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