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 1.18 2004/09/20 03:31:15 bernie
34 *#* Revision 1.17 2004/09/14 21:06:07 bernie
35 *#* Use debug.h instead of kdebug.h; Spelling fixes.
37 *#* Revision 1.16 2004/09/06 21:40:50 bernie
38 *#* Move buffer handling in chip-specific driver.
40 *#* Revision 1.15 2004/08/25 14:12:08 rasky
41 *#* Aggiornato il comment block dei log RCS
43 *#* Revision 1.14 2004/08/24 16:22:57 bernie
44 *#* Thinkos; Doxygen fixes
46 *#* Revision 1.13 2004/08/24 16:20:48 bernie
47 *#* ser_read(): Make buffer argument void *#* for consistency with ANSI C and ser_write()
49 *#* Revision 1.12 2004/08/24 13:49:39 bernie
52 *#* Revision 1.11 2004/08/15 05:32:22 bernie
53 *#* ser_resync(): New function.
55 *#* Revision 1.10 2004/08/10 06:29:50 bernie
56 *#* Rename timer_gettick() to timer_ticks().
58 *#* Revision 1.9 2004/08/08 06:06:20 bernie
59 *#* Use new-style CONFIG_ idiom; Fix module-wide documentation.
61 *#* Revision 1.8 2004/07/29 22:57:09 bernie
62 *#* ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
64 *#* Revision 1.7 2004/07/18 21:49:03 bernie
65 *#* Make CONFIG_SER_DEFBAUDRATE optional.
67 *#* Revision 1.6 2004/06/07 15:56:28 aleph
68 *#* Remove cast-as-lvalue extension abuse
70 *#* Revision 1.5 2004/06/06 16:41:44 bernie
71 *#* ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
73 *#* Revision 1.4 2004/06/03 11:27:09 bernie
74 *#* Add dual-license information.
76 *#* Revision 1.3 2004/06/02 21:35:24 aleph
77 *#* Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
79 *#* Revision 1.2 2004/05/23 18:21:53 bernie
80 *#* Trim CVS logs and cleanup header info.
84 #include <mware/formatwr.h>
91 #include <kern/proc.h>
93 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
94 #include <drv/timer.h>
98 /* Serial configuration parameters */
99 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
100 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
101 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
104 struct Serial ser_handles[SER_CNT];
108 * Inserisce il carattere c nel buffer di trasmissione.
109 * Questa funzione mette il processo chiamante in attesa
110 * quando il buffer e' pieno.
112 * \return EOF in caso di errore o timeout, altrimenti
113 * il carattere inviato.
115 int ser_putchar(int c, struct Serial *port)
117 //ASSERT_VALID_FIFO(&port->txfifo);
118 if (fifo_isfull_locked(&port->txfifo))
120 #if CONFIG_SER_TXTIMEOUT != -1
121 time_t start_time = timer_ticks();
124 /* Attende finche' il buffer e' pieno... */
127 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
128 /* Give up timeslice to other processes. */
131 #if CONFIG_SER_TXTIMEOUT != -1
132 if (timer_ticks() - start_time >= port->txtimeout)
134 port->status |= SERRF_TXTIMEOUT;
137 #endif /* CONFIG_SER_TXTIMEOUT */
139 while (fifo_isfull_locked(&port->txfifo));
142 fifo_push_locked(&port->txfifo, (unsigned char)c);
144 /* (re)trigger tx interrupt */
145 port->hw->table->enabletxirq(port->hw);
147 /* Avoid returning signed estended char */
148 return (int)((unsigned char)c);
153 * Preleva un carattere dal buffer di ricezione.
154 * Questa funzione mette il processo chiamante in attesa
155 * quando il buffer e' vuoto. L'attesa ha un timeout
156 * di ser_rxtimeout millisecondi.
158 * \return EOF in caso di errore o timeout, altrimenti
159 * il carattere ricevuto.
161 int ser_getchar(struct Serial *port)
165 if (fifo_isempty_locked(&port->rxfifo))
167 #if CONFIG_SER_RXTIMEOUT != -1
168 time_t start_time = timer_ticks();
170 /* Wait while buffer is empty */
173 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
174 /* Give up timeslice to other processes. */
177 #if CONFIG_SER_RXTIMEOUT != -1
178 if (timer_ticks() - start_time >= port->rxtimeout)
180 port->status |= SERRF_RXTIMEOUT;
183 #endif /* CONFIG_SER_RXTIMEOUT */
185 while (fifo_isempty_locked(&port->rxfifo));
189 * Get a byte from the FIFO (avoiding sign-extension),
190 * re-enable RTS, then return result.
192 result = (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
193 return port->status ? EOF : result;
198 * Preleva un carattere dal buffer di ricezione.
199 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
200 * immediatamente EOF.
202 int ser_getchar_nowait(struct Serial *port)
204 if (fifo_isempty_locked(&port->rxfifo))
207 /* NOTE: the double cast prevents unwanted sign extension */
208 return (int)(unsigned char)fifo_pop_locked(&port->rxfifo);
214 * Read a line long at most as size and puts it
216 * \return number of chars read or EOF in case
219 int ser_gets(struct Serial *port, char *buf, int size)
221 return ser_gets_echo(port, buf, size, false);
226 * Read a line long at most as size and put it
227 * in buf, with optional echo.
229 * \return number of chars read, or EOF in case
232 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
239 if ((c = ser_getchar(port)) == EOF)
246 if (c == '\r' || c == '\n' || i >= size-1)
250 ser_print(port, "\r\n");
255 ser_putchar(c, port);
260 #endif /* !CONFIG_SER_GETS */
264 * Read at most \a size bytes from \a port and put them in \a buf
266 * \return number of bytes actually read, or EOF in
269 int ser_read(struct Serial *port, void *buf, size_t size)
272 char *_buf = (char *)buf;
277 if ((c = ser_getchar(port)) == EOF)
287 * Write a string to serial.
288 * \return 0 if OK, EOF in case of error.
290 int ser_print(struct Serial *port, const char *s)
294 if (ser_putchar(*s++, port) == EOF)
302 * \brief Write a buffer to serial.
304 * \return 0 if OK, EOF in case of error.
306 * \todo Optimize with fifo_pushblock()
308 int ser_write(struct Serial *port, const void *_buf, size_t len)
310 const char *buf = (const char *)_buf;
314 if (ser_putchar(*buf++, port) == EOF)
325 int ser_printf(struct Serial *port, const char *format, ...)
330 ser_setstatus(port, 0);
331 va_start(ap, format);
332 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
337 #endif /* CONFIG_PRINTF */
340 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
341 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
343 port->rxtimeout = rxtimeout;
344 port->txtimeout = txtimeout;
346 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
348 #if CONFIG_SER_RXTIMEOUT != -1
350 * Discard input to resynchronize with remote end.
352 * Discard incoming data until the port stops receiving
353 * characters for at least \a delay milliseconds.
355 * \note Serial errors are reset before and after executing the purge.
357 void ser_resync(struct Serial *port, time_t delay)
359 time_t old_rxtimeout = port->rxtimeout;
361 ser_settimeouts(port, delay, port->txtimeout);
364 ser_setstatus(port, 0);
367 while (!(ser_getstatus(port) & SERRF_RXTIMEOUT));
369 /* Restore port to an usable status */
370 ser_setstatus(port, 0);
371 ser_settimeouts(port, old_rxtimeout, port->txtimeout);
373 #endif /* CONFIG_SER_RXTIMEOUT */
376 void ser_setbaudrate(struct Serial *port, unsigned long rate)
378 port->hw->table->setbaudrate(port->hw, rate);
382 void ser_setparity(struct Serial *port, int parity)
384 port->hw->table->setparity(port->hw, parity);
389 * Flush both the RX and TX buffers.
391 void ser_purge(struct Serial *port)
393 fifo_flush_locked(&port->rxfifo);
394 fifo_flush_locked(&port->txfifo);
399 * Wait until all pending output is completely
400 * transmitted to the other end.
402 * \note The current implementation only checks the
403 * software transmission queue. Any hardware
406 void ser_drain(struct Serial *ser)
408 while (!fifo_isempty(&ser->txfifo))
410 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
411 /* Give up timeslice to other processes. */
421 struct Serial *ser_open(unsigned int unit)
425 ASSERT(unit < countof(ser_handles));
426 port = &ser_handles[unit];
428 ASSERT(!port->is_open);
429 DB(port->is_open = true;)
433 port->hw = ser_hw_getdesc(unit);
435 /* Initialize circular buffers */
436 fifo_init(&port->txfifo, port->hw->txbuffer, port->hw->txbuffer_size);
437 fifo_init(&port->rxfifo, port->hw->rxbuffer, port->hw->rxbuffer_size);
439 port->hw->table->init(port->hw, port);
441 /* Set default values */
442 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
443 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
445 #if CONFIG_SER_DEFBAUDRATE
446 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
454 * Clean up serial port, disabling the associated hardware.
456 void ser_close(struct Serial *port)
458 ASSERT(port->is_open);
459 DB(port->is_open = false;)
461 port->hw->table->cleanup(port->hw);