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 1.17 2004/09/14 21:06:07 bernie
32 *#* Use debug.h instead of kdebug.h; Spelling fixes.
34 *#* Revision 1.16 2004/09/06 21:40:50 bernie
35 *#* Move buffer handling in chip-specific driver.
37 *#* Revision 1.15 2004/08/25 14:12:08 rasky
38 *#* Aggiornato il comment block dei log RCS
40 *#* Revision 1.14 2004/08/24 16:22:57 bernie
41 *#* Thinkos; Doxygen fixes
43 *#* Revision 1.13 2004/08/24 16:20:48 bernie
44 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
46 *#* Revision 1.12 2004/08/24 13:49:39 bernie
49 *#* Revision 1.11 2004/08/15 05:32:22 bernie
50 *#* ser_resync(): New function.
52 *#* Revision 1.10 2004/08/10 06:29:50 bernie
53 *#* Rename timer_gettick() to timer_ticks().
55 *#* Revision 1.9 2004/08/08 06:06:20 bernie
56 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
58 *#* Revision 1.8 2004/07/29 22:57:09 bernie
59 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
61 *#* Revision 1.7 2004/07/18 21:49:03 bernie
62 *#* Make CONFIG_SER_DEFBAUDRATE optional.
64 *#* Revision 1.6 2004/06/07 15:56:28 aleph
65 *#* Remove cast-as-lvalue extension abuse
67 *#* Revision 1.5 2004/06/06 16:41:44 bernie
68 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
70 *#* Revision 1.4 2004/06/03 11:27:09 bernie
71 *#* Add dual-license information.
73 *#* Revision 1.3 2004/06/02 21:35:24 aleph
74 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
76 *#* Revision 1.2 2004/05/23 18:21:53 bernie
77 *#* Trim CVS logs and cleanup header info.
81 #include <mware/formatwr.h>
88 #include <kern/proc.h>
90 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
91 #include <drv/timer.h>
95 /* Serial configuration parameters */
96 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
97 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
98 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
101 struct Serial ser_handles[SER_CNT];
105 * Inserisce il carattere c nel buffer di trasmissione.
106 * Questa funzione mette il processo chiamante in attesa
107 * quando il buffer e' pieno.
109 * \return EOF in caso di errore o timeout, altrimenti
110 * il carattere inviato.
112 int ser_putchar(int c, struct Serial *port)
114 //ASSERT_VALID_FIFO(&port->txfifo);
115 if (fifo_isfull_locked(&port->txfifo))
117 #if CONFIG_SER_TXTIMEOUT != -1
118 time_t start_time = timer_ticks();
121 /* Attende finche' il buffer e' pieno... */
124 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
125 /* Give up timeslice to other processes. */
128 #if CONFIG_SER_TXTIMEOUT != -1
129 if (timer_ticks() - start_time >= port->txtimeout)
131 port->status |= SERRF_TXTIMEOUT;
134 #endif /* CONFIG_SER_TXTIMEOUT */
136 while (fifo_isfull_locked(&port->txfifo));
139 fifo_push_locked(&port->txfifo, (unsigned char)c);
141 /* (re)trigger tx interrupt */
142 port->hw->table->enabletxirq(port->hw);
144 /* Avoid returning signed estended char */
145 return (int)((unsigned char)c);
150 * Preleva un carattere dal buffer di ricezione.
151 * Questa funzione mette il processo chiamante in attesa
152 * quando il buffer e' vuoto. L'attesa ha un timeout
153 * di ser_rxtimeout millisecondi.
155 * \return EOF in caso di errore o timeout, altrimenti
156 * il carattere ricevuto.
158 int ser_getchar(struct Serial *port)
162 if (fifo_isempty_locked(&port->rxfifo))
164 #if CONFIG_SER_RXTIMEOUT != -1
165 time_t start_time = timer_ticks();
167 /* Wait while buffer is empty */
170 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
171 /* Give up timeslice to other processes. */
174 #if CONFIG_SER_RXTIMEOUT != -1
175 if (timer_ticks() - start_time >= port->rxtimeout)
177 port->status |= SERRF_RXTIMEOUT;
180 #endif /* CONFIG_SER_RXTIMEOUT */
182 while (fifo_isempty_locked(&port->rxfifo));
186 * Get a byte from the FIFO (avoiding sign-extension),
187 * re-enable RTS, then return result.
189 result = (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
190 return port->status ? EOF : result;
195 * Preleva un carattere dal buffer di ricezione.
196 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
197 * immediatamente EOF.
199 int ser_getchar_nowait(struct Serial *port)
201 if (fifo_isempty_locked(&port->rxfifo))
204 /* NOTE: the double cast prevents unwanted sign extension */
205 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
211 * Read a line long at most as size and puts it
213 * \return number of chars read or EOF in case
216 int ser_gets(struct Serial *port, char *buf, int size)
218 return ser_gets_echo(port, buf, size, false);
223 * Read a line long at most as size and put it
224 * in buf, with optional echo.
226 * \return number of chars read, or EOF in case
229 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
236 if ((c = ser_getchar(port)) == EOF)
243 if (c == '\r' || c == '\n' || i >= size-1)
247 ser_print(port, "\r\n");
252 ser_putchar(c, port);
257 #endif /* !CONFIG_SER_GETS */
261 * Read at most \a size bytes from \a port and put them in \a buf
263 * \return number of bytes actually read, or EOF in
266 int ser_read(struct Serial *port, void *buf, size_t size)
269 char *_buf = (char *)buf;
274 if ((c = ser_getchar(port)) == EOF)
284 * Write a string to serial.
285 * \return 0 if OK, EOF in case of error.
287 int ser_print(struct Serial *port, const char *s)
291 if (ser_putchar(*s++, port) == EOF)
299 * \brief Write a buffer to serial.
301 * \return 0 if OK, EOF in case of error.
303 * \todo Optimize with fifo_pushblock()
305 int ser_write(struct Serial *port, const void *_buf, size_t len)
307 const char *buf = _buf;
311 if (ser_putchar(*buf++, port) == EOF)
322 int ser_printf(struct Serial *port, const char *format, ...)
327 ser_setstatus(port, 0);
328 va_start(ap, format);
329 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
334 #endif /* CONFIG_PRINTF */
337 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
338 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
340 port->rxtimeout = rxtimeout;
341 port->txtimeout = txtimeout;
343 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
345 #if CONFIG_SER_RXTIMEOUT != -1
347 * Discard input to resynchronize with remote end.
349 * Discard incoming data until the port stops receiving
350 * characters for at least \a delay milliseconds.
352 * \note Serial errors are reset before and after executing the purge.
354 void ser_resync(struct Serial *port, time_t delay)
356 time_t old_rxtimeout = port->rxtimeout;
358 ser_settimeouts(port, delay, port->txtimeout);
361 ser_setstatus(port, 0);
364 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
366 /* Restore port to an usable status */
367 ser_setstatus(port, 0);
368 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
370 #endif /* CONFIG_SER_RXTIMEOUT */
373 void ser_setbaudrate(struct Serial *port, unsigned long rate)
375 port->hw->table->setbaudrate(port->hw, rate);
379 void ser_setparity(struct Serial *port, int parity)
381 port->hw->table->setparity(port->hw, parity);
386 * Flush both the RX and TX buffers.
388 void ser_purge(struct Serial *port)
390 fifo_flush_locked(&port->rxfifo);
391 fifo_flush_locked(&port->txfifo);
396 * Wait until all pending output is completely
397 * transmitted to the other end.
399 * \note The current implementation only checks the
400 * software transmission queue. Any hardware
403 void ser_drain(struct Serial *ser)
405 while (!fifo_isempty(&ser->txfifo))
407 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
408 /* Give up timeslice to other processes. */
418 struct Serial *ser_open(unsigned int unit)
422 ASSERT(unit < countof(ser_handles));
423 port = &ser_handles[unit];
425 ASSERT(!port->is_open);
426 DB(port->is_open = true;)
430 port->hw = ser_hw_getdesc(unit);
432 /* Initialize circular buffers */
433 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
434 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
436 port->hw->table->init(port->hw, port);
438 /* Set default values */
439 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
440 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
442 #if CONFIG_SER_DEFBAUDRATE
443 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
451 * Clean up serial port, disabling the associated hardware.
453 void ser_close(struct Serial *port)
455 ASSERT(port->is_open);
456 DB(port->is_open = false;)
458 port->hw->table->cleanup(port->hw);