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Diffstat (limited to 'drivers/s3c4510b_uart.c')
| -rw-r--r-- | drivers/s3c4510b_uart.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/s3c4510b_uart.c b/drivers/s3c4510b_uart.c new file mode 100644 index 0000000..44b96a9 --- /dev/null +++ b/drivers/s3c4510b_uart.c @@ -0,0 +1,216 @@ +/* + * Copyright (c) 2004 Cucy Systems (http://www.cucy.com) + * Curt Brune <curt@cucy.com> + * + * (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 + * + * MODULE: $Id:$ + * Description: UART/Serial interface for Samsung S3C4510B SoC + * Runtime Env: ARM7TDMI + * Change History: + * 03-02-04 Create (Curt Brune) curt@cucy.com + * + */ + +#include <common.h> + +#ifdef CONFIG_DRIVER_S3C4510_UART + +#include <asm/hardware.h> +#include "s3c4510b_uart.h" + +static UART *uart; + +/* 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( uart->m_stat.bf.rxReady) { + tmp = uart->m_rx; + } + + 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( !uart->m_stat.bf.txBufEmpty); + + return 0; +} + + +void serial_setbrg (void) +{ + DECLARE_GLOBAL_DATA_PTR; + + UART_LINE_CTRL ulctrl; + UART_CTRL uctrl; + UART_BAUD_DIV ubd; + + serial_flush_output(); + serial_flush_input(); + + /* control register */ + uctrl.ui = 0x0; + uctrl.bf.rxMode = 0x1; + uctrl.bf.rxIrq = 0x0; + uctrl.bf.txMode = 0x1; + uctrl.bf.DSR = 0x0; + uctrl.bf.sendBreak = 0x0; + uctrl.bf.loopBack = 0x0; + uart->m_ctrl.ui = uctrl.ui; + + /* line control register */ + ulctrl.ui = 0x0; + ulctrl.bf.wordLen = 0x3; /* 8 bit data */ + ulctrl.bf.nStop = 0x0; /* 1 stop bit */ + ulctrl.bf.parity = 0x0; /* no parity */ + ulctrl.bf.clk = 0x0; /* internal clock */ + ulctrl.bf.infra_red = 0x0; /* no infra_red */ + uart->m_lineCtrl.ui = ulctrl.ui; + + ubd.ui = 0x0; + + /* see table on page 10-15 in SAMSUNG S3C4510B manual */ + /* get correct divisor */ + switch(gd->baudrate) { + case 1200: ubd.bf.cnt0 = 1301; break; + case 2400: ubd.bf.cnt0 = 650; break; + case 4800: ubd.bf.cnt0 = 324; break; + case 9600: ubd.bf.cnt0 = 162; break; + case 19200: ubd.bf.cnt0 = 80; break; + case 38400: ubd.bf.cnt0 = 40; break; + case 57600: ubd.bf.cnt0 = 26; break; + case 115200: ubd.bf.cnt0 = 13; break; + } + + uart->m_baudDiv.ui = ubd.ui; + uart->m_baudCnt = 0x0; + uart->m_baudClk = 0x0; + +} + + +/* + * 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) +{ + +#if CONFIG_SERIAL1 == 1 + uart = (UART *)UART0_BASE; +#elif CONFIG_SERIAL1 == 2 + uart = (UART *)UART1_BASE; +#else +#error CONFIG_SERIAL1 not equal to 1 or 2 +#endif + + 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( !uart->m_stat.bf.txBufEmpty); + + uart->m_tx = c; + + /* + to be polite with serial console add a line feed + to the carriage return character + */ + if (c=='\n') + serial_putc('\r'); +} + +/* + * Test if an input byte is ready from the serial port. Returns non-zero on + * success, 0 otherwise. + */ +int serial_tstc (void) +{ + return uart->m_stat.bf.rxReady; +} + +/* + * 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) { + return uart->m_rx & 0xFF; + } + } +} + +void serial_puts (const char *s) +{ + while (*s) { + serial_putc (*s++); + } + + /* busy wait for tx complete */ + while ( !uart->m_stat.bf.txComplete); + + /* clear break */ + uart->m_ctrl.bf.sendBreak = 0; + +} + +#endif |