osd-contiki/lib/uart1.c
2011-02-12 18:12:45 -05:00

78 lines
2.6 KiB
C

/*
* Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
* to the MC1322x project (http://mc1322x.devl.org)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of libmc1322x: see http://mc1322x.devl.org
* for details.
*
*
*/
#include <mc1322x.h>
#include <stdint.h>
volatile char u1_tx_buf[64];
volatile uint32_t u1_head, u1_tail;
void uart1_isr(void) {
while( *UART1_UTXCON != 0 ) {
if (u1_head == u1_tail) {
disable_irq(UART1);
return;
}
*UART1_UDATA = u1_tx_buf[u1_tail];
u1_tail++;
if (u1_tail >= sizeof(u1_tx_buf))
u1_tail = 0;
}
}
void uart1_putc(char c) {
/* disable UART1 since */
/* UART1 isr modifies u1_head and u1_tail */
disable_irq(UART1);
if( (u1_head == u1_tail) &&
(*UART1_UTXCON != 0)) {
*UART1_UDATA = c;
} else {
u1_tx_buf[u1_head] = c;
u1_head += 1;
if (u1_head >= sizeof(u1_tx_buf))
u1_head = 0;
if (u1_head == u1_tail) { /* drop chars when no room */
if (u1_head) { u1_head -=1; } else { u1_head = sizeof(u1_tx_buf); }
}
enable_irq(UART1);
}
}
uint8_t uart1_getc(void) {
while(uart1_can_get() == 0) { continue; }
return *UART1_UDATA;
}