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 1.4 2004/06/03 11:27:09 bernie
32 * Add dual-license information.
34 * Revision 1.3 2004/06/02 21:35:24 aleph
35 * Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
37 * Revision 1.2 2004/05/23 18:21:53 bernie
38 * Trim CVS logs and cleanup header info.
42 #include <mware/formatwr.h>
43 #include <drv/kdebug.h>
49 #include <kern/proc.h>
51 #if defined(CONFIG_SER_TXTIMEOUT) || defined(CONFIG_SER_RXTIMEOUT)
52 #include <drv/timer.h>
56 /* Serial configuration parameters */
57 #define SER_CTSDELAY 70 /*!< CTS line retry interval (ms) */
58 #define SER_TXPOLLDELAY 2 /*!< Transmit buffer full retry interval (ms) */
59 #define SER_RXPOLLDELAY 2 /*!< Receive buffer empty retry interval (ms) */
62 struct Serial ser_handles[SER_CNT];
66 * Inserisce il carattere c nel buffer di trasmissione.
67 * Questa funzione mette il processo chiamante in attesa
68 * quando il buffer e' pieno.
70 * \return EOF in caso di errore o timeout, altrimenti
71 * il carattere inviato.
73 int ser_putchar(int c, struct Serial *port)
75 if (fifo_isfull_locked(&port->txfifo))
77 #ifdef CONFIG_SER_TXTIMEOUT
78 time_t start_time = timer_gettick();
81 /* Attende finche' il buffer e' pieno... */
84 #ifdef CONFIG_KERN_SCHED
85 /* Give up timeslice to other processes. */
88 #ifdef CONFIG_SER_TXTIMEOUT
89 if (timer_gettick() - start_time >= port->txtimeout)
91 port->status |= SERRF_TXTIMEOUT;
94 #endif /* CONFIG_SER_TXTIMEOUT */
96 while (fifo_isfull_locked(&port->txfifo));
99 fifo_push(&port->txfifo, (unsigned char)c);
101 /* (re)trigger tx interrupt */
102 port->hw->table->enabletxirq(port->hw);
104 /* Avoid returning signed estended char */
105 return (int)((unsigned char)c);
110 * Preleva un carattere dal buffer di ricezione.
111 * Questa funzione mette il processo chiamante in attesa
112 * quando il buffer e' vuoto. L'attesa ha un timeout
113 * di ser_rxtimeout millisecondi.
115 * \return EOF in caso di errore o timeout, altrimenti
116 * il carattere ricevuto.
118 int ser_getchar(struct Serial *port)
122 if (fifo_isempty_locked(&port->rxfifo))
124 #ifdef CONFIG_SER_RXTIMEOUT
125 time_t start_time = timer_gettick();
127 /* Wait while buffer is empty */
130 #ifdef CONFIG_KERN_SCHED
131 /* Give up timeslice to other processes. */
134 #ifdef CONFIG_SER_RXTIMEOUT
135 if (timer_gettick() - start_time >= port->rxtimeout)
137 port->status |= SERRF_RXTIMEOUT;
140 #endif /* CONFIG_SER_RXTIMEOUT */
142 while (fifo_isempty_locked(&port->rxfifo));
146 * Get a byte from the FIFO (avoiding sign-extension),
147 * re-enable RTS, then return result.
149 result = (int)(unsigned char)fifo_pop(&port->rxfifo);
150 return port->status ? EOF : result;
155 * Preleva un carattere dal buffer di ricezione.
156 * Se il buffer e' vuoto, ser_getchar_nowait() ritorna
157 * immediatamente EOF.
159 int ser_getchar_nowait(struct Serial *port)
161 if (fifo_isempty_locked(&port->rxfifo))
164 /* NOTE: the double cast prevents unwanted sign extension */
165 return (int)(unsigned char)fifo_pop(&port->rxfifo);
170 * Read a line long at most as size and puts it
172 * \return number of chars read or EOF in case
175 int ser_gets(struct Serial *port, char *buf, int size)
177 return ser_gets_echo(port, buf, size, false);
182 * Read a line long at most as size and puts it
183 * in buf, with optional echo.
184 * \return number of chars read or EOF in case
187 int ser_gets_echo(struct Serial *port, char *buf, int size, bool echo)
194 if ((c = ser_getchar(port)) == EOF)
197 if (c == '\r' || c == '\n' || i >= size-1)
201 ser_print(port, "\r\n");
206 ser_putchar(c, port);
214 * Read at most size bytes and puts them
216 * \return number of bytes read or EOF in case
219 int ser_read(struct Serial *port, char *buf, size_t size)
226 if ((c = ser_getchar(port)) == EOF)
236 * Write a string to serial.
237 * \return 0 if OK, EOF in case of error.
239 int ser_print(struct Serial *port, const char *s)
243 if (ser_putchar(*s++, port) == EOF)
251 * \brief Write a buffer to serial.
253 * \return 0 if OK, EOF in case of error.
255 int ser_write(struct Serial *port, const void *buf, size_t len)
259 if (ser_putchar(*((const char *)buf)++, port) == EOF)
269 int ser_printf(struct Serial *port, const char *format, ...)
274 ser_setstatus(port, 0);
275 va_start(ap, format);
276 len = _formatted_write(format, (void (*)(char, void *))ser_putchar, port, ap);
282 #if defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT)
283 void ser_settimeouts(struct Serial *port, time_t rxtimeout, time_t txtimeout)
285 port->rxtimeout = rxtimeout;
286 port->txtimeout = txtimeout;
288 #endif /* defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT) */
291 void ser_setbaudrate(struct Serial *port, unsigned long rate)
293 port->hw->table->setbaudrate(port->hw, rate);
297 void ser_setparity(struct Serial *port, int parity)
299 port->hw->table->setparity(port->hw, parity);
304 * Flush both the RX and TX buffers.
306 void ser_purge(struct Serial *ser)
308 fifo_flush(&ser->rxfifo);
309 fifo_flush(&ser->txfifo);
316 struct Serial *ser_open(unsigned int unit)
320 ASSERT(unit < countof(ser_handles));
322 port = &ser_handles[unit];
324 ASSERT(!port->is_open);
327 port->is_open = true;
329 /* Initialize circular buffer */
330 fifo_init(&port->rxfifo, port->rxbuffer, sizeof(port->rxbuffer));
331 fifo_init(&port->txfifo, port->txbuffer, sizeof(port->txbuffer));
333 port->hw = ser_hw_getdesc(unit);
334 port->hw->table->init(port->hw, port);
336 /* Set default values */
337 #if defined(CONFIG_SER_RXTIMEOUT) || defined(CONFIG_SER_TXTIMEOUT)
338 ser_settimeouts(port, CONFIG_SER_RXTIMEOUT, CONFIG_SER_TXTIMEOUT);
340 ser_setbaudrate(port, CONFIG_SER_DEFBAUDRATE);
347 * Clean up serial port, disabling the associated hardware.
349 void ser_close(struct Serial *port)
351 ASSERT(port->is_open);
353 port->is_open = false;
354 port->hw->table->cleanup(port->hw);