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
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 void (*wake_peer)(struct uart_port *);
70
71 /*
72 * Return a string describing the type of the port
73 */
74 const char *(*type)(struct uart_port *);
75
76 /*
77 * Release IO and memory resources used by the port.
78 * This includes iounmap if necessary.
79 */
80 void (*release_port)(struct uart_port *);
81
82 /*
83 * Request IO and memory resources used by the port.
84 * This includes iomapping the port if necessary.
85 */
86 int (*request_port)(struct uart_port *);
87 void (*config_port)(struct uart_port *, int);
88 int (*verify_port)(struct uart_port *, struct serial_struct *);
89 int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
90 #ifdef CONFIG_CONSOLE_POLL
91 int (*poll_init)(struct uart_port *);
92 void (*poll_put_char)(struct uart_port *, unsigned char);
93 int (*poll_get_char)(struct uart_port *);
94 #endif
95 };
96
97 #define NO_POLL_CHAR 0x00ff0000
98 #define UART_CONFIG_TYPE (1 << 0)
99 #define UART_CONFIG_IRQ (1 << 1)
100
101 struct uart_icount {
102 __u32 cts;
103 __u32 dsr;
104 __u32 rng;
105 __u32 dcd;
106 __u32 rx;
107 __u32 tx;
108 __u32 frame;
109 __u32 overrun;
110 __u32 parity;
111 __u32 brk;
112 __u32 buf_overrun;
113 };
114
115 typedef unsigned int __bitwise__ upf_t;
116 typedef unsigned int __bitwise__ upstat_t;
117
118 struct uart_port {
119 spinlock_t lock; /* port lock */
120 unsigned long iobase; /* in/out[bwl] */
121 unsigned char __iomem *membase; /* read/write[bwl] */
122 unsigned int (*serial_in)(struct uart_port *, int);
123 void (*serial_out)(struct uart_port *, int, int);
124 void (*set_termios)(struct uart_port *,
125 struct ktermios *new,
126 struct ktermios *old);
127 void (*set_mctrl)(struct uart_port *, unsigned int);
128 int (*startup)(struct uart_port *port);
129 void (*shutdown)(struct uart_port *port);
130 void (*throttle)(struct uart_port *port);
131 void (*unthrottle)(struct uart_port *port);
132 int (*handle_irq)(struct uart_port *);
133 void (*pm)(struct uart_port *, unsigned int state,
134 unsigned int old);
135 void (*handle_break)(struct uart_port *);
136 int (*rs485_config)(struct uart_port *,
137 struct serial_rs485 *rs485);
138 unsigned int irq; /* irq number */
139 unsigned long irqflags; /* irq flags */
140 unsigned int uartclk; /* base uart clock */
141 unsigned int fifosize; /* tx fifo size */
142 unsigned char x_char; /* xon/xoff char */
143 unsigned char regshift; /* reg offset shift */
144 unsigned char iotype; /* io access style */
145 unsigned char unused1;
146
147 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
148 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
149 #define UPIO_MEM (SERIAL_IO_MEM) /* 8b MMIO access */
150 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
151 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
152 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
153 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
154
155 unsigned int read_status_mask; /* driver specific */
156 unsigned int ignore_status_mask; /* driver specific */
157 struct uart_state *state; /* pointer to parent state */
158 struct uart_icount icount; /* statistics */
159
160 struct console *cons; /* struct console, if any */
161 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
162 unsigned long sysrq; /* sysrq timeout */
163 unsigned int sysrq_ch; /* char for sysrq */
164 #endif
165
166 /* flags must be updated while holding port mutex */
167 upf_t flags;
168
169 /*
170 * These flags must be equivalent to the flags defined in
171 * include/uapi/linux/tty_flags.h which are the userspace definitions
172 * assigned from the serial_struct flags in uart_set_info()
173 * [for bit definitions in the UPF_CHANGE_MASK]
174 *
175 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
176 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
177 * The remaining bits are serial-core specific and not modifiable by
178 * userspace.
179 */
180 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
181 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
182 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
183 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
184 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
185 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
186 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
187 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
188 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
189 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
190 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
191 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
192 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
193 #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
194 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
195
196 /* Port has hardware-assisted h/w flow control */
197 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
198 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
199 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
200 /* Port has hardware-assisted s/w flow control */
201 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
202 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
203 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
204 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
205 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
206 /* The exact UART type is known and should not be probed. */
207 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
208 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
209 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
210 #define UPF_DEAD ((__force upf_t) (1 << 30))
211 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
212
213 #define __UPF_CHANGE_MASK 0x17fff
214 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
215 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
216
217 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
218 #error Change mask not equivalent to userspace-visible bit defines
219 #endif
220
221 /*
222 * Must hold termios_rwsem, port mutex and port lock to change;
223 * can hold any one lock to read.
224 */
225 upstat_t status;
226
227 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
228 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
229 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
230 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
231 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
232
233 int hw_stopped; /* sw-assisted CTS flow state */
234 unsigned int mctrl; /* current modem ctrl settings */
235 unsigned int timeout; /* character-based timeout */
236 unsigned int type; /* port type */
237 const struct uart_ops *ops;
238 unsigned int custom_divisor;
239 unsigned int line; /* port index */
240 unsigned int minor;
241 resource_size_t mapbase; /* for ioremap */
242 resource_size_t mapsize;
243 struct device *dev; /* parent device */
244 unsigned char hub6; /* this should be in the 8250 driver */
245 unsigned char suspended;
246 unsigned char irq_wake;
247 unsigned char unused[2];
248 struct attribute_group *attr_group; /* port specific attributes */
249 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
250 struct serial_rs485 rs485;
251 void *private_data; /* generic platform data pointer */
252 };
253
serial_port_in(struct uart_port * up,int offset)254 static inline int serial_port_in(struct uart_port *up, int offset)
255 {
256 return up->serial_in(up, offset);
257 }
258
serial_port_out(struct uart_port * up,int offset,int value)259 static inline void serial_port_out(struct uart_port *up, int offset, int value)
260 {
261 up->serial_out(up, offset, value);
262 }
263
264 /**
265 * enum uart_pm_state - power states for UARTs
266 * @UART_PM_STATE_ON: UART is powered, up and operational
267 * @UART_PM_STATE_OFF: UART is powered off
268 * @UART_PM_STATE_UNDEFINED: sentinel
269 */
270 enum uart_pm_state {
271 UART_PM_STATE_ON = 0,
272 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
273 UART_PM_STATE_UNDEFINED,
274 };
275
276 /*
277 * This is the state information which is persistent across opens.
278 */
279 struct uart_state {
280 struct tty_port port;
281
282 enum uart_pm_state pm_state;
283 struct circ_buf xmit;
284
285 struct uart_port *uart_port;
286 };
287
288 #define UART_XMIT_SIZE PAGE_SIZE
289
290
291 /* number of characters left in xmit buffer before we ask for more */
292 #define WAKEUP_CHARS 256
293
294 struct module;
295 struct tty_driver;
296
297 struct uart_driver {
298 struct module *owner;
299 const char *driver_name;
300 const char *dev_name;
301 int major;
302 int minor;
303 int nr;
304 struct console *cons;
305
306 /*
307 * these are private; the low level driver should not
308 * touch these; they should be initialised to NULL
309 */
310 struct uart_state *state;
311 struct tty_driver *tty_driver;
312 };
313
314 void uart_write_wakeup(struct uart_port *port);
315
316 /*
317 * Baud rate helpers.
318 */
319 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
320 unsigned int baud);
321 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
322 struct ktermios *old, unsigned int min,
323 unsigned int max);
324 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
325
326 /* Base timer interval for polling */
uart_poll_timeout(struct uart_port * port)327 static inline int uart_poll_timeout(struct uart_port *port)
328 {
329 int timeout = port->timeout;
330
331 return timeout > 6 ? (timeout / 2 - 2) : 1;
332 }
333
334 /*
335 * Console helpers.
336 */
337 struct earlycon_device {
338 struct console *con;
339 struct uart_port port;
340 char options[16]; /* e.g., 115200n8 */
341 unsigned int baud;
342 };
343
344 struct earlycon_id {
345 char name[16];
346 int (*setup)(struct earlycon_device *, const char *options);
347 } __aligned(32);
348
349 extern int setup_earlycon(char *buf);
350 extern int of_setup_earlycon(unsigned long addr,
351 int (*setup)(struct earlycon_device *, const char *));
352
353 #define EARLYCON_DECLARE(_name, func) \
354 static const struct earlycon_id __earlycon_##_name \
355 __used __section(__earlycon_table) \
356 = { .name = __stringify(_name), \
357 .setup = func }
358
359 #define OF_EARLYCON_DECLARE(name, compat, fn) \
360 _OF_DECLARE(earlycon, name, compat, fn, void *)
361
362 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
363 struct console *c);
364 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
365 char **options);
366 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
367 int *flow);
368 int uart_set_options(struct uart_port *port, struct console *co, int baud,
369 int parity, int bits, int flow);
370 struct tty_driver *uart_console_device(struct console *co, int *index);
371 void uart_console_write(struct uart_port *port, const char *s,
372 unsigned int count,
373 void (*putchar)(struct uart_port *, int));
374
375 /*
376 * Port/driver registration/removal
377 */
378 int uart_register_driver(struct uart_driver *uart);
379 void uart_unregister_driver(struct uart_driver *uart);
380 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
381 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
382 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
383
384 /*
385 * Power Management
386 */
387 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
388 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
389
390 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
391 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
392
393 #define uart_circ_chars_pending(circ) \
394 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
395
396 #define uart_circ_chars_free(circ) \
397 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
398
uart_tx_stopped(struct uart_port * port)399 static inline int uart_tx_stopped(struct uart_port *port)
400 {
401 struct tty_struct *tty = port->state->port.tty;
402 if (tty->stopped || port->hw_stopped)
403 return 1;
404 return 0;
405 }
406
uart_cts_enabled(struct uart_port * uport)407 static inline bool uart_cts_enabled(struct uart_port *uport)
408 {
409 return !!(uport->status & UPSTAT_CTS_ENABLE);
410 }
411
uart_softcts_mode(struct uart_port * uport)412 static inline bool uart_softcts_mode(struct uart_port *uport)
413 {
414 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
415
416 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
417 }
418
419 /*
420 * The following are helper functions for the low level drivers.
421 */
422
423 extern void uart_handle_dcd_change(struct uart_port *uport,
424 unsigned int status);
425 extern void uart_handle_cts_change(struct uart_port *uport,
426 unsigned int status);
427
428 extern void uart_insert_char(struct uart_port *port, unsigned int status,
429 unsigned int overrun, unsigned int ch, unsigned int flag);
430
431 #ifdef SUPPORT_SYSRQ
432 static inline int
uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)433 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
434 {
435 if (port->sysrq) {
436 if (ch && time_before(jiffies, port->sysrq)) {
437 handle_sysrq(ch);
438 port->sysrq = 0;
439 return 1;
440 }
441 port->sysrq = 0;
442 }
443 return 0;
444 }
445 static inline int
uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)446 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
447 {
448 if (port->sysrq) {
449 if (ch && time_before(jiffies, port->sysrq)) {
450 port->sysrq_ch = ch;
451 port->sysrq = 0;
452 return 1;
453 }
454 port->sysrq = 0;
455 }
456 return 0;
457 }
458 static inline void
uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)459 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
460 {
461 int sysrq_ch;
462
463 sysrq_ch = port->sysrq_ch;
464 port->sysrq_ch = 0;
465
466 spin_unlock_irqrestore(&port->lock, irqflags);
467
468 if (sysrq_ch)
469 handle_sysrq(sysrq_ch);
470 }
471 #else
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) { return 0; }
474 static inline int
uart_prepare_sysrq_char(struct uart_port * port,unsigned int ch)475 uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
476 static inline void
uart_unlock_and_check_sysrq(struct uart_port * port,unsigned long irqflags)477 uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
478 {
479 spin_unlock_irqrestore(&port->lock, irqflags);
480 }
481 #endif
482
483 /*
484 * We do the SysRQ and SAK checking like this...
485 */
uart_handle_break(struct uart_port * port)486 static inline int uart_handle_break(struct uart_port *port)
487 {
488 struct uart_state *state = port->state;
489
490 if (port->handle_break)
491 port->handle_break(port);
492
493 #ifdef SUPPORT_SYSRQ
494 if (port->cons && port->cons->index == port->line) {
495 if (!port->sysrq) {
496 port->sysrq = jiffies + HZ*5;
497 return 1;
498 }
499 port->sysrq = 0;
500 }
501 #endif
502 if (port->flags & UPF_SAK)
503 do_SAK(state->port.tty);
504 return 0;
505 }
506
507 /*
508 * UART_ENABLE_MS - determine if port should enable modem status irqs
509 */
510 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
511 (cflag) & CRTSCTS || \
512 !((cflag) & CLOCAL))
513
514 #endif /* LINUX_SERIAL_CORE_H */
515