1 /*
2 * linux/drivers/char/serial_core.h
3 *
4 * Copyright (C) 2000 Deep Blue Solutions Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20 #ifndef LINUX_SERIAL_CORE_H
21 #define LINUX_SERIAL_CORE_H
22
23 #include <linux/bitops.h>
24 #include <linux/compiler.h>
25 #include <linux/interrupt.h>
26 #include <linux/circ_buf.h>
27 #include <linux/spinlock.h>
28 #include <linux/sched.h>
29 #include <linux/tty.h>
30 #include <linux/mutex.h>
31 #include <linux/sysrq.h>
32 #include <uapi/linux/serial_core.h>
33
34 #ifdef CONFIG_SERIAL_CORE_CONSOLE
35 #define uart_console(port) \
36 ((port)->cons && (port)->cons->index == (port)->line)
37 #else
38 #define uart_console(port) ({ (void)port; 0; })
39 #endif
40
41 struct uart_port;
42 struct serial_struct;
43 struct device;
44
45 /*
46 * This structure describes all the operations that can be done on the
47 * physical hardware. See Documentation/serial/driver for details.
48 */
49 struct uart_ops {
50 unsigned int (*tx_empty)(struct uart_port *);
51 void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
52 unsigned int (*get_mctrl)(struct uart_port *);
53 void (*stop_tx)(struct uart_port *);
54 void (*start_tx)(struct uart_port *);
55 void (*throttle)(struct uart_port *);
56 void (*unthrottle)(struct uart_port *);
57 void (*send_xchar)(struct uart_port *, char ch);
58 void (*stop_rx)(struct uart_port *);
59 void (*enable_ms)(struct uart_port *);
60 void (*break_ctl)(struct uart_port *, int ctl);
61 int (*startup)(struct uart_port *);
62 void (*shutdown)(struct uart_port *);
63 void (*flush_buffer)(struct uart_port *);
64 void (*set_termios)(struct uart_port *, struct ktermios *new,
65 struct ktermios *old);
66 void (*set_ldisc)(struct uart_port *, struct ktermios *);
67 void (*pm)(struct uart_port *, unsigned int state,
68 unsigned int oldstate);
69
70 /*
71 * Return a string describing the type of the port
72 */
73 const char *(*type)(struct uart_port *);
74
75 /*
76 * Release IO and memory resources used by the port.
77 * This includes iounmap if necessary.
78 */
79 void (*release_port)(struct uart_port *);
80
81 /*
82 * Request IO and memory resources used by the port.
83 * This includes iomapping the port if necessary.
84 */
85 int (*request_port)(struct uart_port *);
86 void (*config_port)(struct uart_port *, int);
87 int (*verify_port)(struct uart_port *, struct serial_struct *);
88 int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
89 #ifdef CONFIG_CONSOLE_POLL
90 int (*poll_init)(struct uart_port *);
91 void (*poll_put_char)(struct uart_port *, unsigned char);
92 int (*poll_get_char)(struct uart_port *);
93 #endif
94 };
95
96 #define NO_POLL_CHAR 0x00ff0000
97 #define UART_CONFIG_TYPE (1 << 0)
98 #define UART_CONFIG_IRQ (1 << 1)
99
100 struct uart_icount {
101 __u32 cts;
102 __u32 dsr;
103 __u32 rng;
104 __u32 dcd;
105 __u32 rx;
106 __u32 tx;
107 __u32 frame;
108 __u32 overrun;
109 __u32 parity;
110 __u32 brk;
111 __u32 buf_overrun;
112 };
113
114 typedef unsigned int __bitwise upf_t;
115 typedef unsigned int __bitwise upstat_t;
116
117 struct uart_port {
118 spinlock_t lock; /* port lock */
119 unsigned long iobase; /* in/out[bwl] */
120 unsigned char __iomem *membase; /* read/write[bwl] */
121 unsigned int (*serial_in)(struct uart_port *, int);
122 void (*serial_out)(struct uart_port *, int, int);
123 void (*set_termios)(struct uart_port *,
124 struct ktermios *new,
125 struct ktermios *old);
126 void (*set_ldisc)(struct uart_port *,
127 struct ktermios *);
128 unsigned int (*get_mctrl)(struct uart_port *);
129 void (*set_mctrl)(struct uart_port *, unsigned int);
130 int (*startup)(struct uart_port *port);
131 void (*shutdown)(struct uart_port *port);
132 void (*throttle)(struct uart_port *port);
133 void (*unthrottle)(struct uart_port *port);
134 int (*handle_irq)(struct uart_port *);
135 void (*pm)(struct uart_port *, unsigned int state,
136 unsigned int old);
137 void (*handle_break)(struct uart_port *);
138 int (*rs485_config)(struct uart_port *,
139 struct serial_rs485 *rs485);
140 unsigned int irq; /* irq number */
141 unsigned long irqflags; /* irq flags */
142 unsigned int uartclk; /* base uart clock */
143 unsigned int fifosize; /* tx fifo size */
144 unsigned char x_char; /* xon/xoff char */
145 unsigned char regshift; /* reg offset shift */
146 unsigned char iotype; /* io access style */
147 unsigned char quirks; /* internal quirks */
148
149 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
150 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
151 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
152 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
153 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
154 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
155 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
156 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
157
158 /* quirks must be updated while holding port mutex */
159 #define UPQ_NO_TXEN_TEST BIT(0)
160
161 unsigned int read_status_mask; /* driver specific */
162 unsigned int ignore_status_mask; /* driver specific */
163 struct uart_state *state; /* pointer to parent state */
164 struct uart_icount icount; /* statistics */
165
166 struct console *cons; /* struct console, if any */
167 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
168 unsigned long sysrq; /* sysrq timeout */
169 unsigned int sysrq_ch; /* char for sysrq */
170 #endif
171
172 /* flags must be updated while holding port mutex */
173 upf_t flags;
174
175 /*
176 * These flags must be equivalent to the flags defined in
177 * include/uapi/linux/tty_flags.h which are the userspace definitions
178 * assigned from the serial_struct flags in uart_set_info()
179 * [for bit definitions in the UPF_CHANGE_MASK]
180 *
181 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
182 * The remaining bits are serial-core specific and not modifiable by
183 * userspace.
184 */
185 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
186 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
187 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
188 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
189 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
190 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
191 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
192 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
193 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
194 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
195 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
196 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
197 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
198 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
199
200 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
201 /* Port has hardware-assisted h/w flow control */
202 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
203 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
204 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
205 /* Port has hardware-assisted s/w flow control */
206 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
207 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
208 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
209 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
210 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
211 /* The exact UART type is known and should not be probed. */
212 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
213 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
214 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
215 #define UPF_DEAD ((__force upf_t) (1 << 30))
216 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
217
218 #define __UPF_CHANGE_MASK 0x17fff
219 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
220 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
221
222 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
223 #error Change mask not equivalent to userspace-visible bit defines
224 #endif
225
226 /*
227 * Must hold termios_rwsem, port mutex and port lock to change;
228 * can hold any one lock to read.
229 */
230 upstat_t status;
231
232 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
233 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
234 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
235 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
236 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
237
238 int hw_stopped; /* sw-assisted CTS flow state */
239 unsigned int mctrl; /* current modem ctrl settings */
240 unsigned int timeout; /* character-based timeout */
241 unsigned int type; /* port type */
242 const struct uart_ops *ops;
243 unsigned int custom_divisor;
244 unsigned int line; /* port index */
245 unsigned int minor;
246 resource_size_t mapbase; /* for ioremap */
247 resource_size_t mapsize;
248 struct device *dev; /* parent device */
249 unsigned char hub6; /* this should be in the 8250 driver */
250 unsigned char suspended;
251 unsigned char unused[2];
252 const char *name; /* port name */
253 struct attribute_group *attr_group; /* port specific attributes */
254 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
255 struct serial_rs485 rs485;
256 void *private_data; /* generic platform data pointer */
257 };
258
serial_port_in(struct uart_port * up,int offset)259 static inline int serial_port_in(struct uart_port *up, int offset)
260 {
261 return up->serial_in(up, offset);
262 }
263
serial_port_out(struct uart_port * up,int offset,int value)264 static inline void serial_port_out(struct uart_port *up, int offset, int value)
265 {
266 up->serial_out(up, offset, value);
267 }
268
269 /**
270 * enum uart_pm_state - power states for UARTs
271 * @UART_PM_STATE_ON: UART is powered, up and operational
272 * @UART_PM_STATE_OFF: UART is powered off
273 * @UART_PM_STATE_UNDEFINED: sentinel
274 */
275 enum uart_pm_state {
276 UART_PM_STATE_ON = 0,
277 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
278 UART_PM_STATE_UNDEFINED,
279 };
280
281 /*
282 * This is the state information which is persistent across opens.
283 */
284 struct uart_state {
285 struct tty_port port;
286
287 enum uart_pm_state pm_state;
288 struct circ_buf xmit;
289
290 atomic_t refcount;
291 wait_queue_head_t remove_wait;
292 struct uart_port *uart_port;
293 };
294
295 #define UART_XMIT_SIZE PAGE_SIZE
296
297
298 /* number of characters left in xmit buffer before we ask for more */
299 #define WAKEUP_CHARS 256
300
301 struct module;
302 struct tty_driver;
303
304 struct uart_driver {
305 struct module *owner;
306 const char *driver_name;
307 const char *dev_name;
308 int major;
309 int minor;
310 int nr;
311 struct console *cons;
312
313 /*
314 * these are private; the low level driver should not
315 * touch these; they should be initialised to NULL
316 */
317 struct uart_state *state;
318 struct tty_driver *tty_driver;
319 };
320
321 void uart_write_wakeup(struct uart_port *port);
322
323 /*
324 * Baud rate helpers.
325 */
326 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
327 unsigned int baud);
328 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
329 struct ktermios *old, unsigned int min,
330 unsigned int max);
331 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
332
333 /* Base timer interval for polling */
uart_poll_timeout(struct uart_port * port)334 static inline int uart_poll_timeout(struct uart_port *port)
335 {
336 int timeout = port->timeout;
337
338 return timeout > 6 ? (timeout / 2 - 2) : 1;
339 }
340
341 /*
342 * Console helpers.
343 */
344 struct earlycon_device {
345 struct console *con;
346 struct uart_port port;
347 char options[16]; /* e.g., 115200n8 */
348 unsigned int baud;
349 };
350
351 struct earlycon_id {
352 char name[15];
353 char name_term; /* In case compiler didn't '\0' term name */
354 char compatible[128];
355 int (*setup)(struct earlycon_device *, const char *options);
356 };
357
358 extern const struct earlycon_id *__earlycon_table[];
359 extern const struct earlycon_id *__earlycon_table_end[];
360
361 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
362 #define EARLYCON_USED_OR_UNUSED __used
363 #else
364 #define EARLYCON_USED_OR_UNUSED __maybe_unused
365 #endif
366
367 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \
368 static const struct earlycon_id unique_id \
369 EARLYCON_USED_OR_UNUSED __initconst \
370 = { .name = __stringify(_name), \
371 .compatible = compat, \
372 .setup = fn }; \
373 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \
374 __section(__earlycon_table) \
375 * const __PASTE(__p, unique_id) = &unique_id
376
377 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
378 _OF_EARLYCON_DECLARE(_name, compat, fn, \
379 __UNIQUE_ID(__earlycon_##_name))
380
381 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
382
383 extern int of_setup_earlycon(const struct earlycon_id *match,
384 unsigned long node,
385 const char *options);
386
387 #ifdef CONFIG_SERIAL_EARLYCON
388 extern bool earlycon_init_is_deferred __initdata;
389 int setup_earlycon(char *buf);
390 #else
391 static const bool earlycon_init_is_deferred;
setup_earlycon(char * buf)392 static inline int setup_earlycon(char *buf) { return 0; }
393 #endif
394
395 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
396 struct console *c);
397 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
398 char **options);
399 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
400 int *flow);
401 int uart_set_options(struct uart_port *port, struct console *co, int baud,
402 int parity, int bits, int flow);
403 struct tty_driver *uart_console_device(struct console *co, int *index);
404 void uart_console_write(struct uart_port *port, const char *s,
405 unsigned int count,
406 void (*putchar)(struct uart_port *, int));
407
408 /*
409 * Port/driver registration/removal
410 */
411 int uart_register_driver(struct uart_driver *uart);
412 void uart_unregister_driver(struct uart_driver *uart);
413 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
414 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
415 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
416
417 /*
418 * Power Management
419 */
420 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
421 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
422
423 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
424 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
425
426 #define uart_circ_chars_pending(circ) \
427 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
428
429 #define uart_circ_chars_free(circ) \
430 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
431
uart_tx_stopped(struct uart_port * port)432 static inline int uart_tx_stopped(struct uart_port *port)
433 {
434 struct tty_struct *tty = port->state->port.tty;
435 if ((tty && tty->stopped) || port->hw_stopped)
436 return 1;
437 return 0;
438 }
439
uart_cts_enabled(struct uart_port * uport)440 static inline bool uart_cts_enabled(struct uart_port *uport)
441 {
442 return !!(uport->status & UPSTAT_CTS_ENABLE);
443 }
444
uart_softcts_mode(struct uart_port * uport)445 static inline bool uart_softcts_mode(struct uart_port *uport)
446 {
447 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
448
449 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
450 }
451
452 /*
453 * The following are helper functions for the low level drivers.
454 */
455
456 extern void uart_handle_dcd_change(struct uart_port *uport,
457 unsigned int status);
458 extern void uart_handle_cts_change(struct uart_port *uport,
459 unsigned int status);
460
461 extern void uart_insert_char(struct uart_port *port, unsigned int status,
462 unsigned int overrun, unsigned int ch, unsigned int flag);
463
464 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
465 static inline int
uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)466 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
467 {
468 if (port->sysrq) {
469 if (ch && time_before(jiffies, port->sysrq)) {
470 handle_sysrq(ch);
471 port->sysrq = 0;
472 return 1;
473 }
474 port->sysrq = 0;
475 }
476 return 0;
477 }
478 static inline int
uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)479 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
480 {
481 if (port->sysrq) {
482 if (ch && time_before(jiffies, port->sysrq)) {
483 port->sysrq_ch = ch;
484 port->sysrq = 0;
485 return 1;
486 }
487 port->sysrq = 0;
488 }
489 return 0;
490 }
491 static inline void
uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)492 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
493 {
494 int sysrq_ch;
495
496 sysrq_ch = port->sysrq_ch;
497 port->sysrq_ch = 0;
498
499 spin_unlock_irqrestore(&port->lock, irqflags);
500
501 if (sysrq_ch)
502 handle_sysrq(sysrq_ch);
503 }
504 #else
505 static inline int
uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)506 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
507 static inline int
uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)508 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
509 static inline void
uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)510 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
511 {
512 spin_unlock_irqrestore(&port->lock, irqflags);
513 }
514 #endif
515
516 /*
517 * We do the SysRQ and SAK checking like this...
518 */
uart_handle_break(struct uart_port * port)519 static inline int uart_handle_break(struct uart_port *port)
520 {
521 struct uart_state *state = port->state;
522
523 if (port->handle_break)
524 port->handle_break(port);
525
526 #ifdef SUPPORT_SYSRQ
527 if (port->cons && port->cons->index == port->line) {
528 if (!port->sysrq) {
529 port->sysrq = jiffies + HZ*5;
530 return 1;
531 }
532 port->sysrq = 0;
533 }
534 #endif
535 if (port->flags & UPF_SAK)
536 do_SAK(state->port.tty);
537 return 0;
538 }
539
540 /*
541 * UART_ENABLE_MS - determine if port should enable modem status irqs
542 */
543 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
544 (cflag) & CRTSCTS || \
545 !((cflag) & CLOCAL))
546
547 #endif /* LINUX_SERIAL_CORE_H */
548