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 1.19 2004/10/19 08:14:13 bernie
32 *#* Fix a few longstanding bugs wrt status handling (made by rasky on scfirm).
34 *#* Revision 1.18 2004/09/20 03:31:15 bernie
37 *#* Revision 1.17 2004/09/14 21:06:07 bernie
38 *#* Use debug.h instead of kdebug.h; Spelling fixes.
40 *#* Revision 1.16 2004/09/06 21:40:50 bernie
41 *#* Move buffer handling in chip-specific driver.
43 *#* Revision 1.15 2004/08/25 14:12:08 rasky
44 *#* Aggiornato il comment block dei log RCS
46 *#* Revision 1.14 2004/08/24 16:22:57 bernie
47 *#* Thinkos; Doxygen fixes
49 *#* Revision 1.13 2004/08/24 16:20:48 bernie
50 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
52 *#* Revision 1.12 2004/08/24 13:49:39 bernie
55 *#* Revision 1.11 2004/08/15 05:32:22 bernie
56 *#* ser_resync(): New function.
58 *#* Revision 1.10 2004/08/10 06:29:50 bernie
59 *#* Rename timer_gettick() to timer_ticks().
61 *#* Revision 1.9 2004/08/08 06:06:20 bernie
62 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
64 *#* Revision 1.8 2004/07/29 22:57:09 bernie
65 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
67 *#* Revision 1.7 2004/07/18 21:49:03 bernie
68 *#* Make CONFIG_SER_DEFBAUDRATE optional.
70 *#* Revision 1.6 2004/06/07 15:56:28 aleph
71 *#* Remove cast-as-lvalue extension abuse
73 *#* Revision 1.5 2004/06/06 16:41:44 bernie
74 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
76 *#* Revision 1.4 2004/06/03 11:27:09 bernie
77 *#* Add dual-license information.
79 *#* Revision 1.3 2004/06/02 21:35:24 aleph
80 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
82 *#* Revision 1.2 2004/05/23 18:21:53 bernie
83 *#* Trim CVS logs and cleanup header info.
87 #include <mware/formatwr.h>
94 #include <kern/proc.h>
96 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
97 #include <drv/timer.h>
101 /* Serial configuration parameters */
102 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
103 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
104 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
107 struct Serial ser_handles[SER_CNT];
111 * Inserisce il carattere c nel buffer di trasmissione.
112 * Questa funzione mette il processo chiamante in attesa
113 * quando il buffer e' pieno.
115 * \return EOF in caso di errore o timeout, altrimenti
116 * il carattere inviato.
118 int ser_putchar(int c, struct Serial *port)
120 //ASSERT_VALID_FIFO(&port->txfifo);
121 if (fifo_isfull_locked(&port->txfifo))
123 #if CONFIG_SER_TXTIMEOUT != -1
124 time_t start_time = timer_ticks();
127 /* Attende finche' il buffer e' pieno... */
130 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
131 /* Give up timeslice to other processes. */
134 #if CONFIG_SER_TXTIMEOUT != -1
135 if (timer_ticks() - start_time >= port->txtimeout)
137 port->status |= SERRF_TXTIMEOUT;
140 #endif /* CONFIG_SER_TXTIMEOUT */
142 while (fifo_isfull_locked(&port->txfifo));
145 fifo_push_locked(&port->txfifo, (unsigned char)c);
147 /* (re)trigger tx interrupt */
148 port->hw->table->enabletxirq(port->hw);
150 /* Avoid returning signed extended char */
151 return (int)((unsigned char)c);
156 * Preleva un carattere dal buffer di ricezione.
157 * Questa funzione mette il processo chiamante in attesa
158 * quando il buffer e' vuoto. L'attesa ha un timeout
159 * di ser_rxtimeout millisecondi.
161 * \return EOF in caso di errore o timeout, altrimenti
162 * il carattere ricevuto.
164 int ser_getchar(struct Serial *port)
168 if (fifo_isempty_locked(&port->rxfifo))
170 #if CONFIG_SER_RXTIMEOUT != -1
171 time_t start_time = timer_ticks();
173 /* Wait while buffer is empty */
176 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
177 /* Give up timeslice to other processes. */
180 #if CONFIG_SER_RXTIMEOUT != -1
181 if (timer_ticks() - start_time >= port->rxtimeout)
183 port->status |= SERRF_RXTIMEOUT;
186 #endif /* CONFIG_SER_RXTIMEOUT */
188 while (fifo_isempty_locked(&port->rxfifo) && (port->status & SERRF_RX) == 0);
192 * Get a byte from the FIFO (avoiding sign-extension),
193 * re-enable RTS, then return result.
195 if (port->status & SERRF_RX)
197 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
202 * Preleva un carattere dal buffer di ricezione.
203 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
204 * immediatamente EOF.
206 int ser_getchar_nowait(struct Serial *port)
208 if (fifo_isempty_locked(&port->rxfifo))
211 /* NOTE: the double cast prevents unwanted sign extension */
212 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
218 * Read a line long at most as size and puts it
220 * \return number of chars read or EOF in case
223 int ser_gets(struct Serial *port, char *buf, int size)
225 return ser_gets_echo(port, buf, size, false);
230 * Read a line long at most as size and put it
231 * in buf, with optional echo.
233 * \return number of chars read, or EOF in case
236 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
243 if ((c = ser_getchar(port)) == EOF)
250 if (c == '\r' || c == '\n' || i >= size-1)
254 ser_print(port, "\r\n");
259 ser_putchar(c, port);
264 #endif /* !CONFIG_SER_GETS */
268 * Read at most \a size bytes from \a port and put them in \a buf
270 * \return number of bytes actually read, or EOF in
273 int ser_read(struct Serial *port, void *buf, size_t size)
276 char *_buf = (char *)buf;
281 if ((c = ser_getchar(port)) == EOF)
291 * Write a string to serial.
292 * \return 0 if OK, EOF in case of error.
294 int ser_print(struct Serial *port, const char *s)
298 if (ser_putchar(*s++, port) == EOF)
306 * \brief Write a buffer to serial.
308 * \return 0 if OK, EOF in case of error.
310 * \todo Optimize with fifo_pushblock()
312 int ser_write(struct Serial *port, const void *_buf, size_t len)
314 const char *buf = (const char *)_buf;
318 if (ser_putchar(*buf++, port) == EOF)
329 int ser_printf(struct Serial *port, const char *format, ...)
334 va_start(ap, format);
335 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
340 #endif /* CONFIG_PRINTF */
343 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
344 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
346 port->rxtimeout = rxtimeout;
347 port->txtimeout = txtimeout;
349 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
351 #if CONFIG_SER_RXTIMEOUT != -1
353 * Discard input to resynchronize with remote end.
355 * Discard incoming data until the port stops receiving
356 * characters for at least \a delay milliseconds.
358 * \note Serial errors are reset before and after executing the purge.
360 void ser_resync(struct Serial *port, time_t delay)
362 time_t old_rxtimeout = port->rxtimeout;
364 ser_settimeouts(port, delay, port->txtimeout);
367 ser_setstatus(port, 0);
370 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
372 /* Restore port to an usable status */
373 ser_setstatus(port, 0);
374 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
376 #endif /* CONFIG_SER_RXTIMEOUT */
379 void ser_setbaudrate(struct Serial *port, unsigned long rate)
381 port->hw->table->setbaudrate(port->hw, rate);
385 void ser_setparity(struct Serial *port, int parity)
387 port->hw->table->setparity(port->hw, parity);
392 * Flush both the RX and TX buffers.
394 void ser_purge(struct Serial *port)
396 fifo_flush_locked(&port->rxfifo);
397 fifo_flush_locked(&port->txfifo);
402 * Wait until all pending output is completely
403 * transmitted to the other end.
405 * \note The current implementation only checks the
406 * software transmission queue. Any hardware
409 void ser_drain(struct Serial *ser)
411 while (!fifo_isempty(&ser->txfifo))
413 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
414 /* Give up timeslice to other processes. */
424 struct Serial *ser_open(unsigned int unit)
428 ASSERT(unit < countof(ser_handles));
429 port = &ser_handles[unit];
431 ASSERT(!port->is_open);
432 DB(port->is_open = true;)
436 port->hw = ser_hw_getdesc(unit);
438 /* Initialize circular buffers */
439 ASSERT(port->hw->txbuffer);
440 ASSERT(port->hw->rxbuffer);
441 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
442 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
444 port->hw->table->init(port->hw, port);
446 /* Set default values */
447 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
448 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
450 #if CONFIG_SER_DEFBAUDRATE
451 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
459 * Clean up serial port, disabling the associated hardware.
461 void ser_close(struct Serial *port)
463 ASSERT(port->is_open);
464 DB(port->is_open = false;)
466 port->hw->table->cleanup(port->hw);