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 serial_port_device; 32 struct device; 33 struct 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 */ 374 struct 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) 411 412 struct 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 }; 425 426 typedef u64 __bitwise upf_t; 427 typedef unsigned int __bitwise upstat_t; 428 429 struct 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 unsigned char iotype; /* io access style */ 471 unsigned char quirks; /* internal quirks */ 472 473 #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 /* quirks must be updated while holding port mutex */ 483 #define UPQ_NO_TXEN_TEST BIT(0) 484 485 unsigned int read_status_mask; /* driver specific */ 486 unsigned int ignore_status_mask; /* driver specific */ 487 struct uart_state *state; /* pointer to parent state */ 488 struct uart_icount icount; /* statistics */ 489 490 struct console *cons; /* struct console, if any */ 491 /* flags must be updated while holding port mutex */ 492 upf_t flags; 493 494 /* 495 * These flags must be equivalent to the flags defined in 496 * include/uapi/linux/tty_flags.h which are the userspace definitions 497 * assigned from the serial_struct flags in uart_set_info() 498 * [for bit definitions in the UPF_CHANGE_MASK] 499 * 500 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable 501 * The remaining bits are serial-core specific and not modifiable by 502 * userspace. 503 */ 504 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) 505 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) 506 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) 507 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) 508 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) 509 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) 510 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) 511 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) 512 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) 513 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) 514 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) 515 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) 516 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) 517 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) 518 519 #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19)) 520 /* Port has hardware-assisted h/w flow control */ 521 #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20)) 522 #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21)) 523 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) 524 /* Port has hardware-assisted s/w flow control */ 525 #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) 526 #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) 527 #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) 528 #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) 529 #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26)) 530 /* The exact UART type is known and should not be probed. */ 531 #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) 532 #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) 533 #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) 534 #define UPF_DEAD ((__force upf_t) BIT_ULL(30)) 535 #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) 536 #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) 537 538 #define __UPF_CHANGE_MASK 0x17fff 539 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) 540 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) 541 542 #if __UPF_CHANGE_MASK > ASYNC_FLAGS 543 #error Change mask not equivalent to userspace-visible bit defines 544 #endif 545 546 /* 547 * Must hold termios_rwsem, port mutex and port lock to change; 548 * can hold any one lock to read. 549 */ 550 upstat_t status; 551 552 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) 553 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) 554 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) 555 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) 556 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) 557 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) 558 559 bool hw_stopped; /* sw-assisted CTS flow state */ 560 unsigned int mctrl; /* current modem ctrl settings */ 561 unsigned int frame_time; /* frame timing in ns */ 562 unsigned int type; /* port type */ 563 const struct uart_ops *ops; 564 unsigned int custom_divisor; 565 unsigned int line; /* port index */ 566 unsigned int minor; 567 resource_size_t mapbase; /* for ioremap */ 568 resource_size_t mapsize; 569 struct device *dev; /* serial port physical parent device */ 570 struct serial_port_device *port_dev; /* serial core port device */ 571 572 unsigned long sysrq; /* sysrq timeout */ 573 u8 sysrq_ch; /* char for sysrq */ 574 unsigned char has_sysrq; 575 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ 576 577 unsigned char hub6; /* this should be in the 8250 driver */ 578 unsigned char suspended; 579 unsigned char console_reinit; 580 const char *name; /* port name */ 581 struct attribute_group *attr_group; /* port specific attributes */ 582 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ 583 struct serial_rs485 rs485; 584 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ 585 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ 586 struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */ 587 struct serial_iso7816 iso7816; 588 void *private_data; /* generic platform data pointer */ 589 }; 590 591 static inline int serial_port_in(struct uart_port *up, int offset) 592 { 593 return up->serial_in(up, offset); 594 } 595 596 static inline void serial_port_out(struct uart_port *up, int offset, int value) 597 { 598 up->serial_out(up, offset, value); 599 } 600 601 /** 602 * enum uart_pm_state - power states for UARTs 603 * @UART_PM_STATE_ON: UART is powered, up and operational 604 * @UART_PM_STATE_OFF: UART is powered off 605 * @UART_PM_STATE_UNDEFINED: sentinel 606 */ 607 enum uart_pm_state { 608 UART_PM_STATE_ON = 0, 609 UART_PM_STATE_OFF = 3, /* number taken from ACPI */ 610 UART_PM_STATE_UNDEFINED, 611 }; 612 613 /* 614 * This is the state information which is persistent across opens. 615 */ 616 struct uart_state { 617 struct tty_port port; 618 619 enum uart_pm_state pm_state; 620 struct circ_buf xmit; 621 622 atomic_t refcount; 623 wait_queue_head_t remove_wait; 624 struct uart_port *uart_port; 625 }; 626 627 #define UART_XMIT_SIZE PAGE_SIZE 628 629 630 /* number of characters left in xmit buffer before we ask for more */ 631 #define WAKEUP_CHARS 256 632 633 /** 634 * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars 635 * @up: uart_port structure describing the port 636 * @chars: number of characters sent 637 * 638 * This function advances the tail of circular xmit buffer by the number of 639 * @chars transmitted and handles accounting of transmitted bytes (into 640 * @up's icount.tx). 641 */ 642 static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) 643 { 644 struct circ_buf *xmit = &up->state->xmit; 645 646 xmit->tail = (xmit->tail + chars) & (UART_XMIT_SIZE - 1); 647 up->icount.tx += chars; 648 } 649 650 struct module; 651 struct tty_driver; 652 653 struct uart_driver { 654 struct module *owner; 655 const char *driver_name; 656 const char *dev_name; 657 int major; 658 int minor; 659 int nr; 660 struct console *cons; 661 662 /* 663 * these are private; the low level driver should not 664 * touch these; they should be initialised to NULL 665 */ 666 struct uart_state *state; 667 struct tty_driver *tty_driver; 668 }; 669 670 void uart_write_wakeup(struct uart_port *port); 671 672 #define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test, \ 673 for_post) \ 674 ({ \ 675 struct uart_port *__port = (uport); \ 676 struct circ_buf *xmit = &__port->state->xmit; \ 677 unsigned int pending; \ 678 \ 679 for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ 680 if (__port->x_char) { \ 681 (ch) = __port->x_char; \ 682 (put_char); \ 683 __port->x_char = 0; \ 684 continue; \ 685 } \ 686 \ 687 if (uart_circ_empty(xmit) || uart_tx_stopped(__port)) \ 688 break; \ 689 \ 690 (ch) = xmit->buf[xmit->tail]; \ 691 (put_char); \ 692 xmit->tail = (xmit->tail + 1) % UART_XMIT_SIZE; \ 693 } \ 694 \ 695 (tx_done); \ 696 \ 697 pending = uart_circ_chars_pending(xmit); \ 698 if (pending < WAKEUP_CHARS) { \ 699 uart_write_wakeup(__port); \ 700 \ 701 if (pending == 0) \ 702 __port->ops->stop_tx(__port); \ 703 } \ 704 \ 705 pending; \ 706 }) 707 708 /** 709 * uart_port_tx_limited -- transmit helper for uart_port with count limiting 710 * @port: uart port 711 * @ch: variable to store a character to be written to the HW 712 * @count: a limit of characters to send 713 * @tx_ready: can HW accept more data function 714 * @put_char: function to write a character 715 * @tx_done: function to call after the loop is done 716 * 717 * This helper transmits characters from the xmit buffer to the hardware using 718 * @put_char(). It does so until @count characters are sent and while @tx_ready 719 * evaluates to true. 720 * 721 * Returns: the number of characters in the xmit buffer when done. 722 * 723 * The expression in macro parameters shall be designed as follows: 724 * * **tx_ready:** should evaluate to true if the HW can accept more data to 725 * be sent. This parameter can be %true, which means the HW is always ready. 726 * * **put_char:** shall write @ch to the device of @port. 727 * * **tx_done:** when the write loop is done, this can perform arbitrary 728 * action before potential invocation of ops->stop_tx() happens. If the 729 * driver does not need to do anything, use e.g. ({}). 730 * 731 * For all of them, @port->lock is held, interrupts are locally disabled and 732 * the expressions must not sleep. 733 */ 734 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ 735 unsigned int __count = (count); \ 736 __uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count, \ 737 __count--); \ 738 }) 739 740 /** 741 * uart_port_tx -- transmit helper for uart_port 742 * @port: uart port 743 * @ch: variable to store a character to be written to the HW 744 * @tx_ready: can HW accept more data function 745 * @put_char: function to write a character 746 * 747 * See uart_port_tx_limited() for more details. 748 */ 749 #define uart_port_tx(port, ch, tx_ready, put_char) \ 750 __uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({})) 751 752 /* 753 * Baud rate helpers. 754 */ 755 void uart_update_timeout(struct uart_port *port, unsigned int cflag, 756 unsigned int baud); 757 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 758 const struct ktermios *old, unsigned int min, 759 unsigned int max); 760 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); 761 762 /* 763 * Calculates FIFO drain time. 764 */ 765 static inline unsigned long uart_fifo_timeout(struct uart_port *port) 766 { 767 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; 768 769 /* Add .02 seconds of slop */ 770 fifo_timeout += 20 * NSEC_PER_MSEC; 771 772 return max(nsecs_to_jiffies(fifo_timeout), 1UL); 773 } 774 775 /* Base timer interval for polling */ 776 static inline int uart_poll_timeout(struct uart_port *port) 777 { 778 int timeout = uart_fifo_timeout(port); 779 780 return timeout > 6 ? (timeout / 2 - 2) : 1; 781 } 782 783 /* 784 * Console helpers. 785 */ 786 struct earlycon_device { 787 struct console *con; 788 struct uart_port port; 789 char options[32]; /* e.g., 115200n8 */ 790 unsigned int baud; 791 }; 792 793 struct earlycon_id { 794 char name[15]; 795 char name_term; /* In case compiler didn't '\0' term name */ 796 char compatible[128]; 797 int (*setup)(struct earlycon_device *, const char *options); 798 }; 799 800 extern const struct earlycon_id __earlycon_table[]; 801 extern const struct earlycon_id __earlycon_table_end[]; 802 803 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) 804 #define EARLYCON_USED_OR_UNUSED __used 805 #else 806 #define EARLYCON_USED_OR_UNUSED __maybe_unused 807 #endif 808 809 #define OF_EARLYCON_DECLARE(_name, compat, fn) \ 810 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ 811 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \ 812 __aligned(__alignof__(struct earlycon_id)) \ 813 = { .name = __stringify(_name), \ 814 .compatible = compat, \ 815 .setup = fn } 816 817 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) 818 819 int of_setup_earlycon(const struct earlycon_id *match, unsigned long node, 820 const char *options); 821 822 #ifdef CONFIG_SERIAL_EARLYCON 823 extern bool earlycon_acpi_spcr_enable __initdata; 824 int setup_earlycon(char *buf); 825 #else 826 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; 827 static inline int setup_earlycon(char *buf) { return 0; } 828 #endif 829 830 /* Variant of uart_console_registered() when the console_list_lock is held. */ 831 static inline bool uart_console_registered_locked(struct uart_port *port) 832 { 833 return uart_console(port) && console_is_registered_locked(port->cons); 834 } 835 836 static inline bool uart_console_registered(struct uart_port *port) 837 { 838 return uart_console(port) && console_is_registered(port->cons); 839 } 840 841 struct uart_port *uart_get_console(struct uart_port *ports, int nr, 842 struct console *c); 843 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 844 char **options); 845 void uart_parse_options(const char *options, int *baud, int *parity, int *bits, 846 int *flow); 847 int uart_set_options(struct uart_port *port, struct console *co, int baud, 848 int parity, int bits, int flow); 849 struct tty_driver *uart_console_device(struct console *co, int *index); 850 void uart_console_write(struct uart_port *port, const char *s, 851 unsigned int count, 852 void (*putchar)(struct uart_port *, unsigned char)); 853 854 /* 855 * Port/driver registration/removal 856 */ 857 int uart_register_driver(struct uart_driver *uart); 858 void uart_unregister_driver(struct uart_driver *uart); 859 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); 860 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); 861 bool uart_match_port(const struct uart_port *port1, 862 const struct uart_port *port2); 863 864 /* 865 * Power Management 866 */ 867 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); 868 int uart_resume_port(struct uart_driver *reg, struct uart_port *port); 869 870 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) 871 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) 872 873 #define uart_circ_chars_pending(circ) \ 874 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 875 876 #define uart_circ_chars_free(circ) \ 877 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) 878 879 static inline int uart_tx_stopped(struct uart_port *port) 880 { 881 struct tty_struct *tty = port->state->port.tty; 882 if ((tty && tty->flow.stopped) || port->hw_stopped) 883 return 1; 884 return 0; 885 } 886 887 static inline bool uart_cts_enabled(struct uart_port *uport) 888 { 889 return !!(uport->status & UPSTAT_CTS_ENABLE); 890 } 891 892 static inline bool uart_softcts_mode(struct uart_port *uport) 893 { 894 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; 895 896 return ((uport->status & mask) == UPSTAT_CTS_ENABLE); 897 } 898 899 /* 900 * The following are helper functions for the low level drivers. 901 */ 902 903 void uart_handle_dcd_change(struct uart_port *uport, bool active); 904 void uart_handle_cts_change(struct uart_port *uport, bool active); 905 906 void uart_insert_char(struct uart_port *port, unsigned int status, 907 unsigned int overrun, u8 ch, u8 flag); 908 909 void uart_xchar_out(struct uart_port *uport, int offset); 910 911 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 912 #define SYSRQ_TIMEOUT (HZ * 5) 913 914 bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch); 915 916 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 917 { 918 if (!port->sysrq) 919 return 0; 920 921 if (ch && time_before(jiffies, port->sysrq)) { 922 if (sysrq_mask()) { 923 handle_sysrq(ch); 924 port->sysrq = 0; 925 return 1; 926 } 927 if (uart_try_toggle_sysrq(port, ch)) 928 return 1; 929 } 930 port->sysrq = 0; 931 932 return 0; 933 } 934 935 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 936 { 937 if (!port->sysrq) 938 return 0; 939 940 if (ch && time_before(jiffies, port->sysrq)) { 941 if (sysrq_mask()) { 942 port->sysrq_ch = ch; 943 port->sysrq = 0; 944 return 1; 945 } 946 if (uart_try_toggle_sysrq(port, ch)) 947 return 1; 948 } 949 port->sysrq = 0; 950 951 return 0; 952 } 953 954 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 955 { 956 u8 sysrq_ch; 957 958 if (!port->has_sysrq) { 959 spin_unlock(&port->lock); 960 return; 961 } 962 963 sysrq_ch = port->sysrq_ch; 964 port->sysrq_ch = 0; 965 966 spin_unlock(&port->lock); 967 968 if (sysrq_ch) 969 handle_sysrq(sysrq_ch); 970 } 971 972 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 973 unsigned long flags) 974 { 975 u8 sysrq_ch; 976 977 if (!port->has_sysrq) { 978 spin_unlock_irqrestore(&port->lock, flags); 979 return; 980 } 981 982 sysrq_ch = port->sysrq_ch; 983 port->sysrq_ch = 0; 984 985 spin_unlock_irqrestore(&port->lock, flags); 986 987 if (sysrq_ch) 988 handle_sysrq(sysrq_ch); 989 } 990 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ 991 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) 992 { 993 return 0; 994 } 995 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) 996 { 997 return 0; 998 } 999 static inline void uart_unlock_and_check_sysrq(struct uart_port *port) 1000 { 1001 spin_unlock(&port->lock); 1002 } 1003 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, 1004 unsigned long flags) 1005 { 1006 spin_unlock_irqrestore(&port->lock, flags); 1007 } 1008 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ 1009 1010 /* 1011 * We do the SysRQ and SAK checking like this... 1012 */ 1013 static inline int uart_handle_break(struct uart_port *port) 1014 { 1015 struct uart_state *state = port->state; 1016 1017 if (port->handle_break) 1018 port->handle_break(port); 1019 1020 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 1021 if (port->has_sysrq && uart_console(port)) { 1022 if (!port->sysrq) { 1023 port->sysrq = jiffies + SYSRQ_TIMEOUT; 1024 return 1; 1025 } 1026 port->sysrq = 0; 1027 } 1028 #endif 1029 if (port->flags & UPF_SAK) 1030 do_SAK(state->port.tty); 1031 return 0; 1032 } 1033 1034 /* 1035 * UART_ENABLE_MS - determine if port should enable modem status irqs 1036 */ 1037 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ 1038 (cflag) & CRTSCTS || \ 1039 !((cflag) & CLOCAL)) 1040 1041 int uart_get_rs485_mode(struct uart_port *port); 1042 #endif /* LINUX_SERIAL_CORE_H */ 1043