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serial_core.h
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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 <linux/pps_kernel.h>
33 #include <uapi/linux/serial_core.h>
34 
35 struct uart_port;
36 struct serial_struct;
37 struct device;
38 
39 /*
40  * This structure describes all the operations that can be
41  * done on the physical hardware.
42  */
43 struct uart_ops {
44  unsigned int (*tx_empty)(struct uart_port *);
45  void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
46  unsigned int (*get_mctrl)(struct uart_port *);
47  void (*stop_tx)(struct uart_port *);
48  void (*start_tx)(struct uart_port *);
49  void (*send_xchar)(struct uart_port *, char ch);
50  void (*stop_rx)(struct uart_port *);
51  void (*enable_ms)(struct uart_port *);
52  void (*break_ctl)(struct uart_port *, int ctl);
53  int (*startup)(struct uart_port *);
54  void (*shutdown)(struct uart_port *);
55  void (*flush_buffer)(struct uart_port *);
56  void (*set_termios)(struct uart_port *, struct ktermios *new,
57  struct ktermios *old);
58  void (*set_ldisc)(struct uart_port *, int new);
59  void (*pm)(struct uart_port *, unsigned int state,
60  unsigned int oldstate);
61  int (*set_wake)(struct uart_port *, unsigned int state);
62 
63  /*
64  * Return a string describing the type of the port
65  */
66  const char *(*type)(struct uart_port *);
67 
68  /*
69  * Release IO and memory resources used by the port.
70  * This includes iounmap if necessary.
71  */
72  void (*release_port)(struct uart_port *);
73 
74  /*
75  * Request IO and memory resources used by the port.
76  * This includes iomapping the port if necessary.
77  */
78  int (*request_port)(struct uart_port *);
79  void (*config_port)(struct uart_port *, int);
80  int (*verify_port)(struct uart_port *, struct serial_struct *);
81  int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
82 #ifdef CONFIG_CONSOLE_POLL
83  int (*poll_init)(struct uart_port *);
84  void (*poll_put_char)(struct uart_port *, unsigned char);
85  int (*poll_get_char)(struct uart_port *);
86 #endif
87 };
88 
89 #define NO_POLL_CHAR 0x00ff0000
90 #define UART_CONFIG_TYPE (1 << 0)
91 #define UART_CONFIG_IRQ (1 << 1)
92 
93 struct uart_icount {
94  __u32 cts;
95  __u32 dsr;
96  __u32 rng;
97  __u32 dcd;
98  __u32 rx;
99  __u32 tx;
100  __u32 frame;
101  __u32 overrun;
102  __u32 parity;
103  __u32 brk;
104  __u32 buf_overrun;
105 };
106 
107 typedef unsigned int __bitwise__ upf_t;
108 
109 struct uart_port {
110  spinlock_t lock; /* port lock */
111  unsigned long iobase; /* in/out[bwl] */
112  unsigned char __iomem *membase; /* read/write[bwl] */
113  unsigned int (*serial_in)(struct uart_port *, int);
114  void (*serial_out)(struct uart_port *, int, int);
115  void (*set_termios)(struct uart_port *,
116  struct ktermios *new,
117  struct ktermios *old);
118  int (*handle_irq)(struct uart_port *);
119  void (*pm)(struct uart_port *, unsigned int state,
120  unsigned int old);
121  void (*handle_break)(struct uart_port *);
122  unsigned int irq; /* irq number */
123  unsigned long irqflags; /* irq flags */
124  unsigned int uartclk; /* base uart clock */
125  unsigned int fifosize; /* tx fifo size */
126  unsigned char x_char; /* xon/xoff char */
127  unsigned char regshift; /* reg offset shift */
128  unsigned char iotype; /* io access style */
129  unsigned char unused1;
130 
131 #define UPIO_PORT (0)
132 #define UPIO_HUB6 (1)
133 #define UPIO_MEM (2)
134 #define UPIO_MEM32 (3)
135 #define UPIO_AU (4) /* Au1x00 type IO */
136 #define UPIO_TSI (5) /* Tsi108/109 type IO */
137 #define UPIO_RM9000 (6) /* RM9000 type IO */
138 
139  unsigned int read_status_mask; /* driver specific */
140  unsigned int ignore_status_mask; /* driver specific */
141  struct uart_state *state; /* pointer to parent state */
142  struct uart_icount icount; /* statistics */
143 
144  struct console *cons; /* struct console, if any */
145 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
146  unsigned long sysrq; /* sysrq timeout */
147 #endif
148 
149  upf_t flags;
150 
151 #define UPF_FOURPORT ((__force upf_t) (1 << 1))
152 #define UPF_SAK ((__force upf_t) (1 << 2))
153 #define UPF_SPD_MASK ((__force upf_t) (0x1030))
154 #define UPF_SPD_HI ((__force upf_t) (0x0010))
155 #define UPF_SPD_VHI ((__force upf_t) (0x0020))
156 #define UPF_SPD_CUST ((__force upf_t) (0x0030))
157 #define UPF_SPD_SHI ((__force upf_t) (0x1000))
158 #define UPF_SPD_WARP ((__force upf_t) (0x1010))
159 #define UPF_SKIP_TEST ((__force upf_t) (1 << 6))
160 #define UPF_AUTO_IRQ ((__force upf_t) (1 << 7))
161 #define UPF_HARDPPS_CD ((__force upf_t) (1 << 11))
162 #define UPF_LOW_LATENCY ((__force upf_t) (1 << 13))
163 #define UPF_BUGGY_UART ((__force upf_t) (1 << 14))
164 #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
165 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) (1 << 16))
166 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
167 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
168 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
169 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
170 /* The exact UART type is known and should not be probed. */
171 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
172 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
173 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
174 #define UPF_DEAD ((__force upf_t) (1 << 30))
175 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
176 
177 #define UPF_CHANGE_MASK ((__force upf_t) (0x17fff))
178 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
179 
180  unsigned int mctrl; /* current modem ctrl settings */
181  unsigned int timeout; /* character-based timeout */
182  unsigned int type; /* port type */
183  const struct uart_ops *ops;
184  unsigned int custom_divisor;
185  unsigned int line; /* port index */
186  resource_size_t mapbase; /* for ioremap */
187  struct device *dev; /* parent device */
188  unsigned char hub6; /* this should be in the 8250 driver */
189  unsigned char suspended;
190  unsigned char irq_wake;
191  unsigned char unused[2];
192  void *private_data; /* generic platform data pointer */
193 };
194 
195 static inline int serial_port_in(struct uart_port *up, int offset)
196 {
197  return up->serial_in(up, offset);
198 }
199 
200 static inline void serial_port_out(struct uart_port *up, int offset, int value)
201 {
202  up->serial_out(up, offset, value);
203 }
204 
205 /*
206  * This is the state information which is persistent across opens.
207  */
208 struct uart_state {
209  struct tty_port port;
210 
211  int pm_state;
212  struct circ_buf xmit;
213 
214  struct uart_port *uart_port;
215 };
216 
217 #define UART_XMIT_SIZE PAGE_SIZE
218 
219 
220 /* number of characters left in xmit buffer before we ask for more */
221 #define WAKEUP_CHARS 256
222 
223 struct module;
224 struct tty_driver;
225 
226 struct uart_driver {
227  struct module *owner;
228  const char *driver_name;
229  const char *dev_name;
230  int major;
231  int minor;
232  int nr;
233  struct console *cons;
234 
235  /*
236  * these are private; the low level driver should not
237  * touch these; they should be initialised to NULL
238  */
239  struct uart_state *state;
240  struct tty_driver *tty_driver;
241 };
242 
243 void uart_write_wakeup(struct uart_port *port);
244 
245 /*
246  * Baud rate helpers.
247  */
248 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
249  unsigned int baud);
250 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
251  struct ktermios *old, unsigned int min,
252  unsigned int max);
253 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
254 
255 /* Base timer interval for polling */
256 static inline int uart_poll_timeout(struct uart_port *port)
257 {
258  int timeout = port->timeout;
259 
260  return timeout > 6 ? (timeout / 2 - 2) : 1;
261 }
262 
263 /*
264  * Console helpers.
265  */
266 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
267  struct console *c);
268 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
269  int *flow);
270 int uart_set_options(struct uart_port *port, struct console *co, int baud,
271  int parity, int bits, int flow);
272 struct tty_driver *uart_console_device(struct console *co, int *index);
273 void uart_console_write(struct uart_port *port, const char *s,
274  unsigned int count,
275  void (*putchar)(struct uart_port *, int));
276 
277 /*
278  * Port/driver registration/removal
279  */
280 int uart_register_driver(struct uart_driver *uart);
281 void uart_unregister_driver(struct uart_driver *uart);
282 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
283 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
284 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
285 
286 /*
287  * Power Management
288  */
289 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
290 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
291 
292 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
293 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
294 
295 #define uart_circ_chars_pending(circ) \
296  (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
297 
298 #define uart_circ_chars_free(circ) \
299  (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
300 
301 static inline int uart_tx_stopped(struct uart_port *port)
302 {
303  struct tty_struct *tty = port->state->port.tty;
304  if(tty->stopped || tty->hw_stopped)
305  return 1;
306  return 0;
307 }
308 
309 /*
310  * The following are helper functions for the low level drivers.
311  */
312 
313 extern void uart_handle_dcd_change(struct uart_port *uport,
314  unsigned int status);
315 extern void uart_handle_cts_change(struct uart_port *uport,
316  unsigned int status);
317 
318 extern void uart_insert_char(struct uart_port *port, unsigned int status,
319  unsigned int overrun, unsigned int ch, unsigned int flag);
320 
321 #ifdef SUPPORT_SYSRQ
322 static inline int
323 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
324 {
325  if (port->sysrq) {
326  if (ch && time_before(jiffies, port->sysrq)) {
327  handle_sysrq(ch);
328  port->sysrq = 0;
329  return 1;
330  }
331  port->sysrq = 0;
332  }
333  return 0;
334 }
335 #else
336 #define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
337 #endif
338 
339 /*
340  * We do the SysRQ and SAK checking like this...
341  */
342 static inline int uart_handle_break(struct uart_port *port)
343 {
344  struct uart_state *state = port->state;
345 
346  if (port->handle_break)
347  port->handle_break(port);
348 
349 #ifdef SUPPORT_SYSRQ
350  if (port->cons && port->cons->index == port->line) {
351  if (!port->sysrq) {
352  port->sysrq = jiffies + HZ*5;
353  return 1;
354  }
355  port->sysrq = 0;
356  }
357 #endif
358  if (port->flags & UPF_SAK)
359  do_SAK(state->port.tty);
360  return 0;
361 }
362 
363 /*
364  * UART_ENABLE_MS - determine if port should enable modem status irqs
365  */
366 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
367  (cflag) & CRTSCTS || \
368  !((cflag) & CLOCAL))
369 
370 #endif /* LINUX_SERIAL_CORE_H */
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