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/spinlock.h> 15 #include <linux/sched.h> 16 #include <linux/tty.h> 17 #include <linux/mutex.h> 18 #include <linux/sysrq.h> 19 #include <uapi/linux/serial_core.h> 20 21 #ifdef CONFIG_SERIAL_CORE_CONSOLE 22 #define uart_console(port) \ 23 ((port)->cons && (port)->cons->index == (port)->line) 24 #else 25 #define uart_console(port) ({ (void)port; 0; }) 26 #endif 27 28 struct uart_port; 29 struct serial_struct; 30 struct serial_port_device; 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 ctrl_id; /* optional serial core controller id */ 462 unsigned int port_id; /* optional serial core port id */ 463 unsigned int irq; /* irq number */ 464 unsigned long irqflags; /* irq flags */ 465 unsigned int uartclk; /* base uart clock */ 466 unsigned int fifosize; /* tx fifo size */ 467 unsigned char x_char; /* xon/xoff char */ 468 unsigned char regshift; /* reg offset shift */ 469 470 unsigned char iotype; /* io access style */ 471 472 #define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */ 473 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ 474 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ 475 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ 476 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ 477 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ 478 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ 479 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ 480 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ 481 482 unsigned char quirks; /* internal quirks */ 483 484 /* internal quirks must be updated while holding port mutex */ 485 #define UPQ_NO_TXEN_TEST BIT(0) 486 487 unsigned int read_status_mask; /* driver specific */ 488 unsigned int ignore_status_mask; /* driver specific */ 489 struct uart_state *state; /* pointer to parent state */ 490 struct uart_icount icount; /* statistics */ 491 492 struct console *cons; /* struct console, if any */ 493 /* flags must be updated while holding port mutex */ 494 upf_t flags; 495 496 /* 497 * These flags must be equivalent to the flags defined in 498 * include/uapi/linux/tty_flags.h which are the userspace definitions 499 * assigned from the serial_struct flags in uart_set_info() 500 * [for bit definitions in the UPF_CHANGE_MASK] 501 * 502 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable 503 * The remaining bits are serial-core specific and not modifiable by 504 * userspace. 505 */ 506 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 507 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 508 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 509 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 510 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 511 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 512 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 513 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 514 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 515 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 516 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 517 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 518 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 519 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 520 521 #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19)) 522 /* Port has hardware-assisted h/w flow control */ 523 #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20)) 524 #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21)) 525 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 526 /* Port has hardware-assisted s/w flow control */ 527 #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) 528 #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) 529 #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) 530 #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) 531 #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26)) 532 /* The exact UART type is known and should not be probed. */ 533 #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) 534 #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) 535 #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) 536 #define UPF_DEAD ((__force upf_t) BIT_ULL(30)) 537 #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) 538 #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) 539 540 #define __UPF_CHANGE_MASK 0x17fff 541 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 542 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 543 544 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 545 #error Change mask not equivalent to userspace-visible bit defines 546 #endif 547 548 /* 549 * Must hold termios_rwsem, port mutex and port lock to change; 550 * can hold any one lock to read. 551 */ 552 upstat_t status; 553 554 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 555 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 556 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 557 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 558 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 559 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 560 561 bool hw_stopped; /* sw-assisted CTS flow state */ 562 unsigned int mctrl; /* current modem ctrl settings */ 563 unsigned int frame_time; /* frame timing in ns */ 564 unsigned int type; /* port type */ 565 const struct uart_ops *ops; 566 unsigned int custom_divisor; 567 unsigned int line; /* port index */ 568 unsigned int minor; 569 resource_size_t mapbase; /* for ioremap */ 570 resource_size_t mapsize; 571 struct device *dev; /* serial port physical parent device */ 572 struct serial_port_device *port_dev; /* serial core port device */ 573 574 unsigned long sysrq; /* sysrq timeout */ 575 u8 sysrq_ch; /* char for sysrq */ 576 unsigned char has_sysrq; 577 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ 578 579 unsigned char hub6; /* this should be in the 8250 driver */ 580 unsigned char suspended; 581 unsigned char console_reinit; 582 const char *name; /* port name */ 583 struct attribute_group *attr_group; /* port specific attributes */ 584 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 585 struct serial_rs485 rs485; 586 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ 587 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ 588 struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */ 589 struct serial_iso7816 iso7816; 590 void *private_data; /* generic platform data pointer */ 591 }; 592 593 /** 594 * uart_port_lock - Lock the UART port 595 * @up: Pointer to UART port structure 596 */ 597 static inline void uart_port_lock(struct uart_port *up) 598 { 599 spin_lock(&up->lock); 600 } 601 602 /** 603 * uart_port_lock_irq - Lock the UART port and disable interrupts 604 * @up: Pointer to UART port structure 605 */ 606 static inline void uart_port_lock_irq(struct uart_port *up) 607 { 608 spin_lock_irq(&up->lock); 609 } 610 611 /** 612 * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts 613 * @up: Pointer to UART port structure 614 * @flags: Pointer to interrupt flags storage 615 */ 616 static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) 617 { 618 spin_lock_irqsave(&up->lock, *flags); 619 } 620 621 /** 622 * uart_port_trylock - Try to lock the UART port 623 * @up: Pointer to UART port structure 624 * 625 * Returns: True if lock was acquired, false otherwise 626 */ 627 static inline bool uart_port_trylock(struct uart_port *up) 628 { 629 return spin_trylock(&up->lock); 630 } 631 632 /** 633 * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts 634 * @up: Pointer to UART port structure 635 * @flags: Pointer to interrupt flags storage 636 * 637 * Returns: True if lock was acquired, false otherwise 638 */ 639 static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags) 640 { 641 return spin_trylock_irqsave(&up->lock, *flags); 642 } 643 644 /** 645 * uart_port_unlock - Unlock the UART port 646 * @up: Pointer to UART port structure 647 */ 648 static inline void uart_port_unlock(struct uart_port *up) 649 { 650 spin_unlock(&up->lock); 651 } 652 653 /** 654 * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts 655 * @up: Pointer to UART port structure 656 */ 657 static inline void uart_port_unlock_irq(struct uart_port *up) 658 { 659 spin_unlock_irq(&up->lock); 660 } 661 662 /** 663 * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts 664 * @up: Pointer to UART port structure 665 * @flags: The saved interrupt flags for restore 666 */ 667 static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) 668 { 669 spin_unlock_irqrestore(&up->lock, flags); 670 } 671 672 static inline int serial_port_in(struct uart_port *up, int offset) 673 { 674 return up->serial_in(up, offset); 675 } 676 677 static inline void serial_port_out(struct uart_port *up, int offset, int value) 678 { 679 up->serial_out(up, offset, value); 680 } 681 682 /** 683 * enum uart_pm_state - power states for UARTs 684 * @UART_PM_STATE_ON: UART is powered, up and operational 685 * @UART_PM_STATE_OFF: UART is powered off 686 * @UART_PM_STATE_UNDEFINED: sentinel 687 */ 688 enum uart_pm_state { 689 UART_PM_STATE_ON = 0, 690 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 691 UART_PM_STATE_UNDEFINED, 692 }; 693 694 /* 695 * This is the state information which is persistent across opens. 696 */ 697 struct uart_state { 698 struct tty_port port; 699 700 enum uart_pm_state pm_state; 701 702 atomic_t refcount; 703 wait_queue_head_t remove_wait; 704 struct uart_port *uart_port; 705 }; 706 707 #define UART_XMIT_SIZE PAGE_SIZE 708 709 710 /* number of characters left in xmit buffer before we ask for more */ 711 #define WAKEUP_CHARS 256 712 713 /** 714 * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars 715 * @up: uart_port structure describing the port 716 * @chars: number of characters sent 717 * 718 * This function advances the tail of circular xmit buffer by the number of 719 * @chars transmitted and handles accounting of transmitted bytes (into 720 * @up's icount.tx). 721 */ 722 static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) 723 { 724 struct tty_port *tport = &up->state->port; 725 726 kfifo_skip_count(&tport->xmit_fifo, chars); 727 up->icount.tx += chars; 728 } 729 730 static inline unsigned int uart_fifo_out(struct uart_port *up, 731 unsigned char *buf, unsigned int chars) 732 { 733 struct tty_port *tport = &up->state->port; 734 735 chars = kfifo_out(&tport->xmit_fifo, buf, chars); 736 up->icount.tx += chars; 737 738 return chars; 739 } 740 741 static inline unsigned int uart_fifo_get(struct uart_port *up, 742 unsigned char *ch) 743 { 744 struct tty_port *tport = &up->state->port; 745 unsigned int chars; 746 747 chars = kfifo_get(&tport->xmit_fifo, ch); 748 up->icount.tx += chars; 749 750 return chars; 751 } 752 753 struct module; 754 struct tty_driver; 755 756 struct uart_driver { 757 struct module *owner; 758 const char *driver_name; 759 const char *dev_name; 760 int major; 761 int minor; 762 int nr; 763 struct console *cons; 764 765 /* 766 * these are private; the low level driver should not 767 * touch these; they should be initialised to NULL 768 */ 769 struct uart_state *state; 770 struct tty_driver *tty_driver; 771 }; 772 773 void uart_write_wakeup(struct uart_port *port); 774 775 /** 776 * enum UART_TX_FLAGS -- flags for uart_port_tx_flags() 777 * 778 * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer 779 */ 780 enum UART_TX_FLAGS { 781 UART_TX_NOSTOP = BIT(0), 782 }; 783 784 #define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \ 785 for_test, for_post) \ 786 ({ \ 787 struct uart_port *__port = (uport); \ 788 struct tty_port *__tport = &__port->state->port; \ 789 unsigned int pending; \ 790 \ 791 for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ 792 if (__port->x_char) { \ 793 (ch) = __port->x_char; \ 794 (put_char); \ 795 __port->x_char = 0; \ 796 continue; \ 797 } \ 798 \ 799 if (uart_tx_stopped(__port)) \ 800 break; \ 801 \ 802 if (!kfifo_get(&__tport->xmit_fifo, &(ch))) \ 803 break; \ 804 \ 805 (put_char); \ 806 } \ 807 \ 808 (tx_done); \ 809 \ 810 pending = kfifo_len(&__tport->xmit_fifo); \ 811 if (pending < WAKEUP_CHARS) { \ 812 uart_write_wakeup(__port); \ 813 \ 814 if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ 815 __port->ops->stop_tx(__port); \ 816 } \ 817 \ 818 pending; \ 819 }) 820 821 /** 822 * uart_port_tx_limited -- transmit helper for uart_port with count limiting 823 * @port: uart port 824 * @ch: variable to store a character to be written to the HW 825 * @count: a limit of characters to send 826 * @tx_ready: can HW accept more data function 827 * @put_char: function to write a character 828 * @tx_done: function to call after the loop is done 829 * 830 * This helper transmits characters from the xmit buffer to the hardware using 831 * @put_char(). It does so until @count characters are sent and while @tx_ready 832 * evaluates to true. 833 * 834 * Returns: the number of characters in the xmit buffer when done. 835 * 836 * The expression in macro parameters shall be designed as follows: 837 * * **tx_ready:** should evaluate to true if the HW can accept more data to 838 * be sent. This parameter can be %true, which means the HW is always ready. 839 * * **put_char:** shall write @ch to the device of @port. 840 * * **tx_done:** when the write loop is done, this can perform arbitrary 841 * action before potential invocation of ops->stop_tx() happens. If the 842 * driver does not need to do anything, use e.g. ({}). 843 * 844 * For all of them, @port->lock is held, interrupts are locally disabled and 845 * the expressions must not sleep. 846 */ 847 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ 848 unsigned int __count = (count); \ 849 __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \ 850 __count--); \ 851 }) 852 853 /** 854 * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags 855 * @port: uart port 856 * @ch: variable to store a character to be written to the HW 857 * @flags: %UART_TX_NOSTOP or similar 858 * @count: a limit of characters to send 859 * @tx_ready: can HW accept more data function 860 * @put_char: function to write a character 861 * @tx_done: function to call after the loop is done 862 * 863 * See uart_port_tx_limited() for more details. 864 */ 865 #define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \ 866 unsigned int __count = (count); \ 867 __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \ 868 __count--); \ 869 }) 870 871 /** 872 * uart_port_tx -- transmit helper for uart_port 873 * @port: uart port 874 * @ch: variable to store a character to be written to the HW 875 * @tx_ready: can HW accept more data function 876 * @put_char: function to write a character 877 * 878 * See uart_port_tx_limited() for more details. 879 */ 880 #define uart_port_tx(port, ch, tx_ready, put_char) \ 881 __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({})) 882 883 884 /** 885 * uart_port_tx_flags -- transmit helper for uart_port with flags 886 * @port: uart port 887 * @ch: variable to store a character to be written to the HW 888 * @flags: %UART_TX_NOSTOP or similar 889 * @tx_ready: can HW accept more data function 890 * @put_char: function to write a character 891 * 892 * See uart_port_tx_limited() for more details. 893 */ 894 #define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \ 895 __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({})) 896 /* 897 * Baud rate helpers. 898 */ 899 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 900 unsigned int baud); 901 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 902 const struct ktermios *old, unsigned int min, 903 unsigned int max); 904 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 905 906 /* 907 * Calculates FIFO drain time. 908 */ 909 static inline unsigned long uart_fifo_timeout(struct uart_port *port) 910 { 911 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; 912 913 /* Add .02 seconds of slop */ 914 fifo_timeout += 20 * NSEC_PER_MSEC; 915 916 return max(nsecs_to_jiffies(fifo_timeout), 1UL); 917 } 918 919 /* Base timer interval for polling */ 920 static inline unsigned long uart_poll_timeout(struct uart_port *port) 921 { 922 unsigned long timeout = uart_fifo_timeout(port); 923 924 return timeout > 6 ? (timeout / 2 - 2) : 1; 925 } 926 927 /* 928 * Console helpers. 929 */ 930 struct earlycon_device { 931 struct console *con; 932 struct uart_port port; 933 char options[32]; /* e.g., 115200n8 */ 934 unsigned int baud; 935 }; 936 937 struct earlycon_id { 938 char name[15]; 939 char name_term; /* In case compiler didn't '\0' term name */ 940 char compatible[128]; 941 int (*setup)(struct earlycon_device *, const char *options); 942 }; 943 944 extern const struct earlycon_id __earlycon_table[]; 945 extern const struct earlycon_id __earlycon_table_end[]; 946 947 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 948 #define EARLYCON_USED_OR_UNUSED __used 949 #else 950 #define EARLYCON_USED_OR_UNUSED __maybe_unused 951 #endif 952 953 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 954 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 955 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \ 956 __aligned(__alignof__(struct earlycon_id)) \ 957 = { .name = __stringify(_name), \ 958 .compatible = compat, \ 959 .setup = fn } 960 961 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 962 963 int of_setup_earlycon(const struct earlycon_id *match, unsigned long node, 964 const char *options); 965 966 #ifdef CONFIG_SERIAL_EARLYCON 967 extern bool earlycon_acpi_spcr_enable __initdata; 968 int setup_earlycon(char *buf); 969 #else 970 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; 971 static inline int setup_earlycon(char *buf) { return 0; } 972 #endif 973 974 /* Variant of uart_console_registered() when the console_list_lock is held. */ 975 static inline bool uart_console_registered_locked(struct uart_port *port) 976 { 977 return uart_console(port) && console_is_registered_locked(port->cons); 978 } 979 980 static inline bool uart_console_registered(struct uart_port *port) 981 { 982 return uart_console(port) && console_is_registered(port->cons); 983 } 984 985 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 986 struct console *c); 987 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 988 char **options); 989 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 990 int *flow); 991 int uart_set_options(struct uart_port *port, struct console *co, int baud, 992 int parity, int bits, int flow); 993 struct tty_driver *uart_console_device(struct console *co, int *index); 994 void uart_console_write(struct uart_port *port, const char *s, 995 unsigned int count, 996 void (*putchar)(struct uart_port *, unsigned char)); 997 998 /* 999 * Port/driver registration/removal 1000 */ 1001 int uart_register_driver(struct uart_driver *uart); 1002 void uart_unregister_driver(struct uart_driver *uart); 1003 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 1004 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 1005 int uart_read_port_properties(struct uart_port *port); 1006 int uart_read_and_validate_port_properties(struct uart_port *port); 1007 bool uart_match_port(const struct uart_port *port1, 1008 const struct uart_port *port2); 1009 1010 /* 1011 * Power Management 1012 */ 1013 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 1014 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 1015 1016 static inline int uart_tx_stopped(struct uart_port *port) 1017 { 1018 struct tty_struct *tty = port->state->port.tty; 1019 if ((tty && tty->flow.stopped) || port->hw_stopped) 1020 return 1; 1021 return 0; 1022 } 1023 1024 static inline bool uart_cts_enabled(struct uart_port *uport) 1025 { 1026 return !!(uport->status & UPSTAT_CTS_ENABLE); 1027 } 1028 1029 static inline bool uart_softcts_mode(struct uart_port *uport) 1030 { 1031 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 1032 1033 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 1034 } 1035 1036 /* 1037 * The following are helper functions for the low level drivers. 1038 */ 1039 1040 void uart_handle_dcd_change(struct uart_port *uport, bool active); 1041 void uart_handle_cts_change(struct uart_port *uport, bool active); 1042 1043 void uart_insert_char(struct uart_port *port, unsigned int status, 1044 unsigned int overrun, u8 ch, u8 flag); 1045 1046 void uart_xchar_out(struct uart_port *uport, int offset); 1047 1048 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 1049 #define SYSRQ_TIMEOUT (HZ * 5) 1050 1051 bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch); 1052 1053 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 1054 { 1055 if (!port->sysrq) 1056 return 0; 1057 1058 if (ch && time_before(jiffies, port->sysrq)) { 1059 if (sysrq_mask()) { 1060 handle_sysrq(ch); 1061 port->sysrq = 0; 1062 return 1; 1063 } 1064 if (uart_try_toggle_sysrq(port, ch)) 1065 return 1; 1066 } 1067 port->sysrq = 0; 1068 1069 return 0; 1070 } 1071 1072 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 1073 { 1074 if (!port->sysrq) 1075 return 0; 1076 1077 if (ch && time_before(jiffies, port->sysrq)) { 1078 if (sysrq_mask()) { 1079 port->sysrq_ch = ch; 1080 port->sysrq = 0; 1081 return 1; 1082 } 1083 if (uart_try_toggle_sysrq(port, ch)) 1084 return 1; 1085 } 1086 port->sysrq = 0; 1087 1088 return 0; 1089 } 1090 1091 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 1092 { 1093 u8 sysrq_ch; 1094 1095 if (!port->has_sysrq) { 1096 uart_port_unlock(port); 1097 return; 1098 } 1099 1100 sysrq_ch = port->sysrq_ch; 1101 port->sysrq_ch = 0; 1102 1103 uart_port_unlock(port); 1104 1105 if (sysrq_ch) 1106 handle_sysrq(sysrq_ch); 1107 } 1108 1109 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 1110 unsigned long flags) 1111 { 1112 u8 sysrq_ch; 1113 1114 if (!port->has_sysrq) { 1115 uart_port_unlock_irqrestore(port, flags); 1116 return; 1117 } 1118 1119 sysrq_ch = port->sysrq_ch; 1120 port->sysrq_ch = 0; 1121 1122 uart_port_unlock_irqrestore(port, flags); 1123 1124 if (sysrq_ch) 1125 handle_sysrq(sysrq_ch); 1126 } 1127 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ 1128 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 1129 { 1130 return 0; 1131 } 1132 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 1133 { 1134 return 0; 1135 } 1136 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 1137 { 1138 uart_port_unlock(port); 1139 } 1140 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 1141 unsigned long flags) 1142 { 1143 uart_port_unlock_irqrestore(port, flags); 1144 } 1145 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ 1146 1147 /* 1148 * We do the SysRQ and SAK checking like this... 1149 */ 1150 static inline int uart_handle_break(struct uart_port *port) 1151 { 1152 struct uart_state *state = port->state; 1153 1154 if (port->handle_break) 1155 port->handle_break(port); 1156 1157 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 1158 if (port->has_sysrq && uart_console(port)) { 1159 if (!port->sysrq) { 1160 port->sysrq = jiffies + SYSRQ_TIMEOUT; 1161 return 1; 1162 } 1163 port->sysrq = 0; 1164 } 1165 #endif 1166 if (port->flags & UPF_SAK) 1167 do_SAK(state->port.tty); 1168 return 0; 1169 } 1170 1171 /* 1172 * UART_ENABLE_MS - determine if port should enable modem status irqs 1173 */ 1174 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 1175 (cflag) & CRTSCTS || \ 1176 !((cflag) & CLOCAL)) 1177 1178 int uart_get_rs485_mode(struct uart_port *port); 1179 #endif /* LINUX_SERIAL_CORE_H */ 1180