1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * linux/drivers/char/serial_core.h 4 * 5 * Copyright (C) 2000 Deep Blue Solutions Ltd. 6 */ 7 #ifndef LINUX_SERIAL_CORE_H 8 #define LINUX_SERIAL_CORE_H 9 10 #include <linux/bitops.h> 11 #include <linux/compiler.h> 12 #include <linux/console.h> 13 #include <linux/interrupt.h> 14 #include <linux/circ_buf.h> 15 #include <linux/spinlock.h> 16 #include <linux/sched.h> 17 #include <linux/tty.h> 18 #include <linux/mutex.h> 19 #include <linux/sysrq.h> 20 #include <uapi/linux/serial_core.h> 21 22 #ifdef CONFIG_SERIAL_CORE_CONSOLE 23 #define uart_console(port) \ 24 ((port)->cons && (port)->cons->index == (port)->line) 25 #else 26 #define uart_console(port) ({ (void)port; 0; }) 27 #endif 28 29 struct uart_port; 30 struct serial_struct; 31 struct device; 32 struct gpio_desc; 33 34 /** 35 * struct uart_ops -- interface between serial_core and the driver 36 * 37 * This structure describes all the operations that can be done on the 38 * physical hardware. 39 * 40 * @tx_empty: ``unsigned int ()(struct uart_port *port)`` 41 * 42 * This function tests whether the transmitter fifo and shifter for the 43 * @port is empty. If it is empty, this function should return 44 * %TIOCSER_TEMT, otherwise return 0. If the port does not support this 45 * operation, then it should return %TIOCSER_TEMT. 46 * 47 * Locking: none. 48 * Interrupts: caller dependent. 49 * This call must not sleep 50 * 51 * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)`` 52 * 53 * This function sets the modem control lines for @port to the state 54 * described by @mctrl. The relevant bits of @mctrl are: 55 * 56 * - %TIOCM_RTS RTS signal. 57 * - %TIOCM_DTR DTR signal. 58 * - %TIOCM_OUT1 OUT1 signal. 59 * - %TIOCM_OUT2 OUT2 signal. 60 * - %TIOCM_LOOP Set the port into loopback mode. 61 * 62 * If the appropriate bit is set, the signal should be driven 63 * active. If the bit is clear, the signal should be driven 64 * inactive. 65 * 66 * Locking: @port->lock taken. 67 * Interrupts: locally disabled. 68 * This call must not sleep 69 * 70 * @get_mctrl: ``unsigned int ()(struct uart_port *port)`` 71 * 72 * Returns the current state of modem control inputs of @port. The state 73 * of the outputs should not be returned, since the core keeps track of 74 * their state. The state information should include: 75 * 76 * - %TIOCM_CAR state of DCD signal 77 * - %TIOCM_CTS state of CTS signal 78 * - %TIOCM_DSR state of DSR signal 79 * - %TIOCM_RI state of RI signal 80 * 81 * The bit is set if the signal is currently driven active. If 82 * the port does not support CTS, DCD or DSR, the driver should 83 * indicate that the signal is permanently active. If RI is 84 * not available, the signal should not be indicated as active. 85 * 86 * Locking: @port->lock taken. 87 * Interrupts: locally disabled. 88 * This call must not sleep 89 * 90 * @stop_tx: ``void ()(struct uart_port *port)`` 91 * 92 * Stop transmitting characters. This might be due to the CTS line 93 * becoming inactive or the tty layer indicating we want to stop 94 * transmission due to an %XOFF character. 95 * 96 * The driver should stop transmitting characters as soon as possible. 97 * 98 * Locking: @port->lock taken. 99 * Interrupts: locally disabled. 100 * This call must not sleep 101 * 102 * @start_tx: ``void ()(struct uart_port *port)`` 103 * 104 * Start transmitting characters. 105 * 106 * Locking: @port->lock taken. 107 * Interrupts: locally disabled. 108 * This call must not sleep 109 * 110 * @throttle: ``void ()(struct uart_port *port)`` 111 * 112 * Notify the serial driver that input buffers for the line discipline are 113 * close to full, and it should somehow signal that no more characters 114 * should be sent to the serial port. 115 * This will be called only if hardware assisted flow control is enabled. 116 * 117 * Locking: serialized with @unthrottle() and termios modification by the 118 * tty layer. 119 * 120 * @unthrottle: ``void ()(struct uart_port *port)`` 121 * 122 * Notify the serial driver that characters can now be sent to the serial 123 * port without fear of overrunning the input buffers of the line 124 * disciplines. 125 * 126 * This will be called only if hardware assisted flow control is enabled. 127 * 128 * Locking: serialized with @throttle() and termios modification by the 129 * tty layer. 130 * 131 * @send_xchar: ``void ()(struct uart_port *port, char ch)`` 132 * 133 * Transmit a high priority character, even if the port is stopped. This 134 * is used to implement XON/XOFF flow control and tcflow(). If the serial 135 * driver does not implement this function, the tty core will append the 136 * character to the circular buffer and then call start_tx() / stop_tx() 137 * to flush the data out. 138 * 139 * Do not transmit if @ch == '\0' (%__DISABLED_CHAR). 140 * 141 * Locking: none. 142 * Interrupts: caller dependent. 143 * 144 * @start_rx: ``void ()(struct uart_port *port)`` 145 * 146 * Start receiving characters. 147 * 148 * Locking: @port->lock taken. 149 * Interrupts: locally disabled. 150 * This call must not sleep 151 * 152 * @stop_rx: ``void ()(struct uart_port *port)`` 153 * 154 * Stop receiving characters; the @port is in the process of being closed. 155 * 156 * Locking: @port->lock taken. 157 * Interrupts: locally disabled. 158 * This call must not sleep 159 * 160 * @enable_ms: ``void ()(struct uart_port *port)`` 161 * 162 * Enable the modem status interrupts. 163 * 164 * This method may be called multiple times. Modem status interrupts 165 * should be disabled when the @shutdown() method is called. 166 * 167 * Locking: @port->lock taken. 168 * Interrupts: locally disabled. 169 * This call must not sleep 170 * 171 * @break_ctl: ``void ()(struct uart_port *port, int ctl)`` 172 * 173 * Control the transmission of a break signal. If @ctl is nonzero, the 174 * break signal should be transmitted. The signal should be terminated 175 * when another call is made with a zero @ctl. 176 * 177 * Locking: caller holds tty_port->mutex 178 * 179 * @startup: ``int ()(struct uart_port *port)`` 180 * 181 * Grab any interrupt resources and initialise any low level driver state. 182 * Enable the port for reception. It should not activate RTS nor DTR; 183 * this will be done via a separate call to @set_mctrl(). 184 * 185 * This method will only be called when the port is initially opened. 186 * 187 * Locking: port_sem taken. 188 * Interrupts: globally disabled. 189 * 190 * @shutdown: ``void ()(struct uart_port *port)`` 191 * 192 * Disable the @port, disable any break condition that may be in effect, 193 * and free any interrupt resources. It should not disable RTS nor DTR; 194 * this will have already been done via a separate call to @set_mctrl(). 195 * 196 * Drivers must not access @port->state once this call has completed. 197 * 198 * This method will only be called when there are no more users of this 199 * @port. 200 * 201 * Locking: port_sem taken. 202 * Interrupts: caller dependent. 203 * 204 * @flush_buffer: ``void ()(struct uart_port *port)`` 205 * 206 * Flush any write buffers, reset any DMA state and stop any ongoing DMA 207 * transfers. 208 * 209 * This will be called whenever the @port->state->xmit circular buffer is 210 * cleared. 211 * 212 * Locking: @port->lock taken. 213 * Interrupts: locally disabled. 214 * This call must not sleep 215 * 216 * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new, 217 * struct ktermios *old)`` 218 * 219 * Change the @port parameters, including word length, parity, stop bits. 220 * Update @port->read_status_mask and @port->ignore_status_mask to 221 * indicate the types of events we are interested in receiving. Relevant 222 * ktermios::c_cflag bits are: 223 * 224 * - %CSIZE - word size 225 * - %CSTOPB - 2 stop bits 226 * - %PARENB - parity enable 227 * - %PARODD - odd parity (when %PARENB is in force) 228 * - %ADDRB - address bit (changed through uart_port::rs485_config()). 229 * - %CREAD - enable reception of characters (if not set, still receive 230 * characters from the port, but throw them away). 231 * - %CRTSCTS - if set, enable CTS status change reporting. 232 * - %CLOCAL - if not set, enable modem status change reporting. 233 * 234 * Relevant ktermios::c_iflag bits are: 235 * 236 * - %INPCK - enable frame and parity error events to be passed to the TTY 237 * layer. 238 * - %BRKINT / %PARMRK - both of these enable break events to be passed to 239 * the TTY layer. 240 * - %IGNPAR - ignore parity and framing errors. 241 * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun 242 * errors as well. 243 * 244 * The interaction of the ktermios::c_iflag bits is as follows (parity 245 * error given as an example): 246 * 247 * ============ ======= ======= ========================================= 248 * Parity error INPCK IGNPAR 249 * ============ ======= ======= ========================================= 250 * n/a 0 n/a character received, marked as %TTY_NORMAL 251 * None 1 n/a character received, marked as %TTY_NORMAL 252 * Yes 1 0 character received, marked as %TTY_PARITY 253 * Yes 1 1 character discarded 254 * ============ ======= ======= ========================================= 255 * 256 * Other flags may be used (eg, xon/xoff characters) if your hardware 257 * supports hardware "soft" flow control. 258 * 259 * Locking: caller holds tty_port->mutex 260 * Interrupts: caller dependent. 261 * This call must not sleep 262 * 263 * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)`` 264 * 265 * Notifier for discipline change. See 266 * Documentation/driver-api/tty/tty_ldisc.rst. 267 * 268 * Locking: caller holds tty_port->mutex 269 * 270 * @pm: ``void ()(struct uart_port *port, unsigned int state, 271 * unsigned int oldstate)`` 272 * 273 * Perform any power management related activities on the specified @port. 274 * @state indicates the new state (defined by enum uart_pm_state), 275 * @oldstate indicates the previous state. 276 * 277 * This function should not be used to grab any resources. 278 * 279 * This will be called when the @port is initially opened and finally 280 * closed, except when the @port is also the system console. This will 281 * occur even if %CONFIG_PM is not set. 282 * 283 * Locking: none. 284 * Interrupts: caller dependent. 285 * 286 * @type: ``const char *()(struct uart_port *port)`` 287 * 288 * Return a pointer to a string constant describing the specified @port, 289 * or return %NULL, in which case the string 'unknown' is substituted. 290 * 291 * Locking: none. 292 * Interrupts: caller dependent. 293 * 294 * @release_port: ``void ()(struct uart_port *port)`` 295 * 296 * Release any memory and IO region resources currently in use by the 297 * @port. 298 * 299 * Locking: none. 300 * Interrupts: caller dependent. 301 * 302 * @request_port: ``int ()(struct uart_port *port)`` 303 * 304 * Request any memory and IO region resources required by the port. If any 305 * fail, no resources should be registered when this function returns, and 306 * it should return -%EBUSY on failure. 307 * 308 * Locking: none. 309 * Interrupts: caller dependent. 310 * 311 * @config_port: ``void ()(struct uart_port *port, int type)`` 312 * 313 * Perform any autoconfiguration steps required for the @port. @type 314 * contains a bit mask of the required configuration. %UART_CONFIG_TYPE 315 * indicates that the port requires detection and identification. 316 * @port->type should be set to the type found, or %PORT_UNKNOWN if no 317 * port was detected. 318 * 319 * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal, 320 * which should be probed using standard kernel autoprobing techniques. 321 * This is not necessary on platforms where ports have interrupts 322 * internally hard wired (eg, system on a chip implementations). 323 * 324 * Locking: none. 325 * Interrupts: caller dependent. 326 * 327 * @verify_port: ``int ()(struct uart_port *port, 328 * struct serial_struct *serinfo)`` 329 * 330 * Verify the new serial port information contained within @serinfo is 331 * suitable for this port type. 332 * 333 * Locking: none. 334 * Interrupts: caller dependent. 335 * 336 * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd, 337 * unsigned long arg)`` 338 * 339 * Perform any port specific IOCTLs. IOCTL commands must be defined using 340 * the standard numbering system found in <asm/ioctl.h>. 341 * 342 * Locking: none. 343 * Interrupts: caller dependent. 344 * 345 * @poll_init: ``int ()(struct uart_port *port)`` 346 * 347 * Called by kgdb to perform the minimal hardware initialization needed to 348 * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this 349 * should not request interrupts. 350 * 351 * Locking: %tty_mutex and tty_port->mutex taken. 352 * Interrupts: n/a. 353 * 354 * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)`` 355 * 356 * Called by kgdb to write a single character @ch directly to the serial 357 * @port. It can and should block until there is space in the TX FIFO. 358 * 359 * Locking: none. 360 * Interrupts: caller dependent. 361 * This call must not sleep 362 * 363 * @poll_get_char: ``int ()(struct uart_port *port)`` 364 * 365 * Called by kgdb to read a single character directly from the serial 366 * port. If data is available, it should be returned; otherwise the 367 * function should return %NO_POLL_CHAR immediately. 368 * 369 * Locking: none. 370 * Interrupts: caller dependent. 371 * This call must not sleep 372 */ 373 struct uart_ops { 374 unsigned int (*tx_empty)(struct uart_port *); 375 void (*set_mctrl)(struct uart_port *, unsigned int mctrl); 376 unsigned int (*get_mctrl)(struct uart_port *); 377 void (*stop_tx)(struct uart_port *); 378 void (*start_tx)(struct uart_port *); 379 void (*throttle)(struct uart_port *); 380 void (*unthrottle)(struct uart_port *); 381 void (*send_xchar)(struct uart_port *, char ch); 382 void (*stop_rx)(struct uart_port *); 383 void (*start_rx)(struct uart_port *); 384 void (*enable_ms)(struct uart_port *); 385 void (*break_ctl)(struct uart_port *, int ctl); 386 int (*startup)(struct uart_port *); 387 void (*shutdown)(struct uart_port *); 388 void (*flush_buffer)(struct uart_port *); 389 void (*set_termios)(struct uart_port *, struct ktermios *new, 390 const struct ktermios *old); 391 void (*set_ldisc)(struct uart_port *, struct ktermios *); 392 void (*pm)(struct uart_port *, unsigned int state, 393 unsigned int oldstate); 394 const char *(*type)(struct uart_port *); 395 void (*release_port)(struct uart_port *); 396 int (*request_port)(struct uart_port *); 397 void (*config_port)(struct uart_port *, int); 398 int (*verify_port)(struct uart_port *, struct serial_struct *); 399 int (*ioctl)(struct uart_port *, unsigned int, unsigned long); 400 #ifdef CONFIG_CONSOLE_POLL 401 int (*poll_init)(struct uart_port *); 402 void (*poll_put_char)(struct uart_port *, unsigned char); 403 int (*poll_get_char)(struct uart_port *); 404 #endif 405 }; 406 407 #define NO_POLL_CHAR 0x00ff0000 408 #define UART_CONFIG_TYPE (1 << 0) 409 #define UART_CONFIG_IRQ (1 << 1) 410 411 struct uart_icount { 412 __u32 cts; 413 __u32 dsr; 414 __u32 rng; 415 __u32 dcd; 416 __u32 rx; 417 __u32 tx; 418 __u32 frame; 419 __u32 overrun; 420 __u32 parity; 421 __u32 brk; 422 __u32 buf_overrun; 423 }; 424 425 typedef u64 __bitwise upf_t; 426 typedef unsigned int __bitwise upstat_t; 427 428 struct uart_port { 429 spinlock_t lock; /* port lock */ 430 unsigned long iobase; /* in/out[bwl] */ 431 unsigned char __iomem *membase; /* read/write[bwl] */ 432 unsigned int (*serial_in)(struct uart_port *, int); 433 void (*serial_out)(struct uart_port *, int, int); 434 void (*set_termios)(struct uart_port *, 435 struct ktermios *new, 436 const struct ktermios *old); 437 void (*set_ldisc)(struct uart_port *, 438 struct ktermios *); 439 unsigned int (*get_mctrl)(struct uart_port *); 440 void (*set_mctrl)(struct uart_port *, unsigned int); 441 unsigned int (*get_divisor)(struct uart_port *, 442 unsigned int baud, 443 unsigned int *frac); 444 void (*set_divisor)(struct uart_port *, 445 unsigned int baud, 446 unsigned int quot, 447 unsigned int quot_frac); 448 int (*startup)(struct uart_port *port); 449 void (*shutdown)(struct uart_port *port); 450 void (*throttle)(struct uart_port *port); 451 void (*unthrottle)(struct uart_port *port); 452 int (*handle_irq)(struct uart_port *); 453 void (*pm)(struct uart_port *, unsigned int state, 454 unsigned int old); 455 void (*handle_break)(struct uart_port *); 456 int (*rs485_config)(struct uart_port *, 457 struct ktermios *termios, 458 struct serial_rs485 *rs485); 459 int (*iso7816_config)(struct uart_port *, 460 struct serial_iso7816 *iso7816); 461 unsigned int irq; /* irq number */ 462 unsigned long irqflags; /* irq flags */ 463 unsigned int uartclk; /* base uart clock */ 464 unsigned int fifosize; /* tx fifo size */ 465 unsigned char x_char; /* xon/xoff char */ 466 unsigned char regshift; /* reg offset shift */ 467 unsigned char iotype; /* io access style */ 468 unsigned char quirks; /* internal quirks */ 469 470 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 471 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 472 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 473 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 474 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 475 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 476 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 477 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 478 479 /* quirks must be updated while holding port mutex */ 480 #define UPQ_NO_TXEN_TEST BIT(0) 481 482 unsigned int read_status_mask; /* driver specific */ 483 unsigned int ignore_status_mask; /* driver specific */ 484 struct uart_state *state; /* pointer to parent state */ 485 struct uart_icount icount; /* statistics */ 486 487 struct console *cons; /* struct console, if any */ 488 /* flags must be updated while holding port mutex */ 489 upf_t flags; 490 491 /* 492 * These flags must be equivalent to the flags defined in 493 * include/uapi/linux/tty_flags.h which are the userspace definitions 494 * assigned from the serial_struct flags in uart_set_info() 495 * [for bit definitions in the UPF_CHANGE_MASK] 496 * 497 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable 498 * The remaining bits are serial-core specific and not modifiable by 499 * userspace. 500 */ 501 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 502 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 503 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 504 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 505 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 506 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 507 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 508 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 509 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 510 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 511 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 512 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 513 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 514 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 515 516 #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19)) 517 /* Port has hardware-assisted h/w flow control */ 518 #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20)) 519 #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21)) 520 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 521 /* Port has hardware-assisted s/w flow control */ 522 #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) 523 #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) 524 #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) 525 #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) 526 #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26)) 527 /* The exact UART type is known and should not be probed. */ 528 #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) 529 #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) 530 #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) 531 #define UPF_DEAD ((__force upf_t) BIT_ULL(30)) 532 #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) 533 #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) 534 535 #define __UPF_CHANGE_MASK 0x17fff 536 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 537 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 538 539 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 540 #error Change mask not equivalent to userspace-visible bit defines 541 #endif 542 543 /* 544 * Must hold termios_rwsem, port mutex and port lock to change; 545 * can hold any one lock to read. 546 */ 547 upstat_t status; 548 549 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 550 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 551 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 552 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 553 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 554 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 555 556 int hw_stopped; /* sw-assisted CTS flow state */ 557 unsigned int mctrl; /* current modem ctrl settings */ 558 unsigned int frame_time; /* frame timing in ns */ 559 unsigned int type; /* port type */ 560 const struct uart_ops *ops; 561 unsigned int custom_divisor; 562 unsigned int line; /* port index */ 563 unsigned int minor; 564 resource_size_t mapbase; /* for ioremap */ 565 resource_size_t mapsize; 566 struct device *dev; /* parent device */ 567 568 unsigned long sysrq; /* sysrq timeout */ 569 unsigned int sysrq_ch; /* char for sysrq */ 570 unsigned char has_sysrq; 571 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ 572 573 unsigned char hub6; /* this should be in the 8250 driver */ 574 unsigned char suspended; 575 unsigned char console_reinit; 576 const char *name; /* port name */ 577 struct attribute_group *attr_group; /* port specific attributes */ 578 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 579 struct serial_rs485 rs485; 580 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ 581 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ 582 struct serial_iso7816 iso7816; 583 void *private_data; /* generic platform data pointer */ 584 }; 585 586 static inline int serial_port_in(struct uart_port *up, int offset) 587 { 588 return up->serial_in(up, offset); 589 } 590 591 static inline void serial_port_out(struct uart_port *up, int offset, int value) 592 { 593 up->serial_out(up, offset, value); 594 } 595 596 /** 597 * enum uart_pm_state - power states for UARTs 598 * @UART_PM_STATE_ON: UART is powered, up and operational 599 * @UART_PM_STATE_OFF: UART is powered off 600 * @UART_PM_STATE_UNDEFINED: sentinel 601 */ 602 enum uart_pm_state { 603 UART_PM_STATE_ON = 0, 604 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 605 UART_PM_STATE_UNDEFINED, 606 }; 607 608 /* 609 * This is the state information which is persistent across opens. 610 */ 611 struct uart_state { 612 struct tty_port port; 613 614 enum uart_pm_state pm_state; 615 struct circ_buf xmit; 616 617 atomic_t refcount; 618 wait_queue_head_t remove_wait; 619 struct uart_port *uart_port; 620 }; 621 622 #define UART_XMIT_SIZE PAGE_SIZE 623 624 625 /* number of characters left in xmit buffer before we ask for more */ 626 #define WAKEUP_CHARS 256 627 628 /** 629 * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars 630 * @up: uart_port structure describing the port 631 * @chars: number of characters sent 632 * 633 * This function advances the tail of circular xmit buffer by the number of 634 * @chars transmitted and handles accounting of transmitted bytes (into 635 * @up's icount.tx). 636 */ 637 static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) 638 { 639 struct circ_buf *xmit = &up->state->xmit; 640 641 xmit->tail = (xmit->tail + chars) & (UART_XMIT_SIZE - 1); 642 up->icount.tx += chars; 643 } 644 645 struct module; 646 struct tty_driver; 647 648 struct uart_driver { 649 struct module *owner; 650 const char *driver_name; 651 const char *dev_name; 652 int major; 653 int minor; 654 int nr; 655 struct console *cons; 656 657 /* 658 * these are private; the low level driver should not 659 * touch these; they should be initialised to NULL 660 */ 661 struct uart_state *state; 662 struct tty_driver *tty_driver; 663 }; 664 665 void uart_write_wakeup(struct uart_port *port); 666 667 /* 668 * Baud rate helpers. 669 */ 670 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 671 unsigned int baud); 672 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 673 const struct ktermios *old, unsigned int min, 674 unsigned int max); 675 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 676 677 /* 678 * Calculates FIFO drain time. 679 */ 680 static inline unsigned long uart_fifo_timeout(struct uart_port *port) 681 { 682 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; 683 684 /* Add .02 seconds of slop */ 685 fifo_timeout += 20 * NSEC_PER_MSEC; 686 687 return max(nsecs_to_jiffies(fifo_timeout), 1UL); 688 } 689 690 /* Base timer interval for polling */ 691 static inline int uart_poll_timeout(struct uart_port *port) 692 { 693 int timeout = uart_fifo_timeout(port); 694 695 return timeout > 6 ? (timeout / 2 - 2) : 1; 696 } 697 698 /* 699 * Console helpers. 700 */ 701 struct earlycon_device { 702 struct console *con; 703 struct uart_port port; 704 char options[16]; /* e.g., 115200n8 */ 705 unsigned int baud; 706 }; 707 708 struct earlycon_id { 709 char name[15]; 710 char name_term; /* In case compiler didn't '\0' term name */ 711 char compatible[128]; 712 int (*setup)(struct earlycon_device *, const char *options); 713 }; 714 715 extern const struct earlycon_id __earlycon_table[]; 716 extern const struct earlycon_id __earlycon_table_end[]; 717 718 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 719 #define EARLYCON_USED_OR_UNUSED __used 720 #else 721 #define EARLYCON_USED_OR_UNUSED __maybe_unused 722 #endif 723 724 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 725 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 726 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \ 727 __aligned(__alignof__(struct earlycon_id)) \ 728 = { .name = __stringify(_name), \ 729 .compatible = compat, \ 730 .setup = fn } 731 732 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 733 734 extern int of_setup_earlycon(const struct earlycon_id *match, 735 unsigned long node, 736 const char *options); 737 738 #ifdef CONFIG_SERIAL_EARLYCON 739 extern bool earlycon_acpi_spcr_enable __initdata; 740 int setup_earlycon(char *buf); 741 #else 742 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; 743 static inline int setup_earlycon(char *buf) { return 0; } 744 #endif 745 746 static inline bool uart_console_enabled(struct uart_port *port) 747 { 748 return uart_console(port) && (port->cons->flags & CON_ENABLED); 749 } 750 751 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 752 struct console *c); 753 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 754 char **options); 755 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 756 int *flow); 757 int uart_set_options(struct uart_port *port, struct console *co, int baud, 758 int parity, int bits, int flow); 759 struct tty_driver *uart_console_device(struct console *co, int *index); 760 void uart_console_write(struct uart_port *port, const char *s, 761 unsigned int count, 762 void (*putchar)(struct uart_port *, unsigned char)); 763 764 /* 765 * Port/driver registration/removal 766 */ 767 int uart_register_driver(struct uart_driver *uart); 768 void uart_unregister_driver(struct uart_driver *uart); 769 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 770 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 771 bool uart_match_port(const struct uart_port *port1, 772 const struct uart_port *port2); 773 774 /* 775 * Power Management 776 */ 777 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 778 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 779 780 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 781 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 782 783 #define uart_circ_chars_pending(circ) \ 784 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 785 786 #define uart_circ_chars_free(circ) \ 787 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 788 789 static inline int uart_tx_stopped(struct uart_port *port) 790 { 791 struct tty_struct *tty = port->state->port.tty; 792 if ((tty && tty->flow.stopped) || port->hw_stopped) 793 return 1; 794 return 0; 795 } 796 797 static inline bool uart_cts_enabled(struct uart_port *uport) 798 { 799 return !!(uport->status & UPSTAT_CTS_ENABLE); 800 } 801 802 static inline bool uart_softcts_mode(struct uart_port *uport) 803 { 804 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 805 806 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 807 } 808 809 /* 810 * The following are helper functions for the low level drivers. 811 */ 812 813 extern void uart_handle_dcd_change(struct uart_port *uport, 814 unsigned int status); 815 extern void uart_handle_cts_change(struct uart_port *uport, 816 unsigned int status); 817 818 extern void uart_insert_char(struct uart_port *port, unsigned int status, 819 unsigned int overrun, unsigned int ch, unsigned int flag); 820 821 void uart_xchar_out(struct uart_port *uport, int offset); 822 823 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 824 #define SYSRQ_TIMEOUT (HZ * 5) 825 826 bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch); 827 828 static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 829 { 830 if (!port->sysrq) 831 return 0; 832 833 if (ch && time_before(jiffies, port->sysrq)) { 834 if (sysrq_mask()) { 835 handle_sysrq(ch); 836 port->sysrq = 0; 837 return 1; 838 } 839 if (uart_try_toggle_sysrq(port, ch)) 840 return 1; 841 } 842 port->sysrq = 0; 843 844 return 0; 845 } 846 847 static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) 848 { 849 if (!port->sysrq) 850 return 0; 851 852 if (ch && time_before(jiffies, port->sysrq)) { 853 if (sysrq_mask()) { 854 port->sysrq_ch = ch; 855 port->sysrq = 0; 856 return 1; 857 } 858 if (uart_try_toggle_sysrq(port, ch)) 859 return 1; 860 } 861 port->sysrq = 0; 862 863 return 0; 864 } 865 866 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 867 { 868 int sysrq_ch; 869 870 if (!port->has_sysrq) { 871 spin_unlock(&port->lock); 872 return; 873 } 874 875 sysrq_ch = port->sysrq_ch; 876 port->sysrq_ch = 0; 877 878 spin_unlock(&port->lock); 879 880 if (sysrq_ch) 881 handle_sysrq(sysrq_ch); 882 } 883 884 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 885 unsigned long flags) 886 { 887 int sysrq_ch; 888 889 if (!port->has_sysrq) { 890 spin_unlock_irqrestore(&port->lock, flags); 891 return; 892 } 893 894 sysrq_ch = port->sysrq_ch; 895 port->sysrq_ch = 0; 896 897 spin_unlock_irqrestore(&port->lock, flags); 898 899 if (sysrq_ch) 900 handle_sysrq(sysrq_ch); 901 } 902 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ 903 static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) 904 { 905 return 0; 906 } 907 static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) 908 { 909 return 0; 910 } 911 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 912 { 913 spin_unlock(&port->lock); 914 } 915 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 916 unsigned long flags) 917 { 918 spin_unlock_irqrestore(&port->lock, flags); 919 } 920 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ 921 922 /* 923 * We do the SysRQ and SAK checking like this... 924 */ 925 static inline int uart_handle_break(struct uart_port *port) 926 { 927 struct uart_state *state = port->state; 928 929 if (port->handle_break) 930 port->handle_break(port); 931 932 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 933 if (port->has_sysrq && uart_console(port)) { 934 if (!port->sysrq) { 935 port->sysrq = jiffies + SYSRQ_TIMEOUT; 936 return 1; 937 } 938 port->sysrq = 0; 939 } 940 #endif 941 if (port->flags & UPF_SAK) 942 do_SAK(state->port.tty); 943 return 0; 944 } 945 946 /* 947 * UART_ENABLE_MS - determine if port should enable modem status irqs 948 */ 949 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 950 (cflag) & CRTSCTS || \ 951 !((cflag) & CLOCAL)) 952 953 int uart_get_rs485_mode(struct uart_port *port); 954 #endif /* LINUX_SERIAL_CORE_H */ 955