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 devlib/README 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 1.21 2004/11/16 18:10:13 bernie
32 *#* Add sanity checks for missing configuration parameters.
34 *#* Revision 1.20 2004/10/19 11:48:00 bernie
35 *#* Remove unused variable.
37 *#* Revision 1.19 2004/10/19 08:14:13 bernie
38 *#* Fix a few longstanding bugs wrt status handling (made by rasky on scfirm).
40 *#* Revision 1.18 2004/09/20 03:31:15 bernie
43 *#* Revision 1.17 2004/09/14 21:06:07 bernie
44 *#* Use debug.h instead of kdebug.h; Spelling fixes.
46 *#* Revision 1.16 2004/09/06 21:40:50 bernie
47 *#* Move buffer handling in chip-specific driver.
49 *#* Revision 1.15 2004/08/25 14:12:08 rasky
50 *#* Aggiornato il comment block dei log RCS
52 *#* Revision 1.14 2004/08/24 16:22:57 bernie
53 *#* Thinkos; Doxygen fixes
55 *#* Revision 1.13 2004/08/24 16:20:48 bernie
56 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
58 *#* Revision 1.12 2004/08/24 13:49:39 bernie
61 *#* Revision 1.11 2004/08/15 05:32:22 bernie
62 *#* ser_resync(): New function.
64 *#* Revision 1.10 2004/08/10 06:29:50 bernie
65 *#* Rename timer_gettick() to timer_ticks().
67 *#* Revision 1.9 2004/08/08 06:06:20 bernie
68 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
70 *#* Revision 1.8 2004/07/29 22:57:09 bernie
71 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
73 *#* Revision 1.7 2004/07/18 21:49:03 bernie
74 *#* Make CONFIG_SER_DEFBAUDRATE optional.
76 *#* Revision 1.6 2004/06/07 15:56:28 aleph
77 *#* Remove cast-as-lvalue extension abuse
79 *#* Revision 1.5 2004/06/06 16:41:44 bernie
80 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
82 *#* Revision 1.4 2004/06/03 11:27:09 bernie
83 *#* Add dual-license information.
85 *#* Revision 1.3 2004/06/02 21:35:24 aleph
86 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
88 *#* Revision 1.2 2004/05/23 18:21:53 bernie
89 *#* Trim CVS logs and cleanup header info.
95 #include <mware/formatwr.h>
101 * Sanity check for config parameters required by this module.
103 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
104 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
106 #if !defined(CONFIG_SER_RXTIMEOUT)
107 #error CONFIG_SER_TXTIMEOUT missing in config.h
109 #if !defined(CONFIG_SER_RXTIMEOUT)
110 #error CONFIG_SER_RXTIMEOUT missing in config.h
112 #if !defined(CONFIG_SER_GETS) || ((CONFIG_SER_GETS != 0) && CONFIG_SER_GETS != 1)
113 #error CONFIG_SER_GETS must be set to either 0 or 1 in config.h
115 #if !defined(CONFIG_SER_DEFBAUDRATE)
116 #error CONFIG_SER_DEFBAUDRATE missing in config.h
118 #if !defined(CONFIG_PRINTF)
119 #error CONFIG_PRINTF missing in config.h
123 #include <kern/proc.h>
126 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
127 #include <drv/timer.h>
131 /* Serial configuration parameters */
132 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
133 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
134 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
137 struct Serial ser_handles[SER_CNT];
141 * Inserisce il carattere c nel buffer di trasmissione.
142 * Questa funzione mette il processo chiamante in attesa
143 * quando il buffer e' pieno.
145 * \return EOF in caso di errore o timeout, altrimenti
146 * il carattere inviato.
148 int ser_putchar(int c, struct Serial *port)
150 //ASSERT_VALID_FIFO(&port->txfifo);
151 if (fifo_isfull_locked(&port->txfifo))
153 #if CONFIG_SER_TXTIMEOUT != -1
154 time_t start_time = timer_ticks();
157 /* Attende finche' il buffer e' pieno... */
160 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
161 /* Give up timeslice to other processes. */
164 #if CONFIG_SER_TXTIMEOUT != -1
165 if (timer_ticks() - start_time >= port->txtimeout)
167 port->status |= SERRF_TXTIMEOUT;
170 #endif /* CONFIG_SER_TXTIMEOUT */
172 while (fifo_isfull_locked(&port->txfifo));
175 fifo_push_locked(&port->txfifo, (unsigned char)c);
177 /* (re)trigger tx interrupt */
178 port->hw->table->enabletxirq(port->hw);
180 /* Avoid returning signed extended char */
181 return (int)((unsigned char)c);
186 * Preleva un carattere dal buffer di ricezione.
187 * Questa funzione mette il processo chiamante in attesa
188 * quando il buffer e' vuoto. L'attesa ha un timeout
189 * di ser_rxtimeout millisecondi.
191 * \return EOF in caso di errore o timeout, altrimenti
192 * il carattere ricevuto.
194 int ser_getchar(struct Serial *port)
196 if (fifo_isempty_locked(&port->rxfifo))
198 #if CONFIG_SER_RXTIMEOUT != -1
199 time_t start_time = timer_ticks();
201 /* Wait while buffer is empty */
204 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
205 /* Give up timeslice to other processes. */
208 #if CONFIG_SER_RXTIMEOUT != -1
209 if (timer_ticks() - start_time >= port->rxtimeout)
211 port->status |= SERRF_RXTIMEOUT;
214 #endif /* CONFIG_SER_RXTIMEOUT */
216 while (fifo_isempty_locked(&port->rxfifo) && (port->status & SERRF_RX) == 0);
220 * Get a byte from the FIFO (avoiding sign-extension),
221 * re-enable RTS, then return result.
223 if (port->status & SERRF_RX)
225 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
230 * Preleva un carattere dal buffer di ricezione.
231 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
232 * immediatamente EOF.
234 int ser_getchar_nowait(struct Serial *port)
236 if (fifo_isempty_locked(&port->rxfifo))
239 /* NOTE: the double cast prevents unwanted sign extension */
240 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
246 * Read a line long at most as size and puts it
248 * \return number of chars read or EOF in case
251 int ser_gets(struct Serial *port, char *buf, int size)
253 return ser_gets_echo(port, buf, size, false);
258 * Read a line long at most as size and put it
259 * in buf, with optional echo.
261 * \return number of chars read, or EOF in case
264 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
271 if ((c = ser_getchar(port)) == EOF)
278 if (c == '\r' || c == '\n' || i >= size-1)
282 ser_print(port, "\r\n");
287 ser_putchar(c, port);
292 #endif /* !CONFIG_SER_GETS */
296 * Read at most \a size bytes from \a port and put them in \a buf
298 * \return number of bytes actually read, or EOF in
301 int ser_read(struct Serial *port, void *buf, size_t size)
304 char *_buf = (char *)buf;
309 if ((c = ser_getchar(port)) == EOF)
319 * Write a string to serial.
320 * \return 0 if OK, EOF in case of error.
322 int ser_print(struct Serial *port, const char *s)
326 if (ser_putchar(*s++, port) == EOF)
334 * \brief Write a buffer to serial.
336 * \return 0 if OK, EOF in case of error.
338 * \todo Optimize with fifo_pushblock()
340 int ser_write(struct Serial *port, const void *_buf, size_t len)
342 const char *buf = (const char *)_buf;
346 if (ser_putchar(*buf++, port) == EOF)
357 int ser_printf(struct Serial *port, const char *format, ...)
362 va_start(ap, format);
363 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
368 #endif /* CONFIG_PRINTF */
371 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
372 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
374 port->rxtimeout = rxtimeout;
375 port->txtimeout = txtimeout;
377 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
379 #if CONFIG_SER_RXTIMEOUT != -1
381 * Discard input to resynchronize with remote end.
383 * Discard incoming data until the port stops receiving
384 * characters for at least \a delay milliseconds.
386 * \note Serial errors are reset before and after executing the purge.
388 void ser_resync(struct Serial *port, time_t delay)
390 time_t old_rxtimeout = port->rxtimeout;
392 ser_settimeouts(port, delay, port->txtimeout);
395 ser_setstatus(port, 0);
398 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
400 /* Restore port to an usable status */
401 ser_setstatus(port, 0);
402 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
404 #endif /* CONFIG_SER_RXTIMEOUT */
407 void ser_setbaudrate(struct Serial *port, unsigned long rate)
409 port->hw->table->setbaudrate(port->hw, rate);
413 void ser_setparity(struct Serial *port, int parity)
415 port->hw->table->setparity(port->hw, parity);
420 * Flush both the RX and TX buffers.
422 void ser_purge(struct Serial *port)
424 fifo_flush_locked(&port->rxfifo);
425 fifo_flush_locked(&port->txfifo);
430 * Wait until all pending output is completely
431 * transmitted to the other end.
433 * \note The current implementation only checks the
434 * software transmission queue. Any hardware
437 void ser_drain(struct Serial *ser)
439 while (!fifo_isempty(&ser->txfifo))
441 #if CONFIG_KERNEL && CONFIG_KERN_SCHED
442 /* Give up timeslice to other processes. */
452 struct Serial *ser_open(unsigned int unit)
456 ASSERT(unit < countof(ser_handles));
457 port = &ser_handles[unit];
459 ASSERT(!port->is_open);
460 DB(port->is_open = true;)
464 port->hw = ser_hw_getdesc(unit);
466 /* Initialize circular buffers */
467 ASSERT(port->hw->txbuffer);
468 ASSERT(port->hw->rxbuffer);
469 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
470 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
472 port->hw->table->init(port->hw, port);
474 /* Set default values */
475 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
476 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
478 #if CONFIG_SER_DEFBAUDRATE
479 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
482 /* Clear error flags */
483 ser_setstatus(port, 0);
490 * Clean up serial port, disabling the associated hardware.
492 void ser_close(struct Serial *port)
494 ASSERT(port->is_open);
495 DB(port->is_open = false;)
497 port->hw->table->cleanup(port->hw);