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
19 * \li \c CONFIG_SER_HWHANDSHAKE define this preprocessor symbol to enable
20 * support for RTS/CTS handshake. Support is incomplete/untested
22 * \li \c CONFIG_SER_TXTIMEOUT - Enable software serial transmission timeouts
26 * \author Bernardo Innocenti <bernie@develer.com>
31 * Revision 1.8 2004/07/29 22:57:09 bernie
32 * ser_drain(): New function; Make Serial::is_open a debug-only feature; Switch to new-style CONFIG_* macros.
34 * Revision 1.7 2004/07/18 21:49:03 bernie
35 * Make CONFIG_SER_DEFBAUDRATE optional.
37 * Revision 1.6 2004/06/07 15:56:28 aleph
38 * Remove cast-as-lvalue extension abuse
40 * Revision 1.5 2004/06/06 16:41:44 bernie
41 * ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
43 * Revision 1.4 2004/06/03 11:27:09 bernie
44 * Add dual-license information.
46 * Revision 1.3 2004/06/02 21:35:24 aleph
47 * Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
49 * Revision 1.2 2004/05/23 18:21:53 bernie
50 * Trim CVS logs and cleanup header info.
54 #include <mware/formatwr.h>
55 #include <drv/kdebug.h>
61 #include <kern/proc.h>
63 #if CONFIG_SER_TXTIMEOUT != -1 || CONFIG_SER_RXTIMEOUT != -1
64 #include <drv/timer.h>
68 /* Serial configuration parameters */
69 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
70 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
71 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
74 struct Serial ser_handles[SER_CNT];
78 * Inserisce il carattere c nel buffer di trasmissione.
79 * Questa funzione mette il processo chiamante in attesa
80 * quando il buffer e' pieno.
82 * \return EOF in caso di errore o timeout, altrimenti
83 * il carattere inviato.
85 int ser_putchar(int c, struct Serial *port)
87 if (fifo_isfull_locked(&port->txfifo))
89 #if CONFIG_SER_TXTIMEOUT != -1
90 time_t start_time = timer_gettick();
93 /* Attende finche' il buffer e' pieno... */
96 #ifdef CONFIG_KERN_SCHED
97 /* Give up timeslice to other processes. */
100 #if CONFIG_SER_TXTIMEOUT != -1
101 if (timer_gettick() - start_time >= port->txtimeout)
103 port->status |= SERRF_TXTIMEOUT;
106 #endif /* CONFIG_SER_TXTIMEOUT */
108 while (fifo_isfull_locked(&port->txfifo));
111 fifo_push_locked(&port->txfifo, (unsigned char)c);
113 /* (re)trigger tx interrupt */
114 port->hw->table->enabletxirq(port->hw);
116 /* Avoid returning signed estended char */
117 return (int)((unsigned char)c);
122 * Preleva un carattere dal buffer di ricezione.
123 * Questa funzione mette il processo chiamante in attesa
124 * quando il buffer e' vuoto. L'attesa ha un timeout
125 * di ser_rxtimeout millisecondi.
127 * \return EOF in caso di errore o timeout, altrimenti
128 * il carattere ricevuto.
130 int ser_getchar(struct Serial *port)
134 if (fifo_isempty_locked(&port->rxfifo))
136 #if CONFIG_SER_RXTIMEOUT != -1
137 time_t start_time = timer_gettick();
139 /* Wait while buffer is empty */
142 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
143 /* Give up timeslice to other processes. */
146 #if CONFIG_SER_RXTIMEOUT != -1
147 if (timer_gettick() - start_time >= port->rxtimeout)
149 port->status |= SERRF_RXTIMEOUT;
152 #endif /* CONFIG_SER_RXTIMEOUT */
154 while (fifo_isempty_locked(&port->rxfifo));
158 * Get a byte from the FIFO (avoiding sign-extension),
159 * re-enable RTS, then return result.
161 result = (int)(unsigned char)fifo_pop(&port->rxfifo);
162 return port->status ? EOF : result;
167 * Preleva un carattere dal buffer di ricezione.
168 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
169 * immediatamente EOF.
171 int ser_getchar_nowait(struct Serial *port)
173 if (fifo_isempty_locked(&port->rxfifo))
176 /* NOTE: the double cast prevents unwanted sign extension */
177 return (int)(unsigned char)fifo_pop(&port->rxfifo);
183 * Read a line long at most as size and puts it
185 * \return number of chars read or EOF in case
188 int ser_gets(struct Serial *port, char *buf, int size)
190 return ser_gets_echo(port, buf, size, false);
195 * Read a line long at most as size and put it
196 * in buf, with optional echo.
198 * \return number of chars read, or EOF in case
201 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
208 if ((c = ser_getchar(port)) == EOF)
215 if (c == '\r' || c == '\n' || i >= size-1)
219 ser_print(port, "\r\n");
224 ser_putchar(c, port);
229 #endif /* !CONFIG_SER_GETS */
233 * Read at most size bytes and puts them
235 * \return number of bytes read or EOF in case
238 int ser_read(struct Serial *port, char *buf, size_t size)
245 if ((c = ser_getchar(port)) == EOF)
255 * Write a string to serial.
256 * \return 0 if OK, EOF in case of error.
258 int ser_print(struct Serial *port, const char *s)
262 if (ser_putchar(*s++, port) == EOF)
270 * \brief Write a buffer to serial.
272 * \return 0 if OK, EOF in case of error.
274 * \todo Optimize with fifo_pushblock()
276 int ser_write(struct Serial *port, const void *_buf, size_t len)
278 const char *buf = _buf;
282 if (ser_putchar(*buf++, port) == EOF)
293 int ser_printf(struct Serial *port, const char *format, ...)
298 ser_setstatus(port, 0);
299 va_start(ap, format);
300 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
305 #endif /* CONFIG_PRINTF */
308 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
309 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
311 port->rxtimeout = rxtimeout;
312 port->txtimeout = txtimeout;
314 #endif /* CONFIG_SER_RXTIMEOUT || CONFIG_SER_TXTIMEOUT */
317 void ser_setbaudrate(struct Serial *port, unsigned long rate)
319 port->hw->table->setbaudrate(port->hw, rate);
323 void ser_setparity(struct Serial *port, int parity)
325 port->hw->table->setparity(port->hw, parity);
330 * Flush both the RX and TX buffers.
332 void ser_purge(struct Serial *ser)
334 fifo_flush_locked(&ser->rxfifo);
335 fifo_flush_locked(&ser->txfifo);
339 * Wait until all pending output is completely
340 * transmitted to the other end.
342 * \note The current implementation only checks the
343 * software transmission queue. Any hardware
346 void ser_drain(struct Serial *ser)
348 while(!fifo_isempty(&ser->txfifo))
350 #if defined(CONFIG_KERN_SCHED) && CONFIG_KERN_SCHED
351 /* Give up timeslice to other processes. */
361 struct Serial *ser_open(unsigned int unit)
365 ASSERT(unit < countof(ser_handles));
366 port = &ser_handles[unit];
368 ASSERT(!port->is_open);
369 DB(port->is_open = true;)
373 /* Initialize circular buffer */
374 fifo_init(&port->rxfifo, port->rxbuffer, sizeof(port->rxbuffer));
375 fifo_init(&port->txfifo, port->txbuffer, sizeof(port->txbuffer));
377 port->hw = ser_hw_getdesc(unit);
378 port->hw->table->init(port->hw, port);
380 /* Set default values */
381 #if CONFIG_SER_RXTIMEOUT != -1 || CONFIG_SER_TXTIMEOUT != -1
382 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
384 #if CONFIG_SER_DEFBAUDRATE
385 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
393 * Clean up serial port, disabling the associated hardware.
395 void ser_close(struct Serial *port)
397 ASSERT(port->is_open);
398 DB(port->is_open = false;)
400 port->hw->table->cleanup(port->hw);