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74 lines
1.6 KiB
C
74 lines
1.6 KiB
C
/*
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* Uart driver for Lattice Mico32 (lm32) UART
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*/
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/*
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*
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* Jukka Pietarinen <jukka.pietarinen@mrf.fi>, 2008,
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* Micro-Research Finland Oy
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*/
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#include "../include/system_conf.h"
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#include "uart.h"
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#include <bsp.h>
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#include <rtems/libio.h>
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static inline int uartread(unsigned int reg)
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{
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return *((int*)(UART_BASE_ADDRESS + reg));
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}
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static inline void uartwrite(unsigned int reg, int value)
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{
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*((int*)(UART_BASE_ADDRESS + reg)) = value;
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}
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void BSP_uart_init(int baud)
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{
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/* Disable UART interrupts */
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uartwrite(LM32_UART_IER, 0);
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/* Line control 8 bit, 1 stop, no parity */
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uartwrite(LM32_UART_LCR, LM32_UART_LCR_8BIT);
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/* Modem control, DTR = 1, RTS = 1 */
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uartwrite(LM32_UART_MCR, LM32_UART_MCR_DTR | LM32_UART_MCR_RTS);
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/* Set baud rate */
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uartwrite(LM32_UART_DIV, CPU_FREQUENCY/baud);
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}
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void BSP_uart_polled_write(char ch)
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{
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/* Insert CR before LF */
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if (ch == '\n')
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BSP_uart_polled_write('\r');
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/* Wait until THR is empty. */
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while (!(uartread(LM32_UART_LSR) & LM32_UART_LSR_THRE));
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uartwrite(LM32_UART_RBR, ch);
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}
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int BSP_uart_polled_read( void )
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{
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/* Wait until there is a byte in RBR */
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while (!(uartread(LM32_UART_LSR) & LM32_UART_LSR_DR));
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return (int) uartread(LM32_UART_RBR);
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}
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char BSP_uart_is_character_ready(char *ch)
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{
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if (uartread(LM32_UART_LSR) & LM32_UART_LSR_DR)
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{
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*ch = (char) uartread(LM32_UART_RBR);
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return true;
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}
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*ch = '0';
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return false;
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}
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