/* * serialGT.c * * BRIEF MODULE DESCRIPTION *  Low Level Serial Port control for use *  with the Galileo EVB64120A MIPS eval board and *  its on board two channel 16552 Uart. * * Copyright (C) 2000 RidgeRun, Inc. * Author: RidgeRun, Inc. *   glonnon@ridgerun.com, skranz@ridgerun.com, stevej@ridgerun.com * *  This program is free software; you can redistribute  it and/or modify it *  under  the terms of  the GNU General  Public License as published by the *  Free Software Foundation;  either version 2 of the  License, or (at your *  option) any later version. * *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT, *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * *  You should have received a copy of the  GNU General Public License along *  with this program; if not, write  to the Free Software Foundation, Inc., *  675 Mass Ave, Cambridge, MA 02139, USA. * */// Note://   Serial CHANNELS - 0 is the bottom connector of evb64120A.//                       (The one that maps to the "B" channel of the//                       board's uart)//                     1 is the top connector of evb64120A.//                       (The one that maps to the "A" channel of the//                       board's uart)int DEBUG_CHANNEL = 0;		// See Note Aboveint CONSOLE_CHANNEL = 1;	// See Note Above#define DUART 0xBD000000	/* Base address of Uart. */#define CHANNELOFFSET 0x20	/* DUART+CHANNELOFFSET gets you to the ChanA				   register set of the 16552 Uart device.				   DUART+0 gets you to the ChanB register set.				 */#define DUART_DELTA 0x4#define FIFO_ENABLE 0x07#define INT_ENABLE  0x04	/* default interrupt mask */#define RBR 0x00#define THR 0x00#define DLL 0x00#define IER 0x01#define DLM 0x01#define IIR 0x02#define FCR 0x02#define LCR 0x03#define MCR 0x04#define LSR 0x05#define MSR 0x06#define SCR 0x07#define LCR_DLAB 0x80#define XTAL 1843200#define LSR_THRE 0x20#define LSR_BI   0x10#define LSR_DR   0x01#define MCR_LOOP 0x10#define ACCESS_DELAY 0x10000/****************************** Routine: Description: ******************************/int inreg(int channel, int reg){	int val;	val =	    *((volatile unsigned char *) DUART +	      (channel * CHANNELOFFSET) + (reg * DUART_DELTA));	return val;}/****************************** Routine: Description: ******************************/void outreg(int channel, int reg, unsigned char val){	*((volatile unsigned char *) DUART + (channel * CHANNELOFFSET)	  + (reg * DUART_DELTA)) = val;}/****************************** Routine: Description:   Initialize the device driver. ******************************/void serial_init(int channel){	/*	 * Configure active port, (CHANNELOFFSET already set.)	 *	 * Set 8 bits, 1 stop bit, no parity.	 *	 * LCR<7>       0       divisor latch access bit	 * LCR<6>       0       break control (1=send break)	 * LCR<5>       0       stick parity (0=space, 1=mark)	 * LCR<4>       0       parity even (0=odd, 1=even)	 * LCR<3>       0       parity enable (1=enabled)	 * LCR<2>       0       # stop bits (0=1, 1=1.5)	 * LCR<1:0>     11      bits per character(00=5, 01=6, 10=7, 11=8)	 */	outreg(channel, LCR, 0x3);	outreg(channel, FCR, FIFO_ENABLE);	/* Enable the FIFO */	outreg(channel, IER, INT_ENABLE);	/* Enable appropriate interrupts */}/****************************** Routine: Description:   Set the baud rate. ******************************/void serial_set(int channel, unsigned long baud){	unsigned char sav_lcr;	/*	 * Enable access to the divisor latches by setting DLAB in LCR.	 *	 */	sav_lcr = inreg(channel, LCR);#if 0	/*	 * Set baud rate	 */	outreg(channel, LCR, LCR_DLAB | sav_lcr);	//  outreg(DLL,(XTAL/(16*2*(baud))-2));	outreg(channel, DLL, XTAL / (16 * baud));	//  outreg(DLM,(XTAL/(16*2*(baud))-2)>>8);	outreg(channel, DLM, (XTAL / (16 * baud)) >> 8);#else	/*	 * Note: Set baud rate, hardcoded here for rate of 115200	 * since became unsure of above "buad rate" algorithm (??).	 */	outreg(channel, LCR, 0x83);	outreg(channel, DLM, 0x00);	// See note above	outreg(channel, DLL, 0x02);	// See note above.	outreg(channel, LCR, 0x03);#endif	/*	 * Restore line control register	 */	outreg(channel, LCR, sav_lcr);}/****************************** Routine: Description:   Transmit a character. ******************************/void serial_putc(int channel, int c){	while ((inreg(channel, LSR) & LSR_THRE) == 0);	outreg(channel, THR, c);}/****************************** Routine: Description:    Read a received character if one is    available.  Return -1 otherwise. ******************************/int serial_getc(int channel){	if (inreg(channel, LSR) & LSR_DR) {		return inreg(channel, RBR);	}	return -1;}/****************************** Routine: Description:   Used by embedded gdb client. (example; gdb-stub.c) ******************************/char getDebugChar(){	int val;	while ((val = serial_getc(DEBUG_CHANNEL)) == -1);	// loop until we get a character in.	return (char) val;}/****************************** Routine: Description:   Used by embedded gdb target. (example; gdb-stub.c) ******************************/void putDebugChar(char c){	serial_putc(DEBUG_CHANNEL, (int) c);}