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 1.29 2006/05/18 00:39:30 bernie
32 *#* ser_open(): Document a bit more.
34 *#* Revision 1.28 2006/02/17 22:23:06 bernie
35 *#* Update POSIX serial emulator.
37 *#* Revision 1.27 2005/11/27 23:33:40 bernie
38 *#* Use appconfig.h instead of cfg/config.h.
40 *#* Revision 1.26 2005/11/04 16:20:02 bernie
41 *#* Fix reference to README.devlib in header.
43 *#* Revision 1.25 2005/04/11 19:10:27 bernie
44 *#* Include top-level headers from cfg/ subdir.
46 *#* Revision 1.24 2005/01/21 20:13:15 aleph
47 *#* Fix drain at ser_close()
49 *#* Revision 1.23 2005/01/14 00:47:07 aleph
50 *#* ser_drain(): Wait for hw transmission complete.
52 *#* Revision 1.22 2004/12/08 08:56:14 bernie
53 *#* Rename time_t to mtime_t.
55 *#* Revision 1.21 2004/11/16 18:10:13 bernie
56 *#* Add sanity checks for missing configuration parameters.
58 *#* Revision 1.20 2004/10/19 11:48:00 bernie
59 *#* Remove unused variable.
61 *#* Revision 1.19 2004/10/19 08:14:13 bernie
62 *#* Fix a few longstanding bugs wrt status handling (made by rasky on scfirm).
64 *#* Revision 1.18 2004/09/20 03:31:15 bernie
67 *#* Revision 1.17 2004/09/14 21:06:07 bernie
68 *#* Use debug.h instead of kdebug.h; Spelling fixes.
70 *#* Revision 1.16 2004/09/06 21:40:50 bernie
71 *#* Move buffer handling in chip-specific driver.
73 *#* Revision 1.15 2004/08/25 14:12:08 rasky
74 *#* Aggiornato il comment block dei log RCS
76 *#* Revision 1.14 2004/08/24 16:22:57 bernie
77 *#* Thinkos; Doxygen fixes
79 *#* Revision 1.13 2004/08/24 16:20:48 bernie
80 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
82 *#* Revision 1.12 2004/08/24 13:49:39 bernie
85 *#* Revision 1.11 2004/08/15 05:32:22 bernie
86 *#* ser_resync(): New function.
88 *#* Revision 1.10 2004/08/10 06:29:50 bernie
89 *#* Rename timer_gettick() to timer_ticks().
91 *#* Revision 1.9 2004/08/08 06:06:20 bernie
92 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
94 *#* Revision 1.8 2004/07/29 22:57:09 bernie
95 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
97 *#* Revision 1.7 2004/07/18 21:49:03 bernie
98 *#* Make CONFIG_SER_DEFBAUDRATE optional.
100 *#* Revision 1.6 2004/06/07 15:56:28 aleph
101 *#* Remove cast-as-lvalue extension abuse
103 *#* Revision 1.5 2004/06/06 16:41:44 bernie
104 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
106 *#* Revision 1.4 2004/06/03 11:27:09 bernie
107 *#* Add dual-license information.
109 *#* Revision 1.3 2004/06/02 21:35:24 aleph
110 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
112 *#* Revision 1.2 2004/05/23 18:21:53 bernie
113 *#* Trim CVS logs and cleanup header info.
119 #include <mware/formatwr.h>
120 #include <cfg/debug.h>
122 #include <appconfig.h>
125 * Sanity check for config parameters required by this module.
127 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
128 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
130 #if !defined(CONFIG_SER_RXTIMEOUT)
131 #error CONFIG_SER_TXTIMEOUT missing in config.h
133 #if !defined(CONFIG_SER_RXTIMEOUT)
134 #error CONFIG_SER_RXTIMEOUT missing in config.h
136 #if !defined(CONFIG_SER_GETS) || ((CONFIG_SER_GETS != 0) && CONFIG_SER_GETS != 1)
137 #error CONFIG_SER_GETS must be set to either 0 or 1 in config.h
139 #if !defined(CONFIG_SER_DEFBAUDRATE)
140 #error CONFIG_SER_DEFBAUDRATE missing in config.h
142 #if !defined(CONFIG_PRINTF)
143 #error CONFIG_PRINTF missing in config.h
147 #include <kern/proc.h>
150 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
151 #include <drv/timer.h>
155 /* Serial configuration parameters */
156 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
157 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
158 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
161 struct Serial ser_handles[SER_CNT];
165 * Inserisce il carattere c nel buffer di trasmissione.
166 * Questa funzione mette il processo chiamante in attesa
167 * quando il buffer e' pieno.
169 * \return EOF in caso di errore o timeout, altrimenti
170 * il carattere inviato.
172 int ser_putchar(int c, struct Serial *port)
174 //ASSERT_VALID_FIFO(&port->txfifo);
175 if (fifo_isfull_locked(&port->txfifo))
177 #if CONFIG_SER_TXTIMEOUT != -1
178 mtime_t start_time = timer_ticks();
181 /* Attende finche' il buffer e' pieno... */
184 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
185 /* Give up timeslice to other processes. */
188 #if CONFIG_SER_TXTIMEOUT != -1
189 if (timer_ticks() - start_time >= port->txtimeout)
191 port->status |= SERRF_TXTIMEOUT;
194 #endif /* CONFIG_SER_TXTIMEOUT */
196 while (fifo_isfull_locked(&port->txfifo));
199 fifo_push_locked(&port->txfifo, (unsigned char)c);
201 /* (re)trigger tx interrupt */
202 port->hw->table->txStart(port->hw);
204 /* Avoid returning signed extended char */
205 return (int)((unsigned char)c);
210 * Preleva un carattere dal buffer di ricezione.
211 * Questa funzione mette il processo chiamante in attesa
212 * quando il buffer e' vuoto. L'attesa ha un timeout
213 * di ser_rxtimeout millisecondi.
215 * \return EOF in caso di errore o timeout, altrimenti
216 * il carattere ricevuto.
218 int ser_getchar(struct Serial *port)
220 if (fifo_isempty_locked(&port->rxfifo))
222 #if CONFIG_SER_RXTIMEOUT != -1
223 mtime_t start_time = timer_ticks();
225 /* Wait while buffer is empty */
228 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
229 /* Give up timeslice to other processes. */
232 #if CONFIG_SER_RXTIMEOUT != -1
233 if (timer_ticks() - start_time >= port->rxtimeout)
235 port->status |= SERRF_RXTIMEOUT;
238 #endif /* CONFIG_SER_RXTIMEOUT */
240 while (fifo_isempty_locked(&port->rxfifo) && (port->status & SERRF_RX) == 0);
244 * Get a byte from the FIFO (avoiding sign-extension),
245 * re-enable RTS, then return result.
247 if (port->status & SERRF_RX)
249 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
254 * Preleva un carattere dal buffer di ricezione.
255 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
256 * immediatamente EOF.
258 int ser_getchar_nowait(struct Serial *port)
260 if (fifo_isempty_locked(&port->rxfifo))
263 /* NOTE: the double cast prevents unwanted sign extension */
264 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
270 * Read a line long at most as size and put it
272 * \return number of chars read or EOF in case
275 int ser_gets(struct Serial *port, char *buf, int size)
277 return ser_gets_echo(port, buf, size, false);
282 * Read a line long at most as size and put it
283 * in buf, with optional echo.
285 * \return number of chars read, or EOF in case
288 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
295 if ((c = ser_getchar(port)) == EOF)
302 if (c == '\r' || c == '\n' || i >= size-1)
306 ser_print(port, "\r\n");
311 ser_putchar(c, port);
316 #endif /* !CONFIG_SER_GETS */
320 * Read at most \a size bytes from \a port and put them in \a buf
322 * \return number of bytes actually read, or EOF in
325 int ser_read(struct Serial *port, void *buf, size_t size)
328 char *_buf = (char *)buf;
333 if ((c = ser_getchar(port)) == EOF)
343 * Write a string to serial.
344 * \return 0 if OK, EOF in case of error.
346 int ser_print(struct Serial *port, const char *s)
350 if (ser_putchar(*s++, port) == EOF)
358 * \brief Write a buffer to serial.
360 * \return 0 if OK, EOF in case of error.
362 * \todo Optimize with fifo_pushblock()
364 int ser_write(struct Serial *port, const void *_buf, size_t len)
366 const char *buf = (const char *)_buf;
370 if (ser_putchar(*buf++, port) == EOF)
381 int ser_printf(struct Serial *port, const char *format, ...)
386 va_start(ap, format);
387 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
392 #endif /* CONFIG_PRINTF */
395 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
396 void ser_settimeouts(struct Serial *port, mtime_t rxtimeout, mtime_t txtimeout)
398 port->rxtimeout = rxtimeout;
399 port->txtimeout = txtimeout;
401 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
403 #if CONFIG_SER_RXTIMEOUT != -1
405 * Discard input to resynchronize with remote end.
407 * Discard incoming data until the port stops receiving
408 * characters for at least \a delay milliseconds.
410 * \note Serial errors are reset before and after executing the purge.
412 void ser_resync(struct Serial *port, mtime_t delay)
414 mtime_t old_rxtimeout = port->rxtimeout;
416 ser_settimeouts(port, delay, port->txtimeout);
419 ser_setstatus(port, 0);
422 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
424 /* Restore port to an usable status */
425 ser_setstatus(port, 0);
426 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
428 #endif /* CONFIG_SER_RXTIMEOUT */
431 void ser_setbaudrate(struct Serial *port, unsigned long rate)
433 port->hw->table->setBaudrate(port->hw, rate);
437 void ser_setparity(struct Serial *port, int parity)
439 port->hw->table->setParity(port->hw, parity);
444 * Flush both the RX and TX buffers.
446 void ser_purge(struct Serial *port)
448 fifo_flush_locked(&port->rxfifo);
449 fifo_flush_locked(&port->txfifo);
454 * Wait until all pending output is completely
455 * transmitted to the other end.
457 * \note The current implementation only checks the
458 * software transmission queue. Any hardware
461 void ser_drain(struct Serial *ser)
464 * Wait until the FIFO is empty, and then until the byte currently in
465 * the hardware register gets shifted out.
467 while (!fifo_isempty(&ser->txfifo)
468 || ser->hw->table->txSending(ser->hw))
470 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
471 /* Give up timeslice to other processes. */
479 * Initialize a serial port.
481 * \param unit Serial unit to open. Possible values are architecture dependant.
483 struct Serial *ser_open(unsigned int unit)
487 ASSERT(unit < countof(ser_handles));
488 port = &ser_handles[unit];
490 ASSERT(!port->is_open);
491 DB(port->is_open = true;)
495 port->hw = ser_hw_getdesc(unit);
497 /* Initialize circular buffers */
498 ASSERT(port->hw->txbuffer);
499 ASSERT(port->hw->rxbuffer);
500 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
501 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
503 port->hw->table->init(port->hw, port);
505 /* Set default values */
506 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
507 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
509 #if CONFIG_SER_DEFBAUDRATE
510 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
513 /* Clear error flags */
514 ser_setstatus(port, 0);
521 * Clean up serial port, disabling the associated hardware.
523 void ser_close(struct Serial *port)
525 ASSERT(port->is_open);
526 DB(port->is_open = false;)
528 // Wait until we finish sending everything
531 port->hw->table->cleanup(port->hw);
535 * We purge the FIFO buffer only after the low-level cleanup, so that
536 * we are sure that there are no more interrupts.