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 unsigned int (*get_divisor)(struct uart_port *,
131 unsigned int baud,
132 unsigned int *frac);
133 void (*set_divisor)(struct uart_port *,
134 unsigned int baud,
135 unsigned int quot,
136 unsigned int quot_frac);
137 int (*startup)(struct uart_port *port);
138 void (*shutdown)(struct uart_port *port);
139 void (*throttle)(struct uart_port *port);
140 void (*unthrottle)(struct uart_port *port);
141 int (*handle_irq)(struct uart_port *);
142 void (*pm)(struct uart_port *, unsigned int state,
143 unsigned int old);
144 void (*handle_break)(struct uart_port *);
145 int (*rs485_config)(struct uart_port *,
146 struct serial_rs485 *rs485);
147 unsigned int irq; /* irq number */
148 unsigned long irqflags; /* irq flags */
149 unsigned int uartclk; /* base uart clock */
150 unsigned int fifosize; /* tx fifo size */
151 unsigned char x_char; /* xon/xoff char */
152 unsigned char regshift; /* reg offset shift */
153 unsigned char iotype; /* io access style */
154 unsigned char quirks; /* internal quirks */
155
156 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
157 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
158 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
159 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
160 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
161 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
162 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
163 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
164
165 /* quirks must be updated while holding port mutex */
166 #define UPQ_NO_TXEN_TEST BIT(0)
167
168 unsigned int read_status_mask; /* driver specific */
169 unsigned int ignore_status_mask; /* driver specific */
170 struct uart_state *state; /* pointer to parent state */
171 struct uart_icount icount; /* statistics */
172
173 struct console *cons; /* struct console, if any */
174 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
175 unsigned long sysrq; /* sysrq timeout */
176 #endif
177
178 /* flags must be updated while holding port mutex */
179 upf_t flags;
180
181 /*
182 * These flags must be equivalent to the flags defined in
183 * include/uapi/linux/tty_flags.h which are the userspace definitions
184 * assigned from the serial_struct flags in uart_set_info()
185 * [for bit definitions in the UPF_CHANGE_MASK]
186 *
187 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
188 * The remaining bits are serial-core specific and not modifiable by
189 * userspace.
190 */
191 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
192 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
193 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
194 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
195 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
196 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
197 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
198 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
199 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
200 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
201 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
202 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
203 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
204 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
205
206 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
207 /* Port has hardware-assisted h/w flow control */
208 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
209 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
210 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
211 /* Port has hardware-assisted s/w flow control */
212 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
213 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
214 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
215 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
216 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
217 /* The exact UART type is known and should not be probed. */
218 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
219 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
220 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
221 #define UPF_DEAD ((__force upf_t) (1 << 30))
222 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
223
224 #define __UPF_CHANGE_MASK 0x17fff
225 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
226 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
227
228 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
229 #error Change mask not equivalent to userspace-visible bit defines
230 #endif
231
232 /*
233 * Must hold termios_rwsem, port mutex and port lock to change;
234 * can hold any one lock to read.
235 */
236 upstat_t status;
237
238 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
239 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
240 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
241 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
242 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
243 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
244
245 int hw_stopped; /* sw-assisted CTS flow state */
246 unsigned int mctrl; /* current modem ctrl settings */
247 unsigned int timeout; /* character-based timeout */
248 unsigned int type; /* port type */
249 const struct uart_ops *ops;
250 unsigned int custom_divisor;
251 unsigned int line; /* port index */
252 unsigned int minor;
253 resource_size_t mapbase; /* for ioremap */
254 resource_size_t mapsize;
255 struct device *dev; /* parent device */
256 unsigned char hub6; /* this should be in the 8250 driver */
257 unsigned char suspended;
258 unsigned char unused[2];
259 const char *name; /* port name */
260 struct attribute_group *attr_group; /* port specific attributes */
261 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
262 struct serial_rs485 rs485;
263 void *private_data; /* generic platform data pointer */
264 };
265
serial_port_in(struct uart_port * up,int offset)266 static inline int serial_port_in(struct uart_port *up, int offset)
267 {
268 return up->serial_in(up, offset);
269 }
270
serial_port_out(struct uart_port * up,int offset,int value)271 static inline void serial_port_out(struct uart_port *up, int offset, int value)
272 {
273 up->serial_out(up, offset, value);
274 }
275
276 /**
277 * enum uart_pm_state - power states for UARTs
278 * @UART_PM_STATE_ON: UART is powered, up and operational
279 * @UART_PM_STATE_OFF: UART is powered off
280 * @UART_PM_STATE_UNDEFINED: sentinel
281 */
282 enum uart_pm_state {
283 UART_PM_STATE_ON = 0,
284 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
285 UART_PM_STATE_UNDEFINED,
286 };
287
288 /*
289 * This is the state information which is persistent across opens.
290 */
291 struct uart_state {
292 struct tty_port port;
293
294 enum uart_pm_state pm_state;
295 struct circ_buf xmit;
296
297 atomic_t refcount;
298 wait_queue_head_t remove_wait;
299 struct uart_port *uart_port;
300 };
301
302 #define UART_XMIT_SIZE PAGE_SIZE
303
304
305 /* number of characters left in xmit buffer before we ask for more */
306 #define WAKEUP_CHARS 256
307
308 struct module;
309 struct tty_driver;
310
311 struct uart_driver {
312 struct module *owner;
313 const char *driver_name;
314 const char *dev_name;
315 int major;
316 int minor;
317 int nr;
318 struct console *cons;
319
320 /*
321 * these are private; the low level driver should not
322 * touch these; they should be initialised to NULL
323 */
324 struct uart_state *state;
325 struct tty_driver *tty_driver;
326 };
327
328 void uart_write_wakeup(struct uart_port *port);
329
330 /*
331 * Baud rate helpers.
332 */
333 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
334 unsigned int baud);
335 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min,
337 unsigned int max);
338 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
339
340 /* Base timer interval for polling */
uart_poll_timeout(struct uart_port * port)341 static inline int uart_poll_timeout(struct uart_port *port)
342 {
343 int timeout = port->timeout;
344
345 return timeout > 6 ? (timeout / 2 - 2) : 1;
346 }
347
348 /*
349 * Console helpers.
350 */
351 struct earlycon_device {
352 struct console *con;
353 struct uart_port port;
354 char options[16]; /* e.g., 115200n8 */
355 unsigned int baud;
356 };
357
358 struct earlycon_id {
359 char name[15];
360 char name_term; /* In case compiler didn't '\0' term name */
361 char compatible[128];
362 int (*setup)(struct earlycon_device *, const char *options);
363 };
364
365 extern const struct earlycon_id *__earlycon_table[];
366 extern const struct earlycon_id *__earlycon_table_end[];
367
368 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
369 #define EARLYCON_USED_OR_UNUSED __used
370 #else
371 #define EARLYCON_USED_OR_UNUSED __maybe_unused
372 #endif
373
374 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \
375 static const struct earlycon_id unique_id \
376 EARLYCON_USED_OR_UNUSED __initconst \
377 = { .name = __stringify(_name), \
378 .compatible = compat, \
379 .setup = fn }; \
380 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \
381 __section(__earlycon_table) \
382 * const __PASTE(__p, unique_id) = &unique_id
383
384 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
385 _OF_EARLYCON_DECLARE(_name, compat, fn, \
386 __UNIQUE_ID(__earlycon_##_name))
387
388 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
389
390 extern int of_setup_earlycon(const struct earlycon_id *match,
391 unsigned long node,
392 const char *options);
393
394 #ifdef CONFIG_SERIAL_EARLYCON
395 extern bool earlycon_acpi_spcr_enable __initdata;
396 int setup_earlycon(char *buf);
397 #else
398 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
setup_earlycon(char * buf)399 static inline int setup_earlycon(char *buf) { return 0; }
400 #endif
401
402 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
403 struct console *c);
404 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
405 char **options);
406 void uart_parse_options(const char *options, int *baud, int *parity, int *bits,
407 int *flow);
408 int uart_set_options(struct uart_port *port, struct console *co, int baud,
409 int parity, int bits, int flow);
410 struct tty_driver *uart_console_device(struct console *co, int *index);
411 void uart_console_write(struct uart_port *port, const char *s,
412 unsigned int count,
413 void (*putchar)(struct uart_port *, int));
414
415 /*
416 * Port/driver registration/removal
417 */
418 int uart_register_driver(struct uart_driver *uart);
419 void uart_unregister_driver(struct uart_driver *uart);
420 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
421 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
422 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
423
424 /*
425 * Power Management
426 */
427 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
428 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
429
430 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
431 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
432
433 #define uart_circ_chars_pending(circ) \
434 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
435
436 #define uart_circ_chars_free(circ) \
437 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
438
uart_tx_stopped(struct uart_port * port)439 static inline int uart_tx_stopped(struct uart_port *port)
440 {
441 struct tty_struct *tty = port->state->port.tty;
442 if ((tty && tty->stopped) || port->hw_stopped)
443 return 1;
444 return 0;
445 }
446
uart_cts_enabled(struct uart_port * uport)447 static inline bool uart_cts_enabled(struct uart_port *uport)
448 {
449 return !!(uport->status & UPSTAT_CTS_ENABLE);
450 }
451
uart_softcts_mode(struct uart_port * uport)452 static inline bool uart_softcts_mode(struct uart_port *uport)
453 {
454 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
455
456 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
457 }
458
459 /*
460 * The following are helper functions for the low level drivers.
461 */
462
463 extern void uart_handle_dcd_change(struct uart_port *uport,
464 unsigned int status);
465 extern void uart_handle_cts_change(struct uart_port *uport,
466 unsigned int status);
467
468 extern void uart_insert_char(struct uart_port *port, unsigned int status,
469 unsigned int overrun, unsigned int ch, unsigned int flag);
470
471 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
472 static inline int
uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)473 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
474 {
475 if (port->sysrq) {
476 if (ch && time_before(jiffies, port->sysrq)) {
477 handle_sysrq(ch);
478 port->sysrq = 0;
479 return 1;
480 }
481 port->sysrq = 0;
482 }
483 return 0;
484 }
485 #else
486 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
487 #endif
488
489 /*
490 * We do the SysRQ and SAK checking like this...
491 */
uart_handle_break(struct uart_port * port)492 static inline int uart_handle_break(struct uart_port *port)
493 {
494 struct uart_state *state = port->state;
495
496 if (port->handle_break)
497 port->handle_break(port);
498
499 #ifdef SUPPORT_SYSRQ
500 if (port->cons && port->cons->index == port->line) {
501 if (!port->sysrq) {
502 port->sysrq = jiffies + HZ*5;
503 return 1;
504 }
505 port->sysrq = 0;
506 }
507 #endif
508 if (port->flags & UPF_SAK)
509 do_SAK(state->port.tty);
510 return 0;
511 }
512
513 /*
514 * UART_ENABLE_MS - determine if port should enable modem status irqs
515 */
516 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
517 (cflag) & CRTSCTS || \
518 !((cflag) & CLOCAL))
519
520 void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf);
521 #endif /* LINUX_SERIAL_CORE_H */
522
