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
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_mctrl)(struct uart_port *, unsigned int);
127 int (*startup)(struct uart_port *port);
128 void (*shutdown)(struct uart_port *port);
129 void (*throttle)(struct uart_port *port);
130 void (*unthrottle)(struct uart_port *port);
131 int (*handle_irq)(struct uart_port *);
132 void (*pm)(struct uart_port *, unsigned int state,
133 unsigned int old);
134 void (*handle_break)(struct uart_port *);
135 int (*rs485_config)(struct uart_port *,
136 struct serial_rs485 *rs485);
137 unsigned int irq; /* irq number */
138 unsigned long irqflags; /* irq flags */
139 unsigned int uartclk; /* base uart clock */
140 unsigned int fifosize; /* tx fifo size */
141 unsigned char x_char; /* xon/xoff char */
142 unsigned char regshift; /* reg offset shift */
143 unsigned char iotype; /* io access style */
144 unsigned char unused1;
145
146 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
147 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
148 #define UPIO_MEM (SERIAL_IO_MEM) /* 8b MMIO access */
149 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
150 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
151 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
152 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
153
154 unsigned int read_status_mask; /* driver specific */
155 unsigned int ignore_status_mask; /* driver specific */
156 struct uart_state *state; /* pointer to parent state */
157 struct uart_icount icount; /* statistics */
158
159 struct console *cons; /* struct console, if any */
160 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
161 unsigned long sysrq; /* sysrq timeout */
162 #endif
163
164 /* flags must be updated while holding port mutex */
165 upf_t flags;
166
167 /*
168 * These flags must be equivalent to the flags defined in
169 * include/uapi/linux/tty_flags.h which are the userspace definitions
170 * assigned from the serial_struct flags in uart_set_info()
171 * [for bit definitions in the UPF_CHANGE_MASK]
172 *
173 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
174 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
175 * The remaining bits are serial-core specific and not modifiable by
176 * userspace.
177 */
178 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
179 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
180 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
181 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
182 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
183 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
184 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
185 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
186 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
187 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
188 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
189 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
190 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
191 #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
192 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
193
194 /* Port has hardware-assisted h/w flow control */
195 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
196 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
197 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
198 /* Port has hardware-assisted s/w flow control */
199 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
200 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
201 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
202 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
203 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
204 /* The exact UART type is known and should not be probed. */
205 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
206 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
207 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
208 #define UPF_DEAD ((__force upf_t) (1 << 30))
209 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
210
211 #define __UPF_CHANGE_MASK 0x17fff
212 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
213 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
214
215 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
216 #error Change mask not equivalent to userspace-visible bit defines
217 #endif
218
219 /*
220 * Must hold termios_rwsem, port mutex and port lock to change;
221 * can hold any one lock to read.
222 */
223 upstat_t status;
224
225 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
226 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
227 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
228 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
229 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
230
231 int hw_stopped; /* sw-assisted CTS flow state */
232 unsigned int mctrl; /* current modem ctrl settings */
233 unsigned int timeout; /* character-based timeout */
234 unsigned int type; /* port type */
235 const struct uart_ops *ops;
236 unsigned int custom_divisor;
237 unsigned int line; /* port index */
238 unsigned int minor;
239 resource_size_t mapbase; /* for ioremap */
240 resource_size_t mapsize;
241 struct device *dev; /* parent device */
242 unsigned char hub6; /* this should be in the 8250 driver */
243 unsigned char suspended;
244 unsigned char irq_wake;
245 unsigned char unused[2];
246 struct attribute_group *attr_group; /* port specific attributes */
247 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
248 struct serial_rs485 rs485;
249 void *private_data; /* generic platform data pointer */
250 };
251
serial_port_in(struct uart_port * up,int offset)252 static inline int serial_port_in(struct uart_port *up, int offset)
253 {
254 return up->serial_in(up, offset);
255 }
256
serial_port_out(struct uart_port * up,int offset,int value)257 static inline void serial_port_out(struct uart_port *up, int offset, int value)
258 {
259 up->serial_out(up, offset, value);
260 }
261
262 /**
263 * enum uart_pm_state - power states for UARTs
264 * @UART_PM_STATE_ON: UART is powered, up and operational
265 * @UART_PM_STATE_OFF: UART is powered off
266 * @UART_PM_STATE_UNDEFINED: sentinel
267 */
268 enum uart_pm_state {
269 UART_PM_STATE_ON = 0,
270 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
271 UART_PM_STATE_UNDEFINED,
272 };
273
274 /*
275 * This is the state information which is persistent across opens.
276 */
277 struct uart_state {
278 struct tty_port port;
279
280 enum uart_pm_state pm_state;
281 struct circ_buf xmit;
282
283 struct uart_port *uart_port;
284 };
285
286 #define UART_XMIT_SIZE PAGE_SIZE
287
288
289 /* number of characters left in xmit buffer before we ask for more */
290 #define WAKEUP_CHARS 256
291
292 struct module;
293 struct tty_driver;
294
295 struct uart_driver {
296 struct module *owner;
297 const char *driver_name;
298 const char *dev_name;
299 int major;
300 int minor;
301 int nr;
302 struct console *cons;
303
304 /*
305 * these are private; the low level driver should not
306 * touch these; they should be initialised to NULL
307 */
308 struct uart_state *state;
309 struct tty_driver *tty_driver;
310 };
311
312 void uart_write_wakeup(struct uart_port *port);
313
314 /*
315 * Baud rate helpers.
316 */
317 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
318 unsigned int baud);
319 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
320 struct ktermios *old, unsigned int min,
321 unsigned int max);
322 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
323
324 /* Base timer interval for polling */
uart_poll_timeout(struct uart_port * port)325 static inline int uart_poll_timeout(struct uart_port *port)
326 {
327 int timeout = port->timeout;
328
329 return timeout > 6 ? (timeout / 2 - 2) : 1;
330 }
331
332 /*
333 * Console helpers.
334 */
335 struct earlycon_device {
336 struct console *con;
337 struct uart_port port;
338 char options[16]; /* e.g., 115200n8 */
339 unsigned int baud;
340 };
341
342 struct earlycon_id {
343 char name[16];
344 int (*setup)(struct earlycon_device *, const char *options);
345 } __aligned(32);
346
347 extern int setup_earlycon(char *buf);
348 extern int of_setup_earlycon(unsigned long addr,
349 int (*setup)(struct earlycon_device *, const char *));
350
351 #define EARLYCON_DECLARE(_name, func) \
352 static const struct earlycon_id __earlycon_##_name \
353 __used __section(__earlycon_table) \
354 = { .name = __stringify(_name), \
355 .setup = func }
356
357 #define OF_EARLYCON_DECLARE(name, compat, fn) \
358 _OF_DECLARE(earlycon, name, compat, fn, void *)
359
360 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
361 struct console *c);
362 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
363 char **options);
364 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
365 int *flow);
366 int uart_set_options(struct uart_port *port, struct console *co, int baud,
367 int parity, int bits, int flow);
368 struct tty_driver *uart_console_device(struct console *co, int *index);
369 void uart_console_write(struct uart_port *port, const char *s,
370 unsigned int count,
371 void (*putchar)(struct uart_port *, int));
372
373 /*
374 * Port/driver registration/removal
375 */
376 int uart_register_driver(struct uart_driver *uart);
377 void uart_unregister_driver(struct uart_driver *uart);
378 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
379 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
380 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
381
382 /*
383 * Power Management
384 */
385 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
386 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
387
388 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
389 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
390
391 #define uart_circ_chars_pending(circ) \
392 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
393
394 #define uart_circ_chars_free(circ) \
395 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
396
uart_tx_stopped(struct uart_port * port)397 static inline int uart_tx_stopped(struct uart_port *port)
398 {
399 struct tty_struct *tty = port->state->port.tty;
400 if (tty->stopped || port->hw_stopped)
401 return 1;
402 return 0;
403 }
404
uart_cts_enabled(struct uart_port * uport)405 static inline bool uart_cts_enabled(struct uart_port *uport)
406 {
407 return !!(uport->status & UPSTAT_CTS_ENABLE);
408 }
409
uart_softcts_mode(struct uart_port * uport)410 static inline bool uart_softcts_mode(struct uart_port *uport)
411 {
412 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
413
414 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
415 }
416
417 /*
418 * The following are helper functions for the low level drivers.
419 */
420
421 extern void uart_handle_dcd_change(struct uart_port *uport,
422 unsigned int status);
423 extern void uart_handle_cts_change(struct uart_port *uport,
424 unsigned int status);
425
426 extern void uart_insert_char(struct uart_port *port, unsigned int status,
427 unsigned int overrun, unsigned int ch, unsigned int flag);
428
429 #ifdef SUPPORT_SYSRQ
430 static inline int
uart_handle_sysrq_char(struct uart_port * port,unsigned int ch)431 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
432 {
433 if (port->sysrq) {
434 if (ch && time_before(jiffies, port->sysrq)) {
435 handle_sysrq(ch);
436 port->sysrq = 0;
437 return 1;
438 }
439 port->sysrq = 0;
440 }
441 return 0;
442 }
443 #else
444 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
445 #endif
446
447 /*
448 * We do the SysRQ and SAK checking like this...
449 */
uart_handle_break(struct uart_port * port)450 static inline int uart_handle_break(struct uart_port *port)
451 {
452 struct uart_state *state = port->state;
453
454 if (port->handle_break)
455 port->handle_break(port);
456
457 #ifdef SUPPORT_SYSRQ
458 if (port->cons && port->cons->index == port->line) {
459 if (!port->sysrq) {
460 port->sysrq = jiffies + HZ*5;
461 return 1;
462 }
463 port->sysrq = 0;
464 }
465 #endif
466 if (port->flags & UPF_SAK)
467 do_SAK(state->port.tty);
468 return 0;
469 }
470
471 /*
472 * UART_ENABLE_MS - determine if port should enable modem status irqs
473 */
474 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
475 (cflag) & CRTSCTS || \
476 !((cflag) & CLOCAL))
477
478 #endif /* LINUX_SERIAL_CORE_H */
479