if ((tty && tty->flow.stopped) || port->hw_stopped) 1133 return 1; 1134 return 0; 1135 } 1136 uart_cts_enabled(struct uart_port * uport)1137 static inline bool uart_cts_enabled(struct uart_port *uport) 1138 { 1139 return !!(uport->status & UPSTAT_CTS_ENABLE); 1140 } 1141 uart_softcts_mode(struct uart_port * uport)1142 static inline bool uart_softcts_mode(struct uart_port *uport) 1143 { 1144 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 1145 1146 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 1147 } 1148 1149 /* 1150 * The following are helper functions for the low level drivers. 1151 */ 1152 1153 void uart_handle_dcd_change(struct uart_port *uport, bool active); 1154 void uart_handle_cts_change(struct uart_port *uport, bool active); 1155 1156 void uart_insert_char(struct uart_port *port, unsigned int status, 1157 unsigned int overrun, u8 ch, u8 flag); 1158 1159 void uart_xchar_out(struct uart_port *uport, int offset); 1160 1161 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 1162 #define SYSRQ_TIMEOUT (HZ * 5) 1163 1164 bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch); 1165 uart_handle_sysrq_char(struct uart_port * port,u8 ch)1166 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 1167 { 1168 if (!port->sysrq) 1169 return 0; 1170 1171 if (ch && time_before(jiffies, port->sysrq)) { 1172 if (sysrq_mask()) { 1173 handle_sysrq(ch); 1174 port->sysrq = 0; 1175 return 1; 1176 } 1177 if (uart_try_toggle_sysrq(port, ch)) 1178 return 1; 1179 } 1180 port->sysrq = 0; 1181 1182 return 0; 1183 } 1184 uart_prepare_sysrq_char(struct uart_port * port,u8 ch)1185 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 1186 { 1187 if (!port->sysrq) 1188 return 0; 1189 1190 if (ch && time_before(jiffies, port->sysrq)) { 1191 if (sysrq_mask()) { 1192 port->sysrq_ch = ch; 1193 port->sysrq = 0; 1194 return 1; 1195 } 1196 if (uart_try_toggle_sysrq(port, ch)) 1197 return 1; 1198 } 1199 port->sysrq = 0; 1200 1201 return 0; 1202 } 1203 uart_unlock_and_check_sysrq(struct uart_port * port)1204 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 1205 { 1206 u8 sysrq_ch; 1207 1208 if (!port->has_sysrq) { 1209 uart_port_unlock(port); 1210 return; 1211 } 1212 1213 sysrq_ch = port->sysrq_ch; 1214 port->sysrq_ch = 0; 1215 1216 uart_port_unlock(port); 1217 1218 if (sysrq_ch) 1219 handle_sysrq(sysrq_ch); 1220 } 1221 uart_unlock_and_check_sysrq_irqrestore(struct uart_port * port,unsigned long flags)1222 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 1223 unsigned long flags) 1224 { 1225 u8 sysrq_ch; 1226 1227 if (!port->has_sysrq) { 1228 uart_port_unlock_irqrestore(port, flags); 1229 return; 1230 } 1231 1232 sysrq_ch = port->sysrq_ch; 1233 port->sysrq_ch = 0; 1234 1235 uart_port_unlock_irqrestore(port, flags); 1236 1237 if (sysrq_ch) 1238 handle_sysrq(sysrq_ch); 1239 } 1240 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ uart_handle_sysrq_char(struct uart_port * port,u8 ch)1241 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 1242 { 1243 return 0; 1244 } uart_prepare_sysrq_char(struct uart_port * port,u8 ch)1245 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 1246 { 1247 return 0; 1248 } uart_unlock_and_check_sysrq(struct uart_port * port)1249 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 1250 { 1251 uart_port_unlock(port); 1252 } uart_unlock_and_check_sysrq_irqrestore(struct uart_port * port,unsigned long flags)1253 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 1254 unsigned long flags) 1255 { 1256 uart_port_unlock_irqrestore(port, flags); 1257 } 1258 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ 1259 1260 /* 1261 * We do the SysRQ and SAK checking like this... 1262 */ uart_handle_break(struct uart_port * port)1263 static inline int uart_handle_break(struct uart_port *port) 1264 { 1265 struct uart_state *state = port->state; 1266 1267 if (port->handle_break) 1268 port->handle_break(port); 1269 1270 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 1271 if (port->has_sysrq && uart_console(port)) { 1272 if (!port->sysrq) { 1273 port->sysrq = jiffies + SYSRQ_TIMEOUT; 1274 return 1; 1275 } 1276 port->sysrq = 0; 1277 } 1278 #endif 1279 if (port->flags & UPF_SAK) 1280 do_SAK(state->port.tty); 1281 return 0; 1282 } 1283 1284 /* 1285 * UART_ENABLE_MS - determine if port should enable modem status irqs 1286 */ 1287 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 1288 (cflag) & CRTSCTS || \ 1289 !((cflag) & CLOCAL)) 1290 1291 int uart_get_rs485_mode(struct uart_port *port); 1292 #endif /* LINUX_SERIAL_CORE_H */ 1293