/********************************************************************************************
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* File: serial.c
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* Version: 1.0.0
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* Copyright: 2013 (c) Guo Wenxue <guowenxue@gmail.com>
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* Description: The UART on board drivers/functions.
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* ChangeLog: 1, Release initial version on "Mon Feb 25 22:58:49 CST 2013"
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*
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*******************************************************************************************/
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#include "s3c6410.h"
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/*
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* Initialise the serial port with the given baudrate. The settings
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* are always 8 data bits, no parity, 1 stop bit, no start bits.
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*/
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int serial_init(int baudrate)
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{
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unsigned int regv;
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s3c64xx_uart *const uart = s3c64xx_get_base_uart(S3C64XX_UART0);
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/* UART I/O port initialize: GPA0->RXD0, GPA1->TXD0) */
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regv = s3c_readl(GPACON);
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regv = (regv & ~(0xff<<0)) | (0x22<<0);
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s3c_writel(regv, GPACON);
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/* RXD0: Pull-down, TXD0: pull up/down disable */
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regv = s3c_readl(GPAPUD);
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regv = (regv & ~(0xf<<0)) | (0x1<<0);
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s3c_writel(regv, GPAPUD);
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/* Normal Mode, No Parity, 1 Stop Bit, 8 Bit Data */
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uart->ULCON = 3;
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/* PCLK divide, Polling Mode */
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uart->UCON = (0x2<<10) | (1<<9) | (1<<8) | (1<<2) | (1<<0);
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uart->UFCON = 0; /* Disable FIFO */
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uart->UMCON = 0; /* Disable Auto Flow Control */
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/* Baudrate, DIV=PCLK/(bps*16)-1=66000000/(115200*16)-1 = 34; */
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s3c_writel(34, UBRDIV0);
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for (regv=0; regv<0x100; regv++) ;
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uart->UDIVSLOT = 0x80;
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return 0;
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}
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/*
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* Read a single byte from the serial port. Returns 1 on success, 0
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* otherwise. When the function is succesfull, the character read is
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* written into its argument c.
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*/
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int serial_getc(void)
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{
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s3c64xx_uart *const uart = s3c64xx_get_base_uart(S3C64XX_UART0);
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/* wait for character to arrive */
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while (!(uart->UTRSTAT & 0x1)) ;
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return uart->URXH & 0xff;
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}
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/*
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* Output a single byte to the serial port.
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*/
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void serial_putc(const char c)
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{
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s3c64xx_uart *const uart = s3c64xx_get_base_uart(S3C64XX_UART0);
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/* wait for room in the tx FIFO */
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while (!(uart->UTRSTAT & 0x2));
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uart->UTXH = c;
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if (c == '\n') serial_putc('\r'); /* If \n, also do \r */
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}
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/*
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* Test whether a character is in the RX buffer
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*/
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int serial_tstc(void)
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{
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s3c64xx_uart *const uart = s3c64xx_get_base_uart(S3C64XX_UART0);
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return uart->UTRSTAT & 0x1;
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}
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void serial_puts(const char *s)
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{
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while (*s)
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serial_putc(*s++);
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}
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