4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * Copyright 2000 Bernardo Innocenti <bernie@codewiz.org>
6 * This file is part of DevLib - See README.devlib for information.
9 * \brief Buffered serial I/O driver
11 * The serial rx interrupt buffers incoming data in a software FIFO
12 * to decouple the higher level protocols from the line speed.
13 * Outgoing data is buffered as well for better performance.
14 * This driver is not optimized for best performance, but it
15 * has proved to be fast enough to handle transfer rates up to
16 * 38400bps on a 16MHz 80196.
18 * MODULE CONFIGURATION
20 * \li \c CONFIG_SER_HWHANDSHAKE - set to 1 to enable RTS/CTS handshake.
21 * Support is incomplete/untested.
22 * \li \c CONFIG_SER_TXTIMEOUT - Enable software serial transmission timeouts
26 * \author Bernardo Innocenti <bernie@develer.com>
31 *#* Revision 1.30 2006/07/19 12:56:26 bernie
32 *#* Convert to new Doxygen style.
34 *#* Revision 1.29 2006/05/18 00:39:30 bernie
35 *#* ser_open(): Document a bit more.
37 *#* Revision 1.28 2006/02/17 22:23:06 bernie
38 *#* Update POSIX serial emulator.
40 *#* Revision 1.27 2005/11/27 23:33:40 bernie
41 *#* Use appconfig.h instead of cfg/config.h.
43 *#* Revision 1.26 2005/11/04 16:20:02 bernie
44 *#* Fix reference to README.devlib in header.
46 *#* Revision 1.25 2005/04/11 19:10:27 bernie
47 *#* Include top-level headers from cfg/ subdir.
49 *#* Revision 1.24 2005/01/21 20:13:15 aleph
50 *#* Fix drain at ser_close()
52 *#* Revision 1.23 2005/01/14 00:47:07 aleph
53 *#* ser_drain(): Wait for hw transmission complete.
55 *#* Revision 1.22 2004/12/08 08:56:14 bernie
56 *#* Rename time_t to mtime_t.
58 *#* Revision 1.21 2004/11/16 18:10:13 bernie
59 *#* Add sanity checks for missing configuration parameters.
61 *#* Revision 1.20 2004/10/19 11:48:00 bernie
62 *#* Remove unused variable.
64 *#* Revision 1.19 2004/10/19 08:14:13 bernie
65 *#* Fix a few longstanding bugs wrt status handling (made by rasky on scfirm).
67 *#* Revision 1.18 2004/09/20 03:31:15 bernie
70 *#* Revision 1.17 2004/09/14 21:06:07 bernie
71 *#* Use debug.h instead of kdebug.h; Spelling fixes.
73 *#* Revision 1.16 2004/09/06 21:40:50 bernie
74 *#* Move buffer handling in chip-specific driver.
76 *#* Revision 1.15 2004/08/25 14:12:08 rasky
77 *#* Aggiornato il comment block dei log RCS
79 *#* Revision 1.14 2004/08/24 16:22:57 bernie
80 *#* Thinkos; Doxygen fixes
82 *#* Revision 1.13 2004/08/24 16:20:48 bernie
83 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
85 *#* Revision 1.12 2004/08/24 13:49:39 bernie
88 *#* Revision 1.11 2004/08/15 05:32:22 bernie
89 *#* ser_resync(): New function.
91 *#* Revision 1.10 2004/08/10 06:29:50 bernie
92 *#* Rename timer_gettick() to timer_ticks().
94 *#* Revision 1.9 2004/08/08 06:06:20 bernie
95 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
97 *#* Revision 1.8 2004/07/29 22:57:09 bernie
98 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
100 *#* Revision 1.7 2004/07/18 21:49:03 bernie
101 *#* Make CONFIG_SER_DEFBAUDRATE optional.
103 *#* Revision 1.6 2004/06/07 15:56:28 aleph
104 *#* Remove cast-as-lvalue extension abuse
106 *#* Revision 1.5 2004/06/06 16:41:44 bernie
107 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
109 *#* Revision 1.4 2004/06/03 11:27:09 bernie
110 *#* Add dual-license information.
112 *#* Revision 1.3 2004/06/02 21:35:24 aleph
113 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
115 *#* Revision 1.2 2004/05/23 18:21:53 bernie
116 *#* Trim CVS logs and cleanup header info.
122 #include <mware/formatwr.h>
123 #include <cfg/debug.h>
125 #include <appconfig.h>
128 * Sanity check for config parameters required by this module.
130 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
131 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
133 #if !defined(CONFIG_SER_RXTIMEOUT)
134 #error CONFIG_SER_TXTIMEOUT missing in config.h
136 #if !defined(CONFIG_SER_RXTIMEOUT)
137 #error CONFIG_SER_RXTIMEOUT missing in config.h
139 #if !defined(CONFIG_SER_GETS) || ((CONFIG_SER_GETS != 0) && CONFIG_SER_GETS != 1)
140 #error CONFIG_SER_GETS must be set to either 0 or 1 in config.h
142 #if !defined(CONFIG_SER_DEFBAUDRATE)
143 #error CONFIG_SER_DEFBAUDRATE missing in config.h
145 #if !defined(CONFIG_PRINTF)
146 #error CONFIG_PRINTF missing in config.h
150 #include <kern/proc.h>
153 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
154 #include <drv/timer.h>
158 /* Serial configuration parameters */
159 #define SER_CTSDELAY 70 /**< CTS line retry interval (ms) */
160 #define SER_TXPOLLDELAY 2 /**< Transmit buffer full retry interval (ms) */
161 #define SER_RXPOLLDELAY 2 /**< Receive buffer empty retry interval (ms) */
164 struct Serial ser_handles[SER_CNT];
168 * Inserisce il carattere c nel buffer di trasmissione.
169 * Questa funzione mette il processo chiamante in attesa
170 * quando il buffer e' pieno.
172 * \return EOF in caso di errore o timeout, altrimenti
173 * il carattere inviato.
175 int ser_putchar(int c, struct Serial *port)
177 //ASSERT_VALID_FIFO(&port->txfifo);
178 if (fifo_isfull_locked(&port->txfifo))
180 #if CONFIG_SER_TXTIMEOUT != -1
181 mtime_t start_time = timer_ticks();
184 /* Attende finche' il buffer e' pieno... */
187 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
188 /* Give up timeslice to other processes. */
191 #if CONFIG_SER_TXTIMEOUT != -1
192 if (timer_ticks() - start_time >= port->txtimeout)
194 port->status |= SERRF_TXTIMEOUT;
197 #endif /* CONFIG_SER_TXTIMEOUT */
199 while (fifo_isfull_locked(&port->txfifo));
202 fifo_push_locked(&port->txfifo, (unsigned char)c);
204 /* (re)trigger tx interrupt */
205 port->hw->table->txStart(port->hw);
207 /* Avoid returning signed extended char */
208 return (int)((unsigned char)c);
213 * Preleva un carattere dal buffer di ricezione.
214 * Questa funzione mette il processo chiamante in attesa
215 * quando il buffer e' vuoto. L'attesa ha un timeout
216 * di ser_rxtimeout millisecondi.
218 * \return EOF in caso di errore o timeout, altrimenti
219 * il carattere ricevuto.
221 int ser_getchar(struct Serial *port)
223 if (fifo_isempty_locked(&port->rxfifo))
225 #if CONFIG_SER_RXTIMEOUT != -1
226 mtime_t start_time = timer_ticks();
228 /* Wait while buffer is empty */
231 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
232 /* Give up timeslice to other processes. */
235 #if CONFIG_SER_RXTIMEOUT != -1
236 if (timer_ticks() - start_time >= port->rxtimeout)
238 port->status |= SERRF_RXTIMEOUT;
241 #endif /* CONFIG_SER_RXTIMEOUT */
243 while (fifo_isempty_locked(&port->rxfifo) && (port->status & SERRF_RX) == 0);
247 * Get a byte from the FIFO (avoiding sign-extension),
248 * re-enable RTS, then return result.
250 if (port->status & SERRF_RX)
252 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
257 * Preleva un carattere dal buffer di ricezione.
258 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
259 * immediatamente EOF.
261 int ser_getchar_nowait(struct Serial *port)
263 if (fifo_isempty_locked(&port->rxfifo))
266 /* NOTE: the double cast prevents unwanted sign extension */
267 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
273 * Read a line long at most as size and put it
275 * \return number of chars read or EOF in case
278 int ser_gets(struct Serial *port, char *buf, int size)
280 return ser_gets_echo(port, buf, size, false);
285 * Read a line long at most as size and put it
286 * in buf, with optional echo.
288 * \return number of chars read, or EOF in case
291 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
298 if ((c = ser_getchar(port)) == EOF)
305 if (c == '\r' || c == '\n' || i >= size-1)
309 ser_print(port, "\r\n");
314 ser_putchar(c, port);
319 #endif /* !CONFIG_SER_GETS */
323 * Read at most \a size bytes from \a port and put them in \a buf
325 * \return number of bytes actually read, or EOF in
328 int ser_read(struct Serial *port, void *buf, size_t size)
331 char *_buf = (char *)buf;
336 if ((c = ser_getchar(port)) == EOF)
346 * Write a string to serial.
347 * \return 0 if OK, EOF in case of error.
349 int ser_print(struct Serial *port, const char *s)
353 if (ser_putchar(*s++, port) == EOF)
361 * \brief Write a buffer to serial.
363 * \return 0 if OK, EOF in case of error.
365 * \todo Optimize with fifo_pushblock()
367 int ser_write(struct Serial *port, const void *_buf, size_t len)
369 const char *buf = (const char *)_buf;
373 if (ser_putchar(*buf++, port) == EOF)
384 int ser_printf(struct Serial *port, const char *format, ...)
389 va_start(ap, format);
390 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
395 #endif /* CONFIG_PRINTF */
398 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
399 void ser_settimeouts(struct Serial *port, mtime_t rxtimeout, mtime_t txtimeout)
401 port->rxtimeout = rxtimeout;
402 port->txtimeout = txtimeout;
404 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
406 #if CONFIG_SER_RXTIMEOUT != -1
408 * Discard input to resynchronize with remote end.
410 * Discard incoming data until the port stops receiving
411 * characters for at least \a delay milliseconds.
413 * \note Serial errors are reset before and after executing the purge.
415 void ser_resync(struct Serial *port, mtime_t delay)
417 mtime_t old_rxtimeout = port->rxtimeout;
419 ser_settimeouts(port, delay, port->txtimeout);
422 ser_setstatus(port, 0);
425 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
427 /* Restore port to an usable status */
428 ser_setstatus(port, 0);
429 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
431 #endif /* CONFIG_SER_RXTIMEOUT */
434 void ser_setbaudrate(struct Serial *port, unsigned long rate)
436 port->hw->table->setBaudrate(port->hw, rate);
440 void ser_setparity(struct Serial *port, int parity)
442 port->hw->table->setParity(port->hw, parity);
447 * Flush both the RX and TX buffers.
449 void ser_purge(struct Serial *port)
451 fifo_flush_locked(&port->rxfifo);
452 fifo_flush_locked(&port->txfifo);
457 * Wait until all pending output is completely
458 * transmitted to the other end.
460 * \note The current implementation only checks the
461 * software transmission queue. Any hardware
464 void ser_drain(struct Serial *ser)
467 * Wait until the FIFO is empty, and then until the byte currently in
468 * the hardware register gets shifted out.
470 while (!fifo_isempty(&ser->txfifo)
471 || ser->hw->table->txSending(ser->hw))
473 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
474 /* Give up timeslice to other processes. */
482 * Initialize a serial port.
484 * \param unit Serial unit to open. Possible values are architecture dependant.
486 struct Serial *ser_open(unsigned int unit)
490 ASSERT(unit < countof(ser_handles));
491 port = &ser_handles[unit];
493 ASSERT(!port->is_open);
494 DB(port->is_open = true;)
498 port->hw = ser_hw_getdesc(unit);
500 /* Initialize circular buffers */
501 ASSERT(port->hw->txbuffer);
502 ASSERT(port->hw->rxbuffer);
503 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
504 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
506 port->hw->table->init(port->hw, port);
508 /* Set default values */
509 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
510 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
512 #if CONFIG_SER_DEFBAUDRATE
513 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
516 /* Clear error flags */
517 ser_setstatus(port, 0);
524 * Clean up serial port, disabling the associated hardware.
526 void ser_close(struct Serial *port)
528 ASSERT(port->is_open);
529 DB(port->is_open = false;)
531 // Wait until we finish sending everything
534 port->hw->table->cleanup(port->hw);
538 * We purge the FIFO buffer only after the low-level cleanup, so that
539 * we are sure that there are no more interrupts.