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/*
* Driver for Milkymist UART
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*
* COPYRIGHT (c) 2010 Sebastien Bourdeauducq
* COPYRIGHT (c) Yann Sionneau <yann.sionneau@telecom-sudparis.eu> (GSoC 2010)
* Telecom SudParis
*/
#include <rtems.h>
#include <rtems/libio.h>
#include "../include/system_conf.h"
#include "uart.h"
bool BSP_uart_txbusy;
void BSP_uart_init(int baud)
{
MM_WRITE(MM_UART_DIV, CPU_FREQUENCY/baud/16);
}
void BSP_uart_polled_write(char ch)
{
int ip;
rtems_interrupt_level level;
rtems_interrupt_disable(level);
if (BSP_uart_txbusy) {
/* wait for the end of the transmission by the IRQ-based driver */
do {
lm32_read_interrupts(ip);
} while (!(ip & (1 << MM_IRQ_UARTTX)));
lm32_interrupt_ack(1 << MM_IRQ_UARTTX);
}
MM_WRITE(MM_UART_RXTX, ch);
do {
lm32_read_interrupts(ip);
} while (!(ip & (1 << MM_IRQ_UARTTX)));
/* if TX was busy, do not ack the IRQ
* so that the IRQ-based driver ISR is run */
if (!BSP_uart_txbusy)
lm32_interrupt_ack(1 << MM_IRQ_UARTTX);
rtems_interrupt_enable(level);
}
int BSP_uart_polled_read(void)
{
int ip;
char r;
rtems_interrupt_level level;
rtems_interrupt_disable(level);
do {
lm32_read_interrupts(ip);
} while (!(ip & (1 << MM_IRQ_UARTRX)));
lm32_interrupt_ack(1 << MM_IRQ_UARTRX);
r = MM_READ(MM_UART_RXTX);
rtems_interrupt_enable(level);
return r;
}
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