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 1.7 2004/07/18 21:49:03 bernie
32 * Make CONFIG_SER_DEFBAUDRATE optional.
34 * Revision 1.6 2004/06/07 15:56:28 aleph
35 * Remove cast-as-lvalue extension abuse
37 * Revision 1.5 2004/06/06 16:41:44 bernie
38 * ser_putchar(): Use fifo_push_locked() to fix potential race on 8bit processors.
40 * Revision 1.4 2004/06/03 11:27:09 bernie
41 * Add dual-license information.
43 * Revision 1.3 2004/06/02 21:35:24 aleph
44 * Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
46 * Revision 1.2 2004/05/23 18:21:53 bernie
47 * Trim CVS logs and cleanup header info.
51 #include <mware/formatwr.h>
52 #include <drv/kdebug.h>
58 #include <kern/proc.h>
60 #if defined(CONFIG_SER_TXTIMEOUT) || defined(CONFIG_SER_RXTIMEOUT)
61 #include <drv/timer.h>
65 /* Serial configuration parameters */
66 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
67 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
68 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
71 struct Serial ser_handles[SER_CNT];
75 * Inserisce il carattere c nel buffer di trasmissione.
76 * Questa funzione mette il processo chiamante in attesa
77 * quando il buffer e' pieno.
79 * \return EOF in caso di errore o timeout, altrimenti
80 * il carattere inviato.
82 int ser_putchar(int c, struct Serial *port)
84 if (fifo_isfull_locked(&port->txfifo))
86 #ifdef CONFIG_SER_TXTIMEOUT
87 time_t start_time = timer_gettick();
90 /* Attende finche' il buffer e' pieno... */
93 #ifdef CONFIG_KERN_SCHED
94 /* Give up timeslice to other processes. */
97 #ifdef CONFIG_SER_TXTIMEOUT
98 if (timer_gettick() - start_time >= port->txtimeout)
100 port->status |= SERRF_TXTIMEOUT;
103 #endif /* CONFIG_SER_TXTIMEOUT */
105 while (fifo_isfull_locked(&port->txfifo));
108 fifo_push_locked(&port->txfifo, (unsigned char)c);
110 /* (re)trigger tx interrupt */
111 port->hw->table->enabletxirq(port->hw);
113 /* Avoid returning signed estended char */
114 return (int)((unsigned char)c);
119 * Preleva un carattere dal buffer di ricezione.
120 * Questa funzione mette il processo chiamante in attesa
121 * quando il buffer e' vuoto. L'attesa ha un timeout
122 * di ser_rxtimeout millisecondi.
124 * \return EOF in caso di errore o timeout, altrimenti
125 * il carattere ricevuto.
127 int ser_getchar(struct Serial *port)
131 if (fifo_isempty_locked(&port->rxfifo))
133 #ifdef CONFIG_SER_RXTIMEOUT
134 time_t start_time = timer_gettick();
136 /* Wait while buffer is empty */
139 #ifdef CONFIG_KERN_SCHED
140 /* Give up timeslice to other processes. */
143 #ifdef CONFIG_SER_RXTIMEOUT
144 if (timer_gettick() - start_time >= port->rxtimeout)
146 port->status |= SERRF_RXTIMEOUT;
149 #endif /* CONFIG_SER_RXTIMEOUT */
151 while (fifo_isempty_locked(&port->rxfifo));
155 * Get a byte from the FIFO (avoiding sign-extension),
156 * re-enable RTS, then return result.
158 result = (int)(unsigned char)fifo_pop(&port->rxfifo);
159 return port->status ? EOF : result;
164 * Preleva un carattere dal buffer di ricezione.
165 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
166 * immediatamente EOF.
168 int ser_getchar_nowait(struct Serial *port)
170 if (fifo_isempty_locked(&port->rxfifo))
173 /* NOTE: the double cast prevents unwanted sign extension */
174 return (int)(unsigned char)fifo_pop(&port->rxfifo);
179 * Read a line long at most as size and puts it
181 * \return number of chars read or EOF in case
184 int ser_gets(struct Serial *port, char *buf, int size)
186 return ser_gets_echo(port, buf, size, false);
191 * Read a line long at most as size and puts it
192 * in buf, with optional echo.
193 * \return number of chars read or EOF in case
196 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
203 if ((c = ser_getchar(port)) == EOF)
206 if (c == '\r' || c == '\n' || i >= size-1)
210 ser_print(port, "\r\n");
215 ser_putchar(c, port);
223 * Read at most size bytes and puts them
225 * \return number of bytes read or EOF in case
228 int ser_read(struct Serial *port, char *buf, size_t size)
235 if ((c = ser_getchar(port)) == EOF)
245 * Write a string to serial.
246 * \return 0 if OK, EOF in case of error.
248 int ser_print(struct Serial *port, const char *s)
252 if (ser_putchar(*s++, port) == EOF)
260 * \brief Write a buffer to serial.
262 * \return 0 if OK, EOF in case of error.
264 * \todo Optimize with fifo_pushblock()
266 int ser_write(struct Serial *port, const void *_buf, size_t len)
268 const char *buf = _buf;
272 if (ser_putchar(*buf++, port) == EOF)
282 int ser_printf(struct Serial *port, const char *format, ...)
287 ser_setstatus(port, 0);
288 va_start(ap, format);
289 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
295 #if defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT)
296 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
298 port->rxtimeout = rxtimeout;
299 port->txtimeout = txtimeout;
301 #endif /* defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT) */
304 void ser_setbaudrate(struct Serial *port, unsigned long rate)
306 port->hw->table->setbaudrate(port->hw, rate);
310 void ser_setparity(struct Serial *port, int parity)
312 port->hw->table->setparity(port->hw, parity);
317 * Flush both the RX and TX buffers.
319 void ser_purge(struct Serial *ser)
321 fifo_flush(&ser->rxfifo);
322 fifo_flush(&ser->txfifo);
329 struct Serial *ser_open(unsigned int unit)
333 ASSERT(unit < countof(ser_handles));
335 port = &ser_handles[unit];
337 ASSERT(!port->is_open);
340 port->is_open = true;
342 /* Initialize circular buffer */
343 fifo_init(&port->rxfifo, port->rxbuffer, sizeof(port->rxbuffer));
344 fifo_init(&port->txfifo, port->txbuffer, sizeof(port->txbuffer));
346 port->hw = ser_hw_getdesc(unit);
347 port->hw->table->init(port->hw, port);
349 /* Set default values */
350 #if defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT)
351 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
353 #if defined(CONFIG_SER_DEFBAUDRATE)
354 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
362 * Clean up serial port, disabling the associated hardware.
364 void ser_close(struct Serial *port)
366 ASSERT(port->is_open);
368 port->is_open = false;
369 port->hw->table->cleanup(port->hw);