4 * Copyright 2003, 2004, 2006 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 1.32 2006/11/17 17:03:58 batt
32 *#* Implement ser_setstatus and ser_getstatus as functions to avoid race conditions.
34 *#* Revision 1.31 2006/07/21 10:58:00 batt
35 *#* Use timer_clock() instead of obsolete timer_ticks().
37 *#* Revision 1.30 2006/07/19 12:56:26 bernie
38 *#* Convert to new Doxygen style.
40 *#* Revision 1.29 2006/05/18 00:39:30 bernie
41 *#* ser_open(): Document a bit more.
43 *#* Revision 1.28 2006/02/17 22:23:06 bernie
44 *#* Update POSIX serial emulator.
46 *#* Revision 1.27 2005/11/27 23:33:40 bernie
47 *#* Use appconfig.h instead of cfg/config.h.
49 *#* Revision 1.26 2005/11/04 16:20:02 bernie
50 *#* Fix reference to README.devlib in header.
52 *#* Revision 1.25 2005/04/11 19:10:27 bernie
53 *#* Include top-level headers from cfg/ subdir.
55 *#* Revision 1.24 2005/01/21 20:13:15 aleph
56 *#* Fix drain at ser_close()
58 *#* Revision 1.23 2005/01/14 00:47:07 aleph
59 *#* ser_drain(): Wait for hw transmission complete.
61 *#* Revision 1.22 2004/12/08 08:56:14 bernie
62 *#* Rename time_t to mtime_t.
64 *#* Revision 1.21 2004/11/16 18:10:13 bernie
65 *#* Add sanity checks for missing configuration parameters.
67 *#* Revision 1.20 2004/10/19 11:48:00 bernie
68 *#* Remove unused variable.
70 *#* Revision 1.19 2004/10/19 08:14:13 bernie
71 *#* Fix a few longstanding bugs wrt status handling (made by rasky on scfirm).
73 *#* Revision 1.18 2004/09/20 03:31:15 bernie
76 *#* Revision 1.17 2004/09/14 21:06:07 bernie
77 *#* Use debug.h instead of kdebug.h; Spelling fixes.
79 *#* Revision 1.16 2004/09/06 21:40:50 bernie
80 *#* Move buffer handling in chip-specific driver.
82 *#* Revision 1.15 2004/08/25 14:12:08 rasky
83 *#* Aggiornato il comment block dei log RCS
85 *#* Revision 1.14 2004/08/24 16:22:57 bernie
86 *#* Thinkos; Doxygen fixes
88 *#* Revision 1.13 2004/08/24 16:20:48 bernie
89 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
91 *#* Revision 1.12 2004/08/24 13:49:39 bernie
94 *#* Revision 1.11 2004/08/15 05:32:22 bernie
95 *#* ser_resync(): New function.
97 *#* Revision 1.10 2004/08/10 06:29:50 bernie
98 *#* Rename timer_gettick() to timer_ticks().
100 *#* Revision 1.9 2004/08/08 06:06:20 bernie
101 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
103 *#* Revision 1.8 2004/07/29 22:57:09 bernie
104 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
106 *#* Revision 1.7 2004/07/18 21:49:03 bernie
107 *#* Make CONFIG_SER_DEFBAUDRATE optional.
109 *#* Revision 1.6 2004/06/07 15:56:28 aleph
110 *#* Remove cast-as-lvalue extension abuse
112 *#* Revision 1.5 2004/06/06 16:41:44 bernie
113 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
115 *#* Revision 1.4 2004/06/03 11:27:09 bernie
116 *#* Add dual-license information.
118 *#* Revision 1.3 2004/06/02 21:35:24 aleph
119 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
121 *#* Revision 1.2 2004/05/23 18:21:53 bernie
122 *#* Trim CVS logs and cleanup header info.
128 #include <mware/formatwr.h>
129 #include <cfg/debug.h>
130 #include <appconfig.h>
133 * Sanity check for config parameters required by this module.
135 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
136 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
138 #if !defined(CONFIG_SER_RXTIMEOUT)
139 #error CONFIG_SER_TXTIMEOUT missing in config.h
141 #if !defined(CONFIG_SER_RXTIMEOUT)
142 #error CONFIG_SER_RXTIMEOUT missing in config.h
144 #if !defined(CONFIG_SER_GETS) || ((CONFIG_SER_GETS != 0) && CONFIG_SER_GETS != 1)
145 #error CONFIG_SER_GETS must be set to either 0 or 1 in config.h
147 #if !defined(CONFIG_SER_DEFBAUDRATE)
148 #error CONFIG_SER_DEFBAUDRATE missing in config.h
150 #if !defined(CONFIG_PRINTF)
151 #error CONFIG_PRINTF missing in config.h
155 #include <kern/proc.h>
158 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
159 #include <drv/timer.h>
163 /* Serial configuration parameters */
164 #define SER_CTSDELAY 70 /**< CTS line retry interval (ms) */
165 #define SER_TXPOLLDELAY 2 /**< Transmit buffer full retry interval (ms) */
166 #define SER_RXPOLLDELAY 2 /**< Receive buffer empty retry interval (ms) */
169 struct Serial ser_handles[SER_CNT];
173 * Inserisce il carattere c nel buffer di trasmissione.
174 * Questa funzione mette il processo chiamante in attesa
175 * quando il buffer e' pieno.
177 * \return EOF in caso di errore o timeout, altrimenti
178 * il carattere inviato.
180 int ser_putchar(int c, struct Serial *port)
182 //ASSERT_VALID_FIFO(&port->txfifo);
183 if (fifo_isfull_locked(&port->txfifo))
185 #if CONFIG_SER_TXTIMEOUT != -1
186 ticks_t start_time = timer_clock();
189 /* Attende finche' il buffer e' pieno... */
192 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
193 /* Give up timeslice to other processes. */
196 #if CONFIG_SER_TXTIMEOUT != -1
197 if (timer_clock() - start_time >= port->txtimeout)
199 port->status |= SERRF_TXTIMEOUT;
202 #endif /* CONFIG_SER_TXTIMEOUT */
204 while (fifo_isfull_locked(&port->txfifo));
207 fifo_push_locked(&port->txfifo, (unsigned char)c);
209 /* (re)trigger tx interrupt */
210 port->hw->table->txStart(port->hw);
212 /* Avoid returning signed extended char */
213 return (int)((unsigned char)c);
218 * Preleva un carattere dal buffer di ricezione.
219 * Questa funzione mette il processo chiamante in attesa
220 * quando il buffer e' vuoto. L'attesa ha un timeout
221 * di ser_rxtimeout millisecondi.
223 * \return EOF in caso di errore o timeout, altrimenti
224 * il carattere ricevuto.
226 int ser_getchar(struct Serial *port)
228 if (fifo_isempty_locked(&port->rxfifo))
230 #if CONFIG_SER_RXTIMEOUT != -1
231 ticks_t start_time = timer_clock();
233 /* Wait while buffer is empty */
236 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
237 /* Give up timeslice to other processes. */
240 #if CONFIG_SER_RXTIMEOUT != -1
241 if (timer_clock() - start_time >= port->rxtimeout)
243 port->status |= SERRF_RXTIMEOUT;
246 #endif /* CONFIG_SER_RXTIMEOUT */
248 while (fifo_isempty_locked(&port->rxfifo) && (port->status & SERRF_RX) == 0);
252 * Get a byte from the FIFO (avoiding sign-extension),
253 * re-enable RTS, then return result.
255 if (port->status & SERRF_RX)
257 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
262 * Preleva un carattere dal buffer di ricezione.
263 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
264 * immediatamente EOF.
266 int ser_getchar_nowait(struct Serial *port)
268 if (fifo_isempty_locked(&port->rxfifo))
271 /* NOTE: the double cast prevents unwanted sign extension */
272 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
278 * Read a line long at most as size and put it
280 * \return number of chars read or EOF in case
283 int ser_gets(struct Serial *port, char *buf, int size)
285 return ser_gets_echo(port, buf, size, false);
290 * Read a line long at most as size and put it
291 * in buf, with optional echo.
293 * \return number of chars read, or EOF in case
296 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
303 if ((c = ser_getchar(port)) == EOF)
310 if (c == '\r' || c == '\n' || i >= size-1)
314 ser_print(port, "\r\n");
319 ser_putchar(c, port);
324 #endif /* !CONFIG_SER_GETS */
328 * Read at most \a size bytes from \a port and put them in \a buf
330 * \return number of bytes actually read, or EOF in
333 int ser_read(struct Serial *port, void *buf, size_t size)
336 char *_buf = (char *)buf;
341 if ((c = ser_getchar(port)) == EOF)
351 * Write a string to serial.
352 * \return 0 if OK, EOF in case of error.
354 int ser_print(struct Serial *port, const char *s)
358 if (ser_putchar(*s++, port) == EOF)
366 * \brief Write a buffer to serial.
368 * \return 0 if OK, EOF in case of error.
370 * \todo Optimize with fifo_pushblock()
372 int ser_write(struct Serial *port, const void *_buf, size_t len)
374 const char *buf = (const char *)_buf;
378 if (ser_putchar(*buf++, port) == EOF)
389 int ser_printf(struct Serial *port, const char *format, ...)
394 va_start(ap, format);
395 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
400 #endif /* CONFIG_PRINTF */
403 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
404 void ser_settimeouts(struct Serial *port, mtime_t rxtimeout, mtime_t txtimeout)
406 port->rxtimeout = ms_to_ticks(rxtimeout);
407 port->txtimeout = ms_to_ticks(txtimeout);
409 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
411 #if CONFIG_SER_RXTIMEOUT != -1
413 * Discard input to resynchronize with remote end.
415 * Discard incoming data until the port stops receiving
416 * characters for at least \a delay milliseconds.
418 * \note Serial errors are reset before and after executing the purge.
420 void ser_resync(struct Serial *port, mtime_t delay)
422 mtime_t old_rxtimeout = ticks_to_ms(port->rxtimeout);
424 ser_settimeouts(port, delay, ticks_to_ms(port->txtimeout));
427 ser_setstatus(port, 0);
430 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
432 /* Restore port to an usable status */
433 ser_setstatus(port, 0);
434 ser_settimeouts(port, old_rxtimeout, ticks_to_ms(port->txtimeout));
436 #endif /* CONFIG_SER_RXTIMEOUT */
439 void ser_setbaudrate(struct Serial *port, unsigned long rate)
441 port->hw->table->setBaudrate(port->hw, rate);
445 void ser_setparity(struct Serial *port, int parity)
447 port->hw->table->setParity(port->hw, parity);
452 * Flush both the RX and TX buffers.
454 void ser_purge(struct Serial *port)
456 fifo_flush_locked(&port->rxfifo);
457 fifo_flush_locked(&port->txfifo);
461 * Get status of port \c port.
463 serstatus_t ser_getstatus(struct Serial *port)
466 ATOMIC(status = port->status);
473 * Set new \c port status.
475 void ser_setstatus(struct Serial *port, serstatus_t status)
477 ATOMIC(port->status = status);
482 * Wait until all pending output is completely
483 * transmitted to the other end.
485 * \note The current implementation only checks the
486 * software transmission queue. Any hardware
489 void ser_drain(struct Serial *ser)
492 * Wait until the FIFO becomes empty, and then until the byte currently in
493 * the hardware register gets shifted out.
495 while (!fifo_isempty(&ser->txfifo)
496 || ser->hw->table->txSending(ser->hw))
498 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
499 /* Give up timeslice to other processes. */
507 * Initialize a serial port.
509 * \param unit Serial unit to open. Possible values are architecture dependant.
511 struct Serial *ser_open(unsigned int unit)
515 ASSERT(unit < countof(ser_handles));
516 port = &ser_handles[unit];
518 ASSERT(!port->is_open);
519 DB(port->is_open = true;)
523 port->hw = ser_hw_getdesc(unit);
525 /* Initialize circular buffers */
526 ASSERT(port->hw->txbuffer);
527 ASSERT(port->hw->rxbuffer);
528 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
529 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
531 port->hw->table->init(port->hw, port);
533 /* Set default values */
534 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
535 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
537 #if CONFIG_SER_DEFBAUDRATE
538 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
541 /* Clear error flags */
542 ser_setstatus(port, 0);
549 * Clean up serial port, disabling the associated hardware.
551 void ser_close(struct Serial *port)
553 ASSERT(port->is_open);
554 DB(port->is_open = false;)
556 // Wait until we finish sending everything
559 port->hw->table->cleanup(port->hw);
563 * We purge the FIFO buffer only after the low-level cleanup, so that
564 * we are sure that there are no more interrupts.