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Diffstat (limited to 'arch/mips/gt64120/ev64120/serialGT.c')
| -rw-r--r-- | arch/mips/gt64120/ev64120/serialGT.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/arch/mips/gt64120/ev64120/serialGT.c b/arch/mips/gt64120/ev64120/serialGT.c new file mode 100644 index 000000000000..16e34a546e54 --- /dev/null +++ b/arch/mips/gt64120/ev64120/serialGT.c @@ -0,0 +1,212 @@ +/* + * 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 Above +int 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); +} |