diff options
Diffstat (limited to 'drivers/serial/serial_s3c44b0.c')
| -rw-r--r-- | drivers/serial/serial_s3c44b0.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/serial/serial_s3c44b0.c b/drivers/serial/serial_s3c44b0.c new file mode 100644 index 0000000..95d0266 --- /dev/null +++ b/drivers/serial/serial_s3c44b0.c @@ -0,0 +1,218 @@ +/* + * (C) Copyright 2004 + * DAVE Srl + * http://www.dave-tech.it + * http://www.wawnet.biz + * mailto:info@wawnet.biz + * + * (C) Copyright 2002-2004 + * Wolfgang Denk, DENX Software Engineering, <wd@denx.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) + * + * 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 program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <common.h> +#include <asm/hardware.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* flush serial input queue. returns 0 on success or negative error + * number otherwise + */ +static int serial_flush_input(void) +{ + volatile u32 tmp; + + /* keep on reading as long as the receiver is not empty */ + while(UTRSTAT0&0x01) { + tmp = REGB(URXH0); + } + + return 0; +} + + +/* flush output queue. returns 0 on success or negative error number + * otherwise + */ +static int serial_flush_output(void) +{ + /* wait until the transmitter is no longer busy */ + while(!(UTRSTAT0 & 0x02)) { + } + + return 0; +} + + +void serial_setbrg (void) +{ + u32 divisor = 0; + + /* get correct divisor */ + switch(gd->baudrate) { + + case 1200: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 3124; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 3905; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif + break; + + case 9600: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 390; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 487; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif + break; + + case 19200: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 194; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 243; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif + break; + + case 38400: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 97; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 121; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif /* break; */ + + case 57600: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 64; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 80; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif /* break; */ + + case 115200: +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + divisor = 32; +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + divisor = 40; +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif /* break; */ + } + + serial_flush_output(); + serial_flush_input(); + UFCON0 = 0x0; + ULCON0 = 0x03; + UCON0 = 0x05; + UBRDIV0 = divisor; + + UFCON1 = 0x0; + ULCON1 = 0x03; + UCON1 = 0x05; + UBRDIV1 = divisor; + + for(divisor=0; divisor<100; divisor++) { + /* NOP */ + } +} + + +/* + * Initialise the serial port with the given baudrate. The settings + * are always 8 data bits, no parity, 1 stop bit, no start bits. + * + */ +int serial_init (void) +{ + serial_setbrg (); + + return (0); +} + + +/* + * Output a single byte to the serial port. + */ +void serial_putc (const char c) +{ + /* wait for room in the transmit FIFO */ + while(!(UTRSTAT0 & 0x02)); + + UTXH0 = (unsigned char)c; + + /* + to be polite with serial console add a line feed + to the carriage return character + */ + if (c=='\n') + serial_putc('\r'); +} + +/* + * Read a single byte from the serial port. Returns 1 on success, 0 + * otherwise. When the function is succesfull, the character read is + * written into its argument c. + */ +int serial_tstc (void) +{ + return (UTRSTAT0 & 0x01); +} + +/* + * Read a single byte from the serial port. Returns 1 on success, 0 + * otherwise. When the function is succesfull, the character read is + * written into its argument c. + */ +int serial_getc (void) +{ + int rv; + + for(;;) { + rv = serial_tstc(); + + if(rv > 0) + return URXH0; + } +} + +void +serial_puts (const char *s) +{ + while (*s) { + serial_putc (*s++); + } +} |